INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY (IJEST)
Year:2007 | Volume:4 | Issue:2 (14)|Papers Count:16

Various extraction procedures were employed for measuring extractable concentrations of potential toxic elements in soil. The extractability of Cd, Cu, Pb and Zn in four contaminated and four non-contaminated soils of Japan, was compared by single extraction (CaCl2, DTPA, NH4Cl, 0.1 M HCl and 1 M HCl ) and sequential extraction procedures [(six operationally defined chemical phases, viz. water soluble (F1), exchangeable (F2), carbonate (F3), oxide (F4), organic (F5) and residual (F6) fractions)]. Extractability of metals from soils samples varied depending on metals and/or extractants used. Among the extractants, 1 M HCl extracted the largest proportion of Cd (79 to 96% of total), Cu (61 to 83%), Pb (51 to 99%) and Zn (23 to 52%) from soils followed by 0.1 M HCl, NH4Cl, DTPA and CaCl2. In all the extractants, the proportion of extractability of metals was higher in the contaminated soils than the non-contaminated soils. Regardless of soils and extractants, relative extractability was higher for Cd as compared to other three metals. The use of 1 M HCl may be recommended for first-level screening of soil contamination with heavy metals. The other four weak extractants are believed to provide a better assessment of bioavailable/mobile metals content in soils than 1 M HCl extractant. However, 0.1 M HCl mobilized all four metals irrespective of soil types, therefore, might be the best choice if only one extractant is to be used. The sequential extraction procedures showed 22 to 64% of total Cd was in the mobile fraction (sum of F1 to F3), while the corresponding values for Cu, Pb and Zn in this fractions were 2 to 23% suggesting higher mobility of Cd than other three metals. The single extraction procedures are simple and easy to perform and obtained results are comparable with sequential extraction procedure.

Biodegradation has proved to be a versatile technique to remediate benzene, toluene, ethyl benzene and xylene (BTEX) mixtures in contaminated soil and groundwater. In this study, a mixed microbial culture obtained from a wastewater treatment plant was used to degrade liquid phase BTEX, at initial concentrations varying between 15 to 75mg/l. Experiments were conducted according to the 2 k-1 fractional factorial design to identify the main and interaction effects of parameters and their influence on biodegradation of individual BTEX compounds in mixtures. The removal efficiencies of these compounds varied between 2 to 90% depending on the concentration of other compounds and also on their interaction effects. A statistical interpretation of the results was done based on the Fishers variance ratio (F) and probability (P) values. Though all the main effects were found significant (P<0.05) at the 5% confidence level, the interactions between benzene and toluene and benzene and xylene concentrations were also found to be statistically significant and play a major role in affecting the total BTEX removal.

The respirable particle matter (PM10) concentration in urban areas has been a chronic cause concern and principal reason for increased morbidity rate among resident population. The present study aimed at estimating a discrete event like mortality rate associated and attributable to excess particulate matter pollution in the Kathmandu Valley area. The Government of Nepal conducts air monitoring of particulates at its air monitoring site network covering valley area. Adopting the data available with respect to PM10 and with several other considerations like cutoff value for PM10, mean annual concentration, demographic data of valley, exceedance to the reference cutoff value, attributable fraction evolution and computation relative risk attributable to PM10 was computed. Assumption was made about the relative risk of long-term average PM10 exposure on natural mortality estimated and reported from a previous study. The estimation or mortality rate in our case was 0.95% after all these considerations and computation. This implies that 95 deaths out of 10,000 deaths are due to particulate pollution existing in the Kathmandu Valley Area.

