To investigate the effect of gamma irradiation on the disinfection of water and wastewater, water samples were collected from raw and filtered water and wastewater samples were taken from the effluent of the secondary sedimentation, polished effluent (1-day retention time), and also from filtered (rapid sand filter) effluent. The samples were irradiated with gamma collimated beam in a batch system using a Co-60 therapeutic gamma radiation machine with a radioactive source emission rate of 405.38CGy/min at different doses of 20-160 Gy and 80-240 Gy, respectively. The samples were analyzed before and after irradiation for total and fecal coliforms. It was observed that nearly 100% reduction was achieved in total and fecal coliforms in water samples treated with a dose of 160 Gy. Depending on effluent quality, disinfection efficiencies achieved using 240 Gy gamma irradiation for inactivation of total coliforms in wastewater samples were 83, 64, and 56 percent for filtered, clarified, and secondary effluents, respectively. The same values were nearly 81, 58, and 46 percent, respectively, for inactivation of fecal coliforms. At lower doses of 120-240Gy, the coliform bacteria were successfully inactivated. It was concluded that a linear correlation holds between the dose delivered and the inactivation of microorganisms, so that inactivation increases with increasing irradiation time.

In recent years, water scarcity has posed significant challenges to oil refineries. The escalating water demands of developing oil refineries in pace with the progressively stringent environmental, economic, and technical regulatory and suitability constraints necessitate seeking sustainable water and wastewater management strategies that encourage minimizing fresh water consumption through treated wastewater reuse. Thus, the main scope of the present study is to investigate a general procedure using innovative post treatment technologies in order to attain an almost zero discharge water management in real life-Kermanshah's oil refinery case study. The results obtained are proofs enough that the selected post treatment scenario can effectively minimize the overall fresh water demand.

Comprehensive evaluation of organization performance is one of the most powerful tools for decision making. It helps managers to gain necessary information about the status of their organization. One of the most widely welcomed models in this regard is the Balanced Scorecard Model which provides comprehensive evaluation for various aspects in the Water and Wastewater Corporation. The present study was a descriptiveapplied research in terms of objectives. The objectives included selecting a comprehensive evaluation pattern, recognizing and ranking the indexes and main substandards for evaluating the comprehensive performance with BSC model denoting various parts in water and wastewater corporations. The model was used in West Azarbayjan province water and wastewater company as a pilot. Data collection was based on the library and field study via 3 types of questionnaires and interview with staff, financial staff, and by the customers of the given company. Based on the correlation and regression coefficients, the mean variables test and the fuzzy method showed that the BSC fields are in the order of priority in the performance of the mentioned company. These included internal processes, learning and growth, and customer and financial perspective. In the regression dependent variable model, the performance of the company and independent variables included various variables in fields of the balanced scorecards, and the result showed that the most effective factors on the company performance were decreasing the unnecessary costs, increasing and developing new facilities, finding new custumers, providing infrastructures, and organizational resources through learning, increasing customer satisfaction, enhancing the efficiency and quality of the internal processes.

Increase fresh water consumption and wastewater generation in beet sugar mill consequently, will increase both capital and operating costs for effluent treatment system. In this paper, we present water and wastewater minimization in beet sugar mill' through water pinch technology that can help minimize wastewater production and lower treatment costs.      

This study aimed to find an appropriate way to minimize water utility in the petrochemical and petroleum industries. For this purpose, Tehran oil refinery was chosen to analyze feasibilities of regeneration, reuse and recycling in the water network. In this research, two key contaminants including COD and hardness were analyzed. Amount of freshwater was reduced about 180 m3/h (53%) and 216.88 m3/h (63%) regarding COD and hardness respectively. In the next stage, two mentioned contaminants were analyzed simultaneously based on the mass transfer constraints. Results showed that the amount of required water was reduced from 340 m3/h to 197.12 m3/h that was about 42%. Analyzing both methods clearly demonstrated that amount of required water would be determined by mass transfer of COD. In addition, the method based on multiple contaminants gave more precise results rather than single contaminant.

Water is now an important issue in the world, and the effective development of water resources and optimal management of industrial projects are essential for sustainable growth. Limitations and crises of water and wastewater companies in the supply and optimal exploitation of water resources and wastewater disposal require strategic planning and management, thereby increasing the competitive advantages of human societies. Given the importance of optimal management of water and wastewater industry projects, the present research sought to detect and introduce indices and criteria, which affected the optimal management of this industry based on certain models (Porter Diamond Model, Porter's Five Forces, and PESTEL), by examining and analyzing political, economic, and socio-cultural trends and using the results of interpretation and analysis of trends. To this end, the experts in the water and wastewater industry, as well as the managers working in this industry were surveyed. Based on experts' opinions, the results of the certain criteria after screening were finally converted into 22 out of 95 criteria using the fuzzy Delphi technique, and then the 22 criteria selected by the experts were reviewed and any of them with the potential to be quantified and their trends could be examined, were selected and quantified. Finally, the results introduced 12 indices in three categories: economic indices (similar in all industries), specialized indices of water and wastewater, and cultural-educational indices. The Gross Domestic Product (GDP), the complexity of the supply chain of the water and wastewater industry, and cultural infrastructures (Intellectual maturity, management attitude, education, corruption, and population) were respectively representatives of the indices.