Construction of wastewater treatment plant, if energy and water resources are recovered, can justify some undesirable effects such as greenhouse gas emissions. sludge management and treatment is one of  the most complex and costly parts of  treatment  plants  that can cover  up  to  60%  of  initial capital  and  operation  costs of  a  wastewater  treatment  plant. Considering the importance of reducing energy consumption in wastewater treatment plants as an environmental  and  economic  point  of  view,  some investigations  have  done  to construct and modify wastewater plants worldwide in order to the self-sufficiency of energy supply recently year. This article is a practical study that the costs of capital and energy consumption were analyzed in comparison with other processes for MLE1 process with aerobic digestion in wastewater treatment plant in east of Mashhad with flow rate of 80000 m3/d. The results show that energy consumption in this system is about 2 times of similar wastewater treatment plants with optimal process. Also, however, the energy level will decrease from 1 kwh/m3 to 0.58 kwh/m3 with the change of aerobic digestion to anaerobic, but it is necessary to use of CHP system for decrease of energy consumption and recovery in comparison with constructed or optimized of wastewater treatment plants in worldwide. Therefore, it is necessary to pay more attention in selecting the process of liquid and sludge section in wastewater treatment plants under studying or optimizing wastewater treatment plants built in the country because of the numerous benefits of reducing energy consumption in wastewater treatment plants, in order to be self-sufficient in energy supply.

In recent decades, one of the environmental concerns is contamination with emerging pollutants of microplastics. Microplastics enter the environment through wastewater treatment plants and can absorb harmful pollutants. This study investigated microplastic pollution in the sludge of Zahedan wastewater treatment plants. To investigate microplastic pollution in the sludge of Zahedan wastewater treatment plants, 5 kg samples of sludge were passed through stainless-steel sieves and digested using H2O2 solution. NaCl was used based on density to separate microplastics. FESEM and FTIR analyses were used to investigate the surface morphology and polymer type of microplastics. The abundance of microplastic particles in the sludge ranged from 71-95 N/Kgdry.sludge, and their size varied from 25-500 micrometers. The most common color observed was transparent, and the fiber shape was the most prevalent. The study highlights the importance of addressing microplastic pollution in wastewater treatment plants to prevent harmful effects on the environment. Also, the data obtained from this study can be used to improve the treatment process and understand the removal of microplastics in urban wastewater treatment plants.

The presence of antibiotics in the environment, especially aquatic environments, is a major health and environmental concern. Wastewater treatment plants play an important role in the treatment of municipal and industrial wastewater and removal of contaminants. The aim of this study was to determine the concentration of prevalent antibiotics in municipal wastewater of Hamadan, Iran and to evaluate the removal efficiency of wastewater treatment plants. During 3 months (April, May, and June 2016), a total of 12 composite influent and effluent samples were collected from the wastewater treatment plants. Solid-phase extraction (SPE) was used for preparing the samples, which were then analyzed using high-performance liquid chromatography (HPLC) with UV detection. Based on the analysis of 6 antibiotics, three antibiotics, including amoxicillin, imipenem, and cefixime, were detected, and their concentrations were measured at 1.6, 10.7, and 5.8 ug/L, respectively. The removal efficiency of these antibiotics in wastewater treatment plants was 55.66%, 34.01%, and 24.33%, respectively. Due to the presence of examined antibiotics in the effluent and influent wastewater treatment plants, they might cause direct and indirect effects on human health and environment if proper measures are not taken by the authorities. Since the removal of these antibiotics from wastewater treatment plants is relatively poor, it is suggested to use advanced wastewater treatment plants to reduce antibiotics in effluent wastewater and decrease the adverse effects of these micropollutants.

