Iranian Journal of

Background and Objective: In countries such as Iran that are facing with water scarcity and water crisis, paying attention to the quantity, quality and sustainable use of water resources is very significant. Petrochemical processes discharge pollutants into the environment, contaminating surface water resources. Therefore, treatment of the wastewater of these industries is necessary. Due to the capabilities of AHP process such as generalization, consideration of various parameters, multi-dimensional selection and quantifying the qualitative parameters by experts, the current study was carried out to select the best wastewater treatment alternative for HDPE plant of petrochemical research and technology company-Arak center based on AHP in 2016.
Materials and Methods: In this study, both sequencing batch reactors (SBR) and extended aeration activated sludge (EAAS) systems based on environmental, technical-functional, economic and management criteria's according to the expert's opinion were weighted. Then, the paired comparisons of the selected wastewater treatment systems for each criterion were developed. Finally, the results were analyzed to select the best wastewater treatment systems for HDPE unit of petrochemical industries using Expert Choice 11 Software.
Results: The results showed that the SBR wastewater treatment system was the best method for the wastewater treatment of HDPE plant of petrochemical research and technology company-Arak center as compared with the ESSA system. Also, consistency ratio was ranged from 0 to 0.10 in all emphases. Based on the results of the sensitivity analysis, the SBR system had the highest priority of economic and environmental criteria. The ESSA system had the highest priority of technical-functional and management criteria.
Conclusion: Based on the results, although ESSA method requires more maintainance and management than the SBR method, due to increasing requirement for the compliance of the output effluent quality with permissible limits and the need for less land for the establishment of the treatment plant, the SBR method was selected to be the most suitable process for HDPE plant wastewater treatment.
 
 

Background and Objective: The failure mode and effects analysis (FMEA) is one of risk assessment techniques. The aim of this study was to identify, assess and prioritize the risk associated with the process of medical waste management using the FMEA method and provide appropriate strategies and measures for controlling the risk of this process in the Children's Medical Center Hospital.
Materials and Methods: This descriptive cross-sectional study was performed in this hospital during the first 6 months of 2016. For data collection, the standard worksheet of FMEA and object-oriented sampling were used. In this method, each error based on the severity, the occurrence rate and probability of finding an error is scored between 1 and 10, which the priority number of the risk is obtained from the product of these 3 indicators.
Results: In this study, a total of 33 potential risks associated with the management of medical wastes were identified using FMEA risk assessments. The highest priority number for non-washed waste containers is 360 and the lowest priority number is the risk of not having the Safety box for disposal of sharp waste in the wards, which is 30.
Conclusion: One of the most important sources of environmental pollution is medical wastes that have high costs in different stages of waste management in the hospital, thus, the use of the FMEA technique can reduce costs and increase the safety and health of the personnel. It also helps to preserve the environment.
 

Background and Objective: Ultrasonic disintegration is a pretreatment process before stabilization and dewatering that degrades sludge and changes its physical and chemical characteristics. The aim of this study was to investigate the effectiveness of ultrasonic in enhancing hydrolyses, stabilization and dewatering of municipal raw activated sludge.
Materials and Methods:  The samples were taken from returned activated sludge and then they were exposed to ultrasonic (Frequency: 20 and 40 kHz) in different times (0.5, 1, 3, 5, 10, 15, 30, and 60 min). The effectiveness of ultrasonic for hydrolysis, stabilization and dewatering processes were determined with measuring TS, TSS, CST, SRF, VS, nVS, VSss, and VSsol.
Results: VSsol was increased by 73% in 15 min and at frequency of 20 kHz, whereas VSsol increas was100% at 10 min and 40 kHz. The reduction of VS was observed at 15 min and 20 kHz. Then after, it was reached 18% after 60 min. For 40 kHz, VS reduction started at 10 min and reached 24% after 60 min. Specific resistance of sludge at two frequencies of 20 and 40 kHz and contact time of 1 min were decreased by 25 and 20% respectively. The capillary suction time at the frequencies of 20 and 40 kHz and contact time of 1 min was decreased 28 and 21%, respectively.
Conclusion: The optimum effectiveness of ultrasonic in hydrolysis of organic matter of raw biological sludge was at the contact time of 10 min and frequency of 40 kHz. The highest stabilization at the frequency of 40 kHz was observed at 60 min contact time. The best condition for sludge dewatering was at frequency of 20 kHz and contact time of 1 min.
 

