Application of alum plant waste liquor in treatment of alkaline waste waters

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "dejavu="" sans";mso-hansi-theme-font:minor-latin;mso-bidi-font-family:mangal;="" mso-bidi-theme-font:minor-bidi;color:#00000a;mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The presence of acidity and dissolved aluminium in the alum plant waste liquor has been used in the treatment of wastewaters of alkaline nature. The wastewaters from soap plant, textile mill, copper ore-concentrate and milk processing plant were made to in-teract with the alum plant liquor in such volume ratios as to produce equilibrium <i>p</i>H of 7. Parallel runs to produce equilibrium <i>p</i>H 6 of the resulting mixtures were also carried out The percentage of removal of TDS and COD of the interaction fluids at the <i>p</i>H 7 were&nbsp; found to be 95.0 and 97.5, respectively, for in-teraction with the soap plant wastewaters, 82.3 and 93.2 with the textile wastewaters 75.5 and 92.3 with copper ore wastewaters, and 60.9 and 94.4 with milk processing wastewaters. There was also significant lowering in the values of ionic species. Compared to the interaction at the equilibrium <i>p</i>H of 6, that at the equilibrium <i>p</i>H of 7 was found to give a higher degree of removal of the pollutional characteristics of the wastewaters.</span>