INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY (IJEST)
Year:2006 | Volume:3 | Issue:4|Papers Count:14

Various sludge samples from different domestic and industrial wastewater treatment plants were analyzed by Flame Atomic Absorption Spectrometry (FAAS) to evaluate their total and available contents of heavy metals (Pb, Hg, Cd and Zn). The EDTA, pyridine and acetic acid single extraction techniques were applied to these samples with the objective of studying the leaching behavior of the metals in different sludges and also to predict their possible mobility when these wastes are disposed on the environment and landfills. In EDTA, higher extraction efficiency was observed for major part of the elements studied in the industrial sludges except for Hg and Cd, which were also considerably released from domestic sludges. Acetic acid and pyridine gave a better extraction efficiency for Zn in industrial sludge than EDTA. Moreover, the results of total digestions were compared, for total metal contents, with those obtained using pseudototal digestion procedure and a good correlation (r2 = 0.95) was found between the two methods of digestion.      

Surfactants are among the most widely disseminated xenobiotics that contribute significantly to  the pollution profile of sewage and wastewaters of all kinds. Among the currently employed chemical unit processes in the treatment of wastewaters, coagulation-flocculation has received considerable attention for yielding high pollutant removal efficiency. Jar-test experiments are employed in order to determine the optimum conditions for the removal of surfactants, COD and turbidity in terms of effective dosage, and pH control. Treatment with FeCl3 proved to be effective in a pH range between 7 and 9. The process is very effective in the reduction of surfactants and COD, the removals are 99 and 88 % respectively, and increased BOD5/COD index from 0.17 to 0.41. In addition to precipitation coagulation process, adsorptive micellar flocculation mechanism seems contribute to the removal of surfactants and organic matters from this rejection.    

Apple orchards often receive winter-washes to help aid invertebrate pest control. These can have detrimental environmental consequences. The application of winter-wash increased Aculus schlechtendali numbers while a decrease in numbers of the beneficial mite Anystis baccarum was observed. The application of early season pesticide treatments produced mixed results in relation to A. schlechtendali. Pirimiphos-methyl had no apparent detrimental effect on A. baccarum, whereas pirimicarb and phosalone reduced A. baccarum populations. The potential to incorporate an orchard winter-wash and early-season pesticide applications within integrated pest management strategies is discussed.      

The present study reports on secondary school teacher’s environmental attitude in India and Iran. One thousand and four teachers were selected through the stratified random sampling technique from 103 secondary schools of Mysore city (India) and Tehran city (Iran). Subjects consisted of 505 male and 499 females. They were assessed using the Taj Environmental Attitude Scale (TEAS) developed by Hasseen Taj (2001). Results revealed that there are significant differences between Indian and Iranian teachers in their level of environmental attitude. Also there are significant differences between them in environmental attitude across and within two groups with regard to their gender. Also in overall, type of school management (Government and private) is not a factor, which can affect teachers environmental attitude.      

The present study examines variation of ambient aerosol mass and number concentrations in Chiang Mai, Thailand during winter. Aerosol particle samples were collected and measured at four different sites, representative of urban, industrial, residential and rural areas during daytime between December 2003 and January 2004. Average 10 h particulate matter (PM) mass concentrations were found to be in the range of 75-290 ìg/m3, with average value of 149 ± 45 ìg/m3. Urban and industrial areas appeared to have higher PM loading than residential and rural areas. Number concentration and size distribution of particles in the range of 0.3-10.0 ìm did not exhibit any marked variation between sites. Relatively stable number concentrations were reported. Temporal variation of number concentrations was not clearly significant. No short term peak observed during rush hours. During sampling period, the average number concentration for 0.3-0.5, 0.5-1.0, 1.0-5.0 and 5.0-10.0 ìm were 6.60 × 106, 1.18 × 106, 2.11 × 105 and 1.12 × 104/m3, respectively. Particles with diameter smaller than 1.0 ìm accounted for over 90 % of the total number concentration. Concentrations of major metals were determined by atomic absorption spectrophotometer (Pb, Fe, Al, Si, Cr, Cd, Ni, Zn) and flame photometer (K, Na and Ca). Data obtained were used to identify probable sources via a multivariate analysis. Si, Na, Fe, Ca, Al and K were the six dominant elements in the airborne PM. Principle component analysis was carried out and major sources of airborne PM in Chiang Mai were determined, namely, (1) long distance sources such as sea spray, earth soil and industrial combustion, (2) short-distance sources such as crustal re-suspension, vehicular related emissions and vegetation burning, and (3) the unknown distance sources with low influence of traffic emissions.      