Background and Objective: Nowadays, the increasing use of antibiotics to control diseases and mismanagement and inappropriate disposal of medicinal wastes cause environmental problems and threatens human health. The present study was conducted to determine removal of antibiotic Metronidazole as one of the most used drugs during the process of composting.
Materials and Methods: In this experimental study, a mixture of livestock manure, fruit, straw and sludge were used for the preparation of compost. Duration of the process was 40 days. Metronidazole was added to the compost reactors at three concentrations of 20, 50 and 100 mg/kg. Totally, 42 Samples were taken weekly. HPLC was used to analyze the samples. The experiment was repeated twice. SPSS22 software was used to analyze the results.
Results: The rate of Metronidazole removal after day 21 and end of the thermophilic phase was 99.9, 96.73 and 93.48 % in the reactors contained 20, 50 and 100 mg/kg, respectively. Increasing concentrations in the reactors caused the removal rate to decrease, while increasing removal time caused to increase the removal rate. At the end of the process, the removal rate for all three reactors was 99.99 %. The physico-chemical properties of the final compost were within the national standard.
Conclusion: The use of an aerobic composting process to degrade antibiotic Metronidazole is an economical, effective and, environmentally friendly method. At the end of the process, 99.99 % of Metronidazole was degraded.
 

Background and Objective: In recent years, management and disposal of municipal solid waste has become a global problem and the most important environmental concern. Anaerobic digestion is a cost-effective solution for treatment of both solid waste and wastewater. The aim of this study was to investigate the positive or negative effects of calcium chloride content in anaerobic digestion process of municipal solid waste and leachate on biogas production.
Materials and Methods: Experiments with 8 levels of calcium chloride on co-digestion of municipal solid waste and leachate were investigated in 500 ml digesters under mesophilic conditions in a completely randomized design with three replications. Reactors with a ratio of substrate to inoculum of 2 (on VS basis) were operated and the volume of the biogas was measured daily. Volatile and total solids, carbon/nitrogen of waste, COD, BOD and heavy metals were measured by following APHA.
Results: The results of the experiment showed that the pH was decreased with increasing calcium chloride concentration. The highest amount of cumulative biogas production was obtained in CaCl₂ of 2 g/L with the highest VS and TS reduction. Higher concentrations of CaCl₂ (≥3 g/L) caused a reduction in the degradability of volatile and total solids and, as a result, a decreased performance of the digester.
Conclusion: The results clearly confirmed that the addition of calcium chloride was an effective solution to improve biodegradability in co-digestion of the MSW and leachate and consequently to reduce the total and volatile solids and to increase the amount of‌ biogas.
 

Background and Objective: Today, landfill management of municipal waste and soil pollution with heavy metals are major environmental problems. This research was conducted to evaluate the effect of Shazand municipal waste compost and Saveh pomegranate peel biochar on decreasing Pb availability in soil and sorghum plant.
Materials and Methods: Treatments consisted of applying Shazand municipal waste compost (0, 10 and 20 ton/‌ha^‌) and Saveh pomegranate peel biochar (0 and 15 g/‌kg^‌) in a Pb polluted soil (0, 600, 800 and 1000 mg Pb/‌kg soil). After 8 weeks of sorghum planting (Kimya CV.), the soil physio-chemical properties and soil and plant Pb concentration were measured. 
Results: Applying 20 ton/ha‌ municipal waste compost with 15 g/‌kg^‌ biochar increased soil pH by 0.4 units and decreased soil Pb availability by 11%. The similar results were observed for the root and shoot Pb concentrations, when the same amount of  manure in a Pb polluted soil was applied (1000mg Pb/‌kg soil) that decreased the root and shoot Pb concentration by 1.8 and 2.2 times, respectively.
Conclusion: The result of this experiment showed that applying Shazand municipal waste compost and biochar can increase soil sorption properties and decrease soil or plant Pb concentration. However, the role of these organic amendments on supplying plant nutritional needs cannot be ignored.
 

