فهرست مطالب

Environmental Health Science and Engineering - Volume:1 Issue:2, 2004
  • Volume:1 Issue:2, 2004
  • تاریخ انتشار: 1383/04/20
  • تعداد عناوین: 12
  • M. Ebtekar Pages 1-7
    Persistent organic pollutants can be traced in air, water, soil and biota in industrialized and non industrialized regions. Although the production of these chemicals has been banned since 1980''s when their toxicity was proven, their use, trade and disposal as well as persistence due to previous use, continues to contaminate the environment and threaten human health. Recent studies on the immunological consequences of dioxin contamination and exposure indicate that these compounds and specifically 2, 3, 7, 8- Tetrachlorodibenzo-p-dioxin activates the aryl hydrocarbon receptor on lymphocytes. This activation results in an array of effects on T, B and APC cells, biological mediators of the immune response and thereby results in suppression or remodelling of the immune response. This review attempts to shed light on the recent research developments in this field and to provide insight into the vast and long term health consequences of persistent organic pollutants.
  • Z. Yousefi, Cm Davies, Hj Bavor Pages 8-15
    Constructed wetland and detention pond as a treatment system was applied for stormwater management in two adjacent areas in western Sydney. F-specific RNA and somatic coliphages were used as a model for assessing two systems for removal of viral pollution, fate, behavior and survival of viruses in the sediment. Water samples were collected weekly in sterile containers and sediment samples were collected three times using a box dredge sampler via a boat at the inlet, middle and outlet areas of the systems. F-specific RNA coliphages were enumerated using the double layer plaque assay (ISO 1995) with Salmonella typhimurium WG49 as a host. Survival test continued 28 d for each sub-sample. Viral removal in constructed wetland was more effective than the detention pond system. Survival of somatic coliphages in the inlet and middle of the systems was similar. Slope of declining for outlet of two systems was very slow and completely stable in whole of test duration. Constructed wetland may offer an attractive alternative to stormwater management for reducing the load of disease-causing viruses to the receiving waters.
  • M. Karamouz, N. Mahjouri, R. Kerachian Pages 14-27
    Karoon-Dez River basin, with an area of 67000 square kilometers, is located in southern part of Iran. This river system supplies the water demands of 16 cities, several villages, thousands hectares of agricultural lands, and several hydropower plants. The increasing water demands at the project development stage including agricultural networks, fish hatchery projects, and inter-basin water transfers, have caused a gloomy future for water quality of the Karoon and Dez Rivers. A good part of used agricultural water, which is about 8040 million cubic meters, is returned to the rivers through agricultural drainage systems or as non-point, return flows. River water quality zoning could provide essential information for developing river water quality management policies. In this paper, a methodology is presented for this purpose using methods of -mean crisp classification and a fuzzy clustering scheme. The efficiency of these clustering methods was evaluated using water quality data gathered from the monitoring sampling points along Karoon and Dez Rivers. The results show that the proposed methodology can provide valuable information to support decision-making and to help river water quality management in the region.
  • A. Amiriyan, M. Mazaheri Assadi, Va Saggadian, A. Noohi Pages 28-35
    The biosurfactants are believed to be surface active components that are shed into the surrounding medium during the growth of the microorganisms. The oil degrading microorganism Acinetobacter calcoaceticus RAG-1 produces a poly-anionic biosurfactant, hetero-polysaccharide bioemulsifier termed as emulsan which forms and stabilizes oil-water emulsions with a variety of hydrophobic substrates. In the present paper results of the possibility of biosurfactant (Emulsan) production by microorganisms isolated from Iranian oil reservoirs is presented. Fourthy three gram negative and gram positive, non fermentative, rod bacilli and coccobacilli shaped baceria were isolated from the oil wells of Bibi Hakimeh, Siri, Maroon, Ilam, East Paydar and West Paydar. Out of the isolated strains, 39 bacterial strains showed beta haemolytic activity, further screening revealed the emulsifying activity and surface tension. 11 out of 43 tested emulsifiers were identified as possible biosurfactant producers and two isolates produced large surface tension reduction, indicating the high probability of biosurfactant production. Further investigation revealed that, two gram negative, oxidase negative, aerobic and coccoid rods isolates were the best producers and hence designated as IL-1, PAY-4. Whole culture broth of isolates reduced surface tension from 68 mN /m to 30 and 29.1mN/m, respectively, and were stable during exposure to high salinity (10%NaCl) and elevated temperatures(120C for 15 min).
