Project Overview

案例概述

1. The Zero Liquid Discharge Wastewater Project of Linggu Chemical Group Co., Ltd. was put into operation in August 2022, located at No. 8 Xiyi Road, Yixing Economic and Technological Development Zone, Jiangsu Province.

灵谷化工集团有限公司污水零排放项目于2022年8月投用，位于江苏省宜兴经济技术开发区锡宜路8号。

2. The project adopts a treatment process of "pre-treatment + membrane concentration + membrane salt separation + evaporation and crystallization," with an annual capacity to treat approximately 2.8 million tons of various types of wastewater, achieving solid-liquid separation.

项目采用“预处理+膜浓缩+膜分盐+蒸发结晶”的工艺，年处理各种废水约280万吨，实现废水固液分离。

3. Meanwhile, it ensures that all produced water meets the standards for reuse as makeup water in circulating cooling systems, with an annual recycled water volume of about 2.6 million tons.

同时保证装置产水全部达标回用于循环水补水，年回收水量约260万吨。

4. The salts in the wastewater are crystallized into sodium chloride and sodium sulfate, with an annual production of approximately 5,000 tons, meeting the corresponding industrial-grade standards for resource utilization. This achieves true zero liquid discharge of wastewater.

废水中的盐分分别以氯化钠、硫酸钠的形式结晶出来，年产约5000吨，达到相应工业级标准并资源化利用，实现真正意义上的污水零排放。

Company/Organization Profile

机构简介

1. Linggu Chemical Group Co., Ltd., located in the Yixing Economic and Technological Development Zone of Jiangsu Province, currently has an annual production capacity of 1 million tons of synthetic ammonia, 1.17 million tons of urea, 1.3 million tons of urea aqueous solution, 200,000 tons of industrial-grade carbon dioxide, as well as various products such as liquid oxygen, liquid argon, and liquid nitrogen.

灵谷化工集团有限公司位于江苏省宜兴经济技术开发区内，目前年产100万吨合成氨、117万吨尿素、130万吨尿素水溶液、20万吨工业级二氧化碳以及液氧、液氩、液氮等多种产品。

2. In 2024, the company achieved revenues exceeding RMB 4 billion and paid taxes amounting to RMB 468 million. It is a technologically advanced and well-equipped coal-based synthetic ammonia manufacturer in Jiangsu Province and the region south of the Yangtze River.

2024年公司营收超40亿元，上交税收4.68亿，是江苏省暨长江以南地区技术先进、装备领先的煤制合成氨企业。

Project Outcome

项目成果

1. After the commissioning of the Zero Liquid Discharge (ZLD) project, industrial wastewater is no longer discharged externally, reducing the release of pollutants such as COD, ammonia nitrogen, total phosphorus, and total nitrogen from the originally discharged water.

污水零排放项目投运后，不再外排工业废水，减少了原排放水中COD、氨氮、总磷、总氮等各种污染物的排放。

2. Approximately 2.6 million tons of water are recycled annually, decreasing the demand for make-up freshwater.

年回收水量约260万吨，降低了一次水的补充量。

3. Additionally, about 5,000 tons of industrial salt are produced each year, thereby achieving comprehensive recycling and utilization of water resources.

年产约5000吨工业盐，实现了水资源的综合循环利用。

Project Highlights

项目亮点

1. The project was selected as one of the "Top Ten Typical Cases of Eco-Environmental Technological Achievements Boosting Green, Low-Carbon, and Environmental Protection Industries in 2023" released by the Jiangsu Provincial Department of Ecology and Environment.

项目入选江苏省生态环境厅公布的“2023年度生态环境科技成果助力绿色低碳环保产业十大典型案例”。

Project Implementation

项目实施

1. The project, with an investment of nearly RMB 200 million, adopts a process tailored to the characteristics of nitrogen fertilizer wastewater: pretreatment + membrane concentration + membrane-based salt separation + evaporation crystallization.

