Influence of sludge characteristics on coagulant recovery from water treatment sludge: a preliminary study

Nair, Abhilash T.; Ahammed, M. Mansoor

doi:10.1007/s10163-016-0513-0

Cited by 13 publications

(2 citation statements)

References 17 publications

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“…A number of studies focused on to the reuse of water treatment sludge as materials for building construction or soil improvement (Rodriguez et al, 2011; El-Didamony et al, 2014; Fan et al, 2014). However, another alternative is to recover the alum from the sludge and reuse it as a metal ion coagulant due to its amphoteric characteristic (Diaz et al, 2014;Nair and Ahammed, 2017). In addition, the recovery of alum as coagulant is likely more beneficial due to the decreasing amount of bauxite, so that this approach may limit the consumption of alum products (Keeley et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the recovery of alum as coagulant is likely more beneficial due to the decreasing amount of bauxite, so that this approach may limit the consumption of alum products (Keeley et al, 2014). The aluminum residual sludge can be recovered as alum coagulant for further water/ wastewater treatment or as adsorbent for other removal of contaminants (Hong et al, 2005;Diaz et al, 2014;Cherifi et al, 2016;Nair and Ahammed, 2017). The water treatment sludge can be recovered as coagulant through several methods, including acidification as the commonly applied, alkalinization, ion exchange, and membrane processes (Prakash and Sengupta, 2003;Xu et al, 2009;Keeley et al, 2016;Evuti and Lawal, 2011).…”

Section: Introductionmentioning

confidence: 99%

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Recovery of Alum Sludge by using Membrane-Based Electrochemical Process

Bagastyo¹,

Ayu²,

Barakwan³

et al. 2020

J. Ecol. Eng.

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The use of aluminum sulfate (Al 2 SO 4) coagulant in water treatment plants generates large amount of sludge residues containing the alum hydroxide precipitates and organic matter. Due to its amphoteric characteristic, this sludge by-product offers alum coagulant recovery by using electrochemical process, before safe disposal to the environment. This study is aimed at evaluating the efficiency of membrane-based electrochemical processes to recover aluminum from the filtrate of the acidified sludge. The dried alum sludge was acidified using sulfuric acid at pH 3, and then centrifuged to obtain the filtrate. Organic content of the filtrate was measured by means of Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD), i.e., 295.8 mg/L and 9,666.7±942.81 mg/L, respectively. In addition, the concentration of Al, Fe, Cu, and Cr was 1,194 mg/L, 515 mg/L, 0.559 mg/L, and 0.217 mg/L, respectively. The two-compartment electrochemical reactor was separated by using Cation Exchange Membrane (CEM) and Anion Exchange Membrane (AEM), and operated in a batch system for 10 hours with an electrical current of 300 mA. The results showed that the use of CEM in electrolysis with the electrodes distances of 1 cm increased the aluminum recovery up to 66.74% with the TOC removal of 24.04% compared to the use of AEM. An electrochemical process using CEM can be suggested to obtain organic-free recovery stream containing higher recovery of alum.

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Section: Introductionmentioning

confidence: 99%