Polyaluminum Chloride Coagulation Research Articles

The electrochemical production of highly effective polyaluminum chloride

This paper presents a new electrolytic method for the synthesis of PAC (polyaluminum chloride). The ECR (electrochemical reactor) used aluminum sheets as anode and AlCl 3 aqueous solution as electrolyte. This method adopted low voltage and high electric current intensity during electrolysis. Some factors of the electrochemistry and the chemistry of the aqueous solution, affecting the formation of the most effective species of PAC, were also studied. The liquid product of PAC, in which the most effective species, Alb (The polymeric Al component estimated by the ferron method), was above 70% by weight of the total aluminum with a basicity, B (OH/Al molar ratios)=2.4, was successfully generated. The results measured by the ferron method and 27Al NMR method showed that the Alb or Al 13 content of the E-PAC (PAC prepared by electrolysis) were obviously higher than that of the general PAC and other coagulants.

95/04266 Transport demand management in ‘Yuppleland’

A novel lignin-based flocculant was introduced in recycling of the biomass existing in papermaking sludge. The product, lignin-diallyl dimethyl ammonium chloride-acrylamide (LDA) was characterized as a cationic macromolecule polymer with broad structure. To demonstrate its efficiency, LDA was used as coagulant aid with polyferric chloride (PFC) and polyaluminum chloride (PAC) to remove humic acid by coagulation–ultrafiltration processes. Results showed that coagulation aid effect of LDA was not affected by the type of metal salts and removal ratios of dissolved organic carbon were maximum 15.1% and 11.9% larger than single PFC and PAC coagulation, respectively. More concentrated flocs with larger size and open structure as well as low fractal dimension were formed by dual-coagulants. In PFC coagulation system, LDA could absorb negative charge on the surface of Fe(III) coagulated flocs efficiently and achieve the maximum floc strength accordingly. In the ultrafiltration experiment, cake layer fouling was demonstrated to be the foremost fouling mechanism. PAC combined used with LDA resulted in the minimum membrane fouling due to the formation of looser flocs as well as more concentrated floc size distribution. Overall, LDA brought in charge neutralization and absorption bridging effect and played a positive role in coagulation–ultrafiltration processes.

Coagulation Pretreatment for Ultrafiltration of a Surface Water

Polysulfone ultrafiltration membranes were used to treat water from the Seine River—with and without coagulation pretreatment. Pretreatment with polyaluminum or ferric chloride coagulant reduced the rate of reversible fouling and increased the removal of dissolved organic carbon (DOC) but did not reduce the rate or extent of irreversible fouling of the membrane. Seine River water that had been treated by coagulation, filtration, and ozonation, i.e., tap water, also produced significant irreversible fouling. Most of the DOC in flocculated Seine River water and tap water consisted of polysaccharide materials of low molecular weight. Irreversible fouling may be due to the adsorption of these materials on membrane surfaces.

Errata

Journal AWWAVolume 77, Issue 3 ErrataFree Access Errata This article corrects the following: Polyaluminum Chloride and Alum Coagulation of Clay-Fulvic Acid Suspensions Brian A. Dempsey, Hueymeei Sheu, T.M. Tanzeer Ahmed, Jack Mentink, Volume 77Issue 3Journal - American Water Works Association pages: 74-80 First Published online: March 1, 1985 First published: 01 March 1985 https://doi.org/10.1002/j.1551-8833.1985.tb05511.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume77, Issue3March 1985 RelatedInformation

Polyaluminum Chloride and Alum Coagulation of Clay‐Fulvic Acid Suspensions

Polyaluminum chloride is an unconventional coagulant that will soon be introduced to the US market. It is produced by partial hydrolysis of aluminum chloride and is thought to consist of stable cationic polymers of aluminum. The benefits of polyaluminum chloride relative to alum have been investigated as a function of pH, raw water composition, and mixing conditions. Conditions are outlined that might indicate the effective use of polyaluminum chloride instead of alum.