Search Results (26)

With the goal of sustainable urbanization, eco-cities have garnered significant global attention in recent decades. Unlike eco-city renovation or renewal, the construction of a new eco-city represents a comprehensive urbanization process that integrates environmental sustainability with livability. To evaluate the outcomes of new eco-city construction in China, this study employs a dual approach combining objective achievements and residents’ subjective satisfaction to systematically examine the Sino-Singapore Tianjin Eco-City. The analysis encompasses five dimensions: environmental amenity, life safety, residential functionality, traffic capability, and economic well-being, with the relative weights of specific indicators determined through the entropy method, expert scoring, and analytic hierarchy process. The findings reveal that based on objective indicators, the eco-city’s overall performance nearly doubled during its first phase of development, with life safety showing the most notable improvements. However, subjective assessments revealed that overall resident satisfaction remained below 70%, with residential functionality receiving the highest rating. The annual progress of the eco-city did not consistently align with residents’ needs, and no clear correlation was found between the eco-city’s current state and public sentiment. For sustainable development, the eco-city must address its shortcomings and better cater to residents’ demands across various dimensions through targeted and effective strategies. Full article

Urban carbon emissions account for 75% of the total social emissions and are a key area for achieving the country’s “dual carbon” goals. This study takes the Sino-Singapore Tianjin Eco-City as a case, constructs a multi-dimensional carbon emission accounting model, integrates six systems, including buildings, transportation, water systems, solid waste, renewable energy, and carbon sinks, and proposes a comprehensive research method that takes into account both long-term prediction and a short-term dynamic analysis. The long-term emission trends under different scenarios are simulated through the KAYA model. It is found that under the enhanced low-carbon scenario, the Eco-City will reach its peak in 2043 (2.253 million tons of CO₂) and drop to 2.182 million tons of CO₂ in 2050. At the same time, after comparing models, such as random forest and support vector machine, the XGBoost algorithm is adopted for short-term prediction (R² = 0.984, MAE = 0.195). The results show that it is significantly superior to traditional methods and can effectively capture the dynamic changes in fields, such as buildings and transportation. Based on the prediction results, the study proposes six types of collaborative emission-reduction paths: improving building energy efficiency (annual emission reduction of 93800 tons), promoting green travel (58,900 tons), increasing the utilization rate of non-conventional water resources (3700 tons), reducing per capita solid waste generation (14,400 tons), expanding the application of renewable energy (288,200 tons), and increasing green space carbon sinks (135,000 tons). The total annual emission-reduction potential amounts to 594,000 tons. This study provides a valuable reference for developing carbon reduction strategies in urban areas. Full article

Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental pollutants commonly found in water and sediments, posing significant health risks due to their toxicity, carcinogenicity, and mutagenicity. The stable and sustainable degradation of PAHs has garnered significant attention from researchers. Biological electrochemical systems (BESs) offer a promising approach with advantages in energy efficiency, safety, environmental protection, and long-term operation. This review examines the degradation performance and microbial community dynamics of BESs in the treatment of PAH-contaminated water and sediments. Additionally, the metabolites formed during the degradation process were also summarized. This review summarizes the degradation characteristics of PAH-contaminated water and sediments and aims to guide future research and optimize BESs for effective remediation of PAHs in various environmental settings. Full article

Urbanization and climate change increasingly challenge urban water management. In this context, the design of stormwater drainage systems, which traditionally relies on historical rainfall records, is being questioned. Although significant efforts have been dedicated to optimizing drainage networks, the upgrading of existing systems remains understudied. This research devised a set of viable stormwater drainage networks, referencing the road network of the Sino-Singapore Tianjin Eco-City (data from Google Maps). On this basis, utilizing design rainfall data (sourced from the local meteorological center), an extensive array of scenario analyses was conducted. The investigation assessed the performance of implementing two redundancy-based interventions—introducing loops and enlarging pipe diameters—as well as the patterns of flood risk response, and by integrating a multi-objective optimization algorithm, this study proposes a framework for the optimization of grey infrastructure upgrades based on component replacement. The findings suggest that a precise deployment strategy for grey infrastructure is essential. The former improves the effective flow distribution of the drainage system, while the latter enhances its flow capacity, making each intervention suitable for drainage systems with a different degree of centralization. Further research shows that an integrated hybrid scheme brings significant flood risk improvement with strong applicability for most urban drainage systems. The upgrade model proposed in this study could be a valuable initiative, offering theoretical insights for the construction and development of resilient cities. Full article

