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“Research on the Efficient Operation and Optimization of Zero-Discharge Wastewater Treatment Systems in Coal Chemical Industry – Passed the Evaluation. Author/Source: Gasification World. Date: June 23, 2022. Clicks: 22. At the request of companies such as Zhongtian Hechuang Energy Co., Ltd., Sinopec Research Institute of Petroleum Processing, and Sinopec Great Wall Energy Chemical Co., Ltd., on June 15, 2022, the China Coal Industry Association entrusted the China Coal Processing and Utilization Association to organize a meeting of 7 experts in Beijing to conduct an evaluation of the scientific and technological achievements related to the efficient operation and optimization of zero-discharge wastewater treatment systems in the coal chemical industry. Due to the impact of the pandemic, the meeting was held in a hybrid format, combining online and offline elements. This study developed an enhanced hardening removal process based on oxidative complexation disruption pretreatment, along with corresponding complexation disruptants, to address the impact of scale-inhibiting dispersants in zero-discharge wastewater treatment systems for coal chemical industries; this approach improved the efficiency of hardening removal by over 30% through chemical precipitation. It was revealed that excessive carbonate alkalinity is the main cause of calcium scaling on the membrane surface as well as high acid and base consumption. The study demonstrated the incomplete applicability of the solubility product principle in the softening of wastewater with high salt content and negative hardness, and a technology for simultaneous hardening and alkalinity removal was developed based on the collision reaction mechanism. This study resulted in 4 patent applications and 1 core paper publication. Since 2021, industrial trials have been conducted on the wastewater treatment system at Zhongtian Hechuang Chemical Co., Ltd.; the total hardness of the water exiting the high-density tanks was reduced from 126 mg/L to 67.4 mg/L, resulting in a 46% improvement in hard water removal efficiency. The amount of acid and alkali chemicals used was reduced by 50%, the overall cost per ton of water treated was cut by 36%, and the operating life of the membranes was extended by 200%–300%. The treatment cost per ton for high-density ponds dropped from 4.11 yuan/ton in 2019 to 2.63 yuan/ton, a reduction of 36%. In 2021, the volume of water treated was 1050×104 m3, resulting in annual savings of over 16 million yuan in treatment costs. The appraisal committee unanimously agreed that this technology addresses the key issue of low efficiency in chemical methods for removing hardness in zero-discharge treatment systems for high-salinity water in typical coal chemical enterprises; it enables operation with low chemical consumption, low costs, and improved efficiency, and its achievements are at the leading level in China. Suggestion: Change the project name to “Key Technologies for Efficient Hardness Removal in Zero-Discharge Wastewater Treatment Systems for Coal Chemical Industry”.