Analysis of multi dimensional interactions of flow of energy in passenger vehicle is a complex task that necessitates development and utilization of analytical tools. Development of analytical tools with high complexity is usually based on conclusions of many concepts and theories from different scientific disciplines. In this approach, Passenger vehicle is supposed to be organized in the form of a firm and appears in the market that oriented towards establishing an effective energy supply system which may be identified as delivering the product (person kilometer or tone kilometer) with minimum operation costs. To this end, an optimization model named power software founded on theory of firm of microeconomics has been developed using technique of mathematical programming. Base on this theory, the car owner tries to minimize the total cost of the system subject to the satisfaction of the required transport services and technological, economical, environmental and institutional constraints. The approach and the application of the model shall be demonstrated with the help of a case study. The result of this study shows the extent of optimal energy usage subject to meeting the required certain urban transport service.

Bioaccumulation of heavy metals in fauna and flora in the Ijaw area of the Niger Delta of Nigeria were investigated. The fauna-molluscs and crustacea, and flora Hibiscus esculentus and vernonia amygdalina were selected for this study. Results show that Molluscs and crustacea accumulate considerable amounts of heavy metals. Higher levels of all the metals determined Hg, Pb, Cr, Cu, Ni, and Zn were observed in the shells than in the fleshly tissues. Hibiscus esculentus and vernonia amygdalina also accumulated these heavy metals. The mercury levels in the roots of Hibiscus esculents and vernonia amygdaline is 0.010 μg/g ± 0.00, while the stem 0.17 ± 0.03 μg/g and leaves 0.25 ± 0.02μg/g was recorded for the v. amygdalina. The H. esculenta fruit has lead levels of 0.22 ± 0.03 μg/g. The levels of Cu, Ni, and Zn are generally higher than those of Hg, Pb and Cr in all the samples analyzed. There is a growing concern about the physiological and behavioral effects of environmental trace metals in human population. The toxicity of lead at high levels of exposure is well known but of a major concern is the possibility that continual exposure to relatively low levels of these heavy metals through the consumption of these fauna and flora may entail adverse health effects.

Endosulfan, a chlorinated cyclodiene insecticide is of environmental concern because of its apparent persistence and toxicity to many non target organisms. Endosulfan is hydrophobic and persists in soil for more than a year. To overcome the problem of hydrophobic and limited availability, surfactants play a major role in soil remediation. In the present study, the effect of Tween 80 added to the soil on the degradation of endosulfan by Pseudomonas aeruginosa at different pH (7.0 and 8.5) was studied. The addition of synthetic surfactant Tween 80 enhanced the solubility and degradation of endosulfan. A significant degradation (94%) was observed in pH 8.5 and Tween 80 added soil; the bacterial population in the treatment unit T8 was 75×109 CFU/g of soil. The unit T4 inoculated at pH 8.5 showed 86 % alpha and 60% beta endosulfan degradation, the bacterial population was 73×108 CFU/g of soil. The degradation of both the isomers were observed and accompanied with formation of endodiol and endosulfan sulfate.

This study consisted of the determination of the trace metals and some physiochemical properties in drinking water samples from the Brong Ahafo region of the Republic of Ghana, where drinking water samples are not treated before it is consumed. The purpose was to ascertain the quality of water from these sources. Samples were taken from fifteen sampling points and analyzed for the following parameters Fe, Cu, Mn, Zn, Al, NO3-, NO2-, SO42-, PO42-, and F- using the procedure outline in the Palintest Photometer Method. The data showed the variation of the investigated parameters in samples as follows: pH 5.57-7.54, conductivity (EC) 35-1216 μs/cm, turbidity 3.25-72.50 NTU, PO42- 1 0.32-9.30 mg/L, F- 0.32-1.05 mg/L, NO3- 0.09-0.99 mg/L, NO2- 0.006-0.114 mg/L, SO42- 3.33-8.02 mg/L, Cu 1.19-2.75 mg/L Fe 0.05-0.85mg/L, Zn 0.04-0.15 mg/L, Mn 0.003-0.011 mg/L and Al 0.05-0.15 mg/L. The concentrations of most of the investigated parameters in the drinking water samples from Brong Ahafo region were within the permissible limits of the World Health Organization drinking water quality guidelines. There were no correlations between metal concentrations in the drinking water samples.

