International Journal of Environmental Technology and Management (4 papers in press)
Removal of Methyl Orange from Synthetic Wastewater Using Analcime-C, MCM-41 and -Al2O3 Composite Membranes
by Vinoth Kumar R, Kannan Pakshirajan, Pugazhenthi G
Abstract: The present study describes the fabrication of Analcime-C, MCM-41 and γ-Al2O3 composite membranes and their potential in removal of anionic dye from aqueous solution. The hydrothermal crystallization technique was employed to deposit the charged inorganic oxides such as Analcime-C, MCM-41 and γ-Al2O3 on the low cost ceramic support. The formation and purity of Analcime-C, MCM-41 and γ-Al2O3 powders were verified by XRD analysis. The porosity, average pore size and water permeability of Analcime-C composite membrane were calculated as 24% (23 and 29 % for MCM-41 and γ-Al2O3 composite membrane), 0.155
Keywords: Membrane; Removal; Composite; Analcime-C; MCM-41; Dye; FESEM; XRD; Porosity.
A comparative study of hexavalent chromium estimation in drinking water by Direct aspiration method and Chelation extraction method
by Mayur Panchal, Vincent Braganza, Sandipkumar Ghosh
Abstract: With the development and progress of industries, a remarkable increase in the amount and complexity of toxic effluents and their release is occurring and causes detrimental effects on living creatures and the environment. This study is mainly focused on estimation of methods and their comparison of heavy metal, hexavalent chromium in drinking water samples. The study area is the state of Gujarat in India, and touches on south-Gujarat where industries have proliferated. In the present work, a comparative study has been done using two different methods for the estimation of hexavalent chromium in drinking water. Results show that chelation extraction method (CEM) is better as compared to direct aspiration method (DAM). DAM is unable to remove the interfering agents that prevent the estimation of hexavalent chromium accurately in flame atomic absorption spectrophotometer and hence results are less sensitive. In addition to this we have established that the hexavalent chromium content in drinking water samples collected from South-Gujarat area is several hundred to severalrnthousand folds higher as compared to permissive limits suggested by public health goal.
Keywords: Metal toxicity; Chromium estimation; DAM; CEM; Drinking water; Atomic AbsorptionrnSpectrophotometer.
IDENTIFICATION AND CHARACTERIZATION OF TWO NOVEL AZODYE- DEGRADING MICROORGANISMS FROM CONTAMINATED GROUND WATER AND SOIL OF A TEXTILE MILL
by Sudipta Kumar Mohanty, Usharani Longjam, Priyanka Patel, Kumara Swamy Mallappa, Anuradha Maniyam
Abstract: In the present investigation, bacterial isolates were inoculated into the media containing various azodyes to study their biodegradability potential. The decolorization of various dyes was measured spectrophotometrically after incubating from 24 until 72 hours.Among all the isolates, S1 and S2 effectively decolorized all the azodyes tested within 72 hours. These isolates were later characterized as Achromobacter and Bacillus sp.through 16s rDNA gene sequence analysis. The sequences were submitted to gene bank with the accession number, AB936782 and AB936783, respectively.These isolates contained a plasmid DNA, which was isolated by the hot alkaline method.The presence of the resistance traits on plasmids was also evidenced from the curing experiments. Among different curing agents used, SDS (Sodium dodecyl sulfate) and rifampicin at 9 mg/ml was found to be the most effective in plasmid curing. Biochemical characterization revealed that Achromobactersp. was positive for tryptophanase, indole and citrate permease with ability to ferment glucose and produced the gas. While, S2 showed the presence of tryptophanase, but found negative for the urease production. The salt tolerance test revealed that these isolates were able to sustain the salt concentration between 4%-10% suggesting a moderate halotolerance. Further, Bacillus sp. exhibited tolerance to heavy metal salts such as zinc and arsenic up to 8M; copper, cobalt and nickel to an extent of 500mM. The efficient decolorizing activity, heavy metal and salt tolerance capability in normal environmental conditions indicates that the isolated microbial strains can be utilized effectively for the treatment of effluents in the dye industries.
Keywords: Azodyes; microbes; industry; environment; degradation; pollution.
Health Risk and Bioaccessibility Assessment of Lead in Waste from the Malaysian Lynas Rare Earth Processing Plant Using an In Vitro DIN Gastrointestinal Model
by Yasmin Mohd Idris Perama, Muhammad Zulhilmi Hussin, Syazwani Mohd Fadzil, Khoo Kok Siong
Abstract: This study examines the bioaccessibility of lead from water leach purification (WLP) waste collected from the Malaysian Lynas rare earth processing plant using an in vitro DIN digestion model. A contamination factor (Cf) value of 2.7 was obtained from study results, which is considered to be a moderate level of Pb contamination in WLP waste. The bioaccessibility of Pb in digested WLP waste ranged between 0.064
Keywords: lead heavy metal; bioaccessibility; health risk assessment; water leach purification waste; in vitro; estimated daily intake; target hazard quotient; health risk; gastrointestinal model; rare earth.