Search Results (203)

The crystallization of soluble salts is one of the most significant agents of deterioration affecting porous building materials in historical architecture. This process not only compromises the physical integrity of the materials but also results in considerable aesthetic, structural, and economic consequences. Soluble salts involved in these processes may originate from geogenic sources—including soil leachate, marine aerosols, and the natural weathering of parent rocks—or from anthropogenic factors such as air pollution, wastewater infiltration, and the use of incompatible restoration materials. This study examines the role of capillary rise as a primary mechanism responsible for the vertical migration of saline solutions from the soil profile into historic masonry structures, especially those constructed with calcareous stones. It describes how water retained or sustained within the soil matrix ascends via capillarity, carrying dissolved salts that eventually crystallize within the pore network of the stone. This phenomenon leads to a variety of damage types, ranging from superficial staining and efflorescence to more severe forms such as subflorescence, microfracturing, and progressive mass loss. By adopting a multidisciplinary approach that integrates concepts and methods from soil physics, hydrology, petrophysics, and conservation science, this paper examines the mechanisms that govern saline water movement, salt precipitation patterns, and their cumulative effects on stone durability. It highlights the influence of key variables such as soil texture and structure, matric potential, hydraulic conductivity, climatic conditions, and stone porosity on the severity and progression of deterioration. This paper also addresses regional considerations by focusing on the context of Spain, which holds one of the highest concentrations of World Heritage Sites globally and where many monuments are constructed from vulnerable calcareous materials such as fossiliferous calcarenites and marly limestones. Special attention is given to the types of salts most commonly encountered in Spanish soils—particularly chlorides and sulfates—and their thermodynamic behavior under fluctuating environmental conditions. Ultimately, this study underscores the pressing need for integrated, preventive conservation strategies. These include the implementation of drainage systems, capillary barriers, and the use of compatible materials in restoration, as well as the application of non-destructive diagnostic techniques such as electrical resistivity tomography and hyperspectral imaging. Understanding the interplay between soil moisture dynamics, salt crystallization, and material degradation is essential for safeguarding the cultural and structural value of historic buildings in the face of ongoing environmental challenges and climate variability. Full article

This review aims to increase attention on present water quality issues on Central Asia, finding gaps in the literature on ways to address treatment needs, and help ensure future use of Central Asia surface waters and groundwater for all beneficial uses. Central Asia is a landlocked region known for its harsh climatic conditions and scarce water resources, despite being home to some of the world’s largest internal drainage basins. The available literature suggests that increasing salinity has rendered water unsuitable for irrigation and consumption; hazardous trace elements are found throughout Central Asia, most often associated with mining and industrial sources; and that legacy pesticides influence water quality, particularly in agriculturally influenced basins. This study also focuses on the effects of municipal and industrial wastewater discharge. Additionally, the impact of inadequately treated wastewater on water resources is analyzed through a review of available data and reports regarding surface and groundwater quantity and quality. Given the challenges of water scarcity and accessibility, the reuse of treated wastewater is becoming increasingly important, offering a valuable alternative that necessitates careful oversight to ensure public health, environmental sustainability, and water security. However, due to insufficient financial and technical resources, along with underdeveloped regulatory frameworks, many urban areas lack adequate wastewater treatment facilities, significantly constraining their safe and sustainable reuse. Proper management of wastewater effluent is critical, as it directly influences the quality of both surface and groundwater, which serve as key sources for drinking water and irrigation. Due to their persistent and biologically active nature even at trace levels, we discuss contaminants of emerging concern such as antibiotics, pharmaceuticals, and modern agrochemicals. This review thus highlights gaps in the literature reporting on impacts of wastewater inputs to water quality in Central Asia. It is recommended that future research and efforts should focus on exploring sustainable solutions for water quality management and pollution control to assure environmental sustainability and public health. Full article

