فهرست مطالب

Environmental Health Science and Engineering - Volume:4 Issue: 1, Winter 2007

Iranian Journal of Environmental Health Science and Engineering
Volume:4 Issue: 1, Winter 2007

  • 66 صفحه،
  • تاریخ انتشار: 1386/04/25
  • تعداد عناوین: 10
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  • N. Susithra, N. Jothivel, P. Jayakumar, V. I. Paul Pages 1-8
    Sublethal cadmium chloride (0.3 ppm) toxicity induced stress related morphopathological alterations in the accessory respiratory organ of the air-breathing catfish Heteropneustes fossilis (Siluriformes; Heteropneustidae) have been investigated at various intervals of exposure. The histopathological manifestation of the cadmium toxicity includes bulging of the hyperemic secondary lamellae into the lumen of the accessory respiratory organ, necrosis and sloughing of the respiratory epithelium leading to haemorrhage and fusion of SL at various stages of the exposure. Periodic alterations in the densities of epithelial cells and mucous cells along with the development of non-tissue spaces have also been noticed at different exposure periods leading to alterations in the thickness of the respiratory epithelia. The heavy metal salt exposure has affected the mucogenic activity of the respiratory epithelium not only quantitatively but qualitatively also, indicating the probable ameliorative role fish mucus in cadmium toxicity.
    Keywords: Heteropneustes fossilis, histopathology, cadmium chloride toxicity, accessory respiratory organ, catfish
  • M. Sen, M. Ghosh Dastidar Page 9
    Biosorption of Cr(VI) from aqueous solution was studied in a batch bioreactor using the resting cells of filamentous fungal biomass (Aspergillus sp.) isolated from industrial wastewaters. The specific Cr(VI) removal (mg/g of dried biomass) decreased with increase in pH and increased with increase in initial Cr(VI) concentration, upto 500 mg/L. By increasing biomass concentration from 2.4 to 5.2 g/L, the specific metal removal remained almost constant. The studies carried out by using the resting cells from various stages of growth indicated maximum Cr(VI) removal of 34.8 mg/g using the biomass from the beginning of the stationary phase. The adsorption equilibrium constants Qº (42.9 mg/g) and b (0.0091/mg) were obtained from the Langmuir adsorption isotherm model.
    Keywords: Aspergillus sp., batch biosorption, chromium (VI), Langmuir adsorption isotherm, resting cells
  • TREATMENT OF WASTEWATER IN PLATING INDUSTRY BY CHELATE EXTRACTION METHOD
    M. R. Massoudi Nejad, M. Rezazadeh Azary, M. Khatiby Page 13
    One of the most efficient methods to preserve environment is the procedure and method to achieve effective materials and the dual and reapplication of natural sources. In this research, After carrying out a vast study on the growing spot of Iranian oaks , of the 36 species and subspecies already identified, 10 species and subspecies were selected as they cover a vaster surface of Iranian woods in North Alborz Region, Arsabaran region and the western part of Zagros Mountains. 5 samples were collected of each type form diffrenet spots of the country. The effective and usable substances of oak fruit were extracted and isolated by the four methods of maceration, decoction, perculation and soxhlet tannin in one specie show no significant difference; However the amount of tannin in different species show significant differences in statistical term in such a way that the minimum and maximum tannin was found in Q.Brantii, Belangri with 9.7% tannin and Q.Macrantera, with 3.2 percent tannin. This amount was put in contact with wastewater various from plating industries in 20 to 50 mg/L amount. The mentioned wastewaters contained 50 to 750 mg/L heavy metals (chromium, nickel, zinc, copper and silver). The results were analyzed through a biofactor variance analysis model with repetition in each house (Toki) Results showed that the removal output for zinc, copper, nickel and chromium without considering the initial concentration of the metal were 91 to 95 percent, 71 to 83.5 percent, 59 to 90 percent, and 84 to 85 percent, respectively. Also, with repect to the studies carried out with different methods and comparing the percentage of metals removal it was concluded that the removals output through applying 50 mg/L. hydroxide calcium along with 50 mg/L tannin with 82.3 percent average had the most effects in entire metals.
    Keywords: Wood, oak tree, extraction, heavy metals, plating wastewater
  • G. Karthikeyan, S. Siva Ilango Page 21
    Batch adsorption experiments using activated carbon prepared from Morringa Indica bark were conducted to remove fluoride from aqueous solution. A minimum contact time of 25 min was required for optimum fluoride removal. The influence of adsorbent, dose, pH, co-ions (cations and anions) on fluoride removal by the activated carbon has been experimentally verified. The adsorption of fluoride was studied at 30 C, 40 C and 50 C. The kinetics of adsorption and adsorption isotherms at different temperatures were studied. The fluoride adsorption obeyed both Langmuir and Freundlich isotherms and followed a pseudo first order kinetic model. The thermodynamic studies revealed that the fluoride adsorption by Morringa Indica is an endothermic process indicating an increase in sorption rate at higher temperatures. The negative values of G indicate the spontaneity of adsorption. SEM and XRD studies confirmed the surface morphological characteristics of the adsorbent and the deposition of fluoride on the surface of the material.
    Keywords: Fluoride, adsorption, langmuir isotherm, freundlich isotherm, intraparticle diffusion, thermodynamic parameters
  • G. R. Nabi Bidhendi, A. Torabian, H. Ehsani, N. Razmkhah Page 29

