Crayfish shell biochar modified with magnesium chloride and its effect on lead removal in aqueous solution
- 74 Downloads
In this study, crayfish shell was pyrolyzed at 600 °C to obtain an unmodified biochar (CS600). MgCl2 was used as a modifier to pretreat crayfish shell to produce a modified biochar (CS600-MgCl2) under the same pyrolysis conditions. The two biochars were characterized for physicochemical properties and evaluated for lead (Pb2+) sorption ability to determine the modification mechanism. Mono-element batch adsorption experiments were conducted to compare the sorption performances of CS600 and CS600-MgCl2 to Pb2+ in aqueous solutions. All the experiments were carried out at pH of 7. According to the Freundlich–Langmuir model, CS600-MgCl2 had a higher adsorption capacity (152.3 mg/g) than CS600 (134.3 mg/g). FTIR, SEM, XRD, BET, and ICP analyses were applied to inform the interpretation of the mechanism. CS600 was calcium-rich and mainly removed Pb2+ through the ion exchange mechanism by replacing Ca2+ in the biochar. The increased Pb2+ adsorption capacity of CS600-MgCl2 was mainly due to the enlarged specific surface area and the formation of Mg3(OH)5Cl·4H2O on the modified biochar. Findings of this study suggest that both CS600 and CS600-MgCl2 can be used to remove heavy metal ions from wastewater and MgCl2 can improve the sorption performance of biochar.
KeywordsLead removal Crayfish shell Biochar Adsorption Modification Ion exchange
This work was partially supported by the National “Twelfth Five-Year” Plan for Science & Technology Pillar Program (grant number 2014BAL04B04), and the Wuhan Water Engineering & Technology Co. Ltd.
- Hu X, Xue Y, Liu L, Zeng Y, Long L (2018a) Preparation and characterization of Na2S-modified biochar for nickel removal. Environ Sci Pollut Res 34:1–9Google Scholar
- Hu X, Xue Y, Long L, Zhang K (2018b) Characteristics and batch experiments of acid- and alkali-modified corncob biomass for nitrate removal from aqueous solution. Environ Sci Pollut Res 25:1–9Google Scholar
- Kaygusuz MK, Isik NO, Erden KE (2017) THE removal of Pb(II) from aqueous solutions by strong and weak acidic cation exchange resins. Fresenius Environ Bull 26:3448–3454Google Scholar
- Kumar JK, Prasad AD (2011) Identification and comparison of biomolecules in medicinal plants of Tephrosia tinctoria and Atylosia albicans by using FTIR. Rom J Biophys 21:63–71Google Scholar
- Viravaidya C, Li M, Mann S (2004) Microemulsion-based synthesis of stacked calcium carbonate (calcite) superstructures. Chem Commun:2182–2183Google Scholar
- Wang SJ, Guo W, Gao F, Yang R (2017) Characterization and Pb(II) removal potential of corn straw- and municipal sludge-derived biochars. R Soc Open Sci 4:11Google Scholar
- Wu WD, Li JH, Lan T, Muller K, Niazi NK, Chen X, Xu S, Zheng LR, Chu YC, Li JW, Yuan GD, Wang HL (2017) Unraveling sorption of lead in aqueous solutions by chemically modified biochar derived from coconut fiber: a microscopic and spectroscopic investigation. Sci Total Environ 576:766–774CrossRefGoogle Scholar
- Xue Y, Gao B, Yao Y, Inyang M, Zhang M, Zimmerman AR, Ro KS (2012) Hydrogen peroxide modification enhances the ability of biochar (hydrochar) produced from hydrothermal carbonization of peanut hull to remove aqueous heavy metals: batch and column tests. Chem Eng J 200-202:673–680CrossRefGoogle Scholar
- Yin QQ, Liu MT, Ren HP (2019) Removal of ammonium and phosphate from water by Mg-modified biochar: influence of Mg pretreatment and pyrolysis temperature. BioResources 14:6203–6218Google Scholar