Landslides in Ecuador are one of the most common deadly events in natural hazards, such as the one on 26 March 2023. A large-scale landslide occurred in Alausí, Chimborazo province, causing 65 fatalities and 10 people to disappear, significant infrastructural damage, and the destruction of six neighborhoods. This study presents a detailed case analysis of the anthropogenic factors that could have contributed to the instability of the affected area. Field investigations and a review of historical, geological, and social information are the basis for analyzing the complex interactions between natural and human-induced conditions. Key anthropogenic contributors identified include unplanned urban expansion, ineffective drainage systems, deforestation, road construction without adequate geotechnical support, and changes in land use, particularly agricultural irrigation and wastewater disposal. These factors increased the area’s susceptibility to slope failure, which, combined with intense rainfall and past seismic activity, could have caused the rupture process’s acceleration. The study also emphasizes integrating geological, hydrological, and urban planning assessments to mitigate landslide risks in geologically sensitive regions such as Alausí canton. The findings conclude that human activity could be an acceleration factor in natural processes, and the pressure of urbanization amplifies the consequences. This research underscores the importance of sustainable land management, improved drainage infrastructure, and land-use planning in hazard-prone areas. The lessons learned from Alausí can inform risk reduction strategies across other mountainous and densely populated regions worldwide, like the Andean countries, which have similar social and environmental conditions to Ecuador. Full article

This study examined the carbon footprints of freshwater fish farming and Euryale ferox seed (gorgon fruit) production, comparing integrated ecological mode and traditional farming practices based on ISO 14067 and PAS 2050 standards. The ecological mode achieved a 24% lower carbon footprint per unit product than traditional practices, driven by reduced material and energy use. Key emission sources included aeration electricity, feed, and wastewater treatment for fish farming, fertilizers, insecticides, and drainage energy for E. ferox planting. The integrated model combining high-density fish ponds and E. ferox pond reduced the overall carbon footprint (Micropterus salmoides: 4.342 kg CO₂-eq/kg; E. ferox seed: 0.208 kg CO₂-eq/kg) compared to traditional practices (Micropterus salmoides: 5.672 kg CO₂-eq/kg; E. ferox seed: 0.297 kg CO₂-eq/kg). It also lowered production costs, increased profits, and mitigated GHG emissions by using E. ferox and lotus ponds as treatment facilities and reducing fertilizer use. The ecological model showed lower unit costs and higher profits (Micropterus salmoides: 4.01 RMB/kg vs. 2.46 RMB/kg; E. ferox seed: 2.53 RMB/kg vs. 1.93 RMB/kg) than those of the traditional mode. This study underscores the potential of ecologically integrated modes to mitigate water pollution and carbon emissions in agriculture, offering a sustainable solution to meet the rising demand for aquatic products. Full article

The building drainage system (BDS) is a critical building component and must be designed to protect public health by maintaining safe and hygienic conditions within the indoor environment. The recent COVID-19 pandemic and the emergence of other wastewater-related issues, such as the spread of anti-microbial resistance (AMR), place the BDS at the centre of the public health agenda. To understand the complex characteristics of the BDS and its performance, the numerical simulation model AIRNET was used to model whole system responses to discharging events. In this study, the model’s effectiveness and accuracy were evaluated through its application in a case study system representative of a real-world tall building. Data reflecting actual conditions were collected using the drainage test rig at the National Lift Tower (NLT) in Northampton. The data show a strong correlation between the measured and modelled air pressures in the system over time and along the drainage stack height. More importantly, a sample dataset representing various ventilation configurations, flow rates, and water usage combinations shows a strong linear relationship between the simulated and measured pressure values. These results confirm the accuracy and reliability of the AIRNET model in modelling the BDS, even when applied to high-rise buildings. This is crucial for addressing drainage challenges in high-rise building design. Full article

