Pezhman Gheitasian; Seyed Mohammad Tabatabaee jabali; Ahmad Jonidi Jafari; Mohsen Farhadi; Javad Golshani asl; Behzad Valizadeh; Maryam Meserghani
Abstract
Background and Purpose: Tetracycline represents the most prevalent antibiotic group in production and utilization and is extensively employed for the prophylaxis and treatment of infectious diseases in both human and veterinary medicine. The primary objective of this investigation was to assess the efficacy ...
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Background and Purpose: Tetracycline represents the most prevalent antibiotic group in production and utilization and is extensively employed for the prophylaxis and treatment of infectious diseases in both human and veterinary medicine. The primary objective of this investigation was to assess the efficacy of electro-activated persulfate (EC/PS/HR) for eliminating tetracycline from aqueous solutions.Materials and Methods: This study was conducted in a batch mode utilizing an electro-activated persulfate (EC/PS/HR) system. All experiments were carried out under constant temperature conditions. Response surface methodology (RSM) in conjunction with a central composite design (CCD) was employed to optimize the variables associated with the electro-activated persulfate and hydrogen peroxide process, including pH, current density, and the persulfate/hydrogen peroxide molar ratio, with the aim of tetracycline removal. Data analysis in this study was performed using Data Designer 8.0.6 software.Results: The results of this study revealed the use of a quadratic model to predict the impact of independent variables on the efficiency of tetracycline removal in the process. The exceedingly low (p <0.0001) and the high correlation coefficient (R2) of the obtained model signify a robust correlation between experimental and predicted data. The optimal conditions for achieving maximum efficiency in the degradation of tetracycline through electro-activated persulfate were determined to be a pH of 5.6, a persulfate/hydrogen peroxide molar ratio of 1.1, and a current density of 31 mA. Under these conditions, tetracycline degradation reached approximately 95.2%.Conclusion: Based on the findings of this investigation, it can be deduced that the advanced oxidation process relying on electro-activated persulfate (EC/PS/HR) is capable of eliminating contaminants in aqueous environments, influenced by various factors such as hydrogen peroxide dosage, catalyst concentration (persulfate), and pH. The study highlights the capability of the electro-activated persulfate (EC/PS/HR) hybrid process to decompose recalcitrant pollutants like tetracycline from aqueous environments. Overall, the electro-activated persulfate process demonstrates promise for the degradation of tetracycline in aqueous solutions.
Elahe Khayyami; Mahdi Pahlevani; Ebrahim Esmailzadeh
Abstract
Background and purpose:This study aimed to evaluate the performance of biological process treatment (Modified Ludzack Ettinger) of municipal wastewater treatment plant No. 4 in Mashhad- Alteymur.Materials and methods: The performance of treatment plant was evaluated in a 12-month period from March 2020 ...
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Background and purpose:This study aimed to evaluate the performance of biological process treatment (Modified Ludzack Ettinger) of municipal wastewater treatment plant No. 4 in Mashhad- Alteymur.Materials and methods: The performance of treatment plant was evaluated in a 12-month period from March 2020 to February 2021. Based on flow changes, a sampling of raw sewage inlet and outlet effluent was done in combination. Moreover, studied parameters, including BOD5, COD, TSS, TDS, EC, pH, total coliform, and fecal coliform were measured according to the methods presented in the standard method book for water and wastewater tests. ANOVA test was used to analyze the data and compare them.Results: Based on the results, the highest removal efficiencies are related to the parameters of T.C, FC, TSS, BOD5, COD, TDS, and EC, respectively, with 100, 100, 98.48, 97.88, 48.96, 25.97, and 25.88 percent, respectively. The significant removal efficiency of measured parameters in the effluent from wastewater treatment plant No. 4 of Mashhad (Altimour) shows the proper performance of MLE process system. The results of the ANOVA test to compare the removal efficiency of parameters in different seasons showed that the performance of treatment plant was not affected by the change of seasons.Conclusion: The amounts of pollutants were compared with the standard of the Environmental Protection Organization of Iran for discharge to the environment and using the wastewater. According to the studies performed on the tested parameters, the effluent is in line with the standards of the Environmental Protection Organization for irrigation and agriculture, surface water, and absorption wells, but for other uses and proper efficiency of the effluent, all aspects should be considered.
reza shokoohi; Hossain Farji; Seyed Amir Ghiasian; Javad Faradmal; Salah Azizi; mahdi salari
Abstract
Background & Objective: Cadmium is considered as one of the most hazardous heavy metals, a non-essential, non-beneficial and highly toxic element to people. In the current study, the ability of aspergillus terreus fungi biomass was surveyed in the removal of cadmium from aquatic solutions. Materials ...