Territory space is an ecological resource carrier and place for human development. Human activities and ecological systems are the basis of ecological product supply. Promoting territories’ spatial protection and governance by improving the supply of ecological products is very important. In this study, we established an ecological product supply capacity evaluation index system involving three types of ecological products, i.e., ecological environmental products, ecological material products, and ecological cultural products. For the case of the Beijing–Tianjin–Hebei region, we comprehensively used principal component analysis, the equivalent factor method, and the entropy method to evaluate the supply capacity of ecological products from 2011 to 2021. Then, we analyzed the spatio-temporal pattern, combining the natural breakpoint and quantile classification methods, and analyzed the obstacle factors using the obstacle degree model of ecological supply. The results show that the supply capacity of different ecological products in each city are closely related to their ecological resource endowment. The supply capacity of ecological products exhibited an upward trend, with the highest ecological environmental product supply being relatively smaller than the ecological material product supply, while the largest growth rate was for ecological cultural product supply. The supply capacity of different ecological products varied across cities over time and displayed noticeable spatial differentiation. The main obstacle factors included eco-land, eco-tourism, eco-leisure, park green space, and fishery products, although there were variations among cities. Finally, based on the level, spatial-temporal pattern, and obstacle factors of ecological product supply, we proposed strategies for territory spatial protection and governance from the perspectives of the integrated protection of elements, structural regulation, and systematic governance. The results reflected the ecological functional heterogeneity of the territory space, which can provide spatial planning guidance for sustainable development. Full article

Rational planning and the use of renewable energy are effective means to reduce urban carbon emissions. In view of the few urban renewable energy planning cases and unclear methods, the paper takes the Sino-Singapore Tianjin Eco-City renewable energy planning project as a case to provide a renewable energy planning method under the guidance of carbon constraints. Based on scenario analysis, the energy demand of urban buildings, industry and transportation is analyzed and predicted. On the basis of meeting the needs of terminal energy use, with the goal of reducing carbon emissions, the renewable energy planning scheme from 2021 to 2050 under the low-carbon scenario has been formulated, including the promotion of energy-efficient buildings, the utilization of renewable energy in buildings, the electrification of terminal energy use, and the application of large-scale municipal renewable energy. It is planned that, by 2050, the overall renewable energy utilization rate of the Sino-Singapore Tianjin Eco-City will reach 76.76%. It will use renewable energy to heat about 60 million square meters, generate about 766 million kWh of electricity, save about 0.723 million tons of standard coal and reduce 1.287 million tons of carbon dioxide every year, which will have a good effect of energy conservation and emission reduction. In this paper, the renewable energy planning method under the guidance of carbon constraint is established, which can achieve the purposes of saving resources, protecting the environment and driving sustainable development. The Sino-Singapore Tianjin Eco-City is an international co-creation city, which will receive extensive attention and provide theoretical guidance and demonstration cases for urban renewable energy planning in the context of carbon peak and carbon neutrality in the new era. Full article

Attaining optimal eco-efficiency is of paramount importance in promoting the sustainable and harmonious development of the economy and environment within urban agglomerations. Firstly, this paper utilizes the Super-SBM model with undesirable output to measure the eco-efficiency (EE) of 64 cities in the Beijing–Tianjin–Hebei metropolitan region (BTHMR), the Yangtze River Delta (YRD), the Pearl River Delta (PRD), and the Chengdu–Chongqing Economic Zone (CCEZ) from 2006 to 2019. Secondly, this study puts forth a novel and comprehensive index system aimed at evaluating the urbanization efficiency and sheds light on the spatiotemporal changes in EE and urbanization efficiency. Finally, the STIRPAT model is used to examine the influencing factors of EE and to investigate the correlation between EE and urbanization efficiency. The study found that the overall EE of the four typical urban agglomerations is high, but the trend varies with a decrease of about 12.9% from 2006 to 2019. The mean EE is in the order of CCEZ > PRD > BTHMR > YRD, with mean values of 0.941, 0.909, 0.842, and 0.732, respectively. The level of science and technology and the urbanization efficiency have a significant positive impact on EE, while population, industrial structure, FDI, and greening level have an inhibitory effect on urban eco-efficiency. Based on the results, policy suggestions such as paying attention to regional heterogeneity and giving full play to the government’s macro-regulatory role in shaping the economic and industrial structure are proposed to serve as a guide for the coordinated development of urban agglomerations under the Dual Carbon Target. Full article

