Engineering and Technology in India

R. T. Srinivasa Rao ¹, N. T. Manjunath ²

Affiliations
1 J.S.W. Steel Limited, Vijayangar Works, Toranagallu, Bellary, Karnataka, IN
2 Center for Environmental Science, Engineering&technology, University B.D.T. College of Engineering, Davangere, Karnataka, IN

Abstract

Fluoride although beneficial for the mineralization of tissues in the human body, can be toxic to human being with chronic exposure to elevated concentration. Fluoride considered beneficial in drinking water at levels of 0.5 ppm but harmful once it exceed a level of 1.2 ppm. To date various methods to remove fluoride from water and wastewater have been proposed and applied. An attempt has been made in the present paper to summarise the outcome of study carried out to evaluate the feasibility of using alum to precipitate fluoride from synthetic solution under varied experimental conditions viz., pH (6.5 to 9.5), alum dosage (200 to 500 mg/l), initial concentration of fluoride (Co : 3, 4 and 5 mg/l). Inverse relationship between removal efficiency and Co as well as pH were recorded. On the other hand higher dosages of alum was found to be effective for fluoride precipitation. From aqueous solutions maximum of 78.8 per cent removal of fluoride was recorded with alum dosage of 500 mg/l, pH of 6.5, Co being 3 mg/l. However, all the dosages of alum at all the pH values and Co had successfully reduced the fluoride content from the aqueous solution to the permissible limits.

Keywords

Aqueous Solution, Jar Test, Fluoride Precipitation, Initial Concentration, Alum, Ph

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K. V. Manjunath ¹, N. T. Manjunath ²

Affiliations
1 Department of Civil Engineering, Dr. Ambedkar Institute of Technology, Bengaluru, Karnataka, IN
2 Center for Environmental Science, Engineering&technology, University B.D.T. College of Engineering, Davangere, Karnataka, IN

Abstract

Wastewater from industries must ultimately be return to the receiving bodies or to the land. In these wastewaters metals may be present in both soluble and insoluble forms. The concentration of metals must be reduced to acceptable levels before discharging them into environment. Otherwise these could pose threats to public health and may also affect aesthetic quality of receiving bodies. The removal of nickel from aqueous solution by economically feasible adsorbents was investigated, as a part of research work and presented in this paper. The effects of flow rate (contact time) initial concentration of metal ions (Co) for its removal on the adsorbents viz., coconut husk, saw dust and sugar cane leaves have been studied at pH of 4.0. Maximum and minimum removal efficiency under optimum conditions of experimentations were recorded with coconut husk and sugar cane leaves, respectively.

Keywords

Aqueous Solution, Nickel, Adsorption, Low Cost Adsorbents

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