Mohammad Hadi Abolhasani; Niloofar Pirestani; Parinaz Ahmadi
Abstract
Background and Aim: Petroleum products such as crude oil, gasoline and gasoline are the most commonly used in the world, the major pollutants of water. About 10 million tons of oil are burnt annually in the world. Therefore, the development of new technologies for the elimination and purification of ...
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Background and Aim: Petroleum products such as crude oil, gasoline and gasoline are the most commonly used in the world, the major pollutants of water. About 10 million tons of oil are burnt annually in the world. Therefore, the development of new technologies for the elimination and purification of oil pollution is essential. There are several methods for cleaning up oil pollution and its derivatives. In this research, straw and chalk absorber was used as an organic adsorbent to remove diesel oil from wastewater. Materials and method: The straw and chalk were firstly determined using the FT-IR analysis. Then the adsorption experiments were performed discontinuously using diesel oil laboratory solutions. Optimum adsorption conditions were obtained by changing the factors affecting adsorption including pH, initial concentration of contaminant, contact time and adsorbent amount on adsorption at different levels, The oil absorption was determined by weighting method. Ultimately, the use of adsorbent for laboratory wastewater was studied. Results: The highest absorbent efficiency at the time of equilibrium was observed for absorbing oil using straw and chalk absorber in 15 minutes, which did not have a significant difference with other contact times (49.85% absorbance, p < 0.05) and the lowest value was observed without a significant difference in 3 minutes (37.19% absorption). The effect of straw absorbent values in 2 g/L was significantly higher than other amount of adsorbents (51.48% absorption, p < 0.05) and the lowest percentage of adsorption was significantly different from other values in 0.25 And 0.5 grams per liter (38.30%, p < 0.05). The fitting of Isotherm showed that the adsorption of diesel oil by straw and chalk with both Freundwich and Langmuir models were consistent with the high R2 (R2 = 0.99 and R2 = 0.96).
saman mousavi; Ahad Sotoudeh; Hamidreza Azimzade; Bahman Kiani
Abstract
Background and Objectives: Environmental management system attempts to create and pursue requirements for the organizations to prevent catastrophic damages causing to their surroundings. One of the most important environmental aspects of thermal power plants is the impact on water resources. Moreover ...
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Background and Objectives: Environmental management system attempts to create and pursue requirements for the organizations to prevent catastrophic damages causing to their surroundings. One of the most important environmental aspects of thermal power plants is the impact on water resources. Moreover to high level consumption, the produced wastewaters will added to other pollutants. Methods: The produced wastewater from the combined cycle power plant was monitored during one year. To compare pollutants from industrial wastewater with environmental standards, Kolmogorov–Smirnov’s test was employed. The main aspects of wasting and contaminating consumed water resources of power plant has been studied by using Preliminary Hazard Analysis and William fine techniques. Also the effective actions were performed to decrease and monitor the determined aspects. Results: The results have been showed that industrial wastewater has not any heavy elements contamination with 99 percent of certainty. Among the effective risks on water resources, 77 risks with low priority, 60 risks with medium priority and 12 risks with high priority has been identified. The chemistry refinery’s section and steam’s unit had the most identified risks. Among the risk controlling strategies, reducing risk’s intensity with 73 percent is the most effective strategy. Also, 14 percent of strategies refer to exclusion, 10 percent to transfer and three percent to acceptance of risk Conclusion: Combining risk assessment methods and environmental pollutants concentration measurements could increased the accuracy and validity of the results by systemizing the identification process.
Soheil Sobhanardakani; Samireh Mahmodnezhad; Masoumeh Heydari
Abstract
Background & Objective: Heavy metals being among the major pollutants of aquatic ecosystems are considered as high-toxicity pollutants for organisms due to the non-biodegradable and persistent potential in the environment. Therefore, this study was carried out to analyse the presence of heavy metals ...