Background and Objective: Treatment of hospital wastewaters has an important role in reducing the discharge of organics and pharmaceutical compounds into aquatic environments. Nowadays, advanced oxidation processes were extensively used for the removal of organic compounds from treated effluents. The study aimed to examine organic compounds removal from real treated effluent of a hospital treatment plant using a lab scale UV/H₂O₂/TiO₂ process by optimizing the process.
Materials and Methods: The effluent characteristics including COD, TOC and DOC were measured and recorded. A hybrid advanced oxidation process (UV/H₂O₂/TiO₂) was used for the removal of organic compounds. The experiments were designed using surface response methodology (RSM). The effects of the independent factors including pH, duration of UV irradiation, H₂O₂ and TiO₂ concentrations on COD, TOC, DOC and the approximate cost of treatment were assessed by analysis of variance (ANOVA).
Results: The optimal condition was 7.2 for pH, 50 mg/L for H₂O₂, 100 mg/L for TiO₂ and 19.65 min for irradiation time. This condition provided the maximum removal percentage for organic compounds with a minimum cost. The removal efficiency for TOC, DOC and COD were 63.9, 52.9, and 64.7%, respectively. The treatment cost was approximated to be $ 0.71 per one liter of the effluent.
Conclusion: Irradiation and H₂O₂ concentration had the greatest impact on the cost of the treatment. UV/H₂O₂/TiO₂ process seems to be an expensive process for tertiary treatment of wastewater. However, further investigations are required to evaluate the cost effectiveness of the process for a full scale operation.
 
 

Background and Objective: The main objective of this study was to evaluate the surface and deep distribution of Pb, Ni and Cu in the wastewater-irrigated area of south of Tehran using GIS and Hydrus. It was expected to find a comprehensive information of heavy metals distribution and their accumulation in the soil. 
Materials and Methods: This study was carried out in wastewater-irrigated area of south of Tehran. Soil sampling from the top surface layer (0-15 cm) and wastewater channels was done. After sample analysis, ordinary Kriging method using different variogram in GIS was applied to explore the surface distribution of Ni, Pb and Cu heavy metals. Moreover, the deep percolation of heavy metals in the soil profile was simulated by Hydrus-1D in a duration of 210 days and the heavy metals concentrations in the soil were estimated.
Results: Exploration of the distribution of Pb using spherical model showed that the variation of this element was in the range of 20-70 mg/kg. This amount varied to 50-60 mg/kg for Cu and about 30 mg/kg for Ni. Moreover, the simulation of heavy metals deep percolation using Hydrus revealed that the most accumulation of heavy metals happened in the 0-15 cm soil surface layer and for deeper layer, this trend was descending.
Conclusion: Comparing the concentration of Pb, Cu and Ni with the maximum allowable amounts of WHO standards demonstrated that Pb concentration was more than the threshold limit. Finally, the applied models could simulate soil’s heavy metals content for both surface and deep distribution in the studied area.
 

Background and Objective: Antibiotics are a group of emerging contaminants in the aquatic environment. Antibiotic residues threaten the human health and ecosystem in the low concentrations found in the environment. Hence, the present work has been conducted to investigate the occurrence and removal efficiency of most prescribed antibiotics including amoxicillin, penicillin, cefixime, cephalexin, ciprofloxacin, erythromycin and azithromycin detected in two urban wastewater treatment plants (WWTPs) in Tehran.
Materials and Methods: The present work is an applied research based on USEPA method no. 1694, to investigate pharmaceuticals residues in water by HPLC/MS/MS in year 2016. The differences between target antibiotics residues were investigated statistically. After the calculation of the removal efficiencies, the normality of the data was assessed. Then, parametric and non-parametric tests were used to compare the removal efficiencies in both WWTPs.
Results: There was not a significant difference between the influent and effluent concentrations of cefixime and azithromycin (in Ekbatan WWTP) and cefixime (in southern Tehran WWTP). There is a significant difference between the removal efficiencies of cephalexin (p=0.005) and erythromycin (p=0.002) in two WWTPs. The Highest median removal efficiencies were observed for cephalexin 94.41 and 99.47 in Ekbatan WWTP and southern Tehran WWTP, respectively.
Conclusion: In addition to the type of treatment processes, it is physicochemical properties of the selected compound has a significant influence on removal efficiencies.
 

