Effects of Source-Based Waste Management Awareness on Waste Segregation Behavior Among Lower Secondary School Students in Thailand: A Case Study of Phitsanulok Province

Abstract

This study investigated waste segregation awareness and behavior, developed awareness-promoting activities, and evaluated their effectiveness among lower secondary school students in Phitsanulok Province, Thailand. The research was conducted in three phases: Phase I involved baseline data collection using interviews and structured observations. Phase II focused on developing awareness-promoting activities, including training workshops, printed public relations materials, video-based learning, and game-based waste segregation. Phase III evaluated the effectiveness of interventions using a pre-test–post-test design. The research instruments included awareness and behavior questionnaires, behavior observation forms, and records of segregated solid waste quantities. The results showed significant increases in awareness and waste segregation behavior scores after the intervention across all activity types (all p < 0.001). The mean awareness scores increased from 10.27 to 12.74 (p < 0.01), and mean waste segregation behavior scores increased from 11.82 to 13.64 (p < 0.001). However, after adjustment for pre-intervention scores and school, no significant differences were observed among activity types. Higher awareness levels were positively associated with improved waste segregation behavior, as reflected by changes in waste quantity and composition. These findings indicate that awareness-promoting activities can effectively enhance source-based waste management practices and may be applied in similar municipal and educational contexts.

1. Introduction

Solid waste generation in Thailand has increased continuously over the past decade, while the capacity for proper disposal has become increasingly constrained. In particular, the number of disposal sites operating in accordance with technical standards has declined, resulting in the accumulation of untreated municipal solid waste [1,2,3,4]. These challenges reflect the structural limitations of waste management systems, which use end-of-pipe solutions rather than waste reduction and segregation at the source. This is widely recognized as a key principle of sustainable waste management.

From a circular economy (CE) perspective, effective source-based waste segregation is a fundamental prerequisite for material recovery, recycling, and circulation of resources. Inadequate segregation at the source reduces recycling efficiency, increases contamination, and ultimately undermines the circular flow of materials. Consequently, international policy frameworks, including the United Nations Sustainable Development Goals (SDGs)—particularly SDG 11 (Sustainable Cities and Communities) and SDG 12 (Responsible Consumption and Production)—emphasize waste reduction, recycling, and public participation as essential components of sustainable urban development [5,6].

In Thailand, municipal solid waste management is primarily the responsibility of local administrative organizations. However, many municipalities, including those in Phitsanulok Province, continue to face declining disposal capacity and increasing management burdens [7]. Although awareness campaigns and waste management initiatives have been implemented, many existing waste management initiatives have primarily targeted adult populations. This indicates that technical and infrastructural measures alone are insufficient and that behavioral factors must be explicitly addressed to improve source-based waste management.

Waste segregation behavior is strongly influenced by individual knowledge, environmental awareness, attitudes, and social norms [8]. According to the Theory of Planned Behavior (TPB), environmentally responsible behavior is shaped by attitudes toward the task in question, perceived social norms, and notions of behavioral control [9]. Complementary perspectives from environmental education and experiential learning theories further emphasize that individuals are more likely to adopt sustainable practices when they understand environmental impacts and actively engage in participatory learning processes [10,11]. Empirical studies have demonstrated that awareness-raising and experiential educational interventions can lead to measurable improvements in waste segregation and recycling behavior, particularly among children and adolescents [12,13,14,15,16,17,18]. School-based waste management interventions have been implemented in various countries, demonstrating that participatory educational activities can enhance students’ environmental awareness and waste segregation practices in different educational and cultural contexts.

Lower secondary school students represent a strategic target group for promoting long-term behavioral change. Adolescence is a critical developmental stage during which values, attitudes, and habitual behaviors can be effectively shaped. Moreover, students can act as important agents of change by transferring environmentally responsible practices learned at school to their families and communities, thereby extending the impacts of school-based interventions beyond the educational setting [17,18]. Consequently, school-based environmental education is increasingly recognized as a key mechanism for advancing circular economy principles and sustainable development through formal education systems [19,20,21,22].

Despite the growing international literature on environmental education and waste-related behavior, several important gaps remain. Many previous studies have primarily focused on improving environmental awareness or knowledge of waste segregation; relatively few have examined how such awareness translates into observable waste segregation behavior in real-world school environments. In addition, school-based interventions often rely on single-format educational activities—such as lectures or short-term campaigns—which may limit opportunities for experiential learning and sustained behavioral engagement. Furthermore, empirical evidence from small- and medium-sized municipalities in developing countries remains limited, particularly in Thailand, where local administrative organizations play a central role in municipal solid waste management but often face resource and capacity constraints.

To address these gaps, this study developed and evaluated a set of awareness-promoting activities designed to enhance knowledge, attitudes, and behaviors regarding waste segregation among lower secondary school students. This study adopted a theory-informed framework grounded in the Theory of Planned Behavior and experiential learning principles and a before-and-after research design to evaluate changes in awareness and behavior following participation in activities. In addition, the intervention incorporates multiple participatory activity formats intended to promote active engagement and reinforce behavioral learning in a school setting.

By examining changes in behavior among students within a municipal waste management context in Thailand, this study provides empirical evidence on the role of school-based environmental education in strengthening source-based waste segregation. These findings provide insight into how awareness-based educational interventions can support the practical implementation of circular economy principles and contribute to progress in fulfilling the Sustainable Development Goals on the local scale. In addition, this study contributes to ongoing discussions on the knowledge–action gap in environmental behavior research by examining how environmental awareness translates into observable pro-environmental behavior within a school-based institutional context, particularly in a developing country.

Accordingly, the objectives of this study were to (1) examine levels of awareness and waste segregation behavior among lower secondary school students in Bangrakam Mueang Mai Subdistrict Municipality, Phitsanulok Province, Thailand; (2) develop appropriate awareness-promoting activities to enhance waste segregation behavior; and (3) evaluate the effectiveness of the developed activities by comparing students’ awareness and waste segregation behavior before and after participation. These findings are expected to provide empirical evidence to support the design of school-based interventions for source-based waste management and to inform policy and practice among local administrative organizations in similar municipal contexts.

2. Materials and Methods

2.1. Study Area

This study was conducted in the administrative area of Bangrakam Mueang Mai Subdistrict Municipality, Bangrakam District, Phitsanulok Province, Thailand. The municipality comprises 19 villages and includes five lower secondary schools: Ban Tamo Prachasan School, Wat Yang Khwaen-U School, Bangrakam School, Wat Laem Jedi School, and Bangrakam Wittayasuksa School. These schools served as the study sites for assessing awareness and waste segregation behavior.

