Application of potassium permanganate and diatomite in enhanced coagulation treatment of a black-odour water body

In this paper, a small, closed, black-odour water body with poor fluidity in Jurong City was taken as the research object, and the influencing factors and removal efficiency of enhanced coagulation with potassium permanganate (PP) and diatomite (DE) were evaluated. The quadratic regression models based on response surface methodology (RSM) were established to optimize the dosage of each reagent. The experimental results showed that treatment of the black-odour water body by enhanced coagulation combining PP and DE had a significantly greater effect than conventional coagulation with only the addition of polyaluminium chloride (PAC). The optimum pre-oxidation time of PP was 5 min, the optimum dosages of PAC, PP and DE were 34.047, 2.005 and 103.004 mg/L, respectively, and the removal rates of ammonia nitrogen (NH₄ ⁺-N), the chemical oxygen demand (COD) and the UV absorbance (UV₂₅₄) reached 72.824%, 76.599% and 86.927%, respectively. The actual error between the experimental results and the values predicted by the models was less than 5%, indicating that the models can predict the actual effects of the combined use of PP and DE in the treatment of black-odour water well as well as guide engineering applications and reduce chemical costs.