磷酸改性核桃壳能显著提高对Cr(Ⅵ)的吸附率,改性工艺简单、环保。研究了磷酸改性核桃壳的改性工艺,详细探讨了磷酸浓度、核桃壳颗粒度、改性时间、改性温度和核桃壳用量等因素对吸附效果的影响,并通过正交试验和对比实验进一步优化改性工艺。实验确定的最佳工艺条件为:在100mL改性溶液中,磷酸质量分数为15%,核桃壳颗粒度为60目,改性温度为室温,改性时间为5h,核桃壳用量为10g。采用最佳工艺条件制备了磷酸改性核桃壳,在改性核桃壳用量为1.0g、pH=2条件下,处理150mL质量浓度为50mg/L的含Cr(Ⅵ)废水,吸附率达97.23%,吸附量为7.29mg/g。
As Cr(Ⅵ) ions adsorbent,phosphoric acid modified walnut shell has characteristics including environmental friendly and simple modification process,and high adsorption rate for Cr(Ⅵ) ions.Some factors,including phosphoric acid concentration,particle size of walnut shell,reaction time,reaction temperature,and walnut shell dosage,were investigated in detail.Based on single factor experiments,the modification technics were further optimized through orthogonal experiments and comparative experiments.Optimum modification technics were as follows:in 100mL of solution,phosphoric acid concentration was 15%,particle size of walnut shell was 60mesh,reaction temperature was 20℃,reaction time was 5h,and walnut shell dosage was 10g.The adsorbent of 1.0g prepared under the optimal conditions selected was used to dispose 150mL of 50mg/L simulated wastewater containing Cr(Ⅵ) ions.The adsorption rate of Cr(Ⅵ) ions was 97.23% and the adsorption capacity of adsorbent was 7.29mg/g.
[1] Michailides M K,Tekerlekopoulou A G,Akratos C S,et al.Molasses as an efficient low-cost carbon source for biological Cr(Ⅵ) removal[J].Journal of Hazardous Materials,2015,281:95-105.
[2] Barrera C E.A review of chemical,electrochemical and biological methods for aqueous Cr(Ⅵ) reduction[J].Journal of Hazardous Materials,2012,223-224(2):1-12.
[3] Wang J,Chen C.Biosorbents for heavy metals removal and their future[J].Biotechnology Advances,2009,27(2):195-226.
[4] Sud D,Mahajan G,Kaur M.Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions-a review[J].Bioresource Technology,2008,99(14):6017-6027.
[5] Sharma P K,Ayub S,Tripathi C N.Agro and horticultural wastes as low cost adsorbents for removal of heavy metals from wastewater:a review[J].International Refereed Journal of Engineering and Science,2013,2(8):18-27.
[6] Singha B,Das S K.Biosorption of Cr(Ⅵ) ions from aqueous solutions:kinetics,equilibrium,thermodynamics and desorption studies[J].Colloids & Surfaces B Biointerfaces,2011,84(1):221-32.
[7] Bansal M,Garg U,Singh D,et al.Removal of Cr(Ⅵ) from aqueous solutions using pre-consumer processing agricultural waste:a case study of rice husk[J].Journal of Hazardous Materials,2009,162(1):312-320.
[8] Tytlak A,Oleszczuk P,Dobrowolski R.Sorption and desorption of Cr(Ⅵ) ions from water by biochars in different environmental conditions[J].Environmental Science & Pollution Research International,2015,22(8):1-10.
[9] Ilyas M,Khan N,Sultana Q.Thermodynamic and kinetic studies of chromium(Ⅵ) adsorption by sawdust activated carbon[J].Journal Chemical Society of Pakistan,2014,36(6):1003-1012.
[10] Baral S S,Das S N,Rath P.Hexavalent chromium removal from aqueous solution by adsorption on treated sawdust[J].Biochemical Engineering Journal,2006,31(3):216-222.
[11] Garg U K,Kaur M P,Garg V K,et al.Removal of hexavalent chromium from aqueous solution by agricultural waste biomass[J].Journal of Hazardous Materials,2007,140(1/2):60-68.
[12] Raziye Ertas,Nese Öztürk.Removal of Cr(Ⅵ) from aqueous solution onto chestnut shell:application of full factorial design and equilibrium studies[J].Desalination & Water Treatment,2013,51(13):2909-2914.
[13] Liu Z N,Liu Y M,Chen L,et al.Performance study of heavy metal ion adsorption onto microwave-activated banana peel[J].Desalination & Water Treatment,2014,52(37):7117-7124.
[14] Suksabye P,Thiravetyan P.Cr(Ⅵ) adsorption from electroplating plating wastewater by chemically modified coir pith[J].Journal of Environmental Management,2012,102(14):1-8.
[15] Zafarani H R,Bahrololoom M E,Noubactep C,et al.Green walnut shell as a new material for removal of Cr(Ⅵ) ions from aqueous solutions[J].Desalination & Water Treatment,2015,55(2):1-26.
[16] Altun T,Pehlivan E.Removal of Cr(Ⅵ) from aqueous solutions by modified walnut shells[J].Food Chemistry,2012,132(2):693-700.
[17] Gupta A,Balomajumder C.Simultaneous adsorption of Cr(Ⅵ) and phenol onto tea waste biomass from binary mixture:multicomponent adsorption,thermodynamic and kinetic study[J].Journal of Environmental Chemical Engineering,2015,3(2):785-796.
[18] Mahmood-Ul-Hassan M,Suthor V,Rafique E,et al.Removal of Cd,Cr,and Pb from aqueous solution by unmodified and modified agricultural wastes[J].Environmental Monitoring & Assessment,2015,187(2):1-8.
[19] Fethiye G,Elif Dincturk A,Erol P.Removal of Cr(Ⅵ) from aqueous solutions using modified red pine sawdust[J].Journal of Hazardous Materials,2008,152(3):1201-1207.
[20] Tejada Tovar C,Villabona Ortiz A,Ruiz Paternina E.Adsorption kinetics of Cr(Ⅵ) using chemically modified residual biomass in batch and continuous systems[J].Rev Ion,2015,28(1):29-41.
基金资助
国家自然科学基金资助项目(21307168);重庆市自然科学基金资助项目(cstcjjA50016);重庆交通大学实验教学改革与研究基金(syj201724)
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