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CONTENTS
Volume 1, Number 3, September 2012
 

Abstract
Trihalomethanes, produced as a result of chlorination of drinking water, are considered a potential health hazard. The trihalomethane formation potential (THMFP) of a raw water source may indicate the maximum trihalomethanes (THMs) that are likely to be produced when chlorine reacts with natural organic matter (NOM) present in the water. A study was conducted to evaluate the THMFP in even different drinking water sources in the vicinity of Kalpakkam, a rural township, on the east coast of India. Water from seven stations were analysed for THMFP. THMFP was compared with surrogate parameters such as dissolved organic carbon (DOC), ultraviolet absorbance (UV254) and bromide. The data showed that THMFP was high in water from open wells as compared to closed bore wells, possibly due to more photosynthetic activity. Proximity to sea, and consequently the levels of bromide, was an important factor that influenced THM formation. THM surrogate parameters showed good correlation with THMFP.

Key Words
chlorination by-products; trihalomethane formation potential; dissolved organic carbon; ultraviolet absorbance; bromide

Address
R. Rajamohan, Puspalata Rajesh, V.P. Venugopalan and S.V. Narasimhan: Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam, Tamil Nadu, India; Vinitha Ebenezer: Department Of Green Life Sciences, Sangmyung University, South Korea; Usha Natesan and V. Murugesan: Centre for Research, Anna University, Chennai, Tamil Nadu, India

Abstract
A kinetic study of the transesterification of soybean oil was conducted using microwaves under various temperatures, power densities, and reaction times. Results show that power density affects the kinetics and yield. The biodiesel yield increased with increasing microwave power density. The non-thermal effects of microwave irradiation on transesterification reactions were evaluated at a constant reaction temperature (65

Key Words
biodiesel; transesterification; microwave; non-thermal effects; kinetics

Address
Ming-Chien Hsiao and Pei-Hung Liao: Department of Environmental Engineering, Kun Shan University, Tainan City, Taiwan; Li-Wen Chang: Department of Materials Engineering, Kun Shan University, Tainan City, Taiwan

Abstract
The bioavailability of sorbed organic contaminants is one of the most important factors used to determine their fate in the environment. This study was conducted to evaluate the bioavailability of slow-desorbable naphthalene in soils. An air sparging system was utilized to remove dissolved (or desorbed) naphthalene continuously and to limit the bacterial utilization of dissolved naphthalene. A biological air sparging system (air sparging system with bacteria) was developed to evaluate the bioavailability of the slow-desorption fraction in soils. Three different strains (Pseudomonas putida G7, Pseudomonas sp. CZ6 and Burkholderia sp. KM1) and two soils were used. Slow-desorbable naphthalene continuously decreased under air sparging; however, a greater decrease was observed in response to the biological air sparging system. Enhanced bioavailability was not observed in the Jangseong soil. Overall, the results of this study suggests that the removal rate of slow-desorbable contaminants may be enhanced by inoculation of degrading bacteria into an air sparging system during the remediation of contaminated soils. However, the enhanced bioavailability was found to depend more on the soil properties than the bacterial characteristics.

Key Words
bioavailability; slow-desorbable; biodegradation; soil slurry; aromatic contaminants

Address
Guang-Chun Li: Department of Agricultural Resources and Environment, Agricultural College of Yanbian University, Yanji Jilin 133000, P.R. China; Seon-Yong Chung and Jeong-Hun Park: Department of Environmental Engineering, Chonnam National University, Gwangju 500-757, South Korea

Abstract
Bromadiolone (BRD), a second generation anticoagulant often applied to the living environment to control rodents, is usually considered to have low environmental toxicity due to its poor solubility in water. In this study of the effect of humic acid (HA) on BRD using electronic absorption spectroscopy, it has been observed that BRD is appreciably solubilized even in low concentrations of aqueous HA solutions. The BRD solubilization efficiency of aqueous HA was found to be 2.39 ± 0.14 (4.53 ± 0.26 μM ppm-1). It was also seen that BRD is reasonably solubilized in aqueous extract of farm soil.

Key Words
bromadiolone; humic acid; absorbance; solubilization; rodenticide

Address
John Prakash: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India

Abstract
Biosorption of methylene blue (MB) from aqueous solution was studied with respect to the point of zero charge of coconut husk, dye concentration, particle size, pH, temperature, as well as adsorbent and NaCl concentration using coconut husk biomass. Amongst Langmuir and Freundlich adsorption isotherms studied, Langmuir adsorption isotherm showed better agreement. Pseudo second order kinetics model was found to be more suitable for data presentation as compared to pseudo first order kinetics model. Also, involvement of diffusion process was studied using intraparticle diffusion, external mass transfer and Boyd kinetic model. Involvement of intraparticle diffusion model was found to be more relevant (prominent) as compared to external mass transfer (in) for methylene blue biosorption by the coconut husk. Moreover, thermodynamic properties of MB biosorption by coconut husk were studied. Desorption of methylene blue from biomass was studied with different desorbing agents, and the highest desorption achieved was as low as 7.18% with acetone, which indicate stable immobilization. Under the experimental conditions MB sorption was not significantly affected by pH, temperature and adsorbent concentration but low sorption was observed at higher NaCl concentrations.

Key Words
methylene blue; biosorption; adsorption isotherm; coconut husk; kinetic models

Address
Shailesh R. Dave, Vaishali A. Dave and Devayani R. Tipre: Department of Microbiology and Biotechnology, School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat, India


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