Quaternized Chitosan for Ecological Treatment of Bauxite Mining Effluents
One of the major concerns of mining companies is the safety of their tailing dams. Among the cares required to operate such a dam, a proper treatment of the effluent composing its waste stands out, since that, waste must be treated before returned to the environment. In the process of bauxite beneficiation, the effluent level of turbidity is the discard parameter that deserves attention. In this work, quaternized chitosan (TMCCl−) derivative with cationic charge was synthetized and investigated to be used as coagulant in bauxite treatment for tailing dam effluent. The chitosan (CHT) was quaternized by methylation reaction. The quaternized chitosan structure was characterized by the following techniques: FTIR Spectroscopy and 1H nuclear magnetic resonance (NMR). Its thermal stability was analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis. After quaternized chitosan was obtained, analysis with aluminum sulfate, protonated and quaternized chitosan were executed in jar-test apparatus. The tests were conducted in order to find the optimum pH, velocity gradient, coagulant and alkalizer dosages, as well as coagulation, flocculation and decantation time. The studied coagulants showed good results and reduced the effluent turbidity to levels below determined by legislation. By comparing the coagulants, it was possible to state that quaternized chitosan presented higher reduction of effluent turbidity levels; the tests were performed in the same conditions.
KeywordsEffluent treatment Quaternized chitosan Turbidity Coagulant Effluent
We would like to thank FAPERJ and CNPq for the financial support and the CBA/Votorantim for its technical collaboration.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.Robert T, Mercer SM, Clark TJ, Mariampillai BE, Champagne P, Cunningham MF, Jessop PG (2012) Nitrogen-containing polymers as potent ionogens for aqueous solutions of switchable ionic strength: application to separation of organic liquids and clay particles from water. Green Chem 14:3053CrossRefGoogle Scholar
- 8.Carpinteyro-Urban S, Torres LG (2013) Use of response surface methodology in the optimization of coagulation-flocculation of wastewaters employing biopolymers. Int J Environ Res 7(3):717–726Google Scholar
- 9.Nouri J, Mahvi AH, Bazrafshan E (2010) Application of electrocoagulation process in removal of zinc and copper from aqueous solutions by aluminum electrodes. Int J Environ Res 4(2):201–208Google Scholar
- 10.Zulfikar MA, Setiyanto H, Wahyuningrum D, Mukti RR (2014) Peat water treatment using chitosan-silica composite as an adsorbent. Int J Environ Res 8(3):687–710Google Scholar
- 17.Mangala SA, Chalakkal IJ (1977) Characteristic vibrations of—N(CH3)2 and—N+(CH3)3 groups in dimethyl aminophenol’s and their methiodides. J Chem Soc Faraday Trans 2 73:1232–1237Google Scholar
- 27.Di Bernardo L (Coord.) (2003) Tratamento de água para abastecimento por filtração direta. ABES, RiMa 114, 162, 498, Rio de JaneiroGoogle Scholar