The Preparation of Inorganic Materials to Consume and Stabilize Chromium-Containing Waste: A Review

Zhang, Shuai; Zhang, Yanling; Wu, Shaowen; Yu, Kan; Zhao, Zhixiang

doi:10.1007/s11837-022-05153-y

Cited by 5 publications

(2 citation statements)

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“…Although Cr 3+ is stable in the environment, it can be oxidized, under certain conditions, to the more dangerous Cr 6+ . Therefore, industrial wastes with a high concentration of chromium (III) salts, for example in tanning industry, require appropriate treatments to stabilize Cr 3+ to prevent the oxidation processes (Giovannini et al, 2008;Zhang et al, 2022). A recent encapsulation process has been presented by Zhao and colleagues adopting the TiO 2 precipitation route in a ZnCr 2 O 4 spinel like crystal at 1,000 °C, by adding the same amount of ZnO 2 and TiO 2 20wt%, (Zhao et al, 2022)., Other authors approached a less expensive and more friendly encapsulation methods as reported and discussed below (Montañés et al, 2014;Pantazopoulou and Zouboulis 2018;Oproiu et al, 2021;Boldrini et al, 2021).…”

Section: Aim Of This Perspective Articlementioning

confidence: 99%

“…Many approaches have been pursued to stabilize the tannery waste, rich mainly in the cationic form, Cr 3+ , and poor in the anionic form, CrO 4 2- (Nur-E-Alam et al, 2020). In a recent review, the tannery sludge and wastewater have been listed together with other Cr-bearing wastes treated with glass-ceramics, sintered ceramics, cement, and geopolymers (Zhang et al, 2022). Most of those technologies require thermal treatments, while only cementification and alkali activation, sometimes indicated as geopolymerization, can occur at room temperature.…”

Section: Encapsulation Treatments Of Cr-bearing Wastewater From Tanne...mentioning

confidence: 99%

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Sustainable Chromium Encapsulation: Alkali Activation Route

Sgarlata

Leonelli²,

Lancellotti³

et al. 2022

Front. Mater.

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This article highlights recent experimental advances in the use of inorganic substances in the encapsulation of pollutants and, in particular, discusses the potential applicability and constraints of the geopolymerization process for the treatment of wastewater containing chromium. A great percentage of waste containing chromium salts is produced by the leather industry during the tannery process. Such industrial waste is in the form of liquor containing almost 40% of the initial chromium combined with many other pollutants. The stabilization/solidification (S/S) treatment of this type of waste must be combined with chromium encapsulation in an economic, environmentally friendly and efficient process to be industrially feasible. Here we present a novel process in which the wastewater is used as a component of the formulation together with a clay by-product and with the addition of NaOH pellets with the goal of a no-water plus no-waste technology approach. The final solidified “ceramic-like” material successfully immobilized the heavy metal cations as well as anions and macromolecules of surfactants, avoiding environmental damages to soil and groundwater. The article is completed by mentioning other S/S processes where wastewater has been treated and the resulting sludge encapsulated. The future of the S/S technologies in the tannery industry should progress in the direction of significantly reducing the amount of wastewater directed to the treatment plants, with associated reductions in transport and their CO2 emissions. This article intends to be a contribution in the direction of preventing waste, aligning circular economy and waste management objectives.

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