    Textile industry is the major source of water consumption and wastewater pollution. There are various treatment techniques to remove textile wastewater pollution. Coagulation-flocculation is a widely used process to remove pollution due to suspended particles. In this research, different coagulants like Alum, Lime, FeCl3, FeSO4 and MgCl2 were applied to select the suitable ones with optimum removal efficiency. Settling characteristics of flocs formed in the coagulation process were studied in a laboratory scale settling column unit. Parameters such as color, COD, TSS, turbidity and settled sludge volume have been evaluated. The optimum coagulant dose and pH value were determined by comparing the effectiveness of these coagulants. Results showed other coagulants except lime could eliminate color and COD successfully. In this case, FeSO4 was chosen as an optimum coagulant for color removal because of the lowest required coagulant dose, minimum settled sludge volume and maximum decolorization.

    Keywords: Dye, color removal, coagulation, coagulants, textile wastewater, alum, lime
  • S. Taghvaei Ganjali, B. Nahri Niknafs, M. Khosravi Page 37
    Photooxidation is an important process in the degradation of petroleum spilled in the marine environment. Most crude oils spilled at sea spread rapidly to form slicks with greatly increased surface area. Thus, a fundamental understanding of the effect of photooxidation on oil is a prerequisite for providing an accurate description of the recent history and potential fate of oil spilled in a marine environment. The present work describes a reliable method for evolution and studies the nature of the photoproducts and composition of the residual hydrocarbons of an oil film over the seawater. The maltenic fraction of Iranian oil was exposed to sunlight with simulated natural conditions as a film of oil over seawater. The effect of ultraviolet illumination on using a variety of techniques including GC/MS and FT-IR was examined. The saturated hydrocarbons were very resistant, but the aromatic hydrocarbons were particularly sensitive to photochemical degradation. Greater size and increasing alkyl substitution increased the sensitivity of aromatic compounds to photooxidation.
    Keywords: Photooxidation, oil spill, infrared spectrometry, gas chromatography, mass spectroscopy
  • Sh. Sarafraz, M. R. Khani, K. Yaghmaeian Page 43
    Hospital wastewaters are one of the most contaminating wastewaters and need to be paid more attention due to containing infectious agents. In this study, which had been conducted in a period of one year, 7 public hospitals were selected out of 12 public hospitals in Hormozgan Province of Iran. For studying quality of wastewater in hospitals, both influent and effluent wastewaters of treatment plant, if any, were sampled once in each season and totally 30 mixed samples were obtained. In order to determine the quality of hospital wastewaters in all samples, parameters such as pH, BOD5, COD, TSS and temperature were measured. Results of investigation on annual water consumption indicated that average water consumption in hospitals of the province was 194m3/d., considering water-to-wastewater conversion ratio of 0.8 and green yard ratio of 0.3. Wastewater production rate had been estimated to be 47m3/d and 0.362 m3/d.bed. Results indicated that in 7 hospitals of Hormozgan province, mean values of BOD5 ,COD ,TSS in raw wastewater were 242.25 mg/L, 628.1 mg/L and 231.25 mg/L, respectively, pH=7.42 and temperature=30.17 ºC. In Khalij-e-Fars hospital which had wastewater treatment plant, values of these parameters in effluent were 12.53 mg/L and 51.7 mg/L, 19.68 mg/L, respectively, with pH=7.39 and temperature=26.1 ºC. Comparison between values of influent and effluent wastewaters indicated that in understudy cases, contamination rate was higher than determined limits, as compared to environmental standards of the country and it was necessary to establish appropriate treatment plants in these units.
    Keywords: Hospital wastewaters, quantity and qualitaty parameters, wastewater treatment, Hormozgan
  • M. O. Orewole, O. W. Makinde, K. O. Adekalu, K. A. Shittu Page 51