The presence of antibiotics in the environment, especially aquatic environments, is a major health and environmental concern.Wastewater treatment plants play an important role in the treatment of municipal and industrial wastewater and removal of contaminants.The aim of this study was to determine the concentration of prevalent antibiotics in municipal wastewater of Hamadan,Iran and to evaluate the removal efficiency of wastewater treatment plants. During 3 months (April, May, and June 2016), a total of 12 composite influent and effluent samples were collected from the wastewater treatment plants. Solid-phase extraction (SPE) was used for preparing the samples, which were then analyzed using high-performance liquid chromatography (HPLC) with UV detection.Based on the analysis of 6 antibiotics, three antibiotics, including amoxicillin, imipenem, and cefixime, were detected, and their concentrations were measured at 1.6, 10.7, and 5.8 ug/L, respectively. The removal efficiency of these antibiotics in wastewater treatment plants was 55.66%, 34.01%, and 24.33%, respectively. Due to the presence of examined antibiotics in the effluent and influent wastewater treatment plants, they might cause direct and indirect effects on human health and environment if proper measures are not taken by the authorities. Since the removal of these antibiotics from wastewater treatment plants is relatively poor, it is suggested to use advanced wastewater treatment plants to reduce antibiotics in effluent wastewater and decrease the adverse effects of these micropollutants.

Due to the risks of hormones on human health and aquatic life, the aims of this study were to determine the efficiency of estrogen removal in the different stages of Shiraz wastewater treatment plant using activated sludge process and Marvdasht wastewater treatment plant using aerated lagoons process and also comparing the performance of both systems in removing the hormone of estrogen. Methods and Materials: In this study, the instantaneous sampling was used to take a sample from the wastewater treatment plants. The sampling was done for 3 times to determine the removal efficiency of estrogen hormone E2. The samples were transported to the laboratory within the maximum period of 3 hours. The Enhanced Chemiluminescence(ECL) was used to measure the hormone. The device (Elecsy 2010) was made by co-production tech companies (Roche) Germany and (Hitachi) Japan. The results showed that the amount of estrogen in the influent wastewater treatment plants is approximately 40 pgmL-1.The percent of the removal of the hormone in Marvdasht wastewater treatment plant using lagoon aeration process was 52.5%. The hormone removal efficiency in Shiraz wastewater treatment plant using activated sludge was more than 82%. Primary sedimentation removes only 3 to 4 percent of theestradiol hormone. Although the primary wastewater treatment plant was able to remove a trace amount of estrogen, biological treatments plant has an important role in removing the hormone. The capability of activated sludge process in removing estrogen is higher than aerated lagoon.

In general, the conversion of unstable organic materials in wastewater into stable minerals is one of the stages of wastewater treatment in a treatment plant. In other words, urban wastewater treatment plants try to purify municipal wastewater by converting organic materials into stable materials that have the ability to separate from wastewater. One of the most important organic compounds in municipal wastewater are nitrogenous materials and phosphorous materials that in municipal wastewater treatment plants.  By nitrogen removal and phosphor removal in wastewater, provide the possibility of municipal wastewater treatment. Although, the nitrogenous mineral compounds (nitrites and nitrates) and phosphorous mineral compounds are not the cause of contamination of treated wastewater due to their stability, due to their high nutritional properties, their entry into natural water sources greatly increases the growth and reproduction of aquatic organisms such as algae. In fact, phosphorus and nitrogen, because they are minerals, methods of separating nutrients from municipal wastewater in municipal wastewater treatment plants should be studied.

