Analysis of the Causes of Excessive Manganese and Discussion on Treatment Measures in a Waterworks in Cangnan County

Excessive manganese in the effluent of a waterworks in Cangnan County not only leads to sensory abnormalities of drinking water but also poses a potential threat to human health, which has become an urgent water quality problem to be solved. In this study, flame atomic absorption spectrophotometry was adopted to determine the manganese concentration in water samples at each treatment stage, so as to evaluate the actual effect of different manganese removal processes. Aiming at the problem of excessive manganese in raw water, the waterworks optimized the conventional water treatment process by taking measures such as strengthening pre-chlorination and adding potassium permanganate composite salt. The results showed that both measures could effectively oxidize soluble divalent manganese into insoluble tetravalent manganese, which was then intercepted and removed by the filter, and the manganese content in the final effluent was stably controlled below the limit value of 0.1mg/L specified in GB 5749-2022. This study not only effectively solved the problem of excessive manganese in the waterworks but also provided a practical and feasible technical reference for the treatment of excessive manganese in reservoir water sources of similar waterworks in southern China.