Iranian Journal of Environmental Health Science and Engineering
Volume:4 Issue: 2, Spring 2007

A total of 7690 tons of municipal solid waste generated daily at the six major cities of Bangladesh, namely, Dhaka, Chittagong, Khulna, Rajshahi, Barisal and Sylhet, as estimated in 2005. Sampling was done at different waste generation sources such as residential, commercial, institutional and open areas, in different seasons. The composition of the entire waste stream was about 74.4% organic matter, 9.1% paper, 3.5% plastic, 1.9% textile and wood, 0.8% leather and rubber, 1.5% metal, 0.8% glass and 8% other waste. The per capita generation of municipal solid waste was ranged from 0.325 to 0.485 kg/cap/day while the average rate was 0.387 kg/cap/day as measured in the six major cities. The potential for waste recovery and reduction based on the waste characteristics are evaluated and it is predicted that 21.64 million US$/yr can be earned from recycling and composting of municipal solid waste.

Feasibility of the anaerobic baffled reactor process was investigated for the treatment of wheat flour starch wastewater. After removal of suspended solids by simple gravity settling, starch wastewater was used as a feed. Start-up of a reactor (with a volume of 13.5 L and five compartments) with diluted feed of approximately 4500 mg/L chemical oxygen demand was accomplished in about 9 weeks using seed sludge from anaerobic digester of municipal wastewater treatment plant. The reactor with hydraulic retention time of 72h at 35°C and initial organic loading rate of 1.2 kgCOD/m3.d showed 61% COD removal efficiency. The best performance of reactor was observed with an organic loading rate of 2.5 kgCOD/m3.d or hydraulic retention time of 2.45 d and the COD conversion of 67% was achieved. The system also showed very high solids retention with effluent suspended solids concentration of about 50 mg/L for most organic and hydraulic loadings studied. Based on these observations, the ABR process has potential to treat food industrial wastewater as a pretreatment and is applicable for extreme environmental conditions.

Arsenic contamination in water poses a serious threat on human health. The tea fungus known as Kombucha is a waste produced during black tea fermentation. The objective of this study was to examine the main aspect of a possible strategy for the removal of arsenates employing tea fungal biomass. The pretreatment of biomass with FeCl3 was found to improve the biosorption efficiency. Arsenics uptake was found to be rapid for all concentrations and reached to 79% of equilibrium capacity of biosorption in 20 min and reached equilibrium in 90 min. The pseudo second-order and first-order models described the biosorption kinetics of As (V) with good correlation coefficient (R2>0.93) and better than the other equations. The data obtained from the experiment of biosorption isotherm were analyzed using the Freundlich and Langmuir isotherm models. The equation described the isotherm of As (V) biosorption with relatively high correlation coefficient (R2>0.93). According to the Langmuir model, the maximum uptake capacities (qm) of tea fungal biomass for As (V) were obtained 3.9810-3 mmol/gr. The effect of Na, K, Mg and Ca on equilibrium capacities of As was not significant. The variation of sorption efficiency with pH showed that optimum biosorption takes place in the pH ranges of 6 to 8. Promising results were obtained in laboratory experiments and effective As (V) removals were observed.

The carotenoid pigments specifically astaxanthin has many significant applications in food, pharmaceutical and cosmetic industries. The goal of this research was the extraction of Astaxanthin from a certain Persian Gulf shrimp species waste (Penaeus semisulcatus), purification and identification of the pigment by chemical and microbial methods. Microbial fermentation was obtained by inoculation of two Lactobacillus species Lb. plantarum and Lb. acidophilus in the medium culture containing shrimp waste powder by the intervention of lactose sugar, yeast extract, the composition of Both and the coolage (-20oC). The carotenoids were extracted by an organic solvent system. After purification of astaxanthin with the thin layer chromatography method by spectrophotometer, NMR and IR analysis the presence of astaxanthin esters was recognized in this specific species of Persian Gulf shrimp. Results obtained from this study showed that the coolage at –20 oC not only does not have an amplifying effect on the production of astaxanthin but also slightly reduces this effect. Also the effect of intervention of lactose sugar showed more effectiveness in producing astaxanthin than yeast extract or more than with the presence of both. The results also indicated that there is not much difference in the ability of producing the pigment by comparing both Lb. plantarum and Lb. acidophillus. Also results showed the microbial method of extraction of astaxanthin is more effective than chemical method. The pigment extracted from certain amount of shrimp powder, 23.128 mg/g, was calculated.

The Karun and Dez rivers basin are the largest rivers basin in Iran which are situated in the south west of the country. Karun River originates from Zagros mountain ranges and passing through Khuzestan plain, reaches the Persian Gulf. Several cities lie along its path of them the most important is Ahvaz, the center of Khuzestan province. To achieve water quality goals in Karun and Dez rivers, a water quality management model has been developed through the GIS approach and a mathematical water quality model. In Karun and Dez rivers, water quality has decreased due to heavy pollution loads from Khuzestan province cities and surrounding areas. In this survey, pollution sources, land use, geographic features and measured water quality data of the river basin were incorporated into the Arc-view geographic information system database. With the database, the model calculated management type and cost for each management project in the river basin. Until now, river management policy for polluted rivers in Iran has been first of all to get penalties from pollution sources and secondarily, to construct treatment plants for the pollution sources whose wastewater is released untreated and for which the wastewater quality goal of the Iranian Department of the Environment is not met. Different management projects with a time program were proposed and they were compared with the results of the river quality without any management approach. It became clear that the results based on the management approach were much better than those for the unmanaged condition from the viewpoint of the achievement of water quality goals and cost optimization.