  • N. Jafarzadeh, S. Rostami, K. Sepehrfar, A. Lahijanzadeh Pages 36-42
    The purpose of this study was to build up a logic ranked pattern between the most important industrial activities with respect the type of water pollution and the discharge ways or managing the wastewaters in these units. For this purpose all of the statistical data have been gathered by referring to the responsible organizations. After that, by using the desk study, field work and selecting some of the industrial units as studied cases and by referring to their production processes and obtaining the curtained analytical results, the industries have been separated to several groups including Food, Textile, Pulp & Paper/, Chemical, Non-metallic mineral, Metal and Electricity & electronics Comparing the number of active industrial plants within the boundaries of Khuzestan province at 5 catchments area, indicates that Karun, Dez and Jarrahi basins with 1044. 324 and 290 active plants, respectively, are crowded with a lot of industries. Nature of the examined parameters has been selected in view of the production process type and includes pH, turbidity, electrical conductivity, chloride, sulfate, BOD, COD, TSS, iron. Results indicates that Dez river basin, being compared with the other two basins, impose the most degradable organic, nutrient substances and suspended particle loads to Dez River, and the metal pollution load at Karun basin is more than the other two basins, caused by the steel industries concentrated in Ahvaz city.
  • A. Parvaresh, H. Movahedian, L. Hamidian Pages 43-50
    Sludges are stabilized to reduce pathogens, eliminate offensive odors and inhibit, reduce or eliminate the potential for putrification. In this study, stabilization of municipal wastewater sludge with and without earthworms (Eisenia fetida) was tested in a pilot study. The earthworms were fed at the optimum level of 0.75 kg-feed/kg-worm/day. Decomposition and stabilization of wastewater sludge occurred both in the presence and in the absence of earthworms during 9 weeks but the process was accelerated in their presence. Phosphorus content increased in the sludge with earthworms but decreased in it without them. Nitrogen content in the resulting vermicompost showed no difference with its quantity in the original substrate while it increased in the control treatment.
  • A. Mirsepassi Pages 51-57
    The water industry is facing increased pressure to produce higher quality treated water at a lower cost. The efficiency of a treatment process closely is related to the operation of the plant. To improve the operating performance, an Artificial Neural Network (ANN) paradigm has been applied to a water treatment plant. An ANN which is able to learn the non-linear performance relationships of historical data of a plant has been proved to be capable of providing operational guidance for plant operators. A back-propagation network is used to determine the alum and polymer dosages. The results showed that the ANN model was most promising. The correlation coefficients (r) between the actual and predicted values for the alum and polymer dosages were both 0.97 and the average absolute percentage errors were 4.09% and 8.76% for the alum and polymer dosages, respectively. The application of the ANN model was illustrated using data from Wyong Shire Council’s Mardi Water Treatment Plant on the Central Coast of NSW.
  • B. Barkhordar, M. Ghiasseddin Pages 58-64
    avy metals are present in different types of industrial effluents, being responsible for environmental pollution. Biosorption is a promising alternative method to treat industrial effluents, mainly because of its low cost and high metal binding capacity. In this work application of Langmuir and Freundlich sorption models for chromium, copper and nickel biosorption process by Sargassum seaweed biomass was studied in batch system. The work considered the effects of some important parameters such as retention time and initial concentration on remained concentration of heavy metals. Dried Sargassum was contacted with metal solution on different retention times (10, 20, 30, 45 and 60 min) and variation of initial concentration (10, 25, 50, 75 and100mg/l) at constant pH and temperature. The obtained charts were linear for Langmuir and Freundlich equilibriums and their slopes and y-intercepts were calculated (Constants a, b, n, k). Results showed that the constants were in a same range; therefore Langmuir and Freundlich sorption models were in good agreement with experimental results.