    Hospital wastewaters are one of the most contaminating wastewaters and need to be paid more attention due to containing infectious agents. In this study, which had been conducted in a period of one year, 7 public hospitals were selected out of 12 public hospitals in Hormozgan Province of Iran. For studying quality of wastewater in hospitals, both influent and effluent wastewaters of treatment plant, if any, were sampled once in each season and totally 30 mixed samples were obtained. In order to determine the quality of hospital wastewaters in all samples, parameters such as pH, BOD5, COD, TSS and temperature were measured. Results of investigation on annual water consumption indicated that average water consumption in hospitals of the province was 194m3/d., considering water-to-wastewater conversion ratio of 0.8 and green yard ratio of 0.3. Wastewater production rate had been estimated to be 47m3/d and 0.362 m3/d.bed. Results indicated that in 7 hospitals of Hormozgan province, mean values of BOD5 ,COD ,TSS in raw wastewater were 242.25 mg/L, 628.1 mg/L and 231.25 mg/L, respectively, pH=7.42 and temperature=30.17 ºC. In Khalij-e-Fars hospital which had wastewater treatment plant, values of these parameters in effluent were 12.53 mg/L and 51.7 mg/L, 19.68 mg/L, respectively, with pH=7.39 and temperature=26.1 ºC. Comparison between values of influent and effluent wastewaters indicated that in understudy cases, contamination rate was higher than determined limits, as compared to environmental standards of the country and it was necessary to establish appropriate treatment plants in these units.
    Keywords: Point of use, physico chemical, trace metals, water quality, alkalinity, piped water
  • A. Vahabi, J. Rafinejad, P. Mohammadi, F. Biglarian Page 57
    Cockroaches play an important role in transmission of different diseases either mechanically and occasionally biologically. The aim of current study was on the identification of cockroaches and their contamination to different bacteria in two hospitals affiliated to the Kordestan University of Medical Sciences which was performed in 2003. Cockroaches were collected from different parts using sticky traps, direct collection, and by means of vacuum cleaner. Collected cockroaches were identified according to the reliable systematic keys. Some of the collected cockroaches were selected randomly for the presence of bacteria in their external parts as well as in the digestive tract using specific culture media. Totally 450 specimens were collected. From which 44.4% identified as American Cockroach, Periplaneta Americana and remaining German cockroach, Blattella germanica. Among collected cockroaches 58 specimens of German cockroaches and 40 American cockroaches were selected to search for the presence of bacteria. Results of culture media exhibited that 89.8% (88.98) of cockroaches were positive to the bacteria. The bacteria were found mainly on external parts (67%) and remaining from alimentary canal. The main common bacteria was found Escherichia coli, however, only 5.1% was Escherichia sp., which was found on external parts. Among two hospitals it is found that Tohid hospital was more infected (97.5%). In the hospitals the infectivity of American cockroaches was more prevalent than other species. All the American cockroaches and 70% of German cockroaches were infected to at least one bacterium. Result showed that the presence of cockroaches in the hospitals can threaten the health of hospitalized patients. Both cosmopolitan species was found infected in the hospitals. Sanitation of different departments as well as different method of control is recommended in the context of Integrated Vector Management for cockroach control.
    Keywords: Cockroaches, bacteria, hospital, Kordestan
  • P. Ranade Page 61
    Mining activities and the waste products produced can have significant impact on the surrounding environment - ranging from localized surface and ground water contamination to the damaging effects of airborne pollutants on the regional ecosystem. The long term monitoring of environmental impacts requires a cost effective method to characterize land cover and land cover changes over time. As per the guidelines of Ministry of Environment and Forest, Govt. of India, it is mandatory to study and analyze the impacts of mining on its surroundings. The use of remote sensing technology to generate reliable land cover maps is a valuable asset to completing environmental assessments over mining affected areas. In this paper, a case study has been discussed to study the land use – land cover status around 10 Km radius of open cast limestone mine area and the subsequent impacts on environmental as well as social surroundings.
    Keywords: Environmental impact assessment, remote sensing, land use, land cover, remote sensing