Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18, Shuangqing Rd, Beijing, 100085, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18, Shuangqing Rd, Beijing, 100085, China; College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
Water Res. 2019 Jun 1;156:414-424. doi: 10.1016/j.watres.2019.03.043. Epub 2019 Mar 24.
This study focused on evaluating the use of powdered activated carbon (PAC) adsorption for the treatability of various odor compounds with different structures. The adsorption performance of 14 odor compounds under various PAC dosages were fitted with two isotherm models (the Langmuir and Freundlich models) to evaluate the adsorption ability. The results indicated that the adsorption capacities estimated from isotherm model predictions were not suitable for the evaluation of treatability of the odor compound due to the neglection of odor threshold. A novel assessment method, through the comparison of the residual concentration at an inflection point (where the downward trend of the odor compound residual concentration and PAC dosage curve starts to flatten) and the corresponding threshold concentration, was employed. This assessment method considered the different thresholds of the various odor compounds and their absorbability by PAC as well as the cost. The results indicated that only the sulfur odor compounds, including dimethyl disulfide, diethyl disulfide and dimethyl trisulfide, were not suitable for PAC treatment. Other odor compounds could be treated by PAC with varying success. The correlations between the adsