两性蔗渣吸附剂的制备及其对氮、磷富营养因子的吸附效果

Preparation of amphoteric bagasse-based adsorbent for removal of nitrogen and phosphorus wastes from water

以蔗渣为原料,甲基丙烯酰氧乙基三甲基氯化铵(METAC)、丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙烯酸(AMPS)为单体,过硫化钾(K2S2O8)为引发剂,通过自由基聚合技术合成了两性蔗渣吸附剂(MABA)。采用傅里叶红外光谱仪(FT-IR)、热重分析仪(TGA)对两性蔗渣吸附剂的结构与性能进行表征,系统考察了两性蔗渣吸附剂用量、溶液pH和离子强度对其吸附NH^(+)_(4)、PO^(3-)_(4)效果的影响。结果表明,当两性蔗渣吸附剂用量为2.5 g/L、pH为9时,两性蔗渣吸附剂对NH^(+)_(4)的最大吸附量为78.5 mg/g;两性蔗渣吸附剂用量为2.0 g/L、pH为6时,两性蔗渣吸附剂对PO^(3-)_(4)的最大吸附量为74.3 mg/g。两性蔗渣吸附剂对NH^(+)_(4)和PO^(3-)_(4)的吸附较好地符合准二级动力学模型和Langmuir模型。不同生物质资源如小麦秸秆等经过两性改性后对NH^(+)_(4)和PO^(3-)_(4)的吸附性能研究结果表明,改性后的两性生物质吸附剂对NH^(+)_(4)的最大吸附量可达75.38 mg/g,对PO^(3-)_(4)的最大吸附量达到60.85 mg/g。

The amphoteric bagasse-based adsorbent(MABA)was synthesized by free radical polymerization using bagasse as raw material,methyl acrylloxyethyl trimethylammonium chloride(METAC),acrylamide(AM),2-acrylamide-2-methacrylic acid(AMPS)as monomers,and potassium persulfate(K2S2O8)as initiator.The structure and properties of MABA were characterized by Fourier infrared spectroscopy(FT-IR)and thermogravimetric analyzer(TGA).The effects of MABA dosage,pH and ionic strength of solution on the adsorption ability of MABA to NH^(+)_(4)and PO^(3-)_(4)were systematically investigated.The results showed that the maximum adsorption capacity of MABA to NH^(+)_(4)was 78.5 mg/g under the conditions of 2.5 g/L MABA and solution pH of 9.The maximum adsorption capacity of MABA to PO^(3-)_(4)was 74.3 mg/g with 2.0 g/L MABA and pH of 6.The adsorption of NH^(+)_(4)and PO^(3-)_(4)by MABA was in good agreement with the quasi-second-order kinetic model and Langmuir model.In addition,various types of biomass resources,e.g.,wheat straw,were also amphoteric modified and their adsorption abilities to NH^(+)_(4)and PO^(3-)_(4)were also evaluated.It was found that the maximum adsorption capacity of the prepared biomass-based adsorbent to NH^(+)_(4)and PO^(3-)_(4)were 75.38 and 60.85 mg/g,respectively.