ISC-AERMOD dispersion model was used to predict air dispersion plumes from an diesel power plant complex. Emissions of NO2 and SO2 from stacks (5 numbers) and a waste oil incinerator ere studied to evaluate the pollutant dispersion patterns and the risk of nearby population. Emission source strengths from the individual point sources were also evaluated to determine the sources of significant attribution. Results demonstrated the dispersions of pollutants were influenced by the dominant easterly wind direction with the cumulative maximum ground level concentrations of 589.86 μg/m3 (1 h TWA NO2) and 479.26 μg/m3 (1 h TWA SO2). Model performance evaluation by comparing the predicted concentrations with observed values at ten locations for the individual air pollutants using rigorous statistical procedures were found to be in good agreement. Among all the emission sources within the facility complex, SESB-Power (diesel power plant) had been singled out as a significant source of emission that contributed >85% of the total pollutants emitted.

The biodynamic of Cryptosporidium spp. oocysts and Giadia spp. cysts have been assessed in the municipal lake of Yaounde, which is an artificial eutrophic lake that has been constructed on the Mingoa stream of the Mfoundi River Basin of Cameroon. The oocysts were identified by the Ziehl-Neelsen method while the cysts were identified by the Lugol iodine coloration. The values obtained suggest an increase in (oo) cysts density from the surface to the bottom of the lentic ecosystem. The oocysts varied from 56 oocysts/L in the upper layer to 2640 oocysts/L of water in the lowest layer, while the cysts population dynamics ranged from 24 cysts/L at the surface layer of the lake to 1713 cysts/L at the lowest layers of the lake. There was a considerable reduction in the resistant forms of these emerging pathogenic protozoa between the surface water of the Mingoa stream entering the Lake and that coming out from the Lake. The highest value of Cryptosporidium oocysts determined at the entrance of the lake is 1480 oocysts/L while at the outlet the highest value of oocysts identified is 620 oocysts/L. The highest value of Giardia cysts determined at the entrance of the lake is 352 cysts/L while at the outlet the highest value recorded is 294 cysts/L.

Total concentrations of Cd, Cr, Co, Fe, Pb, Ni, Mn and Zn were determined by atomic absorption spectrophotometry in the surface sediments of Taylor Creek, Southern Nigeria. The most concentrated trace metals, ranging from 113.2 to 5160.7 mg/g-dry weights were Fe, Pb, Mn, Ni and Zn. There was no significant variation in sediment-associated metal levels (P>0.05). The Metal Pollution Index (MPI) was highest at Agbia/Nedugo and is attributed to local contamination of the Creek. The concentrations of low molecular weight polycyclic aromatic hydrocarbons (PAHs) were also detected and quantified in the sediments by capillary gas chromatography equipped with a flame ionization detector. The concentration levels of 178.1-1266.3 mg/g-wet weights were high for the PAHs. The results indicate that the pollutants, which are bio-accumulatable, could contribute to inferior biodiversity, and shifts in community composition from sensitive to tolerant taxa.

In recent years, there has been a dramatic increase in the occurrence of waterborne disease outbreaks caused by the Cryptosporidium parvum, and presence of this protozoan parasite in drinking water is a significant health problem faced by the water industry. A new strategy for detection of Cryptosporidium oocysts in water samples is PCR– based techniques. In this study a nested– PCR assay was designed for the specific amplification of a 199 bp DNA fragment of the gene encoding the heat shock protein (hsp70) of Cryptosporidium parvum oocysts. In order to prevent the inhibition of PCR amplification by substances contained in water samples, three DNA purification methods including QIAamp DNA mini kit, InstaGene Matrix, Mag Extractor – Genome were compared in concentrates of tap water samples spiked with the oocysts. After it was found that the QIAamp is only efficient purification technique, the efficiency of QIAamp and immunomagnetic separation for nested–PCR assay of various water samples was compared. The results show that QIAamp provide a useful and rapid tool for removing of PCR inhibitors. It seems that QIA amp purification-nested PCR assay is a sensitive, rapid and cost effective method for detection of Cryptosporidium parvum oocysts in clean water samples with turbidity < 2 nephelometric turbidity unit (NTU).

