废菌渣活性炭的制备及对废水中硝基苯的吸附

Preparation of mushroom residue activated carbon and its adsorption mechanism of nitrobenzene in waste water

以废菌渣为原料制备活性炭,采用能量-色散光谱(EDS)和傅里叶变换红外光谱仪(FTIR)进行表征,结果表明:活性炭表面具有多种官能团,有利于提高对硝基苯的吸附。并研究了活性炭吸附硝基苯的影响因素(pH、初始浓度、吸附时间、投加量)、吸附等温线及热力学。结果表明:在常温中性pH条件下,初始浓度为50mg/L,活性炭用量为0.15g时硝基苯去除率可达98%,出水水质满足《污水综合排放标准》(GB 8978-1996)中对硝基苯浓度低于2.0mg/L的要求。活性炭对硝基苯的吸附具有较快的吸附速率,即1min接近平衡。该吸附行为是自发放热反应,可以用Freundlich模型很好地拟合。废菌渣活性炭对硝基苯的吸附主要是疏水作用和氧化钼活化共同作用的结果。因此,以农业废弃物-废菌渣制备得到的废菌渣活性炭具有良好的经济实用性,可用于废水处理中,实现以废治废的目的。

Mushroom residue as precursor was used to produce activated carbon.Using the energydispersion spectroscopy(EDS)and Fourier transform infrared spectrometer(FTIR)for characterization,the results reveal the surface of the activated carbon is rich in various functional groups to improve the adsorption of nitrobenzene.The factors affecting the adsorption of nitrobenzene(pH,initial concentration,adsorption time,and dosage of activated carbon),adsorption isotherms and thermodynamics were studied.The results show that the removal rate of nitrobenzene is as high as 98%under the conditions of neutral pH,normal temperature,the initial concentration 50mg/L and the activated carbon dosage 0.15g.The effluent water quality meets the requirement for the nitrobenzene concentration below 2.0mg/L in the Integrated Wastewater Discharge Standard(GB 8978-1996).In addition,the adsorption of nitrobenzene by activated carbon has a fast adsorption rate,which is close to equilibrium in 1min.The adsorption behavior is a spontaneous exothermic reaction,which can be well fitted by Freundlich model.The adsorption of nitrobenzene by mushroom residue activated carbon is mainly the result of the combined action of hydrophobicity and molybdenum oxide activation.Therefore,the mushroom residue activated carbon prepared from agricultural waste has a good economic practicality,and can be used in wastewater treatment to achieve the purpose of treating waste with waste.