A B S T R A C TThe use of upstream pre-coagulation coupled with downstream ultra-filtration (UF) has been applied to the clarification of natural organic matter (NOM) laden raw upland water. Such a combination yields a significant increase in possible loading rate and a decrease in the propensity for internal membrane fouling, allowing for an intensification of the process. In particular, the effect of controlling the pre-coagulation regime on the downstream UF has been investigated. It has been shown that zeta potential (ZP) can be used to detect changes in the coagulation process, and hence to determine appropriate dosage levels. This is important, as incomplete coagulation has a detrimental effect on UF membrane performance, particularly in terms of fouling caused by excess iron. Submerged hollow-fibre membrane units yield superior performance with precoagulation, and sufficient slow mixing of coagulant guarantees high permeate flow recovery after backwashing. Fouling by NOM can be remedied by conventional cleaning techniques. However, fouling due to excess iron can only be removed by heating the cleaning solution. The associated costs are thus twofold; that of excess coagulant and that of cleaning.
The effect of controlling the pre‐coagulation regime on downstream ultrafiltration of raw upland waters has been investigated. It has been shown that zeta potential can be used to detect changes in the coagulation process and hence to determine appropriate dosage levels. This is important, as incomplete coagulation has a detrimental effect on ultrafiltration membrane performance, particularly in terms of fouling caused by excess iron. Submerged hollow‐fibre membrane units yield superior performance with pre‐coagulation and sufficient slow mixing of coagulant guarantees high permeate flow recovery after backwashing. Fouling by natural organic matter can be remedied by conventional cleaning techniques. However, fouling due to excess iron can only be removed by heating the cleaning solution. The associated costs are thus two‐fold; that of excess coagulant and that of cleaning.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.