Cellulose-based anion exchanger with tertiary amine functionality for the extraction of arsenic(V) from aqueous media.

J. Environ Manage. 2010 Jul 9. [Epub ahead of print]

Anirudhan T.S. And Jalajamony S.
Department of Chemistry, University of Kerala, Kariavattom, Trivandrum 695 581, India.

ABSTRACT: A novel cellulose-based anion exchanger (Cell-AE) with tertiary amine functionality was synthesized by graft polymerization reaction of cellulose and glycidyl methacrylate using N,N'-methylene-bis-acrylamide as a crosslinker and benzoyl peroxide as an initiator, followed by dimethylamine (amination) and acid (HCl) treatment. The chemical modification was confirmed by infrared spectroscopy and CHN analysis. The anion exchanger was used in batch processes to study AS(V) adsorption in solutions. The operating variables studied were pH, contact time, initial As(V) concentration, sorbent mass, and ionic strength. The process was affected by solution pH with an optimum adsorption occurring at pH 6.0. Adsorption equilibrium was achieved within 1 h. Increasing ionic strength of solution negatively affected the arsenic uptake. The adsorption process performed more than 99.0% of As(V) removal from an initial concentration of 25.0 mg/L. The process of adsorption followed pseudo-second-order kinetics. The adsorption equilibrium isotherm data were analyzed using the Langmuir, Freundlich, Redlich-Peterson and Langmuir-Freundlich equations. The Langmuir-Freundlich isotherm described the adsorption data over the concentration range 25-400 mg/L. The adsorption mechanism appears to be a ligand-exchange process. A simulated groundwater sample was treated with Cell-AE to demonstrate its efficiency in removing As(V). The adsorbed As(V) ions were desorbed effectively by a 0.1 M NaOH solution.

PMID: 20621411 [PubMed - as supplied by publisher]

Distribution of Organophosphorus Pesticides in the Bed Sediments of a Backwater System Located in an Agricultural Watershed: Influence of Seasonal Int

Arch. Environ. Contam Toxicol. 2010 Jul 14. [Epub ahead of print]

Babu V Unnikrishnan P Anu G and Nair SM
Department of Research and Development, Hindustan Insecticides Ltd, Cochin, India.

ABSTRACT:This article focuses on the temporal and spatial distribution of three organophosphorous pesticides-malathion, methyl parathion, and chlorpyrifos-in the sedimentary environment of a backwater ecosystem, Kuttanad backwaters, situated in Kerala, India. Based on salinity distribution, geographic characteristics, and human activities prevailing in the area, the study area was divided into three zones: zone 1 with riverine characteristics, zone 2 with freshwater characteristics during and after the monsoon season and estuarine characteristics during the premonsoon season, and zone 3 with estuarine characteristics. The organophosphorus pesticides in the study area showed the order of enrichment as chlorpyrifos >malathion >methyl parathion. While studying the variations in pesticide concentrations seasonally, higher concentrations were observed during the premonsoon monsoon season, with the concentrations being lower than the detectable level. Sediment characteristics, such as pH, texture, organic carbon, moisture content, etc., had reflective effect on the degradation rates of pesticides. The runoff water from the paddy fields made a larger contribution of pesticide pollution to the study area.

PMID: 20628738 [PubMed - as supplied by publisher]

Water quality status and primary productivity of Valanthakad backwater in Kerala

Indian Journal of Marine Sciences, Vol 39 (1) March 2010, pp 105-113.

S. Meera and Bijoy Nandan
School of Marine Sciences, Cochin University of Science & Technology, Cochin 682 016, India
E Mail: meeras.marine@gmail.com

