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Background: Various suspended organic and inorganic contaminants including biological deposits, different types of algae and barnacles and causative factors of water turbidity result in irreparable damages to pretreatment systems and membranes in reverse osmosis systems. Objectives: In this study, the effect of injection of disinfectant materials such as calcium hypochlorite on the reduction of silt density index (SDI) value at the inlet of reverse osmosis system has been investigated. Methods: In this research, correlations between fundamental parameters in pretreatment system such as turbidity, chlorine injection, residual chlorine content and SDI values were thoroughly analyzed and evaluated at one of the desalination plants located in Persian Gulf. Results: The results indicated that there is a close link between the amount of chlorine injection and SDI inlet value. By adjusting the nephelometric turbidity unit values in specific ranges of 35-55, 55-80 and 80-150 and oxidation reduction potential in the ranges of 280-680, 315-680 and 420-680 mV, favorable SDI value of inlet water was obtained. Conclusions: SDI control via chlorine injection increased the lifetime of cartridge filters at reverse osmosis input units and reduced the operation costs significantly.

Light-harvesting of titanium oxide (TiO2) was enhanced by copper (Cu) doping, and its performance was evaluated by gabapentin (GBP) degradation under UVA-LED irradiation. The morphology and structure of TiO2 and Cu-TiO2 were characterized using XRD, FTIR, FE-SEM, EDX, TEM, PL, DRS, and BET analysis. The complete degradation of 10 mg/L GBP was obtained in the developed photocatalytic process under the optimal conditions: catalyst loading, 0.4 g/L; pH solution, 8; and reaction time, 20 min. The reactive species trapping was studied to identify the degradation mechanism in this system. Among the water matrix experiments, phosphate (PO43−) anion indicated an inverse effect in increasing efficiency. Finally, the main intermediates generation during the GBP degradation was investigated based on LC-MS analysis, and a decomposition pathway was proposed. Accordingly, doping TiO2 with Cu resulted in the development of a UVA-activated photocatalyst for efficiently degrading and mineralizing GBP as a model of a pharmaceutical compound.

One of the basic problems of current cities is solid waste and its correct management. Solid waste material is the unavoidable product of routine life of human being. These wastes affect the quality and quantity of life in the present era. Increased population, development, human activities and shortage of resources have caused the solid waste management a necessity. Waste reduction management and its separation at source are performed with the citizens' participation.The present study aimed to evaluate the waste source separation and determine the participation of citizens in Azimie of Karaj city in Alborz province, Iran. This study is questionnaire based and to achieve the study purpose, question-based questionnaires are distributed randomly among 100 citizens of Azimieh. The data were analyzed. Based on the results of study, in separation at source activity, 70% of people participated and the highest participation was via media and teachers. 100% of subjects were inclined to participate in this program. The effect of this plan was 90% and effectiveness of this plan from economic, social and environmental aspects was high.

Introduction: Today, work-family conflict and occupational stress are considered as a common and costly problem in work environments. Almost all people are faced with such challenges. Work-family conflict is a sub-set of psychological factors. The main purpose of this research was to measure the correlation among work-family conflict, occupational stress, and incident talent. Moreover, we classified the employees in each of these three variables.Methods: In order to collect data in this applied research, we used questionnaire. The statistical population included all the employees of a fiber-optic line construction project. A total of 250 samples were selected randomly. Data were analyzed using Spearman correlation test, frequency distribution, mean, and standard deviation.Results: Findings indicated that job stress and work-family conflict had a positive correlation with the accidental potential among employees. Moreover, we found that among the sub-scales of work-family conflict, the highest score was related to the behavioral conflict in the family (9.19). Among the stress subscales, the highest score was attributed to the job performance subscale (18.43).Conclusion: The results show that the increased work stress and work-family conflict lead to an increase in the level of incidence. Therefore, a psychologist should be present in the work and training environments to control and manage the stress, divide the family and work duties, address these problems, and reduce the incidents.

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