Prediction of effluent quality parameters of wastewater treatment plant is essential in managing water resources, limitation of fresh water resources in the world, furthermore the ever-increasing population growth and the development of urbanization, have made the approach of urban wastewater reuse inevitable. In such a situation, the use of recycled water can be considered as one of the ways to overcome water shortage and prevent wastage of water resources. This research aimed to investigate the performance of Prediction of effluent quality parameters of wastewater treatment plant in using recycled water. On the other hand, due to the health hazards caused by the discharge of wastewater from wastewater treatment plants to water sources, achieving a precise design and correct management of wastewater treatment plants (WWTP: Wastewater Treatment Plant) is one of the important challenges of sustainable water resources management. 4 effective parameters including (BOD), (COD), (TSS) and (pH) of wastewater, were selected as input to the model, during a statistical period of 3 years (1397 to 1399). Also, 70% and 30% sizes were determined as the best sizes for training and testing stages in order to model BODeff and CODeff parameters. In this study, multi-Layer perceptron models (MLP), basic radial neural network models (RABF), as well as the integration of these models with several other algorithms, such as genetic algorithm (GA), particle swarm optimization algorithm (PSO) and sine cosine algorithm (SCA), were used in order to predict the quality parameters of wastewater treatment plant effluent.

Workers in wastewater treatment plants are exposed to a wide range of chemicals as well as biological contaminants.
To ascertain whether exposure to bio-aerosols under the normal working conditions in wastewater treatment plants is associated with any significant changes in the prevalence of respiratory symptoms and lung function capacities.
198 employees of wastewater treatment plants and 99 unexposed persons were studied. American thoracic society (ATS) standard respiratory symptom questionnaire was used to determine the prevalence of respiratory symptoms. Pulmonary function tests were conducted for each participant.
The prevalence of respiratory symptoms among exposed persons was significantly higher than that of unexposed people. Mean values of most pulmonary function test parameters were significantly lower in the exposed compared to the comparison group persons.
Increased prevalence of respiratory symptoms and decrements in pulmonary function test parameters may be attributed to exposure to bio-aerosols released from wastewater treatment plants.

One of the environmental issues in urban planning is finding a suitable site for constructing infrastructures such as water and wastewater treatment plants. There are numerous factors to be considered for this purpose, which make decision-making a complex task. We used an integrated fuzzy logic and multicriteria decision model to select a suitable site for establishing wastewater treatment plant in Kahak, Iran. We used super decision software and a geographic information system (GIS) for scoring the parameters. The western part of Kahak was found to be a suitable place for constructing municipal wastewater treatment plant. Our findings indicated that decision makers and policy makers would be able to achieve better results concerning the most suitable location for wastewater treatment plant easily through combining these two models.

Nowadays wastewater is one of the important sources of environmental pollutions and one of the aims of wastewater treatment is to maintain a healthy environment. Nonstandard wastewater discharges and their use in agriculture or discharge to surface water will follow environmental and health hazards. The aim of this study was to compare the effluent quality of three Tehran، Iran wastewater treatment plants (in Ekbatan، Sahebgharanie and South of Tehran). This study was performed in 2010 on three mentioned treatment plants in Tehran، Iran. Three samples were taken from each wastewater treatment plant. The measured parameters of the effluent include pH، DO (dissolved oxygen)، BOD5 (biochemical oxygen demand)، COD (chemical oxygen demand)، Sulfate chloride، Nitrate، Nitrite، TSS (total suspended solids)، Fecal coliform. Then they were analyzed according to the methods described in the standard method. The results showed that the Nitrite concentration in Sahebgharanie، Ekbatan and South wastewater treatment plants with standard deviation 10. 02، 5. 9 and 0. 142 respectively was 17. 53، 50. 33 and 35. 5 mg/l which were higher than the standard amount. The number of fecal coliform in each three wastewater treatment plant was higher than the standard (2400 MPN/100 ml). BOD5 concentration mean in south wastewater treatment plant effluent with standard deviation 4. 58 was 65 mg/l which in comparison to the standard amount was not significant (P > 0. 05). The mean COD concentration with standard deviation 5 was 121 mg/l and had a significant difference with the standard amount (P < 0. 05). Both of these amounts were higher than the standard. The quality of effluent in Ekbatan and Sahebgharanie wastewater treatment plants was better than South of Tehran but the amount of some parameters like nitrite and fecal coliform in these treatment plants was higher than the standard. Therefore، using the effluents of these wastewater treatment plants for discharging surface water or agricultural use is not recommended.