Evaluation of Membranes for Water Pollution Control,

摘要

An ultra-filtrative alum (aluminum sulfate) recovery and recycling process using synthetic polymeric membranes at low pressure differentials is economical and effective. The quality of the treated water produced by coagulation with the recycled alum as measured by turbidity and color does not suffer when using the optimum dose established by tests with fresh alum. The alum may be recycled four times if the membrane is periodically cleansed with an alkali (sodium hydroxide). An additional advantage is that the volume of sludge is greatly reduced and the remaining sludge is dewaterable. Efforts to attach a cleaning enzyme to the membrane and to use polyethylene and polystyrene as separation membranes were unsuccessful.