低温溶析结晶处理高浓度氯化钠废水及其资源化  

Low-Temperature Solvent-Out Crystallization for Treatment and Recycling of the High Sodium Chloride Wastewater

作　　者：方正楠 孟广源 付涛 常定明 陈鹏[1,2] 张乐华[1,2] FANG Zhengnan;MENG Guangyuan;FU Tao;Chang Dingming;CHEN Peng;ZHANG Lehua(National Engineering Laboratory for Industrial Wastewater Treatment,East China University of Science and Technology;National Key Laboratory of Environmental Risk Assessment and Control for Environmental Protection Chemical Processes,East China University of Science and Technology:Shanghai 200237,China)

机构地区：[1]华东理工大学工业废水无害化与资源化国家工程研究中心 [2]华东理工大学国家环境保护化工过程环境风险评价与控制重点实验室,上海200237

出　　处：《水处理技术》2023年第11期60-65,79,共7页Technology of Water Treatment

基　　金：国家重点研发计划(2019YFC0408202);国家自然科学基金(21876050)。

摘　　要：以能源化工行业常见产物甲醇作为溶析剂,研究了在低温条件下(≤0℃)溶析结晶回收高盐废水中氯化钠的调控方法,并结合氯化钠回收率与能耗分析优化了工艺条件。结果表明,当温度从20℃降低至-25℃时,氯化钠回收率由35.02%~52.07%提高到44.20%~62.81%,低温条件显著提高了氯化钠回收率。同时,随着温度降低,溶析结晶氯化钠晶体粒径变小,晶体形状由长方体逐渐变为正方体。当温度为-25℃,初始浓度300 g/L,搅拌速率500 r/min,搅拌时间60 min,醇水体积比2∶1时,低温溶析结晶法氯化钠回收率可达57.97%,能耗仅为三效蒸发的69%。本文研究甲醇溶析剂低温溶析工艺,为能源化工行业高浓度氯化钠废水的资源化利用提供了参考。In this study,methanol,a common product in the energy and chemical industry,was used as the salting-out agent.The regulation of sodium chloride recovery by low-temperature solvent-out crystallization was studied.Also,suitable conditions in low-temperature solvent-out crystallization were proposed by balancing NaCl recovery rate and energy consumption.The recovery of sodium chloride increased from 35.02%~52.07%at 20℃to 44.20%~62.81%at-25℃.The results showed that the low temperature can observe the increase in NaCl recovery rate,reduction of NaCl crystal size,and the evolution from rectangular shape to square shape.Meanwhile,when the temperature at-25°C,the volume ratio of alcohol and water was 2:1,an initial concentration of 300 g/L,and stirring at 500 r/min for 60 min,the NaCl recovery rate of triple-effect evaporation crystallization can achieve 57.97%,and the energy consumption was about 69%.The low-temperature solvent-out crystallization process using methanol as the saltingout agent provides a new idea for resource utilization of high sodium chloride wastewater.

关 键 词：低温 溶析结晶 氯化钠 甲醇 资源化 

分 类 号：X703.1[环境科学与工程—环境工程]