Sichuan Jinxiang Chemical’s **wastewater recycling technology has passed evaluation**

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Sichuan Jinxiang Chemical’s **wastewater recycling technology has passed evaluation. According to Sichuan Jinxiang Chemical, on September 25, 2020, the China Nitrogen Fertilizer Industry Association organized experts to evaluate the membrane filtration integrated technology for the recycling of phosgene wastewater, which was developed jointly by Sichuan Jinxiang Sairui Chemical Co., Ltd. and Sichuan Lvwo Innovation Environmental Protection Engineering Co., Ltd., as a scientific and technological achievement. An expert group composed of 12 senior experts from fields such as fertilizer industry, coal chemical engineering, and environmental protection, led by Gu Zongqin, the president of the China Fertilizer Industry Association, unanimously concluded after evaluation that the project’s technical specifications are advanced, with its overall technology reaching a leading level in China. The expert group also recommended that the implementing entity continue to develop this technology in order to increase the concentration of the concentrated phase to over 18%, and to minimize the amount of water introduced into the recovered concentrate, thereby reducing the energy consumption for evaporation in the system. The main innovations of this technology are as follows. First, develop an integrated technology for multi-stage reverse osmosis membrane diafiltration concentration. The system does not feature a reverse osmosis design; it employs a cross-flow staged pressurization process to ensure stable operating pressure for each membrane element, thereby improving the efficiency of these elements, reducing the load of membrane fouling, and enabling a service life of over 3 years. Second is the development of high anti-fouling technology for roll-type membrane elements. Prevent high-concentration *ao acid an solutions from causing clogging in the membrane elements, thereby reducing the operational costs of the equipment. Third, maintain the pH of the *ao acid an wastewater between 6.8 and 7.2, and the temperature between 25 and 35°C. Improve the rejection efficiency of the reverse osmosis membrane for *ao acid an, with the concentrate concentration reaching 6%–10%, while obtaining reclaimed water with a conductivity of ≤10 uS/cm. Fourth is system automated control. It enables real-time collection, storage, and analysis of the equipment’s operating status (parameters), providing timely and comprehensive data analysis for system operation, facilitating automatic adjustments, and thereby enhancing the level of intelligence. Automatic control of the concentration ratio can be achieved. When there are significant fluctuations in the process parameters of the materials fed into the device, this technology can reduce such fluctuations, thereby **improving the stability and fault tolerance of the device. This technology has been operating stably at Chuanjinxiang Company for three years. The service life of the main vulnerable component in this device, namely the membrane, is over 3 years. The main cost factor is electricity consumption, which is measured using separate meters for assessment. The overall treatment cost is 2.31 yuan per ton of water. The investment required is 40% less compared to previous ion exchange systems; the payback period is less than 10 months. This approach truly enables our Chuanjinxiang Company to achieve **zero wastewater discharge**, thereby reducing the environmental pressure on the company. There is 1,000 m3 of acidic anion wastewater, which was previously treated using the ion exchange method. The original water conditions for this technology are as follows: the treatment volume is 38–40 m3/h, conductivity is 5000–8000 uS/cm, pH value is 6.5–7.5, and temperature is 25–35°C. The indicators achieved after treatment are: a conductivity of 5–30 uS/cm for the recycled fresh water (**concentration: 4.5–28 mg/L), and a conductivity of 100,000–120,000 uS/cm for the recycled concentrated water (**concentration: approximately 90–112 g/L). The operating load of the equipment can reach 110%.