Removal of aluminum from drinking water treatment sludge using vacuum electrokinetic technology

Xu, Hang; Ding, Mingmei; Shen, Kunlun; Cui, Jianfeng; Chen, Wei

doi:10.1016/j.chemosphere.2017.01.057

Cited by 22 publications

(4 citation statements)

References 32 publications

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“…Nanomaterials are very interesting with regards to their applicability on water purification processes, mainly due to their unique properties, such as their high specific surface area, and its discontinuous properties [3,13,14]. One of the novel materials in this field are carbon nanotubes (CNT), composed of cylindrical graphite sheets arranged in a tubular structure [2,3,[14][15][16]. There are two types of CNTs: single-walled carbon nanotubes (SWCNTs) that consists of a single shell of graphene; and multiwalled carbon nanotubes (MWCNTs), composed of multiple layers of graphene sheets [14,15].…”

Section: Introductionmentioning

confidence: 99%

Enhanced Heavy Metal Removal from Acid Mine Drainage Wastewater Using Double-Oxidized Multiwalled Carbon Nanotubes

Rodríguez

Leiva

2019

Molecules

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Due to the unique properties of carbon nanotubes (CNTs), they have attracted great research attention as an emergent technology in many applications including water and wastewater treatment. However, raw CNTs have few functional groups, which limits their use in heavy metal removal. Nevertheless, their removal properties can be improved by oxidation processes that modify its surface. In this study, we assessed the capacity of oxidized and double-oxidized multiwalled carbon nanotubes (MWCNTs) to remove heavy metals ions from acidic solutions. The MWCNTs were tested for copper (Cu), manganese (Mn), and zinc (Zn) removal, which showed an increment of 79%, 78%, and 48%, respectively, with double-oxidized MWCNTs compared to oxidized MWCNTs. Moreover, the increase in pH improved the sorption capacity for all the tested metals, which indicates that the sorption potential is strongly dependent on the pH. The kinetic adsorption process for three metals can be described well with a pseudo-second-order kinetic model. Additionally, in multimetallic waters, the sorption capacity decreases due to the competition between metals, and it was more evident in the removal of Zn, while Cu was less affected. Besides, XPS analysis showed an increase in oxygen-containing groups on the MWCNTs surface after oxidation. Finally, these analyses showed that the chemical interactions between heavy metals and oxygen-containing groups are the main removal mechanism. Overall, these results contribute to a better understanding of the potential use of CNTs for water treatment.

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Section: Introductionmentioning

confidence: 99%

Enhanced Heavy Metal Removal from Acid Mine Drainage Wastewater Using Double-Oxidized Multiwalled Carbon Nanotubes

Rodríguez

Leiva

2019

Molecules

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“…Likewise, the highest concentration of other metals (Cr and Cu) was detected at pH 2, although overall their presence was substantially lower than in the case of iron and the targeted Al, i.e., in the range of 0.09-1.32 mg/L. As most of the metal ions are likely dissolved at pH 2, Al and other metal ions have an elevated concentration in the acidified alum sludge (Xu et al, 2017). The concentration of metals ions was influenced by the pH values of supernatant, because each metal has different solubility at different pH.…”

Section: Metal Solubility In Alum Sludge Acidificationmentioning

confidence: 83%

“…6). The pH increase in the cathode compartment only reached 4.5 at the end of the process, so that the dominant aluminum specification was in the form of Al 3+ cations (Xu et al, 2017). Al 3+ would react with OHto form Al(OH) 3 as the hydroxide precipitate.…”

Section: Aluminum Recoverymentioning

confidence: 99%

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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“…It usually accomplished by a stage of chemical addition of compounds that may be rich with iron or aluminium, that resulted with a high concentration of these elements in the resulted water sludge. [12]. To identify the thermal stability of sludge, a thermal gravimetric analysis (TGA) conducted with a temperature ranged between 16°C to 1000°C, using TSDSC 16 equipment.…”

Section: Water Treatment Sludgementioning

confidence: 99%

Reuse of Water Treatment Sludge in Coagulation Process for the Treatment of Raw Water From River Nile

Hegazy

Assem

2020

Journal of Al-Azhar University Engineering Sector

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The process of recovery and reuse of water treatment sludge as a coagulant perform a sustainable solution that benefices economically and environmentally. High safety concerns are to be take in consideration during reuse of water sludge in water purification. Most of the previous researchers have applied several full-scale separation methods for an effective purification of coagulant, without pointing to the performance of the coagulant treatment. In this research we studies the characteristics of sludge resulted from the treatment process of raw water from the river Nile, then the produced sludge is chemically treated with an acid in order to reuse it again in coagulation. Acidified water treatment sludge performance in removing turbidity and dissolved organic carbon DOC have been evaluated. The optimum coagulant dose determined for coagulation process of raw Nile water was 36 ml/l, while the optimal pH range concluded for higher turbidity removal was from 6 to 8. The resulted water treatment sludge found to be reliable to use in conventional water treatment process. The study recommended for better performance of coagulation, to add a partial amount (at least 20 % of coagulant dose) of the proper coagulant to the recovered water sludge.

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Removal of aluminum from drinking water treatment sludge using vacuum electrokinetic technology

Cited by 22 publications

References 32 publications

Enhanced Heavy Metal Removal from Acid Mine Drainage Wastewater Using Double-Oxidized Multiwalled Carbon Nanotubes

Enhanced Heavy Metal Removal from Acid Mine Drainage Wastewater Using Double-Oxidized Multiwalled Carbon Nanotubes

Recovery of Alum Sludge by using Membrane-Based Electrochemical Process

Reuse of Water Treatment Sludge in Coagulation Process for the Treatment of Raw Water From River Nile

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