高碱度高盐工业废水资源化利用

Resource Utilization of High Alkalinity and High Salinity Wastewater

选用预处理-反渗透(RO)浓缩-树脂吸附-纳滤分盐-蒸发出盐的工艺处理高碱度高盐工业废水。结果表明,冷冻结晶和蒸发结晶产出的Na_(2)CO_(3)和NaCl产品纯度均大于99%,满足《工业盐》(GB/T5462—2015)工业干盐一级标准和《工业碳酸钠》(GB/T 210—2022)Ⅱ类一等品标准;纳滤分盐步骤产生的纳滤浓水可以代替石灰沉降树脂再生水中的钙离子、镁离子,树脂再生水经纳滤浓水沉淀后钙离子、镁离子均低于100 mg/L。本工艺能够实现高碱高盐工业废水和纳滤浓水的资源化利用。工艺全程保留水中碱度,未投加任何药剂,产生的污泥量少,能够有效减少运行费用并提高废水回收率。

The process of pretreatment-RO concentration-resin adsorption-nanofiltration salt separation-evaporation is selected to treat high alkalinity and high salinity industrial wastewater.The results showed that the purity of Na_(2)CO_(3),and NaCl products produced by freezing crystallization and evaporative crystallization was greater than 99%,meeting the first class standards for industrial dry salt in the Industrial Salt(GB/T 5462-2015)and the class Ⅱ first rate product for Sodium Carbonate for Industrial Use(GB/T 2102022);The nanofiltration concentrated water generated by the nanofiltration salt separation step can replace the calcium and magnesium ions in the lime setling resin regeneration water.The calcium ions and magnesium ions in the resin regeneration water after precipitation with the nanofiltration concentrated water are all below 100 mg/L.This process can achieve the resource utilization of high alkalnity and high salinity industrial wastewater and nanofiltration concentrated water.The process retains the alkalinity of the water throughout the entire process without adding any chemicals,resulting in a small amount of sludge generated,which can effectively reduce operating costs and improve wastewater recovery rate.