REMOVAL OF ARSENIC FROM WASTE WATER.

Abstract

The fundamental study was carried out in order to find out the optimum conditions or the effective addition agents for the removal of arsenic from the waste water. The results indicate that the As content in the solution is reduced to about 0. 1 ppm for the range of pH 3 similar 8 by treating with 5 times Fe** plus ** plus ** plus salt as much as As content in original solution, when As is present as H//3AsO//4. In case of AsO//2**-, however, more than 15 times Fe** plus ** plus ** plus salt as much as As is needed between 6 and 9 in pH value to reach the same As level in the solution. Al and Mg salts were found effective for As elimination in H//3AsO//4 solution at the appropriate pH, but not satisfactory in AsO//2** minus solution. The use of Ca(OH)//2 together with Fe** plus ** plus ** plus salt substantially reduced the amount of Fe** plus ** plus ** plus salt to be used for the removal of As at the same level.