Background and Objective: A scientific questionnaire for assessing the knowledge, attitude and judgment of people on waste management by municipalities has not been developed so far. Therefore, the purpose of this study was to design and validation of an instrument to assess the knowledge, attitude and judgment of people on waste management by municipalities.
Materials and Methods: This analytical study was conducted in District 21 of Tehran in 2017. The initial items of the questionnaire were designed based on previous studies and opinions of the team of specialists and people. Then, the face validity and the content validity of the designed questionnaire was examined. The face validity and the content validity was examined qualitatively and quantitatively, respectively. Finally, the reliability of the attitude and knowledge and evaluation of municipal performance items were measured by Cronbach's alpha and a test-retest method, respectively.
Results: The initial questionnaire had 43 items. In the face validity, 8 items were removed and 8 items were edited. In quantitative content validity, 7 items were excluded, with the content validity index of less than 0.79 and the content validity ratio less than 0.49. Pearson correlation coefficient obtained for knowledge component equal to (r=0.77, p<0.0001) and for component performance (r=0.93, p<0.0001), respectively. Cronbach's alpha coefficient was equal to 0.89 for items attitudes, which were in an acceptable level.
Conclusion: The questionnaire can be used as a valid research instrument to collect information on knowledge, attitude and judgment of people on waste management by municipalities.
 

Background and Objective: Rural wastewater management is recognized as one of the pillars of sustainable development. Therefore, the purpose of this study was to assess needs and prioritization of establishment of rural wastewater management facilities in order to supply a safe and alternative water source in the provinces of Iran experiencing severe water stress.
Materials and Methods: This is a cross-sectional descriptive study which was carried out in rural areas of the provinces with severe water stress (South Khorasan, Khorasan Razavi, Fars, Isfahan, Yazd, Semnan, Qom, Sistan and Baluchistan) in 2017-2018. In this study, the number of sample rural areas was calculated by Cochran method and the determination of the sample rural area was done by stratified sampling. The data related to the sample rural area was collected using a validated constructor questionnaire.
Results: The results of this study showed that the difference among all the studied provinces in terms of their priority in establishing rural waste water management facilities to provide a safe and alternative water source was very low. The provinces of Isfahan, Semnan and Fars were rated at 76 out of 100, while the provinces of South Khorasan and Sistan and Baluchestan scored 71 points.
Conclusion: With emphasis on comprehensive decision making criteria based on sustainable development, the results of this study showed that the provinces with severe water stress have a high priority regarding the establishment of rural sewage management projects in order to provide a safe and alternative water sources.
 

Background and Objective: Clinics, laboratories and health care centers are considered as one of the main waste generating sources in solid waste management. The problems associated with the generated health-care waste in clinics, laboratories and health care centers have been rarely investigated in Iran. Therefore, the present study was developed to investigate the status of health care waste in clinics, laboratories and health care centers of Mahmoudabad, Mazandaran in 2017.
Methods and Materials: This cross-sectional study was conducted to determine the status of solid waste management in 117 medical centers in Mahmoudabad, Mazandaran, 2017. The solid waste data in terms of waste generation rate, storage, collection, and disposal were surveyed through interview and questionnaire that were validated by Iran’s ministry of health.
Results: The average health-care waste generation in medical centers in Mahmoudabad was found to be 248 g/day. The mean and standard deviation for environmental health criteria in all medical centers were 248.3 and 41.1, respectively. In addition, there was a statistically significant difference between the amount of waste generation in private and governmental medical centers (p=0.111).
Conclusion: The results obtained from the present research indicated that the medical waste management in Mahmoudabad, particularly in private centers, face serious problems. Improper waste collection technology, mixing municipal and medical waste, requirement for training the personnel in medical waste management and surveillance can be considered as important concerns in health-care waste management in Mahmoudabad.
 

