摘要：

以西南地区某锌冶炼废水工程为例，针对锌冶炼废水系统存在的产水率低、产水水质差的情况，从工程概况及物料计算出发，重新设计深度处理工艺及选型设备，最终确定采用“中、高压反渗透浓缩减量+低压反渗透脱盐淡化”深度处理工艺。废水依次经过多介质过滤器、外压式超滤装置、螯合树脂软化，出水进入中压反渗透（一级RO）+高压碟管式反渗透（DTRO）浓缩，中高压RO浓水冲渣消耗，中高压RO产水再辅以低压反渗透（二级RO）脱盐淡化，二级RO产水回用作循环水系统的补充水。该改造工程实现了废水高倍浓缩，产水总溶解性固体（TDS）26~37 mg/L、总硬度（以CaCO₃计）2~8 mg/L、电导率34.8~78.2 μS/cm，浓水外排率≤15%，系统回收率≥68%，脱盐率≥98%，废水资源化的运行成本为7.63元/m³（扣减收益），为锌冶炼废水反渗透高倍浓缩处理提供借鉴。

关键词: 锌冶炼废水, 膜高倍浓缩, 水盐平衡, 废水资源化

Abstract:

This paper presented a modified project case of high-efficiency concentrated wastewater from a zinc smelting enterprise in the southwestern region of China. The project overview, existing challenges, material calculations were considered to redesign advanced treatment process and to select equments. The “medium- and high-pressure reverse osmosis (RO) concentration with low-pressure RO desalination” process was introduced. Wastewater was sequentially treated through multimedia filters, ultrafiltration units, and resin softening, followed by medium-pressure RO (first-stage RO) and high-pressure DTRO for concentration. Low-pressure RO was employed to desalinate the permeate from the medium- and high-pressure RO. The resulting water was utilized for new water production, while concentrated brine was used for slag washing. This project achieved a high-efficiency concentration process for wastewater, producing water with total dissolved solids (TDS) of 26 to 37 mg/L, total hardness (as CaCO₃) of 2-8 mg/L, and conductivity of 34.8 μS/cm to 78.2 μS/cm, with brine concentrations ≤15%. The system recovery rate was ≥68%, and the desalination rate was ≥98%. The operational cost for wastewater resource utilization was 7.63 yuan/m³ (after deducting revenue). This study aimed to provide a reference for reverse osmosis applications in high-efficency concentration of zinc smelting wastewater.

Key words: zinc smelting wastewater, high-efficiency membrane concentration, salt-water balance, wastewater resource utilization

中图分类号: 

• X703