Department of Chemical Engineering Technology, Yanbu Industrial College, Yanbu Al-Sinaiyah, Saudi Arabia.
J Hazard Mater. 2012 Sep 30;233-234:97-102. doi: 10.1016/j.jhazmat.2012.06.061. Epub 2012 Jul 6.
One of the problems that encounters desalination industry is the fouling that takes place due to the poor quality of the sea water received, especially when it rains. In such a situation, the sea water reaches the desalination plant having high turbidity. Chitosan was tested as a coagulant in the removal of the turbidity of sea water to replace inorganic coagulants having hazardous effects. Jar test was performed to test some factors that may affect the coagulation process. The factors tested were dose of coagulant (0-370 mg/L), initial pH (2-11), type of coagulant (chitosan versus metal coagulants), and the chitosan solvent. Chitosan's turbidity removal efficiency was found to be greater than ferrous sulfate and comparable to that of alum. While most researches emphasize the use of chitosan in acidic or neutral media, it worked well in the alkaline pH. The highest turbidity removal efficiency of 97.5% was obtained at initial pH of 8.1. The optimum dose was found to be 18 mg/L. Chitosan dissolved in HCl was found to perform better than that dissolved in acetic acid. Comparable turbidity removal efficiencies were obtained using alum and chitosan. However, much higher doses were used when using alum which implies higher cost and increase of residual aluminum concentration in treated water.
海水淡化行业面临的问题之一是由于所接收海水水质较差而导致的结垢问题，尤其是在下雨时。在这种情况下，海水会带着高浊度进入海水淡化厂。壳聚糖被测试为一种混凝剂，用于去除海水的浊度，以替代具有危险影响的无机混凝剂。通过烧杯试验测试了可能影响混凝过程的一些因素。测试的因素有：混凝剂剂量（0-370mg/L）、初始 pH 值（2-11）、混凝剂类型（壳聚糖与金属混凝剂）和壳聚糖溶剂。壳聚糖的浊度去除效率大于硫酸亚铁，与硫酸铝相当。虽然大多数研究强调壳聚糖在酸性或中性介质中的使用，但它在碱性 pH 值下效果良好。在初始 pH 值为 8.1 时，获得了 97.5%的最高浊度去除效率。最佳剂量为 18mg/L。在 HCl 中溶解的壳聚糖比在醋酸中溶解的壳聚糖性能更好。使用硫酸铝和壳聚糖可以获得相当的浊度去除效率。然而，使用硫酸铝时需要使用更高的剂量，这意味着成本更高，处理水中的残留铝浓度增加。
