Comparison of four different neutralizers for the treatment of acidic waste water

Abstract

Four different neutralizers i.e. 1N NaOH, NaOH 98 %, Ca(OH)2 and Na2CO3 were tested to neutralize acidic wash water samples from positive plates having pH 1,2 and negative plates having pH 1, 2 from an automotive battery production plant. Comparison of the results shows that the minimum amount of neutralizer used was 1 N NaOH in the case of positive plate (0.052g) and negative plate (0.016 g) wash water with initial pH of 2.  This was followed by NaOH 98 % 0.06 g in the case of positive plate and 0.025 g in the case of negative plate, then Ca (OH)2 of 0.08 g in the case of positive plate and 0.07 g in the case of negative plate. The maximum amount used was that of Na2CO3 0.1 g both for the positive and negative plate wash water. For pH 1 positive plate wash water 1 N NaOH (0.285 g) was the minimum and NaOH 98 % (0.75 g) was maximum. However for the negative plate wash water of pH 1 the trend was reverse i.e. NaOH 98 (0.215 g) was minimum and 1N NaOH (0.568 g) was maximum for bringing the pH of acidic waste water to a neutral value of 7.