Abstract: The water quality and primary productivity of Valanthakad backwater (90 55' 10. 24” N latitude and 760 20' 01. 23” E longitude) was monitored from June to November 2007. Significant spatial and temporal variations in temperature, transparency, salinity, pH, dissolved oxygen, sulphides, carbon dioxide, alkalinity, biochemical oxygen demand, phosphate-phosphorus, nitrate-nitrogen, nitrite-nitrogen as well as primary productivity could be observed from the study. Transparency was low (53.75 cm to 159 cm) during the active monsoon months when the intensity of solar radiation was minimum, which together with the run off from the land resulted in turbid waters in the study sites. The salinity in both the stations was low (0.10 % to 4.69%) except in August and November 2007. the presence of total sulphide (0.08 mg/l to 1.84mg/l) and higher CO2 (3mg/l to 17 mg/l) could be due to hospital discharges and decaying slaughter house wastes in Station 1 and also from the mangrove vegetation from Station 2. Nitrate-nitrogen and phosphate-phosphorus depicted higher values and pronounced variations in the monsoon season. Maximum net primary production was seen in November (0.87 gC/m3/day) and was reported nil in September. The chlorophyll pigments showed higher values in July, August and November with a negative correlation with phosphate-phosphorus and nitrite-nitrogen. The study indicated that the water quality and productivity of Valanthakad backwater is impacted and is the first report from the region.

What drives the increased phytoplankton biomass in the Arabian Sea?

Current Science, Vol.99, No 1, 10 July 2010, p 101.

S. Prasanna Kumar (1), Raj P. Roshin (1,2), Jayu Narvekar (1), P.K. Dinesh Kumar (1,3) and E. Vivekanandan (1,4)

(1). National Institute of Oceanography, Dona Paula, Goa 403 004, India
(2). Present Address : Bjerknes Centre for Climate Research, University of Bergen, Norway
(3). Regional Centre for National Institute of Oceanography, Kochi 682 018, India
(4). Centre Marine Fisheries Research Institute, Kochi 682 018, India

E-mail: prasanna@nio.org

Abstract: The seasonal variability of phytoplankton biomass in the Arabian Sea, though a well researched topic, its inter-annual variability is less explored and understood. Analysis of the satellite-derived chlorophyll pigment concentration in the Arabian Sea during 1997-2007 showed a weak increasing trend. Contrary to the earlier hypothesis, our analysis showed that this increased phytoplankton biomass was not driven by the strengthening winds during summer monsoon. In fact, the basin-averaged chlorophyll concentrations during monsoon tend to decline, whereas those in September- October and during the winter monsoon showed an increasing trend. Based on the analysis of wind and aerosol optical thickness data, we attribute the increased phytoplankton biomass during September-October to dust induced iron fertilization when there is sufficient buildup of nitrate in the upper ocean. During winter, the enhanced evaporative cooling under the strengthening winds led to the increased convective mixing. Subsequent supply of subsurface nutrients to the euphotic zone coupled with the increased dust delivery support was observed increase in phytoplankton biomass during winter.

Adsorption Characteristics of Cadmium(II) onto FunctionalizedPoly(hydroxyethylmethacrylate)-Grafted Coconut Coir Pith.

Bull Environ Contam Toxicol. 2010 May 7. [Epub ahead of print]

Anirudhan TS, Divya L, Rijith S.

Department of Chemistry, University of Kerala, Kariavattom, Trivandrum, Kerala, 695 581, India

tsani@rediffmail.com.

Abstract:This study explored the feasibility of utilizing a novel adsorbent, poly(hydroxyethylmethacrylate)-grafted coconut coir pith with carboxyl functionality (PGCP-COOH) for the removal of cadmium(II) from water and wastewater. Maximum removal of 99.9% was observed for an initial concentration of 25 mg/L at pH 6.0 and adsorbent dose of 2.0 g/L. The first-order reversible kinetic model and Langmuir isotherm model were resulted in high correlation coefficients and described well the adsorption of Cd(II) onto PGCP-COOH. The complete removal of 22.4 mg/L Cd(II) from fertilizer industry wastewater was achieved by 2.0 g/L PGCP-COOH. The reusability of the PGCP-COOH for several cycles was demonstrated using 0.1 M HCl solution.

PMID: 20449725 [PubMed - as supplied by publisher]

Short-duration cassava genotypes for crop diversification in the humid tropics: growth dynamics, biomass, yield and quality.

J Sci Food Agric. 2010 Jan 30;90(2):188-98.

Suja G. John K.S, Sreekumar J. and Srinivas T.

Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram 695 017, Kerala, India.

BACKGROUND: Short-duration (6-7 months) cassava provides opportunities to smallholder farmers for effective utilisation of resources such as land, moisture and nutrients as well as diversification of enterprise and income. The variation in biomass production and partitioning, seasonal course of growth indices, yield, quality and nutrient uptake of ten short-duration/early-bulking genotypes of cassava and their impact on nutrient contents in soil in a lowland situation akin to rice fallow were examined in this study.

