[Environmental ranking of industries located at west of Tehran based on the quantitative and qualitative characteristics of industrial wastewaters in 2011]

This is a descriptive and cross sectional study. The aim of this study was to investigate the environmental ranking of industries located at west of Tehran based on the quantitative and qualitative characteristics of industrial wastewaters in 2011. This study was conducted by site visit, questionnaire completion, database production and results analysis. The questionnaire was consisted of 30 questions about quantity, quality and management of industrial wastewater. Total number of industries with over than 50 personnel, was 287. Class-weighted sampling was used and the sample size was contained 50 industries. In this study, industries were scored from 1 to 10, based on the flow rate, BOD and COD, generation of wastewater per worker per day and then were ranked according to the total score. The average flow of wastewater generated by these 50 industries was 9422 m[3]/day. Wood and cellulose industries with 730 liters wastewater per worker per day was considered as the greatest wastewater generator. Minimum organic loading was related to non-metallic mineral industries with COD of 205 mg/ L and BOD of 85 mg / L. The maximum COD was related to paper industries with the rate of 8800 mg/ L and maximum BOD was related to food and drug industries with the rate of 1536 mg/ L. This environmental ranking was indicated that while paper industries contributed the most pollution load, non-metallic mineral industries had the least pollution load.

[ effect of solid waste compost on leaching and adsorption of heavy metals from silt-loamy soils]

Leaching of nutrients and heavy metals from municipal solid waste compost leads to accumulation of certain elements in soil layers, causing underground water pollution. The objective of this study was to investigate the effect of compost on leaching and adsorption of heavy metals and nutrients [sodium, potassium, and sulfate] from silt-loamy soils. In this empirical, applied study, three polyethylene columns [height 50 cm, inner diameter 10 cm], filled with sandy clay loam soil, were randomly selected. Then, 10 kg of compost per square meter were sprayed onto the columns, and leachates exiting the columns were routinely analyzed for pH, electrical conductivity, sulfate, sodium, potassium, lead, chromium, and cadmium. Data analysis was performed with Excel and SPSS software using Kruskall-Wallis test. The data showed that the use of enriched and unenriched compost leachate decreased pH [from 7.43 +/- 17.0 to 6.7 +/- 0.25 and 7.07 +/- 0.11, respectively] and increased the electrical conductivity [EC] [from 1.8 +/- 0.3 mSiemens/m to 3.7 +/- 0.12 and 12.87 +/- 0.41 mSiemens/m respectively]. Leakage of metals in the unenriched treatments was not significantly different from the control [p > 0.78], but leakage with three metal-enriched compost applications was significant compared with control [p < 0.001]. Application of composts containing heavy metals onto loamy soils increases leaching of heavy metals from the compost into groundwater. Therefore, frequent use of compost endangers groundwater quality

[Investigation of industrial waste management in industries located between Tehran and Karaj zone in 2009-2010]

In recent years, poor industrial waste managements have created many crises in human societies. The aim of this study was to investigate industrial waste management located between Tehran and Karaj zone in 2009-2010. This study is descriptive and sectional which was done by site visits, [Iranian environmental protection organization] use of questionnaires, database production and results analysis. The questionnaire consisted of 45 questions mainly about industrial waste; quantity, quality and management. Total number of industries with over 50 personnel's, calculated as 283. Class-weighted sampling was used in which the sample size contained 50 industries. Total generated industrial waste was 123451, kg per day. Major hazardous waste generated in industrial sections included: chemical and plastic making. About 45.28% of waste generated disposed by private sectors. Landfill with 62% and reuse with 17% were the first and second alternative of common methods for final disposal of solid waste in this zone. In order to reduce hazardous waste generation in this zone, reuse and recovery maximization of the waste must be noted in short-term. In long-term, some industries such as chemical-plastic and electronics which have high rate of hazardous waste production must be replaced with other industries with low rate production, such as wood-cellulose and paper industries

[Quantitative and qualitative investigation of industrial solid waste in industrial plants located between Tehran and Karaj]

