Background: Modifying and enhancing treatment methods is essential to meet effluent standards for treating landfill leachate. This study investigated the treatment of municipal solid waste leachate (MSWL) using coagulation, flocculation, advanced oxidation, and extended aeration processes. Methods: The effects of different coagulant doses and pH values on coagulation processes were compared. The treatment procedure was analyzed to determine the impact of varying concentrations of potassium persulfate (K2S2O8) and hydrogen peroxide (H2O2) on the results after coagulation with FeCl3. The extended aeration process’s biological stages were studied using a sludge retention time (SRT) of 23 days and the effects of hydraulic retention time (HRT) of 18 and 36 hours. Results: The experimental results show that in the pH range of 5–8, the lower the pH value, the higher the treatment efficiency. The addition of 0.8 g L1− FeCl3 can achieve a 57% removal of chemical oxygen demand (COD). The addition of 2.5 g L1− K2S2O8 and 1.5 g L1− H2O2 with UV-C (15 W) for 70 minutes at pH 7 can effectively remove 86% of COD. Activated sludge extended aeration can attain an 88% removal of COD under optimal operating conditions (HRT = 36 hours, SRT = 23 days, and aeration = 36 hours). The studied hybrid process with the efficiency of 99%, 98%, 95%, 87%, and 83% removal of COD, biochemical oxygen demand (BOD), total suspended solids (TSS), turbidity, and total Kjeldahl nitrogen (TKN), respectively, is suitable for leachate treatment. Conclusion: This study showed that flocculation-coagulation followed by the advanced oxidation process (AOP) and extended aeration can be an efficient and promising treatment method for MSWL.

Wastewater treatment plants help to reduce negative impact on the environment by improving the quality of effluent. Different technologies are used in wastewater treatment, and one of the tasks is to find the most environmentally sound option, taking into account the use of resources and energy during construction and operation of the treatment system. The aim of the study is to assess environmental impacts from two different types of small-scale wastewater treatment systems, a constructed wetland and extended aeration activated sludge treatment system using Life Cycle Assessment method. The system boundaries include construction and operation phases. Assessment has been carried out using SimaPro software and Impact 2002+ and ReCiPe assessment methods with characterisation and normalisation stages. The results show that the main negative impact of constructed wetland is caused by the construction phase and use of lightweight expanded clay aggregate to construct the hybrid filter. Impacts from extended aeration activated sludge treatment system are mainly caused from the use of electricity and the quality of the effluent, therefore, the use phase has a larger impact on the life cycle. Since a large amount of energy is used to produce lightweight expanded clay aggregate, the impact of 1 population equivalent of constructed wetland is larger than the impact of extended aeration activated sludge treatment system. Constructed wetland dominates in human toxicity, acidification, land use, ozone layer depletion and the use of non-renewable resources categories. Extended aeration activated sludge treatment system dominates in categories associated with eutrophication and ecotoxicity.

On average, 67 % of household wastewater is made up of greywater, which includes wastewater produced in household other than toilets. There are different biological treatment processes for greywater treatment. One of these systems is the sequencing batch reactor (SBR), which has proven to be an effective way of treating wastewater. One of the amendments to the SBR process is the intermittent cycle extended aeration system (ICEAS). The purpose of this study was to investigate the performance of an advanced-SBR in the bathroom greywater (BGW) treatment. For this purpose, a rectangular SBR reactor (40 20 20 cm) with a working volume of 12 liters was developed and utilized. The primary microorganisms of this reactor were prepared from the active sludge return to the aeration pond of the Arak municipal wastewater treatment plant. The reactor was fed with the effluent from the initial settling ponds of the same treatment plant. After the system was set up and sufficient microorganisms were grown, the exploitation phase began with synthetic greywater. The experiments were carried out in three cycles of 4, 6 and 8 hours. The concentrations of linear alkyl benzene sulfonates (LAS), chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) at the inlet were 6. 8 mg/L, 385 mg/L and 170 mg/L, and in the outlet, 0. 95 mg/L, 19. 25 mg/L and 8. 5 mg/L, in a 8-hour cycle. Therefore, the removal efficiency of the system in 8 h cycle was 86 %, 93 % and 95 %, respectively.

Advanced compact wastewater treatment processes are being looked for by cities all over the world as effluent standards are becoming more stringent and land available for treatment plants more scarce. In this investigation, a new biofilm process for this purpose was studied. The design and operational criteria of a full scale extended aeration activated sludge system was compared with an H-IFAS reactor which has been operated at a pilot scale. The objective was to define the feasibility of using the H-IFAS (Hybrid Integrated Fixed Film Activated Sludge) reactor for upgrading the existing wastewater treatment plants with conventional processes. The results showed that besides the considerable difference between the organic loading of the two processes, H-IFAS reactor has a very good capability to reduce simultaneously the concentration of nitrogen and phosphorus. Organic degradation rate in extended aeration and H-IFAS systems were 0.3 and 6.22 kgCOD/m3. day at 23.48°C, respectively. Nitrification, denitrification and phosphorus removal rate for the H-IFAS reactor were 343.28 g N/m3.day, 338.17 gN/m3.day, and 204.78gPO4-P/m3.day, respectively. At the same conditions, these criteria for extended aeration activated sludge processes were obtained as 75gN/m3.day, 28.5 gN/m3.day and 7 gPO4-P/m3.day), respectively.

Background and Objective: Estrogen is a steroid hormone that is in the water and cause risks for aquatic organisms, especially fish is. Estrogenic hormones naturally (caused by endocrine) or artificial (due to hormonal contraceptives such as birth control pills) to sewage and hospital to find. This study aimed to determine the amount of estrogen in the sewage and Golestan and Abuzar hospital in Ahvaz were studied.Material and Methods: Sampling was done by tracking estrogen in the aquatic environment. 56 samples 4 months in different parts of the Golestan and Abuzar hospital wastewater treatment plant in Ahvaz were taken. Sample a little electro luminescence (ECL) were analyzed by laboratory Iranian city of Ahvaz. In this study, different forms of estrogen (estrone, 17-beta-estradiol, estriol, 17-alpha-ethinyl estradiol) has been studied as estrogen.Results: Mean hormone found in raw wastewater to the Golestan hospital wastewater treatment plant effluent from the treatment plant hormone 69.08 ng/l and 7.28 ng/l mean. Mean testosterone in Ahvaz Abuzar hospital treatment input 70.61 ng/l and 18.94 ng/l is refinery output. According to the results of high impact biological treatment is the removal of estrogenic compounds.Conclusion: Secondary treatment of sewage is effective in reducing hormones that can do this at this stage of the biological treatment effect.