RESULTS: Triploid 2-18 gave the highest yield (38.34 t ha(-1)), followed by triploid 4-2, Sree Vijaya, Sree Jaya and Vellayani Hraswa, which were on a par (30-32 t ha(-1)). Vellayani Hraswa, Sree Vijaya and triploid 4-2 had significantly higher tuberous root dry matter content (370-380 mg g(-1)) and fairly higher starch content (270-280 mg g(-1)). All genotypes except triploid 4-2, triploid 2-18 and H-165 had low cyanogen content (29.2-43.8 microg g(-1)), well within the tolerable limit. Tuberous root dry matter and total dry matter production, crop growth rate, tuberous root bulking rate and harvest index at the last phase, number of tuberous roots, mean weight of tuberous roots and nutrient uptake showed significant positive correlations with tuberous root yield. Principal component analysis also showed a similar trend.

CONCLUSION: The diploids Sree Vijaya, Sree Jaya, Vellayani Hraswa and Kalpaka are ideal for cultivation in rice fallow for food use owing to their high yield, good cooking quality and low cyanogen content. The triploids are better suited for industrial use owing to their high tuberous root dry biomass production. Copyright (c) 2009 Society of Chemical Industry.

PMID: 20355030 [PubMed - in process]

Survival of enteric bacteria and coliphage MS2 in pure human urine

J Appl Microbiol. 2009 Nov;107(5):1651-7.

Chandran A, Pradhan S K and Heinonen-Tanski H.

School of Environmental Sciences, Mahatma Gandhi University, Kerala, India.

Abstract

AIMS: The survival of Escherichia coli, Salmonella enterica serovar Typhimurium, Enterococcus faecalis and coliphage MS2 was studied in stored, fresh and diluted (1 : 1) human urine at 15 and 30 degrees C.

METHODS AND RESULTS: Survival rate was studied by the plate count method. All the organisms showed rapid inactivation in stored urine, but they survived better in diluted and fresh urine. The high pH level and temperature were the major factors found to influence the survival of the micro-organisms with the survival rate being higher at 15 degrees C than at 30 degrees C.

CONCLUSIONS: The destruction of all micro-organisms in stored urine required <1 week at 30 degrees C. Thus, the storage of urine is a useful way to reduce the risk of contamination while using urine as a fertilizer.

SIGNIFICANCE AND IMPACT OF THE STUDY: The urine fertilization is aimed for the developing countries and the high temperatures in these countries may hasten the destruction of micro-organisms in urine. On the contrary, a higher survival rate of these organisms in fresh and diluted urine is a public health concern because the dilution of urine with water is likely to happen during flushing.

PMID: 19457041 [PubMed - indexed for MEDLINE]

Short-term incorporation of organic manures and biofertilizers influences biochemical and microbial characteristics of soils under an annual crop

Short-term incorporation of organic manures and biofertilizers influences biochemical and microbial characteristics of soils under an annual crop [Turmeric (Curcuma longa L.)]

Bioresour Technol. 2010 Jun;101(12):4697-702.

Dinesh R , Srinivasan V, Hamza S, Manjusha A.

Division of Crop Production and Post Harvest Technology, Indian Institute of Spices Research (IISR), P.O.

rdinesh2005@gmail.com

Abstract:The study was conducted to determine whether short-term incorporation of organic manures and biofertilizers influence biochemical and microbial variables reflecting soil quality. For the study, soils were collected from a field experiment conducted on turmeric (Curcuma longa L.) involving organic nutrient management (ONM), chemical nutrient management (CNM) and integrated nutrient management (INM). The findings revealed that application of organic manures and biofertilizers (ONM and INM) positively influenced microbial biomass C, N mineralization, soil respiration and enzymes activities. Contrarily, greater metabolic quotient levels in CNM indicated a stressed soil microbial community. Principal component analysis indicated the strong relationship between microbial activity and the availability of labile and easily mineralizable organic matter. The findings imply that even short-term incorporation of organic manures and biofertilizers promoted soil microbial and enzyme activities and these parameters are sensitive enough to detect changes in soil quality due to short-term incorporation of biological fertilizers.

PMID: 20163953 [PubMed - indexed for MEDLINE]