RESUMEN
The present study was developed to comprehensively analyze experts' views and content of documents focusing on goals and criteria of sustainable waste management system in Tehran, Iran. To this end, the suitable goals for sustainable waste management system in Tehran city were adopted from domestic, national and international documents. For this purpose, 27 national and international documents and 2 domestic documents related to waste management were selected and analyzed by using content analysis according to Gall, 1994. Further, in order to formulate goals in case of bottlenecks and challenges of waste management in Tehran, the focus group technique was used based on Stewart and Shamdasani, 2014. At this stage, 24 key experts in the field of waste management were interviewed in the form of 4 focus groups. Data collection were performed via audio recording and word-for-word implementation of conversations, taking notes and writing field notes. The data collection continued until reaching theoretical saturation. Next, content analysis and coding methods were used to analyze the data. Finally, the goals of waste management were divided into five general categories including: institutional (with emphasis on the integration and inclusion of the key elements of the urban waste management system), technical and infrastructural (with emphasis on the optimization of existing processes in the use of urban waste management technologies), environmental (with emphasis on minimizing the adverse health and environmental effects of the urban waste management system, economic (with emphasis on the economic and financial sustainability of the urban waste management system), and cultural-social (with emphasis on attracting the maximum participation of citizens and service recipients). The results clearly showed that sustainable waste management measures in Tehran should follow these five components in order to reduce the problems caused by unrealistic waste management and make sustainable use of basic, natural, financial and human resources.
RESUMEN
The increase in the need for food and agricultural development has led to an increase in the use of insecticides. The use of insecticides leads to air, soil and water pollution. This study investigated the pollutant concentration cycle in the environment by analyzing diazinon and deltamethrin in a river and groundwater sources affected by an agricultural area. The samples were analyzed based on the standard method for insecticides in water using a GC-MS. The results showed that the quality of the surface water affected by the agricultural effluents decreased so that the changes of dissolved oxygen, nitrate, turbidity, TOC, BOD, and COD were 15.2%, 189.6%, 00%, 53%, 176%, and 57.5%, respectively. The concentration of diazinon and deltamethrin in agricultural wastewater was 86 µg/L and 11.62 µg/L. The self-treatment capacity of the river reduced the concentration of diazinon in the distance of 2 km and 15 km by 80.8% and 90.3%, respectively. These conditions were observed for deltamethrin in 74.8% and 96.2%, respectively. Also, the concentration of the two insecticides in water resources has temporal and spatial variation. The difference between the maximum and minimum concentration of diazinon and deltamethrin at different times was 183.5 and 1.73, respectively. The concentration of diazinon and deltamethrin in the downstream groundwater of the studied irrigated area was 0.3-0.7 µg/L, respectively. Although the soil structure and the self-purification capacity of the river caused a significant reduction of insecticides, the remained concentration of these pollutants in underground and surface water resources can still be a health and environmental concern.