玉米秸秆对Cr(Ⅵ)的生物吸附及热力学特征研究

被引：80

作者：

李荣华

张增强

孟昭福

李红艳

机构：

[1] 西北农林科技大学理学院

来源：

环境科学学报 | 2009年 / 29卷 / 07期

关键词：

玉米秸秆; 吸附; 氧化还原; Cr(Ⅵ); 热力学特征;

D O I：

10.13671/j.hjkxxb.2009.07.017

中图分类号：

X703 [废水的处理与利用];

学科分类号：

083002 ;

摘要：

以玉米秸秆粉为吸附剂,通过批实验讨论了玉米秸秆粉对Cr(Ⅵ)的去除率、体系初始pH值、吸附剂用量和温度等对水溶液中Cr(Ⅵ)吸附的影响,并讨论了Cr的化学形态变化和吸附过程的热力学特征.结果表明,向50mL浓度为50mg.L-1的Cr(Ⅵ)溶液中加入0.5g玉米秸秆粉,于25℃、200r.min-1、pH1.0的条件下恒温震荡3h,玉米秸秆粉对溶液中Cr(Ⅵ)的去除率达97.77%,吸附过程伴随着氧化还原反应的发生.随着体系温度的升高,玉米秸秆粉对Cr(Ⅵ)的吸附量增加.用Langmuir、Freundlich和Dubinin-Radushkevick模型对吸附等温线进行拟合,发现Langmuir模型能更好地反映吸附过程特征,在298K时最大吸附量为14.46mg.g-1.对吸附热力学参数ΔG0、ΔH0和ΔS0的计算表明,吸附过程是吸热的自发过程.最后结合FTIR和SEM谱图,对吸附机理进行了探讨.研究发现,玉米秸秆粉对Cr(Ⅵ)同时存在吸附和还原能力,玉米秸秆粉是具有吸附污水中铬能力和潜在利用价值的生物质吸附剂.

引用

页码：1434 / 1441

页数：8

共 18 条

[11]

Modelling Thiocyanate Adsorption onto Surfactant-Modified Coir Pith, an Agricultural Solid ‘Waste’[J] . C. Namasivayam,M.V. Sureshkumar.Process Safety and Environmental Protection . 2007 (6)

[12] Reliable evidences that the removal mechanism of hexavalent chromium by natural biomaterials is adsorption-coupled reduction [J].

Park, Donghee ;

Lim, Seong-Rin ;

Yun, Yeoung-Sang ;

Park, Jong Moon .

CHEMOSPHERE, 2007, 70 (02) :298-305

[13] Removal of Cr(VI) from wastewater using rice bran [J].

Singh, KK ;

Rastogi, R ;

Hasan, SH .

JOURNAL OF COLLOID AND INTERFACE SCIENCE, 2005, 290 (01) :61-68

[14]

Comparative study of the biosorption of Pb(II), Ni(II) and Cr(VI) ions onto S. cerevisiae : determination of biosorption heats[J] . Journal of Hazardous Materials . 2003 (1)

[15] Selective adsorption of chromium(VI) in industrial wastewater using low-cost abundantly available adsorbents [J].

Dakiky, M ;

Khamis, M ;

Manassra, A ;

Mer'eb, M .

ADVANCES IN ENVIRONMENTAL RESEARCH, 2002, 6 (04) :533-540

[16] Chromium adsorption and Cr(VI) reduction to trivalent chromium in aqueous solutions by soya cake [J].

Daneshvar, N ;

Salari, D ;

Aber, S .

JOURNAL OF HAZARDOUS MATERIALS, 2002, 94 (01) :49-61

[17] Removal of Cr(VI) from aqueous solution by adsorption onto activated carbon [J].

Selvi, K ;

Pattabhi, S ;

Kadirvelu, K .

BIORESOURCE TECHNOLOGY, 2001, 80 (01) :87-89

[18]

Adsorptive removal of Cr(VI) by Fe-modified steam exploded wheat straw .2 Li Chun,Chen Hongzhang and Li Zuohu. Process Biochemistry . 2004

← 1 2 →