2.2. Study Population and Sample

The study population consisted of lower secondary school students (Grades 7–9) enrolled in the five schools under the jurisdiction of Bangrakam Mueang Mai Subdistrict Municipality, Thailand. The total population of lower secondary school students across the five participating schools was 684 students.

The required sample size was determined using the Yamane [23] formula at a 95% confidence level with an acceptable sampling error of 0.05. Based on this calculation, the minimum required sample size was 354 students. Students from the participating schools were invited to participate in the study with approval from school administrators and teachers.

A total of 354 students completed both the pre-test and post-test questionnaires and were included in the awareness analysis. For the behavioral analysis, 334 valid responses were used after excluding incomplete questionnaires.

Participation in the study was voluntary, and informed consent was obtained from students and school authorities prior to data collection. The study procedures were conducted in accordance with ethical guidelines for research involving human participants.

2.3. Research Design

This study employed a quasi-experimental mixed-methods research design [24], integrating survey research with an action research approach commonly applied in participatory environmental education studies [25]. The quasi-experimental component was used to evaluate changes in students’ awareness and waste segregation behavior before and after participation in awareness-promoting activities, while qualitative baseline assessments were conducted to understand existing waste management practices in the participating schools. The objectives were to develop and evaluate awareness-promoting activities and enhance waste segregation behavior among lower secondary school students. The findings were subsequently used to support waste segregation promotion activities in schools within the municipality. The research process was divided into three phases, as summarized in

Table 1. Implementation schedule of awareness-promoting activities and assessment procedures for waste segregation behavior among lower secondary school students in Bangrakam Mueang Mai Subdistrict Municipality.

Phase	Time	Awareness-Promoting Activities	Research Instruments	Respondents/Data Collectors	Duration
Phase I	Baseline survey period	Assessment of existing solid waste management practices in participating schools	Interview questionnaire Observation checklist of environmental conditions and solid waste management practices	School administrators, teachers, staff, and students	2–3 days
Phase II	1 week before the activity	Baseline monitoring of waste segregation practices	Observation checklist of waste segregation practices Waste quantity recording form	Research team	-
	Before the activity	Pre-activity assessment of students’ awareness and waste segregation behavior	Knowledge test assessing students’ awareness (pre-test) Questionnaire of students’ waste segregation behavior	Students (Groups 1–5)	30 min
	Activity day	Awareness-promoting activities for Groups 2–5, including training workshop, printed educational materials, video-based learning, and game-based activities	-	-	60 min
	After the activity	Post-activity assessment of students’ awareness and waste segregation behavior	Knowledge test assessing students’ awareness (post-test) Questionnaire of students’ waste segregation behavior	Students (Groups 1–5)	30 min
Phase III	3 weeks after the activity	Monitoring students’ waste segregation behavior during routine school activities	Observation checklist of waste segregation practices Waste quantity recording form	Research team	2–3 days

Note: Group 1 = control group; Group 2 = training workshop; Group 3 = printed educational materials; Group 4 = video-based learning; Group 5 = game-based activities.

.

Due to practical constraints within the school setting, participants were assigned to intervention formats based on existing class groupings rather than through random allocation. Consequently, the intervention followed a quasi-experimental pre-test–post-test design with a control group.

2.3.1. Phase I: Baseline Data Collection

Phase I involved field surveys and collection of baseline data related to existing solid waste management practices in the participating schools, including waste collection, segregation, and disposal systems. Data were collected between December 2024 and February 2025 through interviews and structured observations using an interview questionnaire and an observation checklist of environmental conditions and solid waste management practices.

The study also examined existing awareness-raising activities, as well as the attitudes and needs of school administrators, teachers, staff, and students regarding waste management practices in the schools. Participants in this phase were selected using purposive voluntary sampling, with five representatives taken from each school, resulting in a total of 25 participants. Data collection in each school was conducted over a period of approximately 2–3 days (Table 1).

2.3.2. Phase II: Development and Implementation of Awareness-Promoting Activities

Phase II focused on the development and implementation of awareness-promoting activities to improve waste segregation behavior among lower secondary school students. This phase was conducted between February and March 2025.

The intervention comprised five activity formats: a control group (no activity), a training workshop, printed educational materials, video-based learning, and game-based waste segregation activities. Representative examples of the intervention activities implemented in the participating schools are shown in Figure 1. These activities were designed to promote both cognitive understanding and practical waste segregation skills among students. The implementation schedule, duration, and assessment procedures for awareness-promoting activities are summarized in Table 1. The knowledge test and behavioral questionnaire were administered simultaneously and required approximately 30 min to complete.

The training workshop introduced students to key concepts of solid waste management, including the definition and classification of solid waste, environmental and health impacts of improper waste disposal, appropriate waste segregation methods, and responsible behaviors for waste reduction and source separation. Practical examples of waste segregation applicable to daily activities were also provided.

Due to practical constraints within the school setting, participants were allocated to the activity formats primarily based on existing class groupings rather than strict random assignment. This approach enabled the intervention activities to be implemented without disrupting regular school schedules while maintaining feasibility within the school context. Baseline comparisons indicated no statistically significant differences in pre-intervention awareness scores among the groups. Furthermore, the use of analysis of covariance (ANCOVA) controlled for pre-test scores and helped mitigate potential bias associated with the non-random allocation of participants.

2.3.3. Questionnaire Design

The questionnaire was designed to assess students’ awareness and behaviors related to solid waste segregation and management. The instrument consisted of two main sections: (1) awareness of waste segregation and waste management concepts, and (2) self-reported waste segregation behaviors based on the practical application of the 3R principles (Reduce, Reuse, and Recycle). Awareness items were structured using dichotomous responses (correct = 1; incorrect = 0), while behavioral items were measured using a three-point frequency scale (regularly, sometimes, and never) [26]. Example items included questions on separating recyclable waste from general waste, reducing the use of plastic bags, bringing reusable containers or bags when shopping, reusing materials before disposing of them, and using up food to minimize food waste. The questionnaire items were reviewed by three experts in environmental science and public health to ensure content validity and clarity prior to data collection.

2.3.4. Observation Checklist and Waste Measurement

To complement the self-reported questionnaire data, direct observations of students’ waste segregation practices were conducted using a structured observation checklist. The checklist was designed to record students’ actual waste disposal behaviors, including the correct separation of recyclable, general, organic, and hazardous waste in designated containers within the school environment.