Rapid population growth, industrial development, urbanization culture propagation and excessive material consumption are the most important factor which caused over increasing of municipal, industrial and agricultural waste in human society. Inappropriate disposal of generated waste in recent years created several environmental menace and crisis in human society. For investigation about existent situation of industrial waste generation questionnaire had been used. This questionnaire was catered by Iran environmental protection organization. Aforementioned questionnaire contained 45 questions about combination, quality and quantity of industrial waste. Total number of more than 50 personnel industry was 287. But sample contained 50 randomly selected industries. Gathered data have been analyzed with SPSS 18. Total generated industrial waste was 123451KG per day which had volume equal to 781 cubic meters per day. Generated waste capitation per every worker was 5.8 KG. Maximum frequency of industrial was related to machinery and equipment group which maximum generated waste was related to this industrial group too. Maximum hazardous waste was for inflammable waste with 34 weight percent. Major hazardous waste generating industrial was chemical and plastic making industry. Yielded result from this investigation has shown that significant relation existed between waste production rate and personnel number. The more personnel are, the more waste production increase

[Optimization of propylene removal in a complete mixed activated sludge bioreactor by Taguchi method]

Exposure to propylene glycol can lead to many health risks on blood, skin and kidney. Biodegradation of synthetic wastewater containing propylene glycol was studied in a continuous conventional activated sludge bench scale reactor. Optimum conditions of microorganisms growth for biodegradation of propylene glycol were determined by Taguchi method. Primary microorganisms for start up of the bioreactor were obtained from sludge return line of a municipal wastewater treatment plant and adapted to different concentrations of propylene glycol in a conventional activated sludge reactor. Optimum growth conditions of microorganisms and also operational conditions of the system including pH, influent COD, source of nitrogen and salinity were determined in three levels by Taguchi method. COD removal efficiency in conventional activated sludge reactor for influent concentrations of 400, 700, 900, 1100 and 1300 mg/L were 98%, 95%, 95%, 90% and 85% respectively. Optimization of the process by Taguchi method showed that source of nitrogen urea, pH = 8, salinity of 8% and influent COD of 1300 mg/L with importance priority of 41%, 25%, 17.11% and 16.142% were as optimum growth conditions of microorganisms and also, operational conditions of the system for propylene glycol biodegradation respectively. According to the results obtained from this work, it can be concluded that optimum conditions of biological processes and improvement the efficiency of bioreactors can simply be done by the use of such experimental designs

[Biological removal of propylene glycol from wastewater and its degradation in soil by the activated sludge consortia]

Propylene glycol is the main compound of anti-freezing chemicals. A significant amount of propylene glycol is released to the environment after application and contaminates the soil. The main objective of this study was to determine the biological removal of propylene glycol from wastewater and its degradation in soil by the isolated bacteria from activated sludge process. In the present study, the sludge taken from the return flow in a local activated sludge treatment system was used as the initial seed. The performance of the bioreactor in treating the wastewater was evaluated at four different retention times of 18, 12, 6 and 4 h, all with the inlet COD concentration of 1000 mg/L. This phase lasted around 4 months. Then, a part of the adapted microorganisms were transported from the bioreactor to the soil which was synthetically contaminated to the propylene glycol. The average of propylene glycol removal efficiency from the wastewater in detention times of 18, 12, 8 and 4 h in steady state conditions was 98.6%, 97.1%, 86.4% and 62.2% respectively. Also, the maximum degradation in soil was found to be 97.8%. According to the results obtained from this study, it appears that propylene glycol is inherently well biodegradable and can be biodegraded in liquid phase and soil after a short period of adaptation