The biodegradation of Cypermethrin (20 to 125 mg/L) in effluent using batch activated sludge was studied. Degradation was found to occur to a great extent only in the presence of Pseudomonas (IES-Ps-1) culture. Under aerobic conditions using mechanical aerators, Cypermethrin (20 mg/L) was almost completely degraded in just over 48 h at ambient temperature. Further loading of organic compound in subsequent experiments demonstrated that IES-PS-1was capable to degrade 82 % Cypermethrin at 40 mg/L dose in approximately 48 h. When the concentration was increased to 80 mg/L, 50% degradation of this compound was observed. Over this time period the cells could utilize only 17 % of Cypermethrin when it was given 125 mg/L, respectively. These findings indicate that increased concentration of Cypermethrin has a marked effect on biodegradation performance of IES-Ps-1 with a modest increased in the duration of lag phase, but did not lead to complete inhibition or cell death. These results proved that IES-Ps-1 is responsible for Cypermethrin degradation. Such finding may be useful in designing a scale-up in situ or on-site hazardous waste bioremediation process for field application.      

Correlations between trace metals in dissolved and particulate phases, B. bayad and sediments were investigated in five selected sites along Taylor Creek, which lies between longitude 006°17I to 006°21I E and latitude 05°01I to 05°05I N. The degree of correlation between the various metals was different in each of the investigated segments. Between segments, not many significant correlations were recognized. Only Ni and Cd, Mn and Cd, Mn and Ni, and Mn and Pb are correlated in the sediments and in the particulate phase, Fe and Cr, Pb and Cd, and Zn and Ni are correlated, which suggests that the sources are not common for both compartments. Partitioning coefficients (Kd) of trace metals between dissolved and particulate phases are generally low, which is typical for fresh water ecosystems and fairly stable over Taylor Creek all through the seasons. Furthermore, the bio-concentration factors (BCF) of B. bayad were low unlike those of other natural waters. Cluster analysis showed that metal accumulation in the particulate phase differed from those observed in sediments, which also confirms that the pollution of the Creek might be from different sources.      

Environmental impact assessment (EIA) of any project is essential for understanding the sustainability of the project. For sustainable development of hill tracts, electricity is inseparable. Like other parts of Bangladesh hill tracts districts felt increasing demand of electricity. In this paper an attempt has been taken to present the existing environmental condition and analysis the future environmental condition after implementation of project. Electrification will extend the length of the active day. Electrification will improve security (people’s perception of safety and security) at the region. The elements of the project identified as components for analysis are chosen based on DOE’s guideline. The study showed that 87% people say that they feel safer at night since being electrified. Impacts are classified on the basis of EPA’s scaling and DOE, university’s teachers, NGOs expert’s opinions. Value more than 10 is classified significantly affected element of the project. In this paper advantages and disadvantages of the Electrification Project has been presented.    

This paper presents the analysis and interpretation of ambient particulate matter concentrations measured as PM10 at a network of six air monitoring stations in Kathmandu valley during the years, 2003 through 2005. The purpose was to understand the pollution trends associated with different areas considering levels particulate matter concentrations representing the ambient air quality of Kathmandu valley. The study indicate that particulate concentrations (PM10) measured are persistently higher at air sampling sites representing roadside areas compared to the background sites. The inter-station network variability with respect the particulate pollution suggests optimizing resources. The comparison of annual average PM10 concentration observed at six air-monitoring sites in Kathmandu Valley with standard annual average concentration prescribed by World Health Organization as well as Europe Union indicates serious PM10 pollution in Kathmandu valley.      

A greenhouse experiment was conducted to determine the phytotoxic effect of aluminum and chromium on the germination and early growth of two wheat (Triticum aestivum) varieties Anmol and Kiran. Seed were treated with 40, 80, 120 and 160 ppm of aluminum and chromium solution individually and in combined form. Observations were made on seed germination, root, shoot and seedling length, and dry biomass. Seed germination and dry biomass showed no effect of aluminum, chromium and combined treatment. Root, shoot and seedling length of both the varieties showed significant (P<0.05) decrease as compared to control. The growth was also reduced as the concentration of aluminum and chromium increased. Seedling length decreased in both the varieties at all the concentration of different treatment of aluminum, chromium and combined treatment. Attempts are being made in different laboratories to construct novel plants using genetic manipulation technologies that may have a greater tolerance to the presence of toxic metals. The results of the present study may help in understanding the mechanisms involved and their possible use in pytoremediation.    

