Volume 2 Issue 7

Authors: Chander Kumar Singh; Kumari Rina; J. Mallick; R.P. Singh; Neha Singh; S. Shashtri; S. Mukherjee

Abstract: Groundwater is the only available potable source of water for drinking, sanitation and other uses in this region of Thar Desert of India. The intention of this study was to assess the toxicity of fluoride in groundwater and to identify major factors controlling its occurrence. A total of 66 water samples were collected and analyzed from the study area. The analyzed water quality parameters formed the attribute database for statistical and GIS analysis. Chemometric analysis of the water quality parameters was done using factor analysis and principal component analysis to identify the major factors controlling the fluoride enrichment. Piper diagram was used to identify geochemical facies of groundwater samples and to determine the role of water facies for fluoride enrichment in the region. The principal component analysis of the water quality parameters resulted in three major factors which explained 73.65% of the total variance. The factors suggest that mineral dissolution, evaporation, reducing environment and ion exchange are the major processes controlling fluoride hydro-geochemistry. The study concludes that the water is not potable in most of the locations due to high fluoride concentration exceeding the limits as recommended by World Health Organization (WHO) for drinking water.

Keywords: Groundwater; Fluoride, Rajasthan; Principal Component Analysis; Evaporation


Authors: Deepika Dave; Bopeng Zhang; Abdel E Ghaly

Abstract: Creosote has been used as wood preservative and water proofing agent in railway sleepers and utility poles for centuries. However, creosote contains polycyclic aromatic hydrocarbons, phenolic compounds and other heterocyclic organic compounds which can cause potential contamination of soil and water, and threaten the health of human and animals. The bioremediation of phenolic compounds in composting bioreactor with a mixed aerobic culture augmented with the thermophilic actinomycete Thermomonospora curvata was investigated. The temperature profiles showed that the thermpophilic phase (>45˚C) was achieved and successfully maintained in both the control and the inoculated experiments due to the addition of used cooking oil as a bioavailable carbon source and urea as a nitrogen source. The moisture content decreased in both control and inoculated experiments because the water produced by microbial respiration did not compensate for the water lost as vapour with the exhaust gases. The final moisture contents of 42.9% and 39.1% for the control and the inoculated experiments were within the optimum range for composting. An initial increase in the pH was caused by the breakdown of organic nitrogen to ammonium which was then followed by a decrease due to the formation of organic acids from the decomposition of fats and grease and the loss of ammonium with the exhaust gases. The inoculated experiments achieved higher reductions of volatile solids, total carbon and TKN indicating a higher level of activity of microorganisms during the composting process compared with the control. As a result, higher degradation of phenolic compounds, cellulose and lignin were observed in the inoculated experiments. Different degradation rates were observed in the mesophilic and thermophilic stages of composting. The results indicated that the reduced products from both experiments have improved stability and phytotoxicity. The inoculation of cellulolytic-thermophilic actinomycete Thermomonospora curvata accelerated the bioremediation process and as a result higher degradation levels of phenols and lignocellulose were achieved.

Keywords: Wood Waste; Composting; Bioremediation; Mesophilic; Thermophilic; Phenols; Cellulose; Carbon; Nitrogen; Maturity; Stability


Authors: E.E. Kwaansa-Ansah; J. Akoto; A.A. Adimado; D. Nam

Abstract: The concentrations of some toxic elements (mercury, lead and arsenic) and some essential elements (cobalt, copper, chromium, manganese, selenium and zinc) in fish obtained from the Volta Lake in Ghana were determined using a rapid, highly sensitive and accurate method. A stepwise digestion procedure using Optima Fisher concentrated nitric acid and hydrogen peroxide was used for complete oxidation of organic tissue. The concentrations of the various elements were measured using an Agilent 7500c quadrupole Inductively Coupled Plasma Mass Spectrometer (ICPMS; Agilent Technologies, Palo Alto, CA) equipped with a dynamic reaction cell and a Cetac ASX-500 autosampler. A total of 62 fish samples covering four different species of tilapia: Oreochromis niloticus, Tilapia zilli, Tilapia dageti and Sarotherodon galilaeus were analyzed for their elemental contents. Results of the study indicate low levels of exposure to arsenic, chromium, cobalt, copper, lead, manganese, mercury, selenium and zinc through consumption of these species of tilapia and do not pose a significant health risk to the individuals and to a greater extent the general population.

Keywords: Toxic Elements; Essential Elements; Tilapia Species; Volta Lake


Authors: Andrzej Aniszewski

Abstract: This paper addresses the general overview of 2D mathematical models both for inorganic and organic contaminants moving in an aquifer, taking into consideration the most important processes that occur in a ground. These processes impact in different extent on the concentration reduction values for the moving contaminants in a groundwater. In this analysis the following processes have been taken into consideration: reversible physical non-linear adsorption, chemical and biological reactions (as biodegradation-biological denitrification) and radioactive decay (for moving radionuclides). Based on this 2D contaminant transport models it has been possible to calculate numerically the dimensionless concentration values with and without all the chosen processes in relation both to the chosen natural site (piezometers) and the chosen contaminants. In this paper, it has also been possible to compare all the numerically calculated concentration values to the measured concentration ones (in the chosen earlier piezometers) in relation both to the new unpublished measurement series of May 1982 and to the new set of parameters used in these 2D contaminant transport models.

Keywords: Advection; Dispersion; Adsorption; Biodegradation; Radioactive Decay; Numerical Calculations