The ubiquity of diclofenac (DCF) in the environment has raised significant concerns. Diclofenac is a non-steroidal anti-inflammatory drug that has been found in various environmental matrices at minimum concentrations that are harmful to aquatic and terrestrial organisms. Traditional wastewater treatment plants (WWTPs) are not fully equipped to remove a range of pharmaceuticals, and that explains the continued ubiquity of DCF in surface waters. In this study, an Fe₃O₄/SiO₂ nanocomposite prepared from acid mine drainage and coal fly ash was applied for the removal of DCF from wastewater. Major functional groups (Si–O–Si and Fe–O) were discovered from FTIR. TEM revealed uniform SiO₂ nanoparticle rod-like structures with embedded dark spherical nanoparticles. SEM-EDS analysis discovered a sponge-like structure fused with Fe₃O₄ nanoparticles that had significant Si, O, and Fe content. XRD demonstrated the crystalline nature of the nanocomposite. The surface properties of the nanocomposite were evaluated using BET and were 67.8 m²/g, 0.39 cm³/g, and 23.2 nm for surface area, pore volume, and pore size, respectively. Parameters that were suspected to be affecting the removal process were evaluated, including pH, nanocomposite dosage, and sample volume. The detection of DCF was conducted on high-performance liquid chromatography with diode-array detection (HPLC-DAD). Under optimum conditions, the adsorption process was monolayer, and physisorption was described using the Langmuir and Dubinin-Radushkevich (D-R) isotherm models. The kinetic data best fitted the pseudo-first order kinetic model, indicating a physisorption adsorption process. The thermodynamic experimental data confirmed that the adsorption process was spontaneous. The results obtained from real water samples showed 95.28% and 97.44% removal efficiencies from influent and effluent: 94.83% and 88.61% from raw sewage and final sewage, respectively. Overall, this work demonstrated that an Fe₃O₄/SiO₂ nanocomposite could be successfully prepared from coal fly ash and acid mine drainage and could be used to remove DCF in wastewater. Full article

The use of paper sludge as a waste stream from industrial facilities represents a significant environmental challenge due to its quantity and heterogeneous composition. The aim of the study was to evaluate the adsorption characteristics of paper sludge in neutral mine effluents and aquatic solutions of metal ions: Cu(II), Zn(II), Cd(II), and Mn(II). The main novelty of the research is a comparison of the adsorption process in synthetically prepared aquatic solutions and neutral mine drainage from field sampling. The adsorption process of the monitored metals was evaluated in terms of adsorption capacity, parameters of the Freundlich and Langmuir adsorption isotherm, and the separation factor. The adsorption capacity of paper sludge of all metals is significantly lower in neutral mine drainage (NMD) compared to adsorption in aquatic solution. The adsorption capacity of Zn(II) in aqueous solution reaches equilibrium over time, similarly to Cu(II), with values ranging from 0.2 to 1.6 mg/g. For Cd(II), a slight increasing trend in the adsorption capacity of paper sludge is observed at higher initial concentrations (3–5 mg/L) over a contact time of 90–120 min. In general, aqueous solutions of metal ions exhibited higher adsorption capacities compared to NMD, with the highest value recorded for Cu(II) at 4.742 mg/g. As the concentration values in the original solution increased, a decline in K_R (from 268% to 137% at a C0 range of 4–20 mg/L) was observed. In the mine drainage with the addition of Zn(II), K_R values were also lower compared to those in aquatic solutions. The reduction in K_R became more pronounced with increasing initial concentration, showing a decrease of 29.9% to 38.9% at C0 levels ranging from 2 to 10 mg/L. The separation factors for Cu(II), Zn(II), and Cd(II) were lower in NMD, indicating better metal separation from real mine waters. The results confirm the potential of paper sludge as a low-cost adsorbent for the treatment of heavy metal contaminated waters. Full article