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Background & Objective: Heavy metals being among the major pollutants of aquatic ecosystems are considered as high-toxicity pollutants for organisms due to the non-biodegradable and persistent potential in the environment. Therefore, this study was carried out to analyse the presence of heavy metals (Zn, Cd, Cr and Cu) in water of Marivan River in 2013. Material & Methods: In this cross-sectional study, forty samples were taken from five selected stations during spring and summer seasons in 2013. After taken samples preparation, the concentrations of metal ions were investigated by spectrophotometry with three replications. All statistical analyses were performed using the SPSS 19.0 statistical package (p<0/05). Results: The results showed that the mean concentrations of metals (µg/l) in water samples for spring season were equal to 26.20±11.34, 0.73±0.06, 1.50±0.11 and 121.10±14.05 for Zn, Cd, Cr and Cu, respectively and in water samples for summer season were equal to 27.10±24.72, 0.72±0.05, 1.50±0.16 and 123.80±31.27 for Zn, Cd, Cr and Cu, respectively. Also, the mean concentrations of the evaluated metals compared with WHO and Iran DOE permissible limits showed a significant difference (P<0.05). That is, the mean concentrations of Zn, Cd, Cr and Cu were significantly lower than the permissible limits in both spring and summer seasons. Conclusion: Although the water of Marivan River was not contaminated to heavy metals during the study period. But due to the establishment and development of industrial, urban and agricultural activities along the river and its uncontrolled discharges of wastewater into the river, pollution and decrease of water quality in the near future is not unexpected.
Mahdi Sadeghi; Kaveh Khosravi; Seyed Mostafa Khezri; Abotaleb Bay
Abstract
Background and objective: Today, with the development, the need for water in the production processes is increasing and so we have sewage with high level of pollution. This study aimed at determining the effectiveness of electrocoagulation for treatment of dairy industry wastewater in a continuous flow ...
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Background and objective: Today, with the development, the need for water in the production processes is increasing and so we have sewage with high level of pollution. This study aimed at determining the effectiveness of electrocoagulation for treatment of dairy industry wastewater in a continuous flow (case study wastewater of Sabah cheese factory Gonbad-e Qabus). Materials & Methods: This study was descriptive and analytical with experimental approach. The samples were collected from Sabah dairy factory and put into the electrocoagulation reactor with continuous flow. At retention times of 20, 40 and 60 minutes with an electric current of voltages 20, 40 and 60 were purged. The samples were carried to the laboratory and various tests of COD, BOD, pH, turbidity, nitrate and phosphate were done. Then the results were compared and analyzed. Results: The mean of COD, BOD, nitrates, phosphorus and turbidity was 4933 ± 231, 600 ± 50, 48.6 ± 14.8, 28 ± 0.7 mg/L and1329 ± 297.6 NTU respectively. The most removal efficiency of these parameters during the study was 84.62, 66.67,55, 54.2 and 85.1 percent respectively. Conclusion:This study showed that electrocoagulation process as a pre-treatment process can remove organic matters, turbidity and nutrients. It can also reduce organic load and increase wastewater biodegradability and it can be an effective option for treating wastewater effectively and thereby preventing pollution in our environment and water resources.
Nasrin Abdollahi; Mohammad Hadi Dehghani; Kazem Nadafi; Fazlollah Changani; Amir Hossein Mahvi; Niaz Mahdi Esfahani
Abstract
Background and objective: Oil and grease causes damages for aquatic organisms, soil ecosystem, and mutagenic and carcinogenic for human. The aim of this research was to study the reduction of pollution of oil and grease of steel mill wastewater with Air Flotation system. Materials and Method: At first ...
