奈米薄膜過濾水回收模型廠最適化操作探討

Investigating the Optimum Operations of a Nanofiltration Membrane Water Recovery Plant

余嘉誠(CHIA-CHENG YU)

指導教授 ： 莊順興

朝陽科技大學/理工學院/環境工程與管理系/碩士(2017年)

摘要

目前，台灣水回收之實廠多運用逆滲透 (Reverse osmosis, RO) 薄膜系統作為水回收核心技術，雖然逆滲透薄膜系統具有良好產水之品質，但逆滲透系統操作上具有許多缺陷，如：操作壓力高、能源消耗大與進流水水質要求高等缺點。因此，本計畫目的係希望透過運用新興起之奈米過濾(Nanofiltration, NF)，發揮其低壓操作之優勢，利於水再生回收系統發展推動與落實運用。
本研究針對奈米過濾模型廠一段系統及二段系統進行操作與探討，實驗結果顯示，一段系統操作中相同進流量條件下，系統壓力隨著回收率提升亦呈現上升趨勢，其通量亦相對提高，因而造成對於產水中鹽分比例下降，降低產水中導電度，可進一步優化水質。
二段系統操作模式結果顯示，固定進流量模式為二段系統最適化操作模式。進流量 5.4 m3/h 條件下，連續操作 29 天產水平均導電度為 350 µS/cm，操作壓力無顯著上升，平均單位產水量之能源耗損為0.21 kWh/m3，其為本奈米過濾模型廠之最適化操作條件。

關鍵字

水回收 ； 奈米過濾 ； 模型廠 ； 水回收率 ； 截流率 ； 液體壓力損失

並列摘要

Most conventional full scale water recovery plants in Taiwan apply Reverse osmosis (RO) membrane systems as their core recovery technology. Despite the excellent permeate quality of RO systems, it still suffers from drawbacks such as high operating pressures, extensive energy usage and a demand for feed waters of high quality. Therefore, this research hopes to utilize the low operating pressure advantage of Nanofiltration (NF) membrane in developing water recovery systems.

This study operates and investigates a one-stage and two-stage system of a pilot scale NF plant. Experimental results demonstrate that under same feed flow rate in the one-stage system, the pressure and permeate flux increases with the recovery rate. The salts in the permeate are therefore diluted resulting in low conductivities, enhancing its quality.

The two-stage system focuses on operation, and it's determined that constant feed flow rate is the best operation type. After 29 days of continuous operation and 5.4 m3/h feed flow rates, the average conductivity in the permeate was 350 us/cm. No significant increase in pressure was observed. The optimum operation for the NF pilot plant can be achieved when the average energy consumption per unit of per mar production is 0.21 kWh/m3.

並列關鍵字

nanofiltration ； water reuse ； pilot scale ； recovery ； rejection ； pressure drop

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