石灰、液碱、纯碱降低煤气化废水硬度的实验

Study on Reducing Hardness of Coal Gasification Wastewater by Lime,Liquid Alkali and Soda Ash

针对德士古煤气化废水硬度高、碱度高的特点,进行了降低废水硬度的研究。以安徽华谊污水处理站调节池废水为对象,采用加药混凝沉淀法,考察了聚合氯化铝(PAC)、聚丙烯酰胺(PAM)、Ca(OH)_2、NaOH、Na_2CO_3等药剂对废水硬度的影响。结果表明,在不投加石灰的情况下,废水硬度去除效果不明显;投加Ca(OH)_2后,硬度与投药量、搅拌强度及搅拌时间无明显关系,较好的去除率在30%左右;改用NaOH和Na2CO3组合投加,废水的硬度由865.18 mg/L降至98.22 mg/L,去除率达88%以上。实际生产中可优先投加NaOH、Na_2CO_3等药剂,以取得较高的硬度去除效果。

In view of the high hardness and alkalinity of Texaco coal gasification wastewater,the study on reducing the hardness of wastewater was carried out.The influences of PAC,PAM,Ca(OH)2,NaOH and Na2CO3 on the hardness of wastewater in the regulating tank of Anhui Huayi Sewage Treatment Station were investigated by the coagulation precipitation method.The results showed that under the condition without adding lime,the effect of hardness removal was not obvious.After adding Ca(OH)2,the hardness had no obvious relationship with dosage,stirring strength and stirring time,and the better removal rate was about 30%.In addition,the hardness of the wastewater was decreased from 865.18 mg/L to 98.22 mg/L and the removal efficiency was more than 88%by adding NaOH and Na2CO3.In actual production,it was necessary to give priority to adding NaOH,Na2CO3 and other agents so as to achieve a higher hardness removal effect.