Journal of Urban Environmental Management

Abstract This research investigates the potential of walking and strategies for enhancing the walking network in District 3 of Tehran Municipality, aiming to boost public health and urban livability through increased physical activity. A comprehensive model was developed using Geographic Information System (GIS) data to evaluate walkability indexes across different urban areas. The study integrates multiple criteria decision-making tools and ARCGIS to map out walkability, employing ten environmental factors that significantly influence pedestrian activities. Findings indicate that urban design and infrastructure play critical roles in encouraging walking. The model's accuracy in quantifying walkability demonstrates the effectiveness of merging analytical techniques with GIS capabilities, providing a robust tool for urban planners and decision-makers. This approach not only aids in identifying areas with poor walkability but also proposes design improvements to enhance pedestrian pathways and connectivity. The research contributes to the growing field of sustainable urban planning by offering a detailed assessment of the physical and infrastructural elements that promote walking. By facilitating targeted interventions, the proposed model aims to foster a healthier, more active community in Tehran's urban landscape. This study underscores the importance of strategic planning and the application of technology in creating conducive environments for physical activity, reflecting on its implications for public health policy and urban development.

Abstract In the twentieth century, with an emphasis on the principle of sovereign equality of states, a framework for global trade was established. Simultaneously, the importance of achieving balanced development between industrialized and developing countries was highlighted. This period witnessed the integration of development and global trade, alongside a significant increase in the production and international exchange of goods, which unfortunately caused considerable environmental damage. This situation revealed the necessity for more stringent environmental care and control within the structure of global trade. The concept of sustainable development emerged as a bridge between development and trade and quickly gained attention, leading to the formulation of multilateral environmental agreements within the framework of international environmental law. This article examines how sustainable development has been adopted and transformed into a global strategy, its influence on international policies, laws, and documents, and its implementation in international judicial processes. Nevertheless, the facilitation of environmental agreements by the rules of the world trade organization remains unclear, and the inconsistencies between trade practices and environmental measures have rendered the legitimacy and credibility of some of these actions ambiguous. This has led to conservatism and uncertainty in the implementation of environmental agreements, indicating that sustainable development can only be effectively applied in trade policies when it is integrated and intertwined with its constituent elements.

Abstract Leachate from waste disposal is recognized as one of the primary sources of groundwater contamination. Therefore, improving the management of landfill sites is crucial for reducing and controlling environmental threats. This study focuses on modeling the dispersion of leachate in a landfill in the city of Isfahan using the finite element method, located 35 kilometers outside the city. The leachate is considered in this area with dimensions of 100 by 250 meters and a depth of 2 centimeters from the bottom. The transmission and spread of pollution across twenty sub-layers of soil have been modeled using Richards' equations and pollution transport equations in porous media. This research utilizes COMSOL software to merge different environments using two model equations, and the three-dimensional model investigates the movement and absorption of leachate based on these equations. Meshing in the landfill is done finer in the upper and bottom layers where leachate leakage exists and coarser in the lower parts. Also, mesh modeling in the software is done freely and in a hexagonal shape. According to the findings, the soil under the landfill becomes saturated over time, with the saturation occurring faster in the upper layers. Modeling results show that phosphorus metal pollution has penetrated up to a depth of 1.8 meters in the soil over 15 years, and leachate has reached approximately 10 meters deep into the ground. Given the proximity of groundwater to the soil surface, measures such as pumping wells and geomembranes must be considered to prevent pollution from entering the groundwater.

Abstract In the present study, cypress cone raw biochar was modified using walnut peel extract under the chemical modification process and its performance optimization on nickel (Ni) removal in aqueous solutions was affected by various factors was evaluated using the RSM. Contrary to expectation, chemical modification caused a decrease in the specific surface area and a decrease in effective functional groups in Ni removal (functional groups containing oxygen and C-C) compared to the non-modified biochar sample. The investigations of Ni removal by modified biochar also showed a significant reduction of Ni removal by this adsorbent in the same conditions compared to the non-amended sample, so that the average amount of Ni removal in the same conditions in the non-modified adsorbent was 1.8 times more than modified biochar. The investigation of the factors affecting the removal of Ni in two modified and non-modified adsorbents showed that with the increase of the initial concentration of Ni, the removal of Ni had a decreasing trend; while with the increase of other factors, Ni removal showed a relatively increasing trend. The results of the present study show that the modification and engineering of biochars by the mentioned chemical method, with the effect of reducing the physical absorption (reduction the specific surface area) and chemical adsorption (reduction of the intensity of the active groups affecting the adsorption), caused the reduction of Ni removal efficiency compared to the raw sample, which challenges the hypothesis of constant increase of heavy metal removal efficiency by chemical modification of biochar.

Abstract In recent times, there has been a growing recognition of the importance of circular business models (CBM) in advancing environmental sustainability. However, the relationship between CBM and the Internet of Things (IoT) has received little attention in current academic discussions. This paper seeks to fill this gap by initially identifying four key capabilities of IoT—namely monitoring, tracking, optimization, and design evolution—using the ReSOLVE framework to enhance the performance of CBM. Subsequently, through a systematic literature review employing the PRISMA approach, the paper examines how these IoT capabilities contribute to the principles of "Reduce, Reuse, Recycle, Redesign, Remanufacture, and Recover" (the 6R) and CBM. The analysis utilizes cross-section heatmaps and relationship frameworks to elucidate the interaction between CBM and IoT. Additionally, the paper evaluates the quantitative impact of IoT on potential energy savings within CBM contexts. The findings underscore a predominant focus on assessments related to Loop and Optimize business models, where IoT significantly aids through tracking, monitoring, and optimization capabilities. However, there is a noticeable scarcity of (quantitative) case studies concerning Virtualize, Exchange, and Regenerate CBM models, indicating the necessity for further research in these domains. Notably, IoT exhibits promise in reducing energy consumption by approximately 20–30% across referenced applications in the literature. Nonetheless, challenges such as IoT hardware, software and protocol energy consumption, interoperability, security, and financial investments may hinder its wider adoption in CBM practices.

Abstract Groundwater has always been considered as one of the important and basic resources of drinking, agricultural and environmental water supply, especially in dry areas. Simulating the groundwater level of a region plays an important role in water resources management. For this reason, today the simulation of the groundwater level using mathematical and computer models with relatively low time and cost is of interest in groundwater studies. In the present study, the groundwater level of Baft area located in Kerman province was simulated using the radial basis function neural network (RBFNN) model. The parameters of precipitation, evaporation, river flow, water demand of the region, amount of abstraction from the aquifer and the level of groundwater with a time delay period as input and the level of the water table in the desired period as the output of the model in a monthly time scale during the statistical period (2002-2016) was selected. Also, in order to evaluate the performance of the model, the statistical indices of egression coefficient (R2), root mean squared error (RMSE), mean absolute error (MAE), mean square error (MSE), normalized mean square error (NMSE) and Willmott’s index of agreement (d) were used. The results of the statistical indicators showed that the radial basis function neural network with R2, RMSE, MAE, MSE, NMSE and d, 0.9989, 0.1256, 0.064, 0.0158, 0.0011, and 0.9997 have a high ability to simulate the groundwater level and provide reliable results.