| Abstract:This paper introduces a production practice at one paper machine in Zhejiang Jingxing Paper Co., Ltd., where oxidative biocides were optimized to inhibit acidification in the white water system. Based on the existing online addition of reactive oxidative biocides, an additional reaction unit and one more dosing point were installed, and the dosage at each addition point was optimized. After system optimization, the pH of the white water increased by 0.3–0.4 units, and the oxidation-reduction potential (ORP) increased by 50–100 mV. The bacterial count was reduced to the order of 10?. Furthermore, the volatile fatty acids (VFA) content in the paper machine effluent decreased by 28%, and the calcium ion concentration decreased by 22%. The acidification of the white water system was significantly improved. The irritating odor in the workshop was reduced, and the load on the subsequent wastewater treatment was also alleviated. In addition, the consumption of wet-end dry-strength agent decreased by 2.2 kg/t paper, reducing chemical costs by RMB 2.1 yuan/t paper and yielding an annual economic benefit of approximately 840,000 yuan. |