Microplastics (MPs) have been extensively studied in the marine environment, but reliable data on their sources and pathways in freshwater ecosystems, which are the main sources of such pollutants, are still limited. In this study, we investigated the spatiotemporal variations, characteristics, and sources of MPs in Nakivubo catchment, which drains waste and stormwater from Kampala city (Uganda) and empties it into Lake Victoria through the Nakivubo channel. Surface water samples (n = 117) were collected from thirteen sites in the Nakivubo catchment (S1 to S13) during the dry and wet seasons in 2022. The MPs were recovered by wet peroxide oxidation protocol, followed by salinity-based density separation, stereomicroscopy, and micro-attenuated total reflectance Fourier-transform infrared spectroscopy. All the samples had MPs, with mean concentrations ranging from 1568.6 ± 1473.8 particles/m³ during the dry season to 2140.4 ± 3670.1 particles/m³ in the wet season. Nakivubo catchment discharges an estimated 293.957 million particles/day into Lake Victoria. A Two-Way ANOVA revealed significant interactive effects of seasons and sampling sites on MPs abundance (p < 0.05). Spatially, the highest mean concentrations of MPs (5466.67 ± 6441.70 particles/m³) were in samples from site S3, which is characterized by poor solid waste and wastewater management practices. Filaments (79.7%) and fragments (17.9%) made of polyethylene (75.4%) and polyethylene/polypropylene co-polymer (16.0%) were the most common MPs. These are likely from single-use polyethylene and polypropylene packaging bags, water bottles, and filaments shed from textiles during washing. These results highlight the ubiquity of MPs in urban drainage systems feeding into Lake Victoria. To mitigate this pollution, urban authorities need to implement strict waste management policies to prevent plastic debris from entering drainage networks. Full article

Background: This study aims to evaluate the quality of treated wastewater flowing in the Zarqa River to determine its suitability for agricultural use. The assessment is based on physicochemical and biological parameters in accordance with Jordanian standards (JS 893:2021), the CCME water quality index, and the weighted arithmetic water quality index (WAWQI). Additionally, a microbial assessment was conducted to identify the presence of pathogens in the treated wastewater. Methods: A total of 168 water samples were collected from seven different sites along the Zarqa River over a 24-month period. This study focused on microbial assessment and selected parameters from the JS 893:2021, including total dissolved solids (TDSs), biochemical oxygen demand (BOD), dissolved oxygen (DO), chemical oxygen demand (COD), and E. coli levels. Furthermore, data were gathered on additional physicochemical parameters such as pH, mineral content (including Na, Ca, K, Mg, and Cl), salts (HCO₃, SO₄, NO₃, and PO₄), and heavy metals (Fe, Cu, Pb, Mn, and Co). The CCME water quality index and weighted arithmetic WQI scores were calculated to determine the water quality from all seven study sites. Results: In terms of Jordanian standards, Site 1 had the lowest TDS and DO values along with E. coli concentration. Further, in terms of minerals and salts, the maximum concentrations found for the sites are given herewith: Site 2 (K⁺ and NO₃), Site 3 (Cl⁻, Na⁺), Site 5 (Ca, HCO₃), and Site 7 (Mg²⁺, PO₄, and SO₄). In terms of pH, all the study sites had pH values within the acceptable range, i.e., between 6 and 9, for irrigation purposes. The concentrations of certain heavy metals, specifically lead (Pb), manganese (Mn), and cobalt (Co), were observed to be negligible. In contrast, Site 6 exhibited the highest concentration of iron (Fe) (0.0178 mg/L), while Site 5 recorded the maximum concentration of copper (Cu) (0.0210 mg/L) among the study locations. Site 1 demonstrated the most favorable water quality among the seven sites evaluated, whereas Site 6 exhibited the poorest water quality. Overall, the water quality from the majority of the sites was deemed suitable for drainage and for irrigating crops classified under the B category. However, based on the weighted arithmetic water quality index (WQI) values, none of the sites achieved a classification of good or excellent water quality, although the water quality at these sites may still be utilized for irrigation purposes. The current study is the first to report the presence of SARS-CoV-2 in Zarqa River water samples. Conclusions: The current study outcomes are promising and provide knowledgeable insights in terms of water quality parameters, while public health aspects should be considered when planning the WWTPs in parallel to reclaiming the wastewater for irrigation purposes. Full article

