Commonly used chemical absorbents include the following: alkaline solution, acidic solution, sodium hypochlorite solution. Alkaline absorbing liquids usually contain 1-10% sodium hydroxide solution, which is very effective for eliminating hydrogen sulfide. Others such as methyl mercaptan, methyl sulfide, methyl disulfide, and lower fatty acids often cause odor in wastewater treatment plants. The substance, this method can get the best treatment effect.
Acid washing is mainly used to eliminate the odor caused by alkaline gases such as ammonia and trimethylamine. Generally, sulfuric acid (0.5-5% solution) is used as the washing liquid.
Sodium hypochlorite is generally used together with an acid-base absorbent. For the methyl sulfide which is difficult to eliminate by other methods, the control effect of using the sodium hypochlorite absorbent is very good. When treating a high concentration odor in a sewage treatment plant, the concentration of sodium hypochlorite solution (effective chlorine concentration) is about 500-2000 ppm. When treating lower concentrations of odor, the sodium hypochlorite solution is used at a concentration of about 50-500 ppm. In terms of the performance of various oxidants, sodium hypochlorite zui is cheap and the effect is good, so it is most commonly used.