Iranian Journal of

Background and Objective: Nowadays, the development of green entrepreneurship plays an important role in sustainable employment, reducing environmental issues, economic development, and moving towards sustainable development. Thus, the present study has been carried out aiming to identify and analyze the factors facilitating the green entrepreneurship process in the field of urban waste using a mixed (quantitative-qualitative) method.
Materials and Methods: The present study was carried out with a mixed approach (exploration projects). For this purpose, using theoretical sampling logic, 14 experts were selected by snowball technique and the required data were collected through semi-structured in-depth interviews to achieve theoretical saturation. In the quantitative section, data were collected through interaction questionnaires handed out to 26 experts who were selected through purposive sampling, and the integrated DEMATEL-ISM technique was employed to build a regular hierarchical structure.
Results: Layer-by-layer model was displayed in 4 levels using DEMATEL-ISM technique. The first layer consists of improving laws and regulations and designing a suitable landscape as the most infrastructural, the second layer includes improving infrastructure issues, expanding supportive issues, culturalization and increasing public awareness, the third layer includes exploiting the potentials of the region and attracting private sector participation, and the fourth layer comprises of entrepreneurial management.
Conclusion: The results show that the first step in creating a facilitator environment for green entrepreneurship process in the field of urban waste is to improve the macro structures that should be facilitated mainly by the central government, the second step is related to the proper infrastructure and preparation of public space governing the society. In the third step, it was found that the development and utilization of the region’s potential increases its operational effectiveness. Finally, with entrepreneurial management, all activities that occurred at previous levels can be used effectively.

Background and Objective: The consequence of using coagulant materials such as aluminum sulfate and ferric chloride in the coagulation unit of conventional water treatment plants can generate plenty of sludge that contains large amounts of coagulant, which in addition to environmental risks, will also possess disposal costs. Today, intending to preserve the environment and reduce treatment costs, researchers emphasize the recovery and reuse of coagulants from sludge. In this regard, the present study was proposed and implemented to recover and reuse water treatment plant sludge as a low-cost coagulant in wastewater treatment.
Materials and Methods: This research is an experimental-laboratory study. In order to recover the coagulant from the collected sludge, acid hydrolysis method was used. The physicochemical characteristics of the recovered sludge were also determined using FTIR, FE-SEM, and BET analysis. Moreover, the efficiency of recovered sludge in different doses (50 to 300 mg/L) on wastewater treatability in terms of COD, TSS, VSS, turbidity, phosphorus, and coliform indices was compared with aluminum sulfate, ferric chloride coagulants, also the results of the study were analyzed and presented using Excel software (version, 2016).
Results: According to the results, the prepared sludge had no crystalline structure with amorphous morphology. In addition, recovered coagulant from water treatment sludge has demonstrated high efficiency for wastewater treatment, so 66.6%, 82.49%, 79.66%, 80%, 65 %, 99.18% of COD, turbidity, TSS, VSS, phosphorus, total coliform were removed at the highest dosage of recovered coagulant (300 mg/L), respectively. Furthermore, the recovered coagulant dosage had a significant effect on the performance of the coagulation and flocculation process in wastewater treatment.
Conclusion: The results showed that recovered coagulant from the sludge of the water treatment plant can be considered an acceptable option with appropriate effectiveness in the wastewater treatment processes.