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Background and objective: Oil and grease causes damages for aquatic organisms, soil ecosystem, and mutagenic and carcinogenic for human. The aim of this research was to study the reduction of pollution of oil and grease of steel mill wastewater with Air Flotation system. Materials and Method: At first phase of this examination the sampling performed of raw wastewater for determine amount of oil and grease, COD, TS, TDS, TSS, Turbidity and Alkalinity. The second phase flotation with dispersed air performed at pilot vessel and the second sampling performed for determinationof removal efficiency of oil and grease in 3 different concentration and 4 different retention time and measured for other parameters in best concentration and retention time. Results: The retention time were selected 30, 45, 60 and 90 min and concentrations were 591 mg/l, 386 mg/l and 277 mg/l. removal efficiency for parameters of oil and grease, COD, TS, TDS, TSS, Turbidity, Alkalinity, obtained %48, %46, %37, %36, %82, %89, %6. Conclusion: This study showed with increases of retention time from 30minute to 90minute removal efficiency for all of parameters gently increased but between 60 and 90 minute retention time removal efficiency was almost stable. Removal efficiency in high concentration of oil and grease(591mg/l) was more than removal efficiency in low concentration of oil and grease (277mg/l). Paper type: Research article
Golamreza Mousavi; Ahmad Allah-Abadi; Yahya Jalili Darbandi
Abstract
Background & Objectives: With the increasing trend of imports and exports in the country, the number of transport vehicles is also growing at the customs gates across the world. This causes the wastewater disinfection gates to increase in number at the borders of a country. Du to a cationic detergent ...
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Background & Objectives: With the increasing trend of imports and exports in the country, the number of transport vehicles is also growing at the customs gates across the world. This causes the wastewater disinfection gates to increase in number at the borders of a country. Du to a cationic detergent called Benzalkonium chloride, the wastewater produced in these places is not biologically treatable. Therefore, advanced oxidation methods are considered as a viable option for treating the wastewater. In aspect-oriented programming (AOP), catalytic ozonation with activated carbon is regarded as an efficient method of disinfection. The present study aimed to determine the optimal conditions of using activated carbon produced from agricultural waste and activated with NH4CL as a heterogeneous catalyst with Ozone. Methods: In this study, the chemical quality of wastewater was evaluated at the disinfection customs gate of Lotf Abad Using single and catalytic ozonation by NH4Cl-induced activated carbon obtained from agricultural waste as the base material, COD removal was performed in a 200cc continuous reactor. The studied variables were pH, catalyst concentration and the reaction time. In the catalytic ozonation, single absorption and the synergistic effect of the catalysts were also investigated. Results: According to the results of the present study, with the ozone dose of 1 mg/min of alkaline pH in 30 minutes, single ozonation was able to remove only 39.7% of COD while catalytic ozonation with 0.1 g/L of carbon catalyst concentration in the same condition removed 66.8% of COD creating a 13.6% of synergistic effect as well. Conclusion: Activated carbon with NH4CL could noticeably increase the oxidation with ozone. Thus, it could be used as a catalyst in the ozonation reactor in order to remove COD from wastewater. Paper Type: Research Article
Mohammad Reza Alipoor; Hossein Alidadi; Ali Asghar Najafpoor; Roya Peiravi; Hadi Rahmatiyar
Abstract
Background and objective: Industrial developments and urban sprawl have led to the production of huge proportions of wastewater. Wastewater is potentially harmful for humans and it has remarkably adverse effects on the natural environment. With regard to the importance of preserving health and protecting ...
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Background and objective: Industrial developments and urban sprawl have led to the production of huge proportions of wastewater. Wastewater is potentially harmful for humans and it has remarkably adverse effects on the natural environment. With regard to the importance of preserving health and protecting the natural resources against pollution, this study aimed to evaluate the performance of wastewater stabilization ponds in the wastewater treatment plant of Olang, Mashhad. Methods: This cross‐sectional study examined the raw wastewater and effluent of Olang treatment plant from 2011 to 2012. Weekly sampling as well as BOD5, COD and TSS tests were conducted according to the standard methods. The collected data were analyzed by SPSS software, one‐way ANOVA and one‐sample t‐test at a significance level of 0.05. Results: In 2011, the average concentration of BOD5, COD and TSS in the effluent was 75±30.67, 145±19.46 and 86±13.28 mg/L, respectively. In addition, their treatment efficacy was 79.79±10.77%,82.53±4.57% and 77.17±3.92%, respectively. The figures were respectively 83±14.08, 146±23.72 and 109±14.73 mg/L and 82.7±5.11%, 82.82±3.82% and 78.46±3.93% in 2012. Conclusion: The effluent could be used for agricultural irrigation since its features are compatible with the standard parameters. Paper Type: Research Article