A three stage and a one-stage bench-scale biofilter with effective heights of 129 cm filled with same type of packing material were operated at different influent concentrations of ammonia in order to investigate their performance in treating waste gas streams. The columns contained a mixture of municipal compost inoculated with thickened municipal activated sludge as a base material and shredded hard plastic as a bulking agent in a 3:2 v/v ratio; the porosity, density and pH were 52 %, 0.65 and 7.2 respectively. Microbial acclimation to ammonia was achieved by exposing the three stage biofilter to an average inlet loading rate of 2.15g-NH3/m3 h and the one-stage to an average inlet loading rate of 1.32 g NH3/m3 h and an empty bed residence time of 60 s, for 10 days and 17 days respectively. Under steady-state condition, maximum elimination capacity (EC) was 9.85 g-NH3/m3h at a loading rate of 9.86 g-NH3/m3h for three-stage biofilter and 8.08 g NH3/m3h at a loading rate of 8.13 g-NH3/m3h for one-stage biofilter. The average pressure drop across biofilters bed was determined 33.76 Pa/m1 in three-stage biofilter and 180.7 Pa/m1 in one-stage biofilter. The three stage biofilter showed superior performance and gained more elimination capacity, shorter acclimation time, longer operation in steady-state condition and less pressure drop than one-stage biofilter.    

Surface aeration experiments were conducted in two types of rectangular tanks of aspect ratios i.e., length to width ratio (L/W) of 1.5 and 2 and developed simulation equations to correlate the oxygen transfer coefficient, k and power number, P0 with a parameter governing theoretical power per unit volume X. The parameter X is defined as equal to F4/3R1/3, where F and R are impellers’ Froude and Reynolds numbers respectively). Results have shown that the P0 can not be simulated singularly with either Reynolds number, R or Froude number, F, which results in scale effects; there appears to be a need to incorporate the effects of both F and R. It was found that P0 is uniquely related to X for rectangular aeration tanks of both aspect ratios, however, such relationships are different depending upon the aspect ratios. It has been demonstrated that energy can be saved substantially if the aeration tanks are run at relatively higher input powers. It is also demonstrated that smaller sized tanks are more energy conservative and economical when compared to big sized tanks, while aerating the same volume of water, and at the same time by maintaining a constant input power in all the tanks irrespective of their size.      

Landfill has been taken to the bottom of the hierarchy of options for waste disposal but has been  he most used method for urban solid waste disposal. However, landfill has become more difficult to implement because of its increasing cost, community opposition, and more restrictive regulations regarding the sitting and operation of landfills. Land is a finite and scarce resource that needs to be used wisely. Appropriate allocation of landfills involves the selection of areas that are suitable for waste disposal. The present work describes a type of multi-criteria evaluation (MCE) method called weighted linear combination (WLC) in a GIS environment to evaluate the suitability of the study region for landfill. The WLC procedure is characterized by full tradeoff among all factors, average risk and offers much flexibility than the Boolean approaches in the decision making process. The relative importance weights of factors are estimated using the analytical hierarchy process (AHP). In the final aggregated suitability image, zones smaller than 20 hectares are eliminated from the allocation process. Afterwards, the land suitability of a zone is determined by calculating the average of the suitability of the cells belonging to that zone, a process called zonal land suitability. The application of the presented method to the Gorgan city (Iran) indicated that there are 18 zones for landfill with their zonal land suitability varying from 155.426117 to 64.149024. The zones were ranked in descending order by the value of their zonal land suitability. The results showed the use of GIS as a decision support system (DSS) available to policy makers and decision makers in municipal solid waste (MSW) management issues.      

This paper gives impact of Arsenic contaminated water on human health as well as overview of the extent and severity of groundwater arsenic contamination in Bangladesh. Scalp hair is the most important part of the human body to monitor the accumulation of this type of poison. Therefore, an experiment has been carried out by Neutron Activation Analysis (NAA) at Atomic Energy Research Establishment (AERE), Savar, Dhaka, Bangladesh on human hair of corresponding tube well water users of these areas to determine the total accumulation of arsenic to their body. Hair samples collected from the region where the groundwater was found highly contaminated with arsenic. The obtained results of arsenic concentration in the lower age (Hb) categories of users (below 12 years of age users) is in the range of 0.33 to 3.29 μg/g (ppm) and that in the Hu categories (upper 12 years of age users) is 0.47 to 6.64 μg/g (ppm). Where as maximum permissible range is 1 ppm certified from WHO. Results show that the peoples are highly affected where the groundwater is highly contaminated with arsenic and acts as the primary source of arsenic poisoning among the peoples of those areas. The results indicate that human population is affected with arsenic locally using the contaminated water for a long time.