Optimization of bacteriological quality of biosolids by lime addition

Lack of well-stabilized biosolids is a basic problem for many municipal wastewater treatment plants in Iran. Disposed biosolids from west Ahvaz wastewater treatment plant were generally used for agricultural activities. Initial evidence showed that these biosolids were untreated and had the potential to transmit many pollutants to the environment and create hazards for public health, although anaerobic digester was selected for this wastewater treatment plant. The main objective of this research was to evaluate and optimize the bacteriological quality of biosolids by lime addition in west Ahvaz wastewater treatment plant. The stability and reuse potential of biosolids from existing anaerobic digester and lime added biosolids were investigated. Lime addition to biosolids was performed in the reactor with 30 L capacity. Averge amounts of fecal coliforms and viable helminthes ova in disposal biosolids from anaerobic digester were 1.3'1015 MPN / g of dry solids and 314 ova / 4 g of dry solids, respectively. By lime addition with the ratio about 0.265 g Ca [OH]2 per g of dry solids, pH was not dropped under 12 and growth of fecal coliform was not detected after 30 days. In this regard, discharged biosolids from this plant was unstable and very dangerous for reuse or disposal. Lime addition could stabilize the biosolids and reduce fecal coliforms more than 99.99% and had concordance with class B of United State Environmental Protection Agency criteria. Lime-stabilized biosolids could hence be well used for reconditioning the poor soil and for covering of solid waste landfill-sites

[Survey of phenantherene biodegradation's model in contaminated soils by Acinetobacter sp]

Polycyclic aromatic hydrocarbons [PAHs] are a group of hazardous pollutants which have carcinogenic and mutagenic properties and accumulated in environment by different actions, therefore treatment of them is important. Biological treatments are simple and cheep technologies. This technology was recommended as a cost- effective method for treatment of these pollutants. In order to investigate the trend of pollution reduction of petroleum hydrocarbons in bioremediation, the phenanthrene biodegradation's model in contaminated soils was studied. Firstly, PAHs capable degrading bacteria was isolated from petroleum contaminated soils and then their ability for biodegradation of phenanthrene was assessed in slurry phase. After that by using Acinetobacter which have the most potential of removing phenanthrene from soil, the biodegradation model was investigated in bench scale. Phenantherene removal efficiency was obtained 99.4% for 100 mg/kg and 96% for 500 mg/kg concentrations in 33 and 60 days biodegradation period respectively. Phenantherene reduction rate varied from 2.99 to 8.86 and 1.4 to 11.09 mg/kg/day for 100 and 500 mg/kg concentrations, respectively. Rate of phenantherene removal is depended on primary concentration of contamination and by increasing of primary concentration, phenantherene removal rate was increased. Also removal efficiency followed zero and first order kinetic model with good correlation

[Study on the quality and comparing of the compost produced by Khomain and Tehran compost factories]

Over than 70% of solid wastes is consisted of food wastes with high putrecibility in Iran. Due to this regard, construction of composting factories for sanitary disposal or fertilizer production from solid wastes was very appreciated in our country. The objective of this research was to study on the quality and comparing of the compost produced by Khomain and Tehran compost factories. This study was accomplished on the compost produce from Khomain and Tehran compost factories about 9 months. For investigation of chemical qualities of these materials, some indexes such as percentage of organic materials, carbon, nitrogen, phosphorus, potash and heavy metals consists of lead, cadmium, mercury and chromium were measured. Microbial quality of these compost materials were defined by assessing of the amounts of coliforms bacteria, salmonella bacteria and parasites ova. The average amounts of some indexes in compost of Khomain and Tehran were been: organic materials% [37.77, 29.80], carbon%[22.14, 18.12], nitrogen% [2.08, 1.6], lead [229.6, 59.44 ppm], and chromium [70.2, 19.75], respectively. The microbial quality of these compost samples were agreement with class B of USEPA guidelines. This study showed that quality of organic materials percent in Tehran's samples was better than Khomain's samples, but these indexes on these samples were lower than the grade No.2 of compost. The percentage of carbon, nitrogen and potash in these samples were desirable but, phosphorus amount were not in sufficient. The heavy metals especially lead and chromium in Tehran's samples were higher than Khomain's samples, but these samples were usually in agreement with guidelines of compost. Due to the defined microbial qualities, these samples could be used as well as amendment agents for poor soil