Nature Environment and Pollution Technology

P. N. Sudha ¹, S. Celine ²

Affiliations
1 Department of Chemistry, Dhanabagyam krishnaswamy Mudaliar Women's College, Vellore-632 001, T.N., IN
2 Department of Biotechnology, Mother Teresa Women’s University, Kodikanal-623 101, IN

Abstract

Of the various toxic heavy metals discharged into the environment, cadmium is highly toxic and has a serious health concern. Removal of metals from industrial wastewaters has conventionally been accomplished by precipitation, ion exchange and electrolytic technology. More recently, adsorption using commercial activated carbon and carbon from different plant materials is in force. Use of activated carbon is quite expensive. Hence, the use of carbon from natural biopolymers has attracted attention of industrialists. Recently, surface modified carbon has generated diversity with far superior adsorption capacity. Among the various low cost adsorbents identified, chitosan has the highest adsorption capacity for several metals. But chitosan is slightly soluble at low pH, soft and has a tendency to agglomerate or form a gel in aqueous solutions, which makes the active binding sites of chitosan not readily available for sorption. Hence, providing a physical support will increase the accessibility of the metal binding sites. In the present investigation an attempt has been made to overcome these mass transfer limitations by synthesizing a biosorbent by coating chitosan on the surface of coconut shell charcoal. The chitosan coated charcoal showed higher efficiency of adsorption of cadmium than the pure charcoal.

Keywords

Heavy Metal, Cadmium, Chitosan, Coconut Shell Charcoal, Adsorption.

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S. Santha Lakshmi ¹, M. Gayathri ², P. N. Sudha ¹

Affiliations
1 Department of Chemistry, Dhanabagyam krishnaswamy Mudaliar Women's College, Vellore-632 001, T.N., IN
2 Department of Biochemistry, Dhanabagyam krishnaswamy Mudaliar Women's College, Vellore-632 001, T.N., IN

Abstract

The removal of Cr(VI) from aqueous solution using sulphonated black rice husk ash (SBRHA) and sulphonated white rice husk ash (SWRHA) at various pH and adsorbent doses has been studied. The uptake percentage of Cr(VI) from the solution was determined spectrophotometrically by DPC method. It was found that the amount of Cr(VI) adsorbed increases significantly with decrease in pH from 5.0 to 1.0 for SWRHA and 5.0 to 2.0 for SBRHA. The Cr(VI) adsorption increased significantly with increasing dose of the adsorbent.

Keywords

Chromium (VI), Adsorption, Rice Husk Ash, DPC Method.

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P. N. Sudha ¹, D. Manley Backyavathy ², K. Sudhakar ³

Affiliations
1 Department of Chemistry, D. K. M. College for Women, Vellore-632 001, T.N., IN
2 Department of Zoology, Voorhees College, Vellore-632 001, T.N., IN
3 Department of Biological Sciences, Chezhian College of Education, Polur-606 803, T.N., IN

Abstract

Malathion, a pesticide in the organophosphate chemical family is the most commonly used pesticide in our country. Symptoms of exposure to malathion include headache, nausea, vomiting, burning in eyes, difficulty in breathing and lethargy. Earthworms have been used as biomarkers for assessing chemical environmental pollution. Due to their low cost, easy handling, their direct body contact with the soil and ethical issues related to mammalian studies, earthworms were chosen for the present study. Three doses of malathion 150, 300 and 600 mg/kg soil were used as treated soil. The effect of application of malathion on the earthworm Lampito mauritii was studied for 5, 10, 15 and 30 days exposure by evaluating the body weight, number of cocoons laid and the hatching efficiency of the cocoons. The results showed that there is a direct dose response relationship with respect to both, the concentration and time of application of malathion. The results have been statistically analysed.

Keywords

Pesticides, Melathion, Earthworm, Lampito mauritii, Non-Target Organism, Cocoons, Biomarkers.

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