Adsorption behavior comparison of trivalent and hexavalent chromium on biochar derived from municipal sludge

Removal behaviors and mechanisms of hexavalent chromium from aqueous solution by cephalosporin residue and derived chars

“…These removal efficiences of Cr(VI) of CR and derived chars were much higher than that (63.28%) of AC at 1.5 of pH(Deveci and Kar, 2013). Meanwhile, the slightly raising pH was observed because of the11 buffering capacities of CR-chars, which may originate from the release of alkaline substances from the chars(Chen et al, 2015). Cr(III) could be remained in solution at low pH while Cr(III) adsorption could occur when solution pH was 5.0(Miretzky and Cirelli, 2010;Zhang and Zheng, 2015).…”

“…Among them, adsorption has evolved to the cutting-edge technique for Cr(VI) treatment due to its operation simplicity, economic efficiency and high selectivity (Qi, et al, 2016). Therefore, the selection of low-cost and eco-friendly adsorbent becomes extremely urgent (Miretzky and Cirelli, 2010;Chen et al, 2015). 3 The high cost of conventional adsorbents like activated carbon (AC), stimulates the researchers to use by-products and low-cost agricultural products as adsorbents for the removal of Cr(VI) in wastewaters (Park et Agricultural residues, containing pectin, lignin, cellulose and several other compounds have potential functional groups such as carbonyl, hydroxyl, alkoxy, carboxylic and amino, exhibiting have great affinity towards Cr(VI) (Kamel et al, 2012).…”

“…However, the adsorption capacity of BC in terms of hazardous ions is comparable with that of AC(Zhou et al, 2016). BC can be one of the best replacements of commercial AC due to its abundant functional groups and lower cost(Chen et al, 2015; Zhou et al, 2016). Moreover, the behavior and mechanism for removing Cr(VI) by BC largely depend on the conditions of heat treatment and the source materials which influence chemical composition and properties of BC(Sun et al, 2012).…”

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

“…No simple explanation could clarify these phenomena but some specific characteristics of these two metals must be pointed out. Indeed, the behavior of both Al 3+ and Cr 3+ is highly pH dependent, with complex speciation patterns [26–28]. Since the pH value was not kept constant during tests, the pH variations probably led to changes in speciation of the two metals, leading to this unexpected behavior compared to the other metals.…”

Characterization and adsorption properties of low-cost sewage sludge-derived carbon by using poly-aluminium chloride as pore-forming agent

“…Subsequently, many scientific researches have been reported about the sewage sludge-derived adsorbents on a laboratory scale for environmental applications [7][8][9][10]. They have been proved to be excellent adsorbents for the removal of gaseous pollutants, metal cations, dyes and organic matters, etc [8,[10][11][12][13]. Generally, these carbonaceous materials can be produced by direct thermal pyrolysis, physical activation, or chemical activation under high carbonization temperatures.…”