Laboratory scale studies were conducted in an up-flow anoxic bioreactor (UFAB) using synthetic fertilizer wastewater for ascertaining the denitrification efficiency. The performance of the reactor was compared using ethanol and topioca starch as the carbon source. The initial NO3-N concentrations (50-250 mg/L) and hydraulic retention time (HRT, 12-24 h) were varied to evaluate the COD and NO3-N removal. The results from this study shows that ethanol gave very good denitrification efficiency (78-98%) compared to topioca starch (68-96%).

The role of gas turbine power plants in electrical energy production has been considerably increased in the last two to three decades. Various methods have been proposed to improve the performance of gas turbine cycles. In this research, two methods, a reheat cycle (RC) and a cycle with a reheat and a recuperator (RHC), were investigated and compared with a simple cycle (SC). The main objective of this paper is to study the performance of an RC and RHC under actual conditions. In this regard, all processes are treated as actual, and in particular a relatively simple and reliable approach is used to predict the amount of cooling air. The results obtained on the basis of a model developed for this research show that reheating in the context of a realistic study may lead to an improvement both in efficiency and in specific net work using recuperator cause to decrease NOx emission.

Exhausted Reactive dye bath samples of Turquoise Blue, Olive Green and Navy Blue shades were collected from cotton knit wear dyeing units in Tirupur. Ozonation was conducted in a column reactor system fed with ozone at the rate of 0.16 g/min to assess its efficiency in reducing the color, chemical oxygen demand and total organic carbon. Complete decolorization of the effluent was achieved in 10 min contact time and ozone consumption of 153 mg/L for Turquoise Blue, 128 for Olive Green and 143 for Navy Blue shades effluents respectively. The corresponding COD removal was 43%, 44% and 43% for the three shades while TOC removal efficiency was 45%, 45% and 40% respectively. The results from the reusability studies indicate that the dyeing quality was not affected by the reuse of decolorized dye bath for two successive cycles. It is concluded that ozonation is efficient in decolorization of exhausted dye bath effluents containing conventional reactive dyes. However, the corresponding removal of COD from the textile effluent was not significant.

The emissions from palm oil industry through incineration and open burning are the major sources of air pollutions contribution in Malaysia. The consequence of increasing the particulate concentration, the particulate matter dissolves with vapor and grows into droplets when the humidity exceeds approximately 70% and causing opaque situation known as haze. This work focuses on the dispersion particulate matter from palm oil mill. Gaussian Plume Model from a point source, subject to various atmospheric conditions is used to calculate particulate matter concentration then display the distribution of plume dispersion using geographic information system. Atmospheric Stability, mixing height, wind direction, wind speed, natural and artificial features play an important role in dispersion process. Study on the dispersion of particulate matters and the haze potential are presented as a case study in this paper. The data obtained will be served as the purpose of modeling the transport of particulate matter for obtaining permits and prevention of significant deterioration to the environment.  

Biodegradation of oil depends on the nature of the oil, the type of microbial community and a variety of environmental factors. Green oils are being used as consumer goods and as raw materials in industries such as food processing, pharmaceutical and cosmetic. Microbial contaminations of green oils have been the cause of degradation problems. Serratia Marcessens produced cytochrome oxidase, catalase, Dextrose, Lactose, Manose and sorbitol enzymes were the main reason for the degradation af palmarosa oil. Changes of colour and turbidity was also the evidence for green oil degradation by bacteria. More oxygen included protons (O-CH2) group was produced in the presence of bacterial species and the addition of oxygen took place during bacterial degradation of palmarosa oil. The biodegradation of palmarosa oil by Serratia marcescens have been carried out using High Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic spectroscopy (NMR) analysis. Carboxyl group present in the palmorasa oil is utilised as a sole carbon sources for the Serratia marcescens.