中国面临水资源短缺和水环境污染的严峻挑战，循环冷却水（占工业用水的70%–80%）的高效利用和水质管理显得尤为重要。循环冷却水系统的结垢、腐蚀和菌藻滋生问题突出。本研究提出一种循环冷却水选择性离子控制技术，通过选择性去除有害离子同时保留有益的含氧阴离子，有效控制系统的腐蚀、结垢和菌藻滋生问题，同时显著提高浓缩倍数。

本文通过失重和电化学测试，以及蒸发和结垢测试，深入研究了不同浓度含氧阴离子对腐蚀行为及其对水蒸发和钙垢生成的影响。全面调研和分析了加药控制下中央空调循环冷却水系统的运行参数与水质特征，为中试设备的运行研究提供了基础数据。通过实验优化了反冲洗、再生等设备运行参数，评估了中试设备的水质控制效果、运行稳定性、废水净化可行性和运行成本。

论文取得如下研究成果：

（1）含氧阴离子浓度的差异是引起金属腐蚀行为变化的主要原因。高浓度的HCO₃^-通过在碳钢表面形成钝化膜，将腐蚀速率控制在规范限值内。含氧阴离子的缓蚀能力依次为SiO₃^2-＞MoO₄^2-＞WO₄^2-＞HCO₃^-。尽管在高浓缩倍数下，仅依靠富集的含氧阴离子无法完全控制由Cl^-引发的腐蚀，但可以减少25%的商业缓蚀剂使用量，并显著降低系统的蒸发损耗。

（2）中央空调循环冷却水系统的补充水水质总体稳定，磷浓度几乎为零。加药法控制下系统腐蚀速率略超标，总铁浓度符合规范，但循环冷却水的水质异常浑浊，浊度、COD_Cr、Mg²⁺×SiO₂和钙硬度+全碱度显著超过规范限值。最高总磷浓度达到42 mg L^-1，浊度（2.3–61 NTU）和有机物浓度分别为工业规范限值的0.23–6.1倍和1.1–3.5倍。以电导率、Ca²⁺、Mg²⁺、Cl^-、SO₄^2-和有机物计的浓缩倍数分别为8.9–13、7–8、10–19、19–46、11–27和31–45倍。频繁添加的药剂是循环冷却水中总磷、浊度和总氮的主要来源，加剧了菌藻问题，导致水质异常浑浊，需探索更有效的水质控制策略。

（3）循环冷却水系统的补充水量和流量分别主要受当日最高气温和系统开启状态影响。优化的反冲洗（10 min）、再生（0.5 mol L^-1 NaCl, 60 min）及水洗（1.5 min）流程有效保障了生产性实验设备对循环冷却水的稳定净化。通过回用静置后的反冲洗废水和化学沉淀法（先加NaOH，再加Na₂CO₃）处理后的废弃再生液，显著降低26%的运行成本。选择性离子控制技术下的循环冷却水系统在超高浓缩倍数和补充水质波动条件下，实现了长期稳定运行，系统腐蚀速率在规范限值内，有效控制了循环冷却水系统的腐蚀、硬度、浊度及菌藻。循环冷却水感官上澄清透明，以电导率计的最大浓缩倍数达到30倍，是常规加药法最高水平的2.3倍，最高浊度仅为加药法的1/10，Ca²⁺和Mg²⁺浓度仅为加药法的1/10–1/6和1/12–1/6。设备运行成本为0.23元每立方米，展现了选择性离子控制技术在水质控制领域的巨大潜力。

China is facing severe challenges of water scarcity and water environmental pollution, making the efficient utilization and quality management of circulating cooling water (accounting for 70%–80% of industrial water use) particularly important. The issues of scaling, corrosion, and microbial growth are prominent in circulating cooling water systems. In this study, a selective ion control technology for circulating cooling water is proposed, which can effectively control the corrosion, scaling and microbial growth of the system by selectively removing harmful ions while retaining beneficial oxygenated anions, and at the same time significantly increase the concentration ratio.

Through weight loss and electrochemical tests, as well as evaporation and scaling tests, this study deeply investigated the effects of different concentrations of oxygenated anions on corrosion behavior and their impact on water evaporation and calcium scale formation. The operating parameters and water quality characteristics of the central air conditioning circulating cooling water system under dosing control were comprehensively investigated and analyzed, providing foundational data for pilot-scale equipment operation research. The operating parameters of the backwashing and regeneration equipment were optimized through experiments, and the water quality control effect, operating stability, wastewater purification feasibility and operating cost of the pilot equipment were evaluated.

The study achieved the following research results:

(1) Differences in the concentration of oxygenated anions are the primary cause of variations in metal corrosion behavior. High concentrations of HCO₃^- form a passivation film on the surface of carbon steel, keeping the corrosion rate within regulatory limits. The corrosion inhibition capability of oxygenated anions is in the order of SiO₃^2- > MoO₄^2- > WO₄^2- > HCO₃^-. Although the corrosion initiated by Cl^- cannot be completely controlled by relying only on the enriched oxygenated anions at high concentration ratios, it is possible to reduce the use of commercial corrosion inhibitors by 25% and significantly reduce system evaporation losses.

(2) The supplementary water quality of the central air conditioning recirculating cooling water system is generally stable, with almost zero phosphorus concentration. The corrosion rate of the system under the dosing method slightly exceeded the standard, and the total iron concentration complied with standards, but the water quality of the circulating cooling water was abnormally turbid, and the turbidity, COD_Cr, Mg²⁺×SiO₂, and calcium hardness + total alkalinity significantly exceeded standard limits. The highest total phosphorus concentration reached 42 mg L^-1, and the turbidity (2.3–61 NTU) and organic matter concentrations were 0.23–6.1 and 1.1–3.5 times the industrial standard limits, respectively. Concentration multiples in terms of conductivity, Ca²⁺, Mg²⁺, Cl^-, SO₄^2-, and organic matter were 8.9–13, 7–8, 10–19, 19–46, 11–27 and 31–45 times. The frequent addition of chemicals is the main source of total phosphorus, turbidity, and total nitrogen in the circulating cooling water, exacerbating the bacterial and algal problems and leading to abnormally turbid water quality, necessitating the exploration of more effective water quality control strategies.

(3) The supplementary water volume and flow rate in the circulating cooling water system are primarily influenced by the day's maximum temperature and the operational status of the system. The optimized processes of backwashing (10 min), regeneration (0.5 mol L^-1 NaCl, 60 min), and water rinsing (1.5 min) effectively ensured the stable purification of recirculating cooling water by the production experimental facility. By reusing settled backwash wastewater and treating the discarded regeneration solution with a chemical precipitation method (initially adding NaOH, then Na₂CO₃), the operating cost was reduced by 26%. The recirculating cooling water system under selective ion control technology achieved long-term stable operation under the conditions of ultra-high concentration ratios and fluctuations in the quality of supplemental water. The system corrosion rate remains within regulatory limits, effectively controlling corrosion, hardness, turbidity, and microbial growth in the recirculating cooling water system. The circulating cooling water was organoleptically clarified and transparent, with the maximum concentration ratio of 30 in terms of conductivity, which was 2.3 times that of conventional dosing method. The maximum turbidity was only 1/10 of that method, and the concentrations of Ca²⁺ and Mg²⁺ were only 1/10–1/6 and 1/12–1/6, respectively. The operating cost of the equipment was 0.23 yuan per cubic meter, showing the great potential of selective ion control technology in the field of water quality control.