In order to balance the economic development and ecological impact of tourism, it is essential to study tourism eco-efficiency in the context of sustainable development. This study analyzed regional tourism eco-efficiency based on the panel data of the 13 cities of the Beijing–Tianjin–Hebei region using the super-SBM DEA model. Then, we analyzed the driving factors, compared regional differences, and investigated influencing factors of tourism eco-efficiency by applying the global Malmquist–Luenberger (GML) index, Theil index, and geographically and temporally weighted regression (GTWR) models. The results demonstrate the following: (1) The overall tourism eco-efficiency in the Beijing–Tianjin–Hebei region between 2010 and 2019 was low, but it had an increasing trend. (2) The advancement of technological progress factors was mostly responsible for the increase in tourist eco-efficiency. (3) The results for tourism eco-efficiency were significantly polarizing, but the gap among the 13 cities is gradually narrowing. Regional differences are the main contributors to differences in tourism eco-efficiency. (4) Per capita GDP, the proportion of tertiary industry in GDP, the number of patents granted, and the proportion of urban population in the total population were the main factors affecting tourism eco-efficiency. This study could serve as a model for similar countries and regions seeking to enhance tourism eco-efficiency and achieve the Sustainable Development Goals. Full article

The accurate prediction of building heat demand plays the critical role in refined management of heating, which is the basis for on-demand heating operation. This paper proposed a prediction model framework for building heat demand based on reinforcement learning. The environment, reward function and agent of the model were established, and experiments were carried out to verify the effectiveness and advancement of the model. Through the building heat demand prediction, the model proposed in this study can dynamically control the indoor temperature within the acceptable interval (19–23 °C). Moreover, the experimental results showed that after the model reached the primary, intermediate and advanced targets in training, the proportion of time that the indoor temperature can be controlled within the target interval (20.5–21.5 °C) was over 35%, 55% and 70%, respectively. In addition to maintaining indoor temperature, the model proposed in this study also achieved on-demand heating operation. The model achieving the advanced target, which had the best indoor temperature control performance, only had a supply–demand error of 4.56%. Full article

In recent years, advanced oxidation process (AOPs) based on sulfate radical (SO₄^●−) and singlet oxygen (¹O₂) has attracted a lot of attention because of its characteristics of rapid reaction, efficient treatment, safety and stability, and easy operation. SO₄^●− and ¹O₂ mainly comes from the activation reaction of peroxymonosulfate (PMS) or persulfate (PS), which represent the oxidation reactions involving radicals and non-radicals, respectively. The degradation effects of target pollutants will be different due to the type of oxidant, reaction system, activation methods, operating conditions, and other factors. In this paper, according to the characteristics of PMS and PS, the activation methods and mechanisms in these oxidation processes, respectively dominated by SO₄^●− and ¹O₂, are systematically introduced. The research progress of PMS and PS activation for the degradation of organic pollutants in recent years is reviewed, and the existing problems and future research directions are pointed out. It is expected to provide ideas for further research and practical application of advanced oxidation processes dominated by SO₄^●− and ¹O₂. Full article

Pickled mustard tuber, a worldwide condiment, is increasing at a fast growth rate. Its production generates a considerable amount of hypersaline wastewater containing NaCl of 7 wt.%, COD of 30,000 mg L⁻¹, NH₃-N of 400 mg L⁻¹, and TP of 300 mg L⁻¹. Pickled mustard tuber wastewater (PMTW) has severe effects on crops, deterioration of water quality, soil infertility and ecological systems. Due to the technic difficulties and insufficient support from the local governments; however, PMTW has not yet been widely investigated and well summarized. Therefore, this manuscript reviewed the relatively latest advances in PMTW. Physicochemical and biological hybrid processes mainly treat PMTW and the corresponding cost is 6.00 US dollars per ton. In the context of double carbon capture capacity in China and the development of the pickled mustard industry, PMTW sauce and sustainable reuse such as nutrient recovery, acid and alkaline regeneration and renewable energy may be bright prospects. Full article