Background and Objective: Olive Mill Wastewater (OMWW) is one of the most polluted sanitary wastewaters that its ineffective treatment will cause severe pollution of the environment. In this study, OMWW treatment wasinvestigated using combined electrocoagulation and novel advanced oxidation process.
Materials and Methods: Biodegradability, efficiency and kinetics of removal of turbidity and organic matter from the OMWW by applying the operational parameters of electrocoagulation such as current density (0-0.77 A/dm²), type of anode electrode, reaction time (0-45 min) were investigated. Various types of advanced oxidation processes were performed to determine the the efficiency of removal of TOC and kinetics and biobegradability.
Results: The optimum condition for removing turbidity, BOD, TOC and consumed Iron anode electrod in electrocoagulation were 78%, 57%, 72% and 583 mg/ per liter of wastewater, respectively. Thus, the kinetic of TOC removal was first-order and was 0.027 min^-1. The TOC removal efficiency of pretreated OMWW in oxidation processes of US, H₂O₂, SOP, O₃ / H₂O₂, COP, COP/US and H₂O₂/COP/US were measured as 8%, 15%, 20%, 25%, 61%, 68% and 75%, respectively. The highest biodegradability index (BOD/TOC) in the COP/US/H₂O₂ process was increased 1.5 times.
Conclusion: The advenced oxidation process of COP/US/H₂O₂ follwed by electrocagulation demonstrated an effective treatment of OMWW and improved its biodegradability. Therefore, this process can be used for efficient treatment of OMWW in olive and similar industries.
 

Background and Objective: Wastewater from pharmaceutical industry has high chemical oxygen demand as a result of the presence of organic drugs and antibiotics. In order to meet the environmental requirements, several treatment methods like chemical and electrochemical methods have been widely applied due to their high ability to remove organic compounds from pharmaceutical wastewater. Therefore, the present study aimed to evaluate the efficiency of chemical coagulation/Electro-Fenton treatment method to degrade the organic matter-containing pharmaceutical industry wastewater.
Materials and Methods: The experimental tests were carried out using batch mode. The chemical coagulation process was evaluated as a function of aluminum chloride concentration (25-300 mg/L) and pH (3-10). The effluent from chemical coagulation process was transferred to Electro-Fenton reactor. Effects of H₂O₂ concentration (100-4000 mg/L), reaction time (up to 120 min), voltage (10-30 V), and pH (3-10) were evaluated. The removal efficiency was determined in term of COD removal.
Results: The results showed that the highest removal of COD in the chemical coagulation was 49% (coagulant dose of 200 mg/L, and pH of 7). In addition, the Electro-Fenton process could be eliminating of 93.5% of COD at the optimum conditions concentration (100 mg/L H₂O₂, voltage of 20, pH of 3, and contact time of 30 min).
Conclusion: According to the results, it can be concluded that the combination of chemical and electrochemical processes was found to be effective methods for treatment of pharmaceutical wastewater in comparison to the application of each process separately. To reach to the maximum removal efficiency, the environmental parameters should be carefully controlled at their optimum values in each single process.
 

Background and Objective: Medical waste is among the environmental problems. Failure to manage these wastes leads to the prevalence of various diseases. This study aimed to rank the educational hospitals of SBUMS by assessing medical waste reduction.
Materials and Methods: First, a review of past national and international studies was performed and accordingly, 12 criteria and 30 sub-criteria for reduction of medical waste production were selected. After developing a questionnaire based on such criteria, data was collected from six SBUMS hospitals. Then, TOPSIS and VIKOR techniques in MATLAB were used as ranking methods of hospitals.
Results: The combined results of TOPSIS and VIKOR methods using weighted average indicated that Hospital (C), Hospitals (B) and (A) were respectively ranked first, second and third in terms of waste management. Moreover, the effective measures to reduce the amount of waste production and to improve the waste management system include human resource, management support, proper management of supplies, proper model of service delivery, quality of supplies and equipment, and waste sorting at source.
Conclusion: A combined method consisting of TOPSIS and VIKOR for evaluation of ranking of hospitals in terms of waste management can be a helpful tool in planning waste management, and can provide a basis for improving measures and promoting programs and activities.
 

