以西瓜皮为原料提取不溶性膳食纤维(IDF),并通过HCl改性,对比HCl改性西瓜皮不溶性膳食纤维(HCl-IDF)和未改性IDF对亚硝酸盐的吸附作用,探讨pH值、振荡温度、HCl-IDF添加量、吸附时间、NO-2 初始质量浓度对HCl-IDF吸附NO-2 的影响.结果表明,经HCl改性后,西瓜皮IDF对NO-2 的吸附量提升为原来的2倍;当HCl-IDF添加量为12. 5 g/L时,去除率为64. 6% ,并趋于吸附平衡;NO-2 初始质量浓度达到40 mg/L时,吸附量接近饱和;升高温度、降低pH值、延长吸附时间有利于HCl-IDF对NO-2 的吸附,在pH值1. 5、温度328 K、吸附时间70 min时可达吸附平衡;HCl-IDF对NO-2 的吸附平衡可以通过Langmuir等温方程拟合,吸附动力学行为符合Langergren准二级动力学模型,该吸附过程以化学吸附为主;HCl-IDF对NO-2 的吸附是一个吸热自发反应.%Insoluble dietary fiber (IDF) was extracted from watermelon peel and modified by hydrochloric acid. The adsorptions of nitrite by hydrochloric acid modified insoluble dietary fiber ( HCl-IDF) and IDF were evaluated. The effects of pH value, oscillating temperature, HCl-IDF dosage, adsorption time, NO-2 initial concentration on NO-2 adsorption of HCl-IDF were tested. The results showed that the adsorption capacity of NO-2 was doubled after modification. When the addition amount of HCl-IDF was 12. 5 g/L, the removal rate was 64. 6% and tended to adsorption equilibrium. When the initial concentration of NO-2 was 40 mg/L, the adsorption was close to saturation. Increasing temperature, lowering pH and prolonging adsorption time were beneficial to the adsorption of NO-2 by HCl-IDF, and the adsorption equilibrium was reached at pH 1. 5, 328 K and 70 min. The adsorption equilibrium of HCl-IDF for NO-2 could be fitted by Langmuir isotherm equation, and the adsorption kinetics conformed to Langergren quasi-second-order kinetic model, which was mainly chemical adsorption. Thermodynamic studies showed that the adsorption of NO-2 by HCl-IDF was an endothermic spontaneous reaction.
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