项目投资近2亿元，针对氮肥行业污水特性，采用“预处理+膜浓缩+膜分盐+蒸发结晶”的工艺技术。

2. During the pretreatment and membrane concentration stages, ultrafiltration and reverse osmosis technologies are used to filter out impurities such as macromolecular organics, colloids, and soluble compounds.

在预处理、膜浓缩过程中，使用超滤和反渗透过滤技术，滤除污水中大分子有机物、胶体、溶解性化合物等杂质。

3. In the critical salt separation step, nanofiltration and high-pressure reverse osmosis are employed to divide the high-salinity wastewater into two streams: sodium chloride-rich water and sodium sulfate-rich water.

最关键的分盐环节采用纳滤和高压反渗透技术，将高盐废水分离成氯化钠浓水及硫酸钠浓水两部分。

4. The salt recovery technology applied in the project is a combination of membrane separation and evaporation crystallization. The nanofiltration unit separates sodium chloride from sodium sulfate in the water.

项目采用的盐回收技术是膜分离+蒸发结晶工艺，纳滤单元将水中的氯化钠与硫酸钠分离。

5. The sodium chloride-rich stream undergoes triple-effect concentration, crystallization, separation, and drying; while the sodium sulfate-rich stream is treated by freeze crystallization to precipitate Glauber's salt, which is then thermally melted, concentrated, and crystallized into sodium sulfate crystals before drying.

含氯化钠的一侧采用蒸发工艺三效浓缩结晶并分离干燥结晶盐，含硫酸钠一侧采用冷冻结晶工艺析出芒硝再热熔，浓缩析出硫酸钠晶体并干燥结晶盐。

6. This process route is a mainstream conventional approach for high-salinity wastewater treatment, with relatively mature and stable operation.

该工艺路线是高盐水处理的主流常规路线，技术较成熟，运行稳定。

7. Since the Zero Liquid Discharge (ZLD) project was put into operation, no industrial wastewater has been discharged externally, reducing the release of pollutants such as COD, ammonia nitrogen, total phosphorus, and total nitrogen from the original effluent.

污水零排放项目投运后，不再外排工业废水，减少了原排放水中COD、氨氮、总磷、总氮等各种污染物的排放。

8. Approximately 2.6 million tons of water are recycled annually, reducing the demand for fresh makeup water. About 5,000 tons of industrial salt are produced each year, achieving comprehensive recycling and utilization of water resources.

年回收水量约260万吨，降低了一次水的补充量；年产约5000吨工业盐，实现了水资源的综合循环利用。

9. Comparison Before and After Implementation: Before the project, industrial wastewater was discharged externally, causing pollutant emissions and wasting water resources; after implementation, wastewater is fully recycled, pollutants are zero-emission, and salts are resourcefully utilized, achieving environmental and economic benefits.

实施前后对比：项目实施前，工业废水外排，产生污染物排放且浪费水资源；实施后，废水全量回收利用，污染物零排放，盐分资源化利用，实现环境效益与经济效益双赢。

Project Impact & Sustainability

项目影响力、可推广性与可持续性

1. According to the "Jiangsu Province Taihu Lake Water Pollution Prevention and Regulation Ordinance," the construction, expansion, or renovation of enterprises and projects that discharge pollutants such as phosphorus and nitrogen is prohibited in the first, second, and third-grade protected areas of the Taihu Lake Basin.

根据《江苏省太湖水污染防治条例》，太湖流域一、二、三级保护区禁止新建、改建、扩建排放含磷、氮等污染物的企业和项目。

2. The Zero Liquid Discharge (ZLD) project of Linggu Chemical Group Co., Ltd. provides technical support for the company’s upgrading and transformation, while also offering a new approach for the sustainable development of enterprises within the protected zones of the Taihu Lake Basin.

灵谷化工集团有限公司的污水零排放项目为企业升级改造提供了技术支撑，也为太湖流域保护区内企业可持续发展提供新思路。

(Using AI translation)

（使用AI翻译）