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Background & Objective: Cadmium is considered as one of the most hazardous heavy metals, a non-essential, non-beneficial and highly toxic element to people. In the current study, the ability of aspergillus terreus fungi biomass was surveyed in the removal of cadmium from aquatic solutions. Materials & Methods: This cross-sectional study was carried out in 2015 using fungal biomass culture on a shake flask. The dead biomass of aspergillus terreus fungi was applied as an adsorbent for the treatment of aquatic solution under the conditions of cadmium concentrations: 20, 40, 60, 80, 100 and 120 mg/l, pH: 3, 5, 7 and 9, retention time: 15, 30, 45, 60, 90, and 120 min and adsorbent dose: 0.1, 0.2, 0.5, 1 and 2 g. The remained concentrations of cadmium after adsorption were determined by atomic absorption spectrophotometer. Results: Results indicated that under condition of retention time: 90 min, pH: 7, initial cadmium concentration: 20mg/l and adsorbent dose: 1g, the biomass had a removal efficiency of 94%. Moreover, Adsorption process fitted to Freundlich isotherm with R2=0.9463 and first order kinetic with R2=0.9935. Conclusion: In current study, it was observed that the factors of pH, retention time, dose of aspergillus terreus fungi and initial cadmium concentration had a noticeable effect on the adsorption amount. with regard to the high adsorption capacity of the biomass in comparison to other adsorbents in the removal of cadmium, this biomass can be used as a good adsorbent in wastewater treatment.
B. Heidari; M.H Mehdi Nejad; A.A. Najafpour; A. Zafarzadeh; H. Elahi
Abstract
Background & Objective: The issues of environmental engineering , due to its technical , environmental, social and economic factors are complicated. So, it is difficult to determine which variables are more effective. The purpose of this study was to investigate the effective variables by using ...
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Background & Objective: The issues of environmental engineering , due to its technical , environmental, social and economic factors are complicated. So, it is difficult to determine which variables are more effective. The purpose of this study was to investigate the effective variables by using AHP and choose the best method of wastewater treatment (Soleimani Village). Materials & Methods: This is a descriptive study with applying approach. By using AHP is the preferred choices were determined. This method was evaluated by using software Expert Choice. In this regard, after considering the factors affecting or affected by, 3 criteria and 15 sub-criteria, and then the analytic hierarchy process were used. Then, the wastewater treatment processes were prioritized. The processes are constructed wetland systems, rotating biological discs, extended aeration with floating Media and activated sludge. They were based on technical criteria, economic, efficient of treatment process, sub- criteria, weighting and prioritization. Results:The results showed that weight scores of constructed wetland, rotary biological disc, extended aeration with floating Media and activated sludge were 0.36, 0.28, 0.2 and 0.15, respectively. Therefore, the treatment of choice in rural areas was constructed wetland treatment. Conclusions: The results show economic criteria are more effective to make the final decision. By the way, the technical criteria were also considered (e.g., ease of operation and construction, etc.) It can be concluded that the wetland method is the best alternative for Soleimani village.
Muhammad Pazira
Abstract
Background and objective: Paper, pulp and cardboard manufacturing industries discharge large amounts of waste which contain a variety of pollutants and paints. These wastes are believed to generate the most environmentally hazardous industrial wastewaters. Biological procedures alone may not suffice ...
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Background and objective: Paper, pulp and cardboard manufacturing industries discharge large amounts of waste which contain a variety of pollutants and paints. These wastes are believed to generate the most environmentally hazardous industrial wastewaters. Biological procedures alone may not suffice the treatment of such wastes due to having a high BOD5/COD ratio. On the other hand, applying costly chemical approaches to remove all these pollutants in a short time often results in the production of large quantities of sludge. Therefore, these industries are obliged to combine both these methods in order to optimize wastewater treatment. Methods: In this experimental study, the sample wastewater was provided from the discharge channel of Pazh cardboard factory located in Tous Industrial Zone of Mashhad, Iran. The wastewater samples were collected from this factory by composite sampling. Coagulation of these samples was accomplished by clay soil as the single coagulant. The optimum pH of the treatment was determined by Jar tests in various pHs (from 4 to 9). Afterwards, the optimum concentration of the coagulant was also verified at the optimum pHof 8 by Jar tests. Results: The optimum dosage and pH of treatment by clay soil wasdetermined to be 75 g/L and 8, respectively. Under optimized conditions, the removal efficiency of COD, BOD5 and TSS was calculated as 47%, 26% and 57%, respectively. In addition, the pH adjustment at 8 resulted in a 60% reduction of clay consumption. Conclusion: According to the results of this study, the coagulation of cardboard wastes by clay soil could be a suitable pretreatment method. This particular material makes it possible to improve the quality of wastewater in subsequent bio treatments in a much less costly way compared to other conventional coagulants or adsorbents. It was also observed that the ratio of BOD5/COD reduced from 4.5 to about 3. Although the clay dosage required for the wastewater treatment is relatively high, this approach could stillbe recommended for the pretreatment of this type of wastewater as well as the wastes produced by similar industries mainly because the overall cost of this treatment is insignificant. Paper Type: Research Article