For biological treatment of water, there are many different biofilm systems in use. Examples of them are trickling filters, rotating biological contactors, fixed media submerged biofilters, granular media biofilters and fluidized bed reactors. They all have their advantages and disadvantages. Hence, the Moving Bed Biofilm Reactor process was developed in Norway in the late 1980s and early 1990s to adopt the best features of the activated sludge process as well as those of the biofilter processes, without including the worst. Two cylindrical moving bed biofilm reactors were used in this study working in upflow stream conditions. Experiments have been done in aerobic batch flow regime. Laboratory experiments were conducted at room temperature (23–28C) and synthetic wastewater comprising a composition of phenol and hydroquinone in each reactor as the main organic constituents, plus balanced nutrients and alkalinity were used to feed the reactor. The ratio of influent to effluent COD was determined at different retention times. The results indicated that the removal efficiency of each selected compound is affected by the detention time. At low phenol and hydroquinone concentration (from 700 to 1000 mg/L) maximum removal efficiency (over 80 %) was obtained. By further increasing in COD loading rate up to 3000 mg/L, a decrease in COD removal rate was occurred. In the reactor containing pyrogallol in COD of 1500 mg/L, the removal rate decreased to 10 percent because of its toxicity for microorganisms.

Noise is one of the most serious challenges in modern community. In some specific industries, according to the nature of process, this challenge is more threatening. This paper describes a means of noise control for spinning machine based on experimental measurements. Also advantages and disadvantages of the control procedure are added. Different factors which may affect the performance of the barrier in this situation are also mentioned. To provide a good estimation of the control measure, a theoretical formula is also described and it is compared with the field data. Good agreement between the results of filed measurements and theoretical presented model was achieved. No obvious noise reduction was seen by partial indoor barriers in low absorbent enclosed spaces, since the reflection from multiple hard surfaces is the main dominated factor in the tested environment. At the end, the situation of the environment and standards, which are necessary in attaining the ideal results, are explained.

At this study, an environmental impact assessment establishment of Shahzand Industrial Estate in Arak at the central part of Iran was investigated. After collection of data and analysis of the findings, the positive and negative impacts resulted from establishment of the industrial estate were investigated, using the Leopold Matrix and Scaling checklist methods providing the managerial solutions in order to minimize the environmental harmful impacts. The existing environmental situation was investigated and then environmental impact alternatives were determined. This was done regarding to the amount and kind of predicted pollutions for industrial estate at the construction and operational phases. The environmental impact assessment of the investigated estate was studied at the three terms of immediate, direct and indirect impacts at the short, medium and long term. By expanding of Leopold Matrix to four parted matrix, in addition to amount, importance and extend of the impacts, the remaining duration of impact in the environment were assessed as a separate factor in environmental impact assessment. The results of the study with two alternatives, such as; No (performance of the project with no concern for environmental issue) and as yes (performance of the project with application of the environmental harmful impacts) were studied in construction and operation phases. The impact assessment of "NO" property resulted (-1065), therefore the execution of project was rejected, but after reducing the harmful impact performance which were resulted (O×) has been accepted. Therefore, method of reducing harmful environmental impacts along with environmental management programs introduced and accepted in this study.

The present study investigates the removal of pesticide by electrocoagulation process. A glass tank in 1.56 L volume with four iron plate electrodes was used to perform the experiments. The electrodes connected to a DC power supply (bipolar mode). The tank was filled with synthetic wastewater were which contained diazinon pesticide in concentration of 10, 50 and 100 mg/L. The percent of diazinon removal was measured at pH= 3, 7 and 10 and in electric potential range of 20-40V by thin layer chromatography method. The results indicated that initial concentration of diazinon can affect efficiency removal and for higher concentrations of diazinon, higher electrical potential or more reaction time is needed. The results showed that for a given time, the removal efficiency increased significantly with increase of voltage. The highest electrical potential (40V) produced the quickest treatment with >99% diazinon reduction occurring after 60 min. The final pH for iron electrodes was always higher than initial pH. Finally it can be concluded that electrocoagulation process (using iron electrodes) is a reliable, efficient and cost-effective method for removal of diazinon from aqueous environments, especially designed for pH=3 and voltage=40V.

This study investigated the relationship between Useful Field of View and simulator-driving performance measures. Ninety professional drivers, aged 22-65 years from several government organizations voluntarily participated at this study. Useful Field of View was measured by a computerized task was developed at the present study. The participants then performed a driving simulator task and experienced a scenario that could lead to an accident. Reaction time and speed were measured and recorded by simulator and general driving performance and collision events were recorded by examiner. The reduction of Useful Field of View based on subject’s error score on Useful Field of View subtests between young and old group statistically was analyzed. Correlation analyses used to examine the relationship among the Useful Field of View as an independent variable and driving performance measures as a dependent variables. A univariate logistic regression analysis was used to determine the extent to which reduction of Useful Field of View predicts risk of accident in simulated car driving. There was a significant and negative correlation between Useful Field of View and simulator performance, on the divided peripheral subtest (Correlation Coefficient=-0.28). Student’s t-tests revealed significant differences in peripheral scores of Useful Field of View subtests between accident involved and non-involved groups. The result of logistic regression indicated that 40% reduction of Useful Field of View, regardless of age, increased risk of accident involvement. Useful Field of View could be used to predict driving performance and risk of accident. The obtained result can help to identify a high risk driver which is useful to licensing authorities.