不同热解温度制备的鸡粪生物炭对废水中磷的吸附.docx
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不同热解温度制备的鸡粪生物炭对废水中磷的吸附
Phosphate Adsorption in Wastewater by Bio-carbon
Prepared from Pyrolysis of Chicken Manure at Different Temperature
HU Fei-fei1,HE Pi-wen1,2 (1.School of City
Construction, Yangtze
University, Jingzhou 434023, Hubei, China;
2.School of Environmental Science and Technology,
Huazhong University of
Science and Technology, Wuhan 430074, China)
Abstract: Using bio-carbon prepared from pyrolysis of
chicken manure as materials,
the adsorption kinetics and
isotherm of phosphate by
bio-carbon at different
temperatures(500,600,700 and 750 ℃) were studied. The
results showed that the
adsorption of phosphate
followed the pseudo
second-order kinetics model.
The equilibrium of adsorption
capacity and adsorption rate
were increased with the increase
of pyrolysis temperature. Langmuir and Freundlich
models were used to fit
experimental data. The
Freundlich model could
describe the adsorption
isotherm better, suggesting that multiple processes
controlled the sorption of
phosphate by bio-carbon. The
adsorption activation energy
of bio-carbon at different temperatures were 7.67,
12.48, 11.02, 8.80 kJ/mol,
indicating that it belonged to physics adsorption. The
preliminary adsorption
mechanism of phosphate removed by the bio-carbon was studied
through heterogeneously
processed adsorption onto the
colloidal and nano-sized MgO particles on bio-carbon
surface.
Key words: chicken manure; bio-carbon; phosphate
removal; kinetics of
adsorption; adsorption
isotherm
中国农业废弃物主要以秸秆及动物粪便为主,年产量巨大,有
效利用率低,且粪便的长期露天堆积,渗滤液会随径流污染地
下水[1]。生物炭主要以植物残体、动物粪便等农林废弃物
为原料在隔绝氧气条件下热解制备的,通过热解制备的生物炭
其产量一般可达到原料的40%~50%。生物炭施加于土壤
,可以改良土壤,促进作物生长,改变碳循环路径,增加土壤
碳汇,减少温室气体的排放[2]。由于生物炭具有复杂的孔
隙结构和良好的表面特性,能够代替活性炭等材料作为一种廉 价的吸附剂用于废水处理已经受到关注[3,4]。
磷是导致水体富营养化的主要元素之一,是地球上重要的不可
再生资源之一[5,6]。处理并回收水中的磷成为解决水体
富营养化及磷资源短缺的重要途径。其中用吸附法除磷以其高
效快捷、设备简单、运行可靠,同时能回收利用磷资源而备受
关注。本研究以鸡粪为原料在不同温度下制备生物炭作为吸附
剂,对生物炭吸附去除磷的机理做了初步的探讨,并比较不同
热解温度制备的生物炭对水中磷的吸附动力学、等温线及活化
能,旨在为废弃物资源化以及对水中磷的去除提供参考依据。 1材料与方法
1.1材料
鸡粪取自武
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