Abstract

Presence and deposition of sparingly soluble salts, known as scale, has been one of utmost damaging problems of circulating water. In industry, the scaling phenomenon may cause technical problems such as reduction of heat transfer efficiency in cooling systems and obstruction of pipes. Therefore, adding scale inhibitors that exhibit desired efficiencies to control scale is so important to mitigate adverse effect in water circulation systems because of their high tolerance for cations, such as Ca²⁺, Mg²⁺, and their ability to efficiently dissolve the unstable polymorphs of inorganic salts at the early stages of crystallization, thus impairing scaling. This paper reviews the research progress and state-of-the-art developments of scale inhibitors, including natural scale inhibitors and synthetic scale inhibitors. Natural scale inhibitors, including natural organic and plant extract scale inhibitors, are non-toxic, inexpensive, widely used, biodegradable and in line with the characteristics of green chemistry. Synthetic scale inhibitors mainly composed of phosphorous, polycarboxylic acid and polyaspartic acid are widely used due to their excellent performance. Detailed comparison between natural scale inhibitors and synthetic additives alongside future directions towards antiscalant are also discussed. The former are less water-soluble, while the latter require a large dosage, which causes a great burden to the environment. In particular, the need for developing green, efficient, easy preparation, and pollution-free scale inhibitors, studying the interactions between scale inhibitors and metal ions is stressed. It is expected that this paper could offer an insight in deeper understanding the scale inhibitors in industry and provide some clues for exploring more advanced scale inhibitors technologies.

中文翻译：

---

工业循环水系统的阻垢剂：综述

摘要

难溶盐的存在和沉积（称为水垢）一直是循环水的最大破坏性问题之一。在工业中，结垢现象可能会导致冷却系统传热效率降低和管道阻塞等技术问题。因此，添加具有所需效率的阻垢剂以控制水垢对于减轻水循环系统中的不利影响非常重要，因为它们对阳离子（如 Ca ²⁺、Mg ^{2+ ）具有很高的耐受性}，以及它们在结晶早期有效溶解不稳定的无机盐多晶型物的能力，从而削弱结垢。本文综述了阻垢剂的研究进展和最新进展，包括天然阻垢剂和合成阻垢剂。天然阻垢剂，包括天然有机阻垢剂和植物提取物阻垢剂，无毒、价格低廉、应用广泛、可生物降解，符合绿色化学的特点。主要由磷、聚羧酸和聚天冬氨酸组成的合成阻垢剂因其优异的性能而被广泛使用。还讨论了天然阻垢剂和合成添加剂之间的详细比较以及阻垢剂的未来方向。前者水溶性较差，而后者用量大，对环境造成很大负担。特别强调开发绿色、高效、易制备、无污染的阻垢剂，研究阻垢剂与金属离子的相互作用。期望本文能为更深入地了解工业阻垢剂提供见解，并为探索更先进的阻垢剂技术提供一些线索。