Biological reduction of sulphates has gradually replaced unit chemical processes for the treatment of acid mine drainage (AMD), which exerts a significant environmental impact due to its elevated acidity and high concentrations of heavy metals. Bioremediation is optimally suited for the treatment of AMD because it is cost-effective and efficient. Anaerobic bioremediation employing sulphate-reducing bacteria (SRB) presents a promising solution by facilitating the reduction of sulphate to sulphide. The formed can precipitate and immobilise heavy metals, assisting them in their removal from contaminated wastewater. This paper examines the current status of SRB-based bioremediation, with an emphasis on recent advances in microbial processes, reactor design, and AMD treatment efficiencies. Reviewed studies showed that SRB-based bioreactors can achieve up to 93.97% of sulphate reduction, with metal recovery rates of 95% for nickel, 98% for iron and copper, and 99% for zinc under optimised conditions. Furthermore, bioreactors that used glycerol and ethanol as a carbon source improved the efficiency of sulphate reduction, achieving a pH neutralisation from 2.8 to 7.5 within 14 days of hydraulic retention time. Despite the promising results achieved so far, several challenges remain. These include the need for optimal environmental conditions, the management of toxic hydrogen sulphide production, and the economic feasibility of large-scale applications. Future directions are proposed to address these challenges, focusing on the genetic engineering of SRB, integration with other treatment technologies, and the development of cost-effective and sustainable bioremediation strategies. Ultimately, this review provides valuable information to improve the efficiency and scalability of SRB-based remediation methods, contributing to more sustainable mining practices and environmental conservation. To ensure relevance and credibility, relevance and regency were used as criteria for the literature search. The literature sourced is directly related to the subject of the review, and the latest research, typically from the last 5 to 10 years, was prioritised. Full article

Illicit or inappropriate inflows into urban drainage systems cause significant operational issues, impacting utilities, communities, and the environment. The continued deterioration of system assets increases these inflows. Groundwater infiltration, rain-derived inflows, and misconnections contribute to reduced system performance, amongst other detrimental inflows. Climate change effects and the revised EU Wastewater Treatment Directive put pressure on utilities to reduce combined sewage and polluted stormwater discharges and overflows while promoting carbon neutrality. The effective management of undue inflows requires identifying cause–effect relationships and quantifying their consequences. This paper proposes a performance-based methodology with metrics and reference values to assess and categorise various undue inflows in wastewater, stormwater, or combined systems. This approach allows the tracking of performance over time, the comparing of systems, and requires data commonly available to utilities. The reliable quantification of inflows depends on the availability and accuracy of flow data from relevant system locations, rainfall data, and pertinent contextual information. This paper uses data from eight utilities and the Portuguese regulator to validate its approach, calculate metrics, refine reference values and enable better-targeted control measures. The results enhance the value of a unified approach to this problem in making better decisions to improve the urban water drainage system’s performance, enhance pollution control, and promote sustainable water management. Full article

Mining discharge, namely acid mine drainage (AMD), is a significant environmental issue due to mining activities and site-specific factors. These pose challenges in choosing and executing suitable treatment procedures that are both sustainable and effective. Ceramic membranes, with their durability, long lifespan, and ease of maintenance, are increasingly used in industrial wastewater treatment due to their superior features. This review provides an overview of current remediation techniques for mining effluents, focusing on the use of ceramic membrane technology. It examines pressure-driven ceramic membrane systems like microfiltration, ultrafiltration, and nanofiltration, as well as the potential of vacuum membrane distillation for mine drainage treatment. Research on ceramic membranes in the mining sector is limited due to challenges such as complex effluent composition, low membrane packing density, and poor ion separation efficiency. To assess their effectiveness, this review also considers studies conducted on simulated water. Future research should focus on enhancing capital costs, developing more effective membrane configurations, modifying membrane outer layers, evaluating the long-term stability of the membrane performance, and exploring water recycling during mineral processing. Full article

