切削液废水处理技术研究进展

在机械加工和制造业中，切削液被广泛应用于工件的冷却、清洗、防锈和润滑，产生大量废切削液。切削液废水中含有大量乳化油、添加剂(表面活性剂、缓蚀剂、消泡剂)，以及废油、粉尘和金属屑等杂质，排放前需经过严格的处理。切削液废水处理大致分为物理、化学和生物法3大类。不同的处理方法有各自的优缺点。物理法中的膜分离技术具有效率高、占地小、无二次污染等优点，是处理切削液废水的有效技术；但膜污染问题限制了膜过滤技术的大规模引用，开发机械强度高、亲水性的新型膜材料是重要的研究方向。传统的混凝法处理成本较低，然而混凝产生的大量矾花沉淀还需进行二次处理。氧化法能够将污染物矿化为无害无机物，但处理成本很高。由于切削液废水的成分复杂，具有生物毒性，无法对其进行单独的生物处理；可将生物处理单元与氧化过程联用，先通过氧化法提高废水的可生化性，再进行成本低廉的生物处理；这样既能够节约氧化剂用量，也可完成切削液废水的深度处理。本文在综述切削液废水处理技术的研究进展基础上，提出了现有处理工艺中存在的问题，探讨了解决的思路，可为切削液废水处理技术的发展提供参考。

Progresses in the treatment processes and techniques for cutting fluid wastewater

In machining and manufacturing, cutting fluids are widely used for cooling, cleaning, rust prevention and lubrication of workpieces, resulting in a great amount of waste cutting fluids. Cutting fluid wastewater contains emulsified oil, additives (surfactants, corrosion inhibitors, defoamers), and impurities such as waste oil, dust, and metal chips, which must be appropriately treated prior to environmental discharge. Cutting fluid wastewater treatment could be divided into three main approaches: physical, chemical and biological methods. Different treatment methods have distinct advantages and disadvantages. Membrane separation is a typical physical treatment approach, carrying the advantages of high efficiency, small area, and no secondary pollution, among others, which has been regarded as an effective technology for handling cutting fluid wastewater. Nonetheless, the problem of membrane pollution limits the large-scale application of membrane filtration technology. The development of high mechanical strength, new hydrophilic membrane materials are an important research direction. The traditional coagulation method is a chemical method, and the treatment cost is relatively low. Nevertheless, a large amount of alum precipitation produced by coagulation needs to be processed twice. The oxidation method can mineralize pollutants into harmless inorganic substances, but the processing cost is high. Because the composition of cutting fluid wastewater is complex and toxic, it cannot be subjected to separate biological treatment. The biological treatment unit can be combined with the oxidation process, and the biodegradability of the wastewater can be improved by the oxidation method, and then the low-cost biological treatment can be carried out. This can not only save the amount of oxidant but also complete the advanced treatment of cutting fluid wastewater. Based on the state-of-the-arts of cutting fluid wastewater treatment technology, this article puts forward the existing problems in current treatment processes, and discusses potentials to optimize cutting fluid wastewater treatment technology.