  • A. Mohseni, Bandpi, H. Bazari Pages 65-69
    A bench scale aerobic Sequencing Batch Reactor (SBR) was investigated to treat the wastewater from an industrial milk factory. The reactor was constructed from plexi glass material and its volume was 22.5 L. The reactor was supplied with oxygen by fine bubble air diffuser. The reactor was fed with milk factory and synthetic wastewater under different operational conditions. The COD removal efficiency was achieved more than 90%, whereas COD concentration varied from 400 to 2500 mg/l. The optimum dissolved oxygen in the reactor was 2 to 3 mg/l and MLVSS was around 3000 mg/l. Easy operation, low cost and minimal sludge bulking condition make the SBR system an interesting option for the biological medium strength industrial wastewater treatment. The study demonstrated the capability of aerobic SBR for COD removal from dairy industrial wastewater.
  • Sj Shahtaheri, M. Abdollahi, F. Golbabaei, A. Rahimi, Froushani, F. Ghamari Pages 70-80
    Ethyl benzene is an important constituent of widely used solvents in industries and laboratories, causing widespread environmental and industrial pollutions. For evaluation of occupational exposure to such pollutants, biological monitoring is an essential process, in which, preparation of environmental and biological samples is one of the most time-consuming and error-prone aspects prior to chromatographic techniques. The use of solid-phase extraction (SPE) has been grown and is a fertile technique of sample preparation as it provides better results than those of liquid-liquid extraction (LLE). In this study, SPE using bonded silica has been optimized with regard to sample pH, sample concentration, elution solvent, elution volume, sorbent type, and sorbent mass. Through experimental evaluation, a strong anion exchange silica cartridge (SAX) has been found successful in simplifying sample preparation. The present approach proved that, mandelic acid could be retained on SAX sorbent based on specific interaction. Further study was employed using 10% acetic acid to extract the analyte from spiked urine and gave a clean sample for HPLC-UV system. In this study, a high performance liquid chromatography, using reverse-phase column was used. The isocratic run was done at a constant flow rate of 0.85 ml/min, the mobile phase was water/methanol/acetic acid and a UV detector was used, setting at 225 nm. At the developed conditions the extraction recovery was exceeded 98%. The factors were evaluated statically and also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments.
  • J. Nouri, R. Sharifipour Pages 81-90
    Execution of development and creation of appropriate points for rural development without considering ecological capability will result in the appearance of several environmental, economic and social problems. This research is done in an analysis approach frame of a system with the aim of choosing the most suitable location for rural development in Abadeh with an area of 22,000 km2. in 2002 by applying geographic information system (GIS) precious tools. Based on the above objective, ecological resources of concerned area were recognized and surveyed. The obtained data changed into digital figures and together with the other descriptive data were shifted to Arc/Info and Arcview systems for the purpose of creation of data base. Based on specific ecological models of Iran and special conditions of the area and by using structured query language (SQL) in Arcview, the ecological capability of concerned area for rural development was determined. By considering current natural limitations, such as limited severe earthquake danger in central areas, limitation of flood danger in some of the central and western areas, development of evaporating deposits and salt domes in east and precipitation under 500mm in the studied area, no suitable place for the first grade rural development was found. However, it showed capability for second-grade rural development aspect. This area includes 3.8% of total area of the studied place. For improving present management in the studied region, it is recommended that in future development of the region, offered appropriated points while emphasizing on the land having low production capability to be considered.
  • H. Ganjidoust, B. Ayati Pages 91-96
    Wood fiber industries are producing large amounts of wastewater, which are discharged into the environment everyday. This type of wastewater with high pollution potential in suspended solids, COD and color, are required to be treated before entering to the receiving environment. North part of Iran is covered by huge land of forests. Several pulp and paper industries are located in the area. One of these industries is Iran Wood Fiber Company in which many researches have been done in both laboratory and pilot scale by the main author in recent years. One of the studies was to investigate the Sequencing Batch Reactors (SBRs) efficiency for treating the wastewater. Considering parameters such as influent COD, detention time, nutrient concentration, and their effects on COD, turbidity and total solids removal efficiency of the system, four serial SBRs in laboratory scale were investigated. The results of the system with 10 hours detention time, 1000-2500 mg/L COD and 100:5.1:1 C/N/P had the best efficiency with 92, 84, 52 percent removal for COD, turbidity and total solids, respectively. Pilot scale plant studies using SBRs were also done in the company. The results indicated good removal efficiencies that also discussed in this paper.