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Biosorption Of Heavy Metals From Mining Influenced Water Onto Chitin Products
Citation:
Pinto, P. X., S. R. AL-ABED, AND D. J. REISMAN. Biosorption Of Heavy Metals From Mining Influenced Water Onto Chitin Products. S.J. Allen, M. Deshusses, D. Dionysiou, G. Marin, J. Santamaria, and K.L. Yeung (ed.), Chemical Engineering Journal. Elsevier BV, AMSTERDAM, Netherlands, 166(3):1002-1009, (2011).
Impact/Purpose:
The purpose of this research was to evaluate the effectiveness of two crab-shell derived products (Chitorem SC-20® and Chitorem SC-80®) as biosorbents used in heavy metals removal from MIW in batch tests, and to identify the involved removal mechanisms.
Description:
Mining influenced water (MIW) emanating from mine sites poses a major environmental concern due to its impact on water contamination caused by low pH and the presence of high concentrations of toxic metals. Chitorem SC-20® (raw crushed crab shells containing 40% w/w CaCO3, 30% protein, 20% chitin, 7% moisture, and 3% ash) and Chitorem SC-80® (the chitin polymer containint 88% chitin and 12% moisture) were used to evaluate heavy metals removal from MIW. It was found that SC-20 was very effective at neutralizing the strong acidity of MIW, even at loads as low as 1 g/L the equilibrium pH was neutral. At a load of 2 g/L, SC-20 showed a final pH of 7.94 with almost complete (>99.8%) removal of iron (120 mg/L), lead (1.1 mg/L) and zinc (79 mg/L), along with partial removal of cadmium (96% of 1.3 mg/L), cobalt (54% of 0.78 mg/L), copper (42% of 72 mg/L), and manganese (64% of 52 mg/L) from MIW. Metal removal was achieved primarily by neutralization and precipitation mainly due to the dissolution of the CaCO3 from the SC-20. SC-80 was used to differentiate the effect of alkalinity and the amount of metal adsorption achievable by the chitin polymer. Lead (up to 1.24 mg/g), cadmium (up to 1.81 mg/g), and cobalt (up to 0.93 mg/g) from single-metal solutions were adsorbed onto the chitin polymer (SC-80). Metal adsorption onto the chitin polymer seemed to have a minor role as a mechanism of metal removal from MIW. Overall, this study demonstrated that crab-shell products can be an important alternative for MIW remediation.
URLs/Downloads:
BIOSORPTION OF HEAVY METALS FROM MINING INFLUENCED WATER ONTO CHITIN PRODUCTS
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