Growing concerns about urban runoff pollution and water scarcity caused by urbanization have prompted the application of bioretention facilities to manage urban stormwater. The purpose of this study was to evaluate the performance of proposed bioretention facilities regarding road runoff pollutant removal and the variation characteristics of the media physicochemical properties and microbial diversity in dry-cold regions. Two types of bioretention facilities were designed and then constructed in Tianjin Eco-city, China, on the basis of combined soil filter media screened by a laboratory-scale test with a modified bioretention facility (MBF) containing soil moisture conservation ropes. Redundancy analysis was performed to evaluate the relationships between the variation in media physicochemical properties and microbial communities. An increase in media moisture could promote an increase in the relative abundance of several dominant microbial communities. In the MBF, the relatively low nitrate-nitrogen (NO₃-N) (0.75 mg/L) and total nitrogen (TN) (4.71 mg/L) effluent concentrations, as well as better removal efficiencies for TN and NO₃-N in challenge tests, were mainly attributed to the greater relative abundance of Proteobacteria (25.2%) that are involved in the microbial nitrogen transformation process. The MBF also had greater media microbial richness (5253 operational taxonomic units) compared to the conventional bioretention facility and in situ saline soils. The results indicate that stormwater runoff treated by both bioretention facilities has potential use for daily greening and road spraying. The proposed design approach for bioretention facilities is applicable to LID practices and sustainable stormwater management in other urban regions. Full article

The remote-sensing ecological index (RSEI), which is built with greenness, moisture, dryness, and heat, has become increasingly recognized for its use in urban eco-environment quality assessment. To improve the reliability of such assessment, we propose a new RSEI-based urban eco-environment quality assessment method where the impact of RSEI indicators on the eco-environment quality and the seasonal change of RSEI are examined and considered. The northern Chinese municipal city of Tianjin was selected as a case study to test the proposed method. Landsat images acquired in spring, summer, autumn, and winter were obtained and processed for three different years (1992, 2005, and 2018) for a multitemporal analysis. Results from the case study show that both the contributions of RSEI indicators to eco-environment quality and RSEI values vary with the season and that such seasonal variability should be considered by normalizing indicator measures differently and using more representative remote-sensing images, respectively. The assessed eco-environment quality of Tianjin was, overall, improving owing to governmental environmental protection measures, but the damage caused by rapid urban expansion and sea reclamation in the Binhai New Area still needs to be noted. It is concluded that our proposed urban eco-environment quality assessment method is viable and can provide a reliable assessment result that helps gain a more accurate understanding of the evolution of the urban eco-environment quality over seasons and years. Full article

In the context of rural revitalization strategies and humans’ increasing leisure pursuit, leisure agriculture starts to act as a new engine of rural economic growth and industrial upgradation. Unraveling the agri-leisure developmental regularity from a spatial perspective facilitates urban-rural integration and poverty alleviation in rural regions. Given the lack of spatially analyzing agri-leisure (e.g., sightseeing picking orchards) especially at the macro-spatial scale (e.g., the national scale), this study aims to explore the spatiality of leisure agriculture and its fundamental driving mechanisms based on geo-visual (spatially visualizing) analytical tools looking at 20,778 picking orchards in China. Results show that: (1) Picking orchards are distributed in the form of clusters with striking disparity at multiple spatial scales; (2) Five spatial agglomerations are found involving the regions around Beijing and Tianjin, Shandong hinterland, Henan hinterland, the core district of the Yangtze Delta, and the core district of the Pearl River Delta; (3) The driving mechanisms are revealed, and the spatial pattern of picking orchards is found to be largely influenced by morphology, distance to central cities, traffic conditions, economic level, and tourism resources. This study is conducive to optimizing the spatial planning of rural eco-tourism towards sustainable agro-development. Full article

The integrated electricity–gas energy system (IEGES) coordinates the power system and natural gas system through P2G equipment, gas turbines and other coupling components. The IEGES can realize wide-range and long-distance transmission of electricity, heat and natural gas, and truly realize large-scale cross-regional energy supply in space. At present, the theoretical system applicable to the comprehensive benefit evaluation of the IEGES has not been established, and the economic, environmental and social benefits of the system are still at a preliminary study stage. Therefore, the comprehensive benefit evaluation model of the IEGES is constructed, and the integrated benefit evaluation indicator system of the IEGES is designed along the investment and planning, energy supply, equipment operation, power distribution and terminal user. Through the combination of subjective and objective indicator weighting methods, the weights of each indicator are clarified and the matter-element extension theory (MEE) is used to improve the technique for order preference by similarity to ideal solution (TOPSIS), and the comprehensive benefit evaluation model of the IEGES is established. Finally, taking Beijing Yanqing IEGES, Tianjin Eco-city No. 2 Energy Station and Hebei IEGES III as an example, the practicability and effectiveness of the evaluation indicator system and model are verified. Full article