USE OF LOCAL SOILS IN ADSORPTION OF CHROMIUM(VI) BY COLUMN STUDY

Abstract

Polluted water has many pollutants contributing to its state, one of the major being heavy metals like lead, cadmium, chromium etc. This paper focuses on the removal of chromium by adsorption on local soils, since chromium is among the toxic pollutants, since the pollutant on reaching into the human body has proven to be carcinogenic. Chromium is released as waste from mainly tanning, metal finishing industries etc. Chromium exists in different oxidation states and Cr+6 being the pre-dominant. The temporary and permanent health hazards include diarrhea, stomach and intestinal bleeding, cramps in liver and in some cases even kidney damage. The different codes and standards define the permissible limits of chromium in drinking water. Since its permissible limits are necessary to assess the degree of pollution and treatment that is to be given. Since the leachate from the waste on transferring on to the landfill must not percolate via the compacted layers and testing of soils for its adsorption capacity becomes a major concern since the water table will be contaminated and therefore urges for a material that is locally available and can be used as filler material in landfills that can withheld the oozing of the contaminant (i.e. better adsorption capacity of the soil) as well as the leachate intercepting the streams during wet season. The steps to be followed to conduct this observation mainly include study of soil properties, preparation of standard/stock solution and the method of analysis. The method that is adopted for adsorption of Chromium includes Batch test and Column test with the arrival of the results with its reference to the isotherms that are drawn from the experimental results. The maximum percentage removal of chromium occurs at the adsorbent depth of 30cm and occurs maximum for 4ppm, i.e. 31.25%.