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| Optimized preparation of lanthanum uploaded biochar and its application in adsorbing pentavalent arsenic ions from aqueous solution |
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Abstract Lanthanum uploaded biochar (La-biochar) that utilized for removing pentavalent arsenic ions from aqueous solutions was prepared on the basis of corn straw. The operation conditions during production procedure of La-biochar were optimized, and then La-biochar was characterized. Compared with control biochar (CK), the surface of La-biochar was rougher, and specific surface area increased 4.6 times. XRF Results showed La-biochar possessed an amount of lanthanum. Through response surface method, the optimized preparation parameters for the maximum adsorption capacity of pentavalent arsenic ions were obtained, and the parameters were as follows: material ratio (w (La)/w (straw) )= 9.47%, residence time = 20min, pyrolysis temperature = 300oC. Both Acid conditions and neutral conditions were preferable for adsorbing arsenic ions, while alkaline conditions would decrease the removal efficiency of arsenic ions. The effect of three negative ions (CO32-, F-, and Cl-) on the adsorbing process was investigated, and results showed that only high concentration of CO32- could decrease the removal efficiency of pentavalent arsenic ions. Through the production of La-biochar, several goals were achieved, including the reutilization of corn straw, reduction of lanthanum consumption, and dramatically increase of the adsorption capacity of pentavalent arsenic ions from aqueous solutions.
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Received: 26 January 2015
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