Observations were carried out by the research team during routine school activities to understand students’ typical waste segregation practices. Baseline monitoring of waste segregation practices was carried out one week prior to the implementation of the awareness-promoting activities (Phase II). Follow-up observations were subsequently conducted three weeks after the intervention to monitor students’ waste segregation behavior during routine school activities (Phase III).

In addition, the quantity and composition of segregated solid waste were recorded using standardized waste quantity recording forms. Waste was categorized into major types, including recyclable waste, general waste, organic waste, and hazardous waste. These observational data and waste quantity measurements were used to complement the self-reported behavioral responses and enhance the robustness of evaluating intervention outcomes.

2.3.5. Phase III: Evaluation of Activity Effectiveness

Phase III involved data collection and analysis to evaluate the effectiveness of the awareness-promoting activities developed in Phase II. Students’ awareness levels and waste segregation behaviors were assessed. This phase was conducted between April and May 2025, with behavioral monitoring conducted three weeks after the intervention.

Awareness scores were calculated using dichotomous scoring (correct = 1; incorrect = 0). Total scores ranged from 0 to 20 and were classified into four levels: very high (16–20 points), high (11–15 points), moderate (6–10 points), and low (0–5 points) [26,27,28].

Waste segregation behavior scores were derived from the behavioral questionnaire responses using a three-point frequency scale (regularly = 2; sometimes = 1; never = 0). The total scores were classified into three levels: high to very high (13–24 points), moderate (7–12 points), and low (0–6 points) [27].

2.4. Data Analysis

2.4.1. Phase I: Baseline Data Analysis

Qualitative data obtained from interviews and structured observations were analyzed using descriptive qualitative analysis. The data were categorized, compared, and synthesized to describe existing waste management practices, operational conditions, and key challenges in the study schools included.

2.4.2. Phase II: Analysis of the Activity Development Process

All research instruments were reviewed by three experts in the fields of environmental science and public health to assess content validity, clarity of language, and relevance to the research objectives. Content validity was evaluated using the Index of Item–Objective Congruence (IOC). For each item, IOC values ranged from 0.67 to 1.00, indicating acceptable to excellent congruence between the items and the study objectives. Items with IOC values below 0.50 were revised or removed prior to data collection to ensure the validity and reliability of the research instruments.

2.4.3. Phase III: Statistical Analysis of Intervention Outcomes

Awareness scores, waste segregation behavior scores, and quantities of segregated solid waste collected before and after the intervention were summarized using descriptive statistics (means and standard deviations for continuous variables, and numbers and percentages for categorical variables). Differences between pre- and post-intervention scores were examined using paired t-tests. Changes in paired awareness classification distributions between the pre-test and post-test were assessed using the Stuart–Maxwell test for marginal homogeneity. Differences in awareness-promoting outcomes among the five activity groups were analyzed using analysis of covariance (ANCOVA), with adjustment for pre-test scores and school. When overall group differences were statistically significant, pairwise comparisons were performed using the Bonferroni correction method. All statistical analyses were performed using Stata version 19.5 (StataCorp, College Station, TX, USA). Statistical significance was set at p < 0.05.

3. Results and Discussion

3.1. Phase I: Baseline Conditions of Waste Management in Schools

From interviews with school administrators, teachers, staff, and lower secondary school students, we established that most schools had established formal policies and operational measures for solid waste management. These measures emphasized source-based waste segregation in accordance with the 3Rs principle, including the provision of color-coded waste bins, designated waste collection points, and the assignment of waste management responsibilities to students under teacher supervision (

Table 2. Summary of school waste management conditions derived from interviews.

Management Dimension	Synthesized Findings from Interviews
School policies and measures	Most schools had established policies promoting waste separation based on the 3Rs principle, used color-coded bins, and designated waste collection points within school premises. Some schools participated in the Zero Waste school program.
Implementation processes	Internal planning, teacher supervision, awareness-raising activities, training sessions, public communication, and disciplinary measures were applied to promote consistent waste segregation behaviors among students.
Monitoring and evaluation	Student behaviors, cleanliness, and daily waste quantities were regularly observed, with periodic reporting and review of waste management-related activities.
Problems and constraints	Inconsistent student knowledge and behaviors, entrenched habits, lack of continuity, insufficient budget and equipment, and limited cooperation from parents and surrounding communities.
Supporting factors and opportunities	Strong roles of teachers and student leaders, easier management in small-sized schools, external support from relevant agencies, and potential spillover effects from schools to households and communities.
Future policy directions	Strengthening integration with local government organizations, increasing budgetary and material support, developing waste separation learning modules across all grade levels, promoting school-based waste bank activities, and enhancing source-based waste management from schools to communities.

Note: Data were obtained from interviews with school administrators, teachers, staff, and lower secondary school students in Bangrakam Mueang Mai Subdistrict Municipality.

). These practices align with the concept of source-based waste management in educational institutions, providing an enabling structural environment for waste segregation behavior.

Despite the presence of institutional policies and basic infrastructure, several challenges were identified. Key obstacles included heterogeneity in students’ knowledge and behavior, entrenched habitual practices and social norms that were not conducive to proper waste segregation, and a lack of continuity in activity implementation. In addition, limited engagement from parents and surrounding communities reduced the effectiveness of school-based waste management initiatives. As a result, incomplete waste segregation, accumulation of residual waste, and occasional odor problems were reported within school premises, although no severe impacts on nearby communities were observed (

Table 3. Environmental conditions related to waste management in lower secondary schools in Bangrakam Mueang Mai Subdistrict Municipality based on field observations.

Observation Dimension	Key Findings	School
		1	2	3	4	5
Waste infrastructure	Waste bins were provided at key locations throughout all school areas.	✓	✓	✓	✓	✓
Waste collection system	General waste was collected by the local administrative organization; all schools provided waste containers.	✓	✓	✓	✓	✓
Waste segregation practice	Segregation of recyclable and general waste was implemented.	✓	✓	✓	✓	✓
	Segregation of organic waste was implemented.	✓	✓	✓	-	✓
	Hazardous and infectious waste was segregated at school prior to transfer to local administrative organization for final disposal.	-	✓	✓	✓	✓
Waste disposal methods	Recyclable waste was separated and sold to secondhand shops.	✓	✓	✓	✓	✓
	Organic waste was used as animal feed and/or applied as soil amendments.	✓	✓	✓	-	✓
	General waste was disposed of in sanitary landfills.	✓	✓	✓	✓	✓
	Hazardous and infectious waste was collected and managed by local administrative organization.	-	✓	✓	✓	✓
	Open-air waste burning was observed.	-	✓	✓	✓	✓
Environmental impacts	Air pollution resulting from waste burning was observed.	-	✓	✓	✓	✓
	Odors from organic waste was reported.	✓	-	✓	✓	-

Note: School 1 = Bantamoprachasun School; School 2 = Watyangkhan-ou School; School 3 = Watlamjedee School; School 4 = Bangrakam School; School 5 = Bangrakam Wittayasuksa School. ✓ = Implemented/Observed; - = Not observed.

).

From a behavioral perspective, these findings suggest that the existence of facilities and formal rules alone is insufficient to ensure consistent waste segregation behavior. In line with the Theory of Planned Behavior [9], while schools provided a degree of perceived behavioral control through facilities and regulations, gaps remained in students’ attitudes and internalized social norms. These gaps limited the sustainability of waste segregation practices and underscore the importance of interventions that address awareness, motivation, and habitual behavior in addition to physical infrastructure.

At the policy and management level, all schools expressed a strong need for integrated collaboration among internal school units and local administrative organizations to strengthen source-based waste management. Suggested measures included financial and equipment support, clearer designation of waste segregation areas, the use of creative and competitive activities to motivate students, the promotion of waste management innovations and technologies, the establishment of school-based waste banks, and stronger linkages between school, household, and community waste management systems (Table 2). These recommendations closely align with circular economy principles, which emphasize stakeholder participation, material recovery, and system-wide integration across institutional and community levels.

Observations conducted prior to the implementation of awareness-promoting activities further indicated that all lower secondary schools within Bangrakam Mueang Mai Subdistrict Municipality were equipped with waste collection containers located at key areas, including administrative buildings, classrooms, cafeterias, and sports fields. This reflects a basic level of infrastructural readiness for school-based waste management.

In most schools, waste was separated into four categories (Figure 2): (1) recyclable waste, which was sold to generate income for purchasing waste management materials; (2) general waste; (3) hazardous or infectious waste, which, in practice, was often mixed with general waste and collected by the municipality for final disposal; and (4) biodegradable waste, particularly food waste from school cafeterias, which was commonly reused as animal feed within or near school premises. These practices demonstrate partial alignment with source-based waste segregation and material recovery principles.

However, observations in November 2024 coincided with provincial-level waste management disruption, during which final disposal facilities in Phitsanulok Province were unable to operate normally. As a result, some schools resorted to on-site waste burning, posing short-term air pollution risks (Table 3). This situation highlights the vulnerability of school waste management systems to disruptions in downstream disposal infrastructure and underscores the interdependence between source-based practices and end-of-pipe waste management systems.

Overall, the baseline findings indicate that while schools possessed basic infrastructure and initial segregation practices, substantial limitations remained in the separate management of hazardous waste, the systematic treatment of organic waste, and the heavy reliance on municipal disposal systems. These constraints suggest that infrastructural readiness alone is insufficient to ensure sustainable waste management. Instead, policy support, system resilience, and behavioral interventions are required concurrently. Strengthening students’ awareness and waste segregation behavior, alongside institutional and municipal collaboration, is therefore essential for advancing circular economy-oriented waste management in school settings [5,6].

3.2. Phase II: Development of Awareness-Promoting Activities

3.2.1. Effects of Awareness-Promoting Activities on Waste Segregation

(1)

Comparison of Awareness between the Control Group and the Pre-Intervention Group

The analysis indicated no statistically significant difference in waste segregation awareness scores between the control group and students prior to participation in the awareness-promoting activities (p = 0.985). This result confirms that the two groups had comparable baseline awareness levels, thereby supporting the validity of the control group as a reference for evaluating post-intervention changes.

(2)

Changes in Awareness before and after Participation in the Activities

Table 4. Changes in students’ waste segregation awareness scores before and after participation in awareness-promoting activities.

Category	n	Pre-Test Mean ± SD	Post-Test Mean ± SD	Mean Difference 95% CI	p-Value
Activity format
A1 (Control)	67	11.31 ± 4.53	12.81 ± 3.86	2.01 (1.21–2.82)	<0.001
A2 (Training workshop)	73	12.57 ± 2.97	12.70 ± 4.05	2.32 (1.59–3.04)	<0.001
A3 (Printed media)	74	11.47 ± 3.49	13.24 ± 3.10	2.85 (2.09–3.61)	<0.001
A4 (Video-based learning)	68	12.48 ± 3.87	12.25 ± 3.87	1.99 (1.15–2.82)	<0.001
A5 (Game-based activity)	72	11.24 ± 3.93	12.65 ± 3.94	3.10 (2.08–4.12)	<0.001
School
Bangrakam	52	9.60 ± 4.24	12.10 ± 3.68	2.50 (1.58–3.42)	<0.001
Bangrakam Wittayasuksa	240	9.69 ± 3.75	12.15 ± 3.66	2.46 (1.99–2.93)	<0.001
Bantamoprachasun	17	12.76 ± 3.47	14.94 ± 2.68	2.18 (0.27–4.09)	0.028
Watyangkhan-ou	12	11.25 ± 3.91	15.08 ± 3.06	3.83 (1.35–6.31)	0.006
Watlamjedee	33	13.94 ± 3.60	16.06 ± 2.93	2.12 (1.31–2.94)	<0.001
Overall	354	10.27 ± 4.03	12.74 ± 3.77		<0.001
Classify group, n (%)					<0.001 *
Low (0–5)		45 (12.71)	10 (2.82)
Moderate (6–10)		144 (40.68)	97 (27.40)
High (11–15)		122 (34.46)	153 (43.22)
Very high (16–20)		43 (12.15)	94 (26.55)

Note: Values are presented as mean ± standard deviation (SD) unless otherwise indicated. Difference values represent mean paired differences (post-test minus pre-test) obtained from paired t-test analysis. p-values were obtained from paired t-tests comparing pre-test and post-test scores. * Changes in paired awareness classification distributions between the pre- and post-test were evaluated using the Stuart–Maxwell test for marginal homogeneity. n = number of participants in each group. Statistical significance was set at p < 0.05.

presents the changes in students’ waste segregation awareness scores before and after participation in the awareness-promoting activities. Overall, students’ waste segregation awareness scores increased significantly after participation in the awareness-promoting activities. The mean awareness score rose from 10.27 ± 4.03 at pre-test to 12.74 ± 3.77 at post-test (overall change was 2.47, 95% CI: 2.10–2.83, p < 0.001). Statistically significant improvements were observed across all activity formats and all participating schools (all p < 0.05), indicating enhanced understanding of waste segregation principles among lower secondary school students.

Consistent with these results, the distribution of awareness categories changed significantly following the intervention (p < 0.001, Stuart–Maxwell test). The proportion of students classified as having high and very high awareness increased substantially, whereas the proportions of students in the low and moderate awareness categories declined after the intervention.

When analyzed by activity format, all groups—including the control group (A1)—showed statistically significant increases in awareness scores (2.01, 95% CI: 1.21–2.82, p < 0.001). The improvement observed in the control group may be due to several contextual factors within the school environment. Students may have been indirectly exposed to waste segregation information through routine school activities, environmental campaigns, or informal discussions with peers participating in the intervention activities. Such interactions can lead to information diffusion or partial contamination between groups, which is a common limitation of school-based intervention research. In addition, repeated exposure to the survey during the pre- and post-tests may have increased students’ attention to waste segregation issues, contributing to modest awareness gains even in the absence of structured interventions. Self-reported responses may also be influenced by social desirability bias, whereby students provide answers consistent with perceived environmental expectations.

These considerations suggest that the improvements observed in the control group likely reflect broader contextual influences within the school environment rather than direct intervention effects. Therefore, the intervention outcomes reported in this study should be interpreted as incremental improvements beyond baseline awareness changes that occurred within the school setting.

Among the intervention groups, printed media (A3) and game-based activity (A5) showed relatively larger increases in mean awareness scores (2.85, 95% CI: 2.09–3.61 and 3.10, 95% CI: 2.08–4.12, respectively), indicating the potential effectiveness of visually engaging with interactive learning approaches. In contrast, the video-based learning (A4) demonstrated a comparatively smaller change (1.99, 95% CI: 1.15–2.82), suggesting that passive learning methods may have a more limited impact on short-term improvements in awareness.

The analysis by school revealed statistically significant increases in awareness scores across all of the participating schools (p < 0.05). Watyangkhan-ou School and Watlamjedee School demonstrated the largest gains in awareness (3.83, 95% CI: 1.35–6.31 and 2.12, 95% CI: 1.31–2.94, respectively), while Bangrakam School (9.6, 95% CI: 8.42–10.78) and Bangrakam Wittayasuksa School (9.69, 95% CI: 9.21–10.16) also showed clear post-intervention improvements, despite lower baseline scores These results indicate that awareness-promoting activities were effective across different school contexts, regardless of initial awareness levels.

(3)

Effects of Activity Formats and School Context on Post-Test Awareness

To further examine the effects of activity formats on post-intervention awareness while controlling for baseline differences and variations in school context, an analysis of covariance (ANCOVA) was conducted (

Table 5. Summary of analysis of covariance (ANCOVA) for post-test awareness scores by activity format, controlling for pre-test scores.

Source	SS	df	MS	F	p-Value
Activity format	36.96	4	9.24	1.03	0.390
Pre-test score (covariate)	1283.16	1	1283.16	143.37	<0.001
School	135.63	4	33.91	3.79	0.005
Error	3078.88	344	8.95
Total	5010.57	353	14.19

Note: ANCOVA was conducted to examine differences in post-test awareness scores among activity formats while controlling for pre-test scores. SS = sum of squares; df = degrees of freedom; MS = mean square; F = F-statistic.

). After adjusting for pre-test awareness scores, there were no statistically significant differences in post-test awareness scores among the five activity formats (F = 1.03, p = 0.390). In contrast, the pre-test awareness score was a strong and significant predictor of the post-test awareness score (F = 143.37, p < 0.001), indicating that students’ baseline awareness played a major role in determining post-intervention outcomes.

This finding is consistent with behavior change theory, which emphasizes the influence of prior knowledge and beliefs on subsequent learning and attitude formation [9]. Although activity format did not independently influence awareness outcomes, school context was significantly associated with post-test awareness scores (F = 3.79, p = 0.005). This finding suggests that institutional and social environments within schools play an important role in shaping learning effectiveness beyond the effects of the intervention format.

School-level factors, such as teacher involvement, peer interaction, and supportive school culture, may strengthen subjective norms and perceived behavioral control, thereby reinforcing students’ internalization of waste segregation awareness. These mechanisms align with the Theory of Planned Behavior, which highlights the roles of subjective norms and perceived behavioral control in shaping pro-environmental behavior [9,29].

To further explore school-level differences in post-intervention awareness, pairwise comparisons of adjusted post-test awareness scores were conducted using the Bonferroni correction (

Table 6. Pairwise comparisons of adjusted post-test awareness scores among schools using the Bonferroni correction method.

School Comparison	Mean Difference	95% CI	p-Value
Bangrakam Wittayasuksa vs. Bangrakam	0.01	−1.28, 1.30	>0.99
Bantamoprachasun vs. Bangrakam	1.24	−1.15, 3.63	>0.99
Watyangkhan-ou vs. Bangrakam	2.14	−0.58, 4.85	0.269
Watlamjedee vs. Bangrakam	1.76	−0.19, 3.71	0.113
Bantamoprachasun vs. Bangrakam Wittayasuksa	1.23	−0.93, 3.38	>0.99
Watyangkhan-ou vs. Bangrakam Wittayasuksa	2.12	−0.38, 4.63	0.172
Watlamjedee vs. Bangrakam Wittayasuksa	1.75	0.10, 3.40	0.030
Watyangkhan-ou vs. Bantamoprachasun	0.90	−2.30, 4.09	>0.99
Watlamjedee vs. Bantamoprachasun	0.52	−2.01, 3.05	>0.99
Watlamjedee vs. Watyangkhan-ou	−0.38	−3.25, 2.49	>0.99

Note: Pairwise comparisons were performed on adjusted post-test awareness scores using Bonferroni correction for multiple comparisons. CI = confidence interval.

). Most school comparisons did not show statistically significant differences. However, Watlamjedee School and Bangrakam Wittayasuksa School differed significantly, with Watlamjedee School exhibiting higher adjusted post-test awareness scores (mean difference = 1.75; 95% CI: 0.10–3.40; p = 0.030). No other school pairs showed significant differences after adjustment for multiple comparisons.

Overall, the pairwise comparison results support the conclusion that awareness-promoting activities produced broadly consistent awareness outcomes across participating schools, with only minor variations attributable to specific school contexts. Schools with supportive supervision, consistent messaging, and active engagement from teachers can reinforce students’ perceived importance of the relevance of waste segregation practices, thereby enhancing awareness outcomes [10,11].

(4)

Summary of Awareness Outcomes

In summary, the awareness-promoting activities in this study effectively increased students’ awareness of waste segregation across activity formats and school settings. While no single activity format was found to be superior after controlling for baseline awareness, the improvements observed across all groups underscore the importance of integrating awareness-based interventions into school-based waste management programs. These results provide a critical foundation for subsequent analyses of behavioral change following the intervention.

3.2.2. Effects of the Activities on Waste Segregation Behavior

(1)

Comparison of Behavior between the Control Group and Pre-Intervention Group

The analysis revealed no statistically significant difference in waste segregation behavior scores between the control group and students prior to participation in the awareness-promoting activities (p = 0.440). This result confirms that both groups exhibited comparable baseline behavioral patterns, allowing the control group to be used as a valid reference for evaluating post-intervention behavioral changes.

(2)

Changes in Waste Segregation Behavior before and after Participation in Awareness-Promoting Activities

Following the implementation of awareness-promoting activities, students demonstrated a significant improvement in waste segregation behavior across all activity formats and schools (

Table 7. Summary of behavior scores before and after awareness-promoting activities.

Category	n	Pre-Test Mean ± SD	Post-Test Mean ± SD	Mean Difference 95% CI	p-Value
Activity format
A1 (Control)	62	11.31 ± 4.53	13.94 ± 3.72	2.63 (1.61–3.65)	<0.001
A2 (Training workshop)	67	12.57 ± 2.97	13.96 ± 3.65	1.39 (0.70–2.08)	<0.001
A3 (Printed media)	70	11.47 ± 3.49	12.94 ± 3.48	1.47 (0.75–2.19)	<0.001
A4 (Video-based learning)	69	12.48 ± 3.87	14.16 ± 3.51	1.68 (0.96–2.40)	<0.001
A5 (Game-based activity)	66	11.24 ± 3.93	13.24 ± 3.55	2.00 (1.17–2.83)	<0.001
School
Bangrakam	47	12.68 ± 3.38	14.43 ± 3.53	1.74 (0.79–2.70)	<0.001
Bangrakam Wittayasuksa	232	11.11 ± 3.75	12.94 ± 3.51	1.82 (1.38–2.27)	<0.001
Bantamoprachasun	17	12.29 ± 3.06	15.06 ± 2.14	2.76 (1.85–3.68)	<0.001
Watyangkhan-ou	9	13.78 ± 3.87	14.11 ± 2.71	0.33 (−1.16–1.82)	0.620
Watlamjedee	29	15.24 ± 2.85	17.03 ± 2.86	1.79 (0.67–2.91)	0.028
Overall	334	11.82 ± 3.80	13.64 ± 3.59		<0.001
Classify group, n (%)					<0.001 *
Low (0–6)		29 (8.68)	7 (2.1)
Moderate (7–12)		176 (52.69)	130 (38.92)
High to Very high (13–24)		129 (38.62)	197 (58.98)

Note: Values are presented as mean ± standard deviation (SD) unless otherwise indicated. Difference values represent mean paired differences (post-test minus pre-test) obtained from paired t-test analysis. * Changes in paired behavioral classification distributions between pre- and post-test were evaluated using the Stuart–Maxwell test for marginal homogeneity. n = number of participants in each group. Statistical significance was set at p < 0.05.

). Overall, students’ waste segregation behavior scores improved significantly following awareness-promoting activities. The mean behavior score increased from 11.82 ± 3.80 at pre-test to 13.64 ± 3.59 at post-test (with an overall change of 1.82, 95% CI: 1.47–2.17, p < 0.001), indicating a positive behavioral response to the intervention.

Consistent with the continuous score results, the distribution of waste segregation behavior categories changed significantly after the intervention (p < 0.001, Stuart–Maxwell test). The proportion of students classified as having high to very high scores for waste segregation behavior increased substantially, while the proportions in the low- and moderate-level behavior categories decreased following the intervention.

At the activity level, statistically significant improvements in behavior were observed across all formats, including training workshops (1.39, 95% CI: 0.70–2.08), printed media (1.47, 95% CI: 0.75–2.19), video-based learning (1.68, 95% CI: 0.96–2.40), and game-based activities (2.00, 95% CI: 1.17–2.83) (all p < 0.001). These findings indicate that awareness-promoting activities, regardless of the format in which they are delivered, were effective in enhancing students’ waste segregation behavior.

At the school level, significant increases in behavior scores were observed in Bangrakam School (1.74, 95% CI: 0.79–2.70), Bangrakam Wittayasuksa School (1.82, 95% CI: 1.38–2.27), Bantamoprachasun School (2.76, 95% CI: 1.85–3.68), and Watlamjedee School (1.79, 95% CI: 0.67–2.91) (p < 0.05). In contrast, no statistically significant change was observed at Watyangkhan-ou School (0.33, 95% CI: −1.16 to 1.82) (p = 0.620). This result may be partly attributable to the relatively high baseline behavior scores and smaller sample size at this school, which may have resulted in a ceiling effect. Similar patterns have been reported in previous studies, suggesting that awareness-raising interventions may yield limited additional behavioral change when baseline practices are already favorable or when intervention durations are relatively short [10,12].

(3)

Effects of Activity Formats and School Context on Post-Test Behavior

To further examine the effects of activity formats on post-intervention waste segregation behavior while controlling for baseline behavior and school context, ANCOVA was conducted to study differences in post-test waste segregation behavior scores among activity formats. This was conducted while controlling for pre-test behavior scores and school (

Table 8. Analysis of covariance (ANCOVA) for post-test waste segregation behavior scores by group activities, controlling for pre-test scores.

Source	SS	df	MS	F	p-Value
Activity format	44.15	4	11.04	1.41	0.229
Pre-test score (covariate)	1158.83	1	1158.83	148.38	<0.001
School	121.06	4	30.26	3.88	0.004
Error	2530.45	324	7.81
Total	4290.89	333	12.89

Note: ANCOVA was conducted to examine differences in post-test waste segregation behavior scores among activity formats while controlling for pre-test scores. SS = sum of squares; df = degrees of freedom; MS = mean square; F = F-statistic.

). The results showed that activity format did not have a statistically significant effect on post-test behavior scores (F = 1.41, p = 0.229).

In contrast, pre-test behavior score was a strong and statistically significant covariate (F = 148.38, p < 0.001). This indicates that baseline behavior is a primary determinant of post-intervention behavior outcomes. Students who already practiced appropriate waste segregation behaviors prior to the intervention were more likely to maintain or further improve these behaviors following participation.

School context had a statistically significant effect on post-test behavior scores (F = 3.88, p = 0.004), indicating that institutional or social factors at the school level influenced behavioral outcomes beyond individual baseline behavior. From a theoretical perspective, this finding aligns with the Theory of Planned Behavior (TPB), which emphasizes the role of perceived behavioral control and social reinforcement in facilitating pro-environmental behavior change [9,21]. Similar evidence has been reported in previous studies highlighting the importance of teacher involvement and peer influence in sustaining waste segregation behavior among students [10,11].

To further explore school-level differences, pairwise comparisons of adjusted post-test behavior scores were conducted using the Bonferroni correction method (

Table 9. Pairwise comparisons of marginal linear predictions for post-test waste segregation behavior among schools using the Bonferroni test.

School Comparison	Mean Difference	95% CI	p-Value
Bangrakam Wittayasuksa vs. Bangrakam	−0.67	−1.95, 0.60	>0.99
Bantamoprachasun vs. Bangrakam	0.82	−1.42, 3.05	>0.99
Watyangkhan-ou vs. Bangrakam	−0.82	−3.71, 2.07	>0.99
Watlamjedee vs. Bangrakam	1.28	−0.61, 3.18	0.561
Bantamoprachasun vs. Bangrakam Wittayasuksa	1.49	−0.50, 3.48	0.352
Watyangkhan-ou vs. Bangrakam Wittayasuksa	−0.14	−2.86, 2.57	>0.99
Watlamjedee vs. Bangrakam Wittayasuksa	1.96	0.32, 3.60	0.008
Watyangkhan-ou vs. Bantamoprachasun	−1.63	−4.90, 1.63	>0.99
Watlamjedee vs. Bantamoprachasun	0.47	−1.97, 2.91	>0.99
Watlamjedee vs. Watyangkhan-ou	2.10	−0.93, 5.13	0.506

Note: Values are based on marginal linear predictions from the ANCOVA model. Confidence intervals (CIs) are adjusted using the Bonferroni correction. Statistical significance was set at p < 0.05.

). Among all school comparisons, only one statistically significant difference was observed: the students from Watlamjedee demonstrated significantly higher post-test behavior scores compared with those from Bangrakam Wittayasuksa School (mean difference = 1.96, 95% CI: 0.32 to 3.60, p = 0.008). All other pairwise comparisons between schools were not statistically significant, indicating broadly comparable post-intervention behavior outcomes across most school settings after adjusting for multiple comparisons.

(4)

Summary of Behavioral Outcomes

Overall, the results indicate that awareness-promoting activities effectively enhanced waste segregation behavior among lower secondary school students across activity formats and school contexts. While no specific activity format exerted a statistically superior effect after controlling for baseline behavior, school context played a significant role in shaping post-intervention behavioral outcomes. These findings suggest that awareness-based interventions are most effective when integrated with supportive school environments, consistent supervision, adequate waste segregation infrastructure, and collaboration with local administrative organizations. Such integrated approaches are essential for achieving sustained improvements in source-based waste management while advancing circular economy-oriented practices in educational institutions.

3.2.3. Relationship Between Awareness and Waste Segregation Behavior

The results indicate that awareness of solid waste segregation was positively correlated with students’ waste segregation behavior among lower secondary school students in Bangrakam Mueang Mai Subdistrict Municipality (Figure 3). The Pearson correlation coefficient was r = 0.21 (95% CI: 0.10–0.31), indicating a weak positive relationship and a small effect size according to Cohen’s benchmarks for correlation coefficients [30]. Although statistically significant at the 0.01 level, this finding suggests that awareness contributes to behavioral outcomes but explains only a limited proportion of the variance in students’ waste segregation behavior. In practical terms, increasing awareness alone may not necessarily lead to substantial behavioral change.

Similar findings have been reported in previous studies on environmental education and waste management behavior. Awareness-based interventions often produce only modest improvements in pro-environmental behavior unless they are supported by institutional and environmental conditions that support these practices. For example, Vicente-Molina et al. [31] reported that environmental knowledge contributes to behavioral change but explains only a limited portion of actual pro-environmental actions. Likewise, Otto and Pensini [32] found that environmental awareness must be complemented by contextual support and experiential learning to influence environmental behaviors effectively in students.

From a theoretical perspective, these findings can be interpreted using the Theory of Planned Behavior (TPB). Within this framework, environmental awareness is a cognitive component of pro-environmental behavior, reflecting individuals’ understanding of environmental issues and behavioral consequences. Such awareness contributes to the formation of behavioral beliefs and attitudes, which, in turn, influence behavioral intentions and observable actions. However, TPB also emphasizes that behavior is shaped by additional mediating factors, including subjective norms and perceived behavioral control [9].

In the school context, institutional routines, peer interactions, and teacher supervision may shape students’ attitudes toward waste segregation and reinforce social expectations regarding environmentally responsible behavior. Moreover, the availability of clearly labeled waste segregation facilities and practical guidance may influence students’ perceived behavioral control. When such enabling conditions are limited, the direct influence of awareness on observable behavior may be weakened, thereby contributing to the relatively small correlation coefficient observed in this study. These findings also reflect the widely discussed “value–action gap” in environmental behavior research, where individuals with adequate environmental awareness may still fail to translate this awareness into consistent pro-environmental behavior due to various internal and external constraints [12].

Nevertheless, the positive relationship confirms that awareness remains a fundamental component of environmentally responsible behavior. To translate awareness into sustained behavioral change in practice, educational interventions should be supported by institutional measures such as adequate waste segregation infrastructure, routine supervision, integration of waste segregation practices into school activities, and collaboration with local administrative organizations responsible for municipal waste management.

During the implementation of awareness-promoting activities, several practical challenges were encountered. Time limitations within school schedules occasionally restrict interactive learning activities, while variations in students’ prior knowledge require facilitators to adapt training approaches. Coordinating activities across multiple schools also requires close collaboration with teachers and school administrators to maintain consistent participation.

Several limitations should also be acknowledged. Participation in the study was voluntary, which may introduce potential selection bias, as participating students may have had greater prior interest in environmental issues than non-participants. The use of self-reported behavioral measures may also introduce reporting bias. In addition, the relatively broad scoring categories for awareness and behavior may limit the sensitivity of instruments to detect subtle differences among activity formats. Variations in sample sizes across schools and the relatively short intervention period may further affect the precision of the estimated effects and the assessment of long-term behavioral changes.

Another methodological consideration concerns the improvements observed in the control group. Although students in the control group did not participate in the awareness-promoting activities, modest improvements in awareness and behavior were still detected. These changes may reflect contextual influences within the school environment, such as routine environmental activities, informal peer interactions between students participating in the intervention and those in the control group, or exposure to environmental information during the study period. Repeated exposure to the pre-test and post-test questionnaires may also have increased students’ attention to waste segregation practices. Consequently, the intervention effects should be interpreted as incremental improvements beyond broader changes occurring within the school context rather than as purely isolated treatment effects.

In addition, the dataset has a hierarchical structure in which students are nested within schools. While multilevel modeling could provide a more detailed examination of school-level influences on students’ awareness and behavior, such an approach was not feasible in the present study due to the limited number of participating schools (n = 5). Therefore, the analysis relied on single-level statistical methods. This limitation should be considered when interpreting the findings, and future research involving a larger number of schools may benefit from multilevel analytical approaches to better account for institutional and contextual effects.

Despite these limitations, the findings provide practical insights for schools and local governments seeking to promote source-based waste management. Integrating awareness-based education with supportive school environments, adequate waste segregation infrastructure, and collaboration with local administrative organizations can strengthen students’ pro-environmental behaviors and contribute to the advancement of circular economy principles at the community level.

3.2.4. Changes in Solid Waste Quantity After the Implementation of Awareness-Promoting Activities

The results indicate that waste segregation practices among lower secondary school students can improve following the implementation of awareness-promoting activities, as reflected by changes in both the quantity and composition of solid waste generated within the schools studied. Specifically, the amounts of general waste, organic waste, hazardous waste, and infectious waste exhibited decreasing trends from 13.31, 4.19, 0.41, and 0.41 kg to 12.61, 3.67, 0.39, and 0.40 kg, respectively.

Figure 4 illustrates a clear shift in the composition of solid waste after the implementation of awareness-promoting and behavior change activities. Notably, the quantity of recyclable waste increased substantially from 1.87 kg before the intervention to 2.63 kg after the intervention, corresponding to an increase in its proportion from 4.5% to 13.4%. This change indicates improved source-based waste segregation and enhanced recovery of recyclable materials within the school environment.

In contrast, the proportions of general waste and compostable waste showed more modest reductions, decreasing from 65.9% to 64.0% and from 20.8% to 18.6%, respectively. Marked decreases were also observed for hazardous and infectious waste, both of which declined from approximately 4.4% prior to the intervention to around 2% following the intervention. These shifts suggest improved separation practices for waste categories associated with higher environmental and health risks [19].

Overall, the observed changes indicate that awareness-promoting activities were associated with more effective source-based waste segregation, characterized by the increased recovery of recyclable materials [33] and reduced proportions of hazardous and infectious waste. However, the relatively limited reductions in some waste categories may be attributable to structural and contextual constraints beyond individual behavioral control. These include fixed food consumption patterns in school cafeterias, limited on-site systems for managing hazardous and infectious waste, and continued reliance on municipal waste collection and disposal processes.

From a systems perspective, these findings underscore the importance of aligning behavioral interventions with supportive waste management infrastructure to achieve meaningful waste reduction outcomes. Environmentally responsible behavior is shaped not only by individual awareness and attitudes, but also by institutional arrangements, infrastructure availability, and policy support [9,12,20,21,34]. Within the framework of the circular economy, which prioritizes source separation and material recovery over end-of-pipe solutions [6,33], effective waste segregation at the source is a critical prerequisite for recycling and resource circulation [4].

Furthermore, improvements in source-based waste segregation directly contribute to broader sustainability objectives, including responsible consumption and production as well as sustainable urban development. Although awareness-based behavioral interventions can produce measurable improvements in waste segregation outcomes, achieving broader and more consistent reductions across all waste categories requires complementary system-level measures [6,35]. These include adequate waste treatment infrastructure, institutionalized monitoring mechanisms, and strengthened collaboration between schools and local administrative organizations. Such integrated approaches are consistent with socio-ecological models of environmental behavior. They are essential for translating awareness and behavior into sustained improvements in school-based waste management systems.

4. Conclusions

This study demonstrates that awareness-promoting activities implemented in lower secondary schools are effective at significantly enhancing both waste segregation awareness and source separation behavior among students. The findings support learning-based behavior change frameworks, indicating that improvements in knowledge and awareness can lead to observable behavioral changes [35,36]. The positive, albeit weak, relationship identified between awareness and waste segregation behavior further suggests that cognitive and attitudinal factors play an important contributory role in shaping environmentally responsible practices among adolescents [37,38,39,40].

The results also indicate that different activity formats—including training workshops, printed campaign materials, video-based learning, and game-based activities—were similarly effective in improving students’ awareness and waste segregation behavior [38,39]. The absence of statistically significant differences among activity formats suggests that schools can flexibly select intervention approaches that best fit their institutional contexts, resource availability, and student characteristics while still achieving comparable outcomes.

In addition, this study highlights the role of educational institutions as key drivers of source-based waste management. Improvements in waste segregation behavior were accompanied by observable changes in waste composition, particularly an increase in recovery of recyclable materials and reduction in hazardous and infectious waste. These outcomes are consistent with circular economy principles, which emphasize waste separation at the source as a prerequisite for material recovery and recycling, and contributing toward sustainable consumption and production [37,39].

From a policy perspective, the findings suggest that school-based waste segregation initiatives can serve as an effective upstream strategy supporting municipal waste management systems. Municipal waste planners and local administrative organizations can strengthen these initiatives by providing appropriate segregation infrastructure, coordinating waste collection systems, and supporting educational campaigns within schools. At the same time, provincial education offices can play an important role in integrating structured environmental education and practical waste segregation activities into school programs and extracurricular learning.

Furthermore, aligning school-based behavioral interventions with Thailand’s national solid waste management strategy can help strengthen long-term waste reduction and recycling performance at the municipal level [37,40]. By fostering environmental awareness and responsible waste practices among students, schools can contribute to broader societal transitions toward circular economy-oriented waste management. The awareness-promoting activity framework developed in this study may, therefore, serve as a practical reference for educational institutions, municipal authorities, and policymakers seeking to promote sustainable waste management and circular resource use in similar municipal contexts.