This is a pioneering study on the main drainage system in Gujranwala District, where untreated mixed wastewater is discharged and subsequently used for vegetable irrigation, leading to potential health and environmental risks. This study seeks to develop the spatial pattern of toxic metal accumulation in soil across an 11 km stretch of land used for vegetable cultivation. By using 90 samples of mixed wastewater and sludge, as well as 10 quadruplicate samples of rhizospheric soils and crops from ten vegetable fields, it was observed that the concentrations of Cr, Cu, Cd, Zn, Fe, Pb, Mg, and Ni in cauliflower (Brassica oleracea var. botrytis L.), coriander (Coriandrum sativum L.), radish (Raphanus sativus L.), mustard (Brassica juncea L.), spinach (Spinacia oleracea L.), meadow clover (Trifolium sp. L.), sorghum (Sorghum bicolour L.), garlic (Allium sativum L.), brinjal (Solanum melongena L.), and mint (Mentha L.) were beyond the permissible limits set by the FAO/WHO, 2001. The declining trend of the toxic metal concentrations in the effluent was Mg > Cr > Ni > Zn > Pb > Cd > Cu > Fe, and in sludge, soil, and plants, it varied in the order of Mg > Fe > Cr > Ni > Zn > Pb > Cd > Cu. Radish, mint, and brinjal had the highest quantities of toxic metals. The spatial pattern of toxic metals was determined by using proximity interpolation, Inverse Distance Weighted (IDW), the fine tuning of the interpolation characteristics, and the kriging of selected sample variograms. Toxic metals were found in the following order: plants > soil > sludge > effluents. The most prevalent cause of metal pollution was soil irrigation with polluted water. This study provides crucial information about the extent of contamination, which could help in the identification of public health risk, the assessment of environmental impacts, and also sustainable water management. Full article

Carbon emissions accounting of wastewater treatment systems is essential for understanding their energy efficiency and greenhouse gas emissions. To overcome the inefficiencies and high uncertainty of traditional carbon emission accounting methods in wastewater treatment, carbon emission prediction software for biological wastewater treatment systems was developed. This system is based on biochemical reactions that occur during biological wastewater treatment processes and the classification of carbon emission sources within the system. By utilizing stoichiometric relationships, a carbon emission accounting platform for wastewater treatment processes was created using programming languages, such as Python. The platform was used to calculate the carbon emissions of two typical urban wastewater treatment plants in Xi’an. The results indicated that oxidation ditches in conventional urban wastewater treatment processes demonstrated superior performance, with lower energy consumption and total carbon emissions. Carbon emission calculations also revealed that septic tanks, which are critical components of building drainage systems, are frequently underestimated and overlooked as significant carbon emission sources. Full article

This article describes the results of research to develop a new technology to treat storm and drainage water generated on a territory of industrial enterprises and reuse it as a feed water for boiler feed and steam generation. To develop such a system, it is necessary to resolve issues related to pretreatment, scaling, and fouling, as well as to provide a minimal discharge in the company’s sanitation network. Principles of the new approach to reach high calcium removal are based on the use of two or three stages of low-pressure nanofiltration membranes instead of the conventional facilities that contain one stage of reverse osmosis membranes. High permeability, low pressure, high recovery, and reduced reagent consumption provide an economic effect. The technology uses low-rejection membranes “nano NF” developed and produced by “Membranium Co.” (Vladimir, Russia). In the article, the results of investigations on the evaluation of scaling rates in membrane modules and rates of homogeneous crystallization in concentrate flow are presented. Processing these results enables us to detect recovery values when scaling begins on the membrane surface as well as to determine the maximum recovery value for the beginning of homogenous nucleation in the concentrate flow. Full article