Department of Chemical Engineering, National Technical University of Athens, Zographou Campus, PC 157 73 Athens, Greece.
Water Sci Technol. 2010;61(3):581-9. doi: 10.2166/wst.2010.859.
The aim of this work is to examine copper removal from sludge permeate with the use of low-cost minerals of Mediterranean origin combined with ultrafiltration membranes. The minerals used were zeolite (clinoptilolite), bentonite and vermiculite. Activated sludge was enriched with 0.01 N (317.7 ppm) of Cu(II). Fixed concentrations of minerals were added to sludge and the pH value was adjusted at 5.5. The mixture was agitated for 2 hours at 800 rpm at room temperature and was then filtered through a batch ultrafiltration system for 1 hour. This experiment was repeated, for comparison purposes, with sludge enriched with 0.01 N of Cu(II) with no mineral addition. The results showed that ultrafiltration membranes with no mineral addition were able to remove a significant amount of copper with removal efficiencies ranging from 59.4-78.3%. The addition of 10 g/l and 20 g/l of bentonite combined with ultrafiltration membranes resulted in removal efficiencies of 94.9% and 99.4% respectively and that of 10 g/l and 20 g/l of vermiculite in removal efficiencies of 93.8% and 96.8%, respectively. The ion exchange capacity of minerals followed the order bentonite > vermiculite > zeolite. Furthermore, membrane fouling was investigated. The addition of zeolite and bentonite reduced membrane fouling, while the addition of vermiculite did not impact on fouling. The use of low-cost minerals in combination with ultrafiltration membranes can be employed to treat industrial wastewater, resulting in a final effluent with very low copper concentrations.
本工作旨在研究使用来自地中海的廉价矿物与超滤膜结合去除污泥渗透液中的铜。所使用的矿物为沸石（斜发沸石）、膨润土和蛭石。活性污泥中含有 0.01 N（317.7 ppm）的 Cu(II)。向污泥中添加固定浓度的矿物，并将 pH 值调节至 5.5。将混合物在室温下以 800 rpm 搅拌 2 小时，然后通过分批超滤系统过滤 1 小时。为了进行比较，重复了该实验，在没有添加矿物的情况下，用含有 0.01 N Cu(II)的污泥进行实验。结果表明，没有添加矿物的超滤膜能够去除大量的铜，去除效率在 59.4-78.3%之间。添加 10 g/l 和 20 g/l 的膨润土与超滤膜结合，去除效率分别为 94.9%和 99.4%，添加 10 g/l 和 20 g/l 的蛭石的去除效率分别为 93.8%和 96.8%。矿物的离子交换能力顺序为膨润土>蛭石>沸石。此外，还研究了膜污染。沸石和膨润土的添加降低了膜污染，而蛭石的添加对污染没有影响。使用廉价的矿物与超滤膜结合可以处理工业废水，得到铜浓度非常低的最终出水。