Background and Objective: Algal wastewater treatment is a new and economic technology to remove and recycle nutrients from wastewater. In order to investigate the effect of vinasse on microalgae growth and also the effect of its growth on nitrogen and phosphate removal in a mixture of urban wastewater and vinasse, the growth of Spirulina platensis was studied.
Materials and Methods: Growth ability of spirulina in the urban wastewater and the effect of vinasse on growth rate was investigated by the calculation of biomass. The effect of concentration of vinasse, intensity of light and light-dark cycle on growth rate were studied by DESIGN EXPERT and CCD method. By selecting the optimized conditions, rates of nitrogen, phosphate and COD removal was investigated at the end of the growth period.
Results: The results showed that adding vinasse to wastewater increased the growth rate and the highest amount of biomass of 3.19 mg/mL was obtained in the sedimentary stream containing 0.25% vinasse. By evaluating the effect of vinasse concentration, intensity of light and light-dark cycle on growth rate, optimal conditions at vinasse concentration 0.4% (v/v), light intensity of 5000 lux and light period of 10 hours, 480 (mg/L) of biomass was obtained. The percentage of removal of nitrogen, phosphate and COD was 63%, 97% and 73% respectively.
Conclusion: The results of this study indicated the capability of urban wastewater and vinasse in order to replace Zarouk's culture medium for growth of Spirulina microalgae. These microalgae were able to remove high percentage of nutrients in the wastewater.
 

Background and Objective: Hospital wastes with the content of infectious, pathologic, sharp, pharmaceupitical and genotoxic materials are classified as hazardous wastes. Of which, genotoxic residues wirh mutagenic and teratogenic effects are of most great concern on human health. Genetic wastes are referred to as cytotoxic, chemical, and radioactive drugs used to treat cancer or treat transplantation. The purpose of this study was to evaluate the management of hospital wastes in Mazandaran province with emphasis on genotoxic waste.
Materials and Methods: This descriptive cross-sectional study was carried out in 35 governmental and social hospitals in Mazandaran province to determine the satus of hospital waste with focus on geotoxic waste. The quanity, quality and management approaches of hospital and genotoxic wastes in the studied hospitals were surveyed with a validated questionnaire. Results obtained from the present study were analyzed with Excel software.
Results: The average waste per each hospital bed was estimated to be 3.51 kilograms. Of which, 2.2, 1.24, 1.9 kg were categorized as municipal, chemical, and genotoxic wastes, respectively. The average of the hospital waste management index in Mazandaran province was found to be about 84 out of 100, indicating good management of these wastes. The management of genotoxic waste in 7 specialized chemotherapy hospitals was estimated to be 64 out of 100, indicating the average state of genotoxic waste management for these hospitals. In 28 non-chemotherapy hospitals, the genotoxic waste management index was approximated 42 out of 100, indicating poor management of these wastes.
Conclusion: The main weaknesses in hospital waste management are associated with the management of chemical-pharmaceutical and genotoxic wastes. Accordingly, improvement the quality of genotoxic and chemical-pharmaceutical wastes should be concerned in the future planning.
 

Background and Objective: Knowledge about the quantity of municipal solid waste (MSW) generation plays a key role in formulating policies of waste management. So far, different methods have been applied to estimate the quantity of waste generation. In this study, eight specific forms of mathematical functions were evaluated to predict waste generation by the regression analysis method based on population.
Materials and Methods: The significance test of each model and the existence necessity of predictor parameters were performed using the F- and t-statistic, respectively. The statistical indicators of determination coefficient ( ), adjusted determination coefficient ( ), root mean square error (RMSE), mean bias error (MBE) and mean percentage error (MPE) were used for model’s goodness of fit. The predicted determination coefficient ( ) was calculated to assess the predictive ability of models by method of Leave-one-out cross validation.
Results: The results showed that polynomial models of second order and more are not significant (at 0.01 level) despite good accuracy and are not suitable for long-term prediction. Linear, power and exponential models are best with equal to 0.942, 0.932 and 0.936 and  equal to 0.904, 0.893 and 0.898 respectively. However, the uncertainty was greater in the exponential model.
Conclusion: The status of waste generation was investigated in four scenarios based on growth rate of population (increasing, fixing and decreasing births) at Tehran metropolis in 2021-2051. In all scenarios, annual generation and per capita of waste are increased to 2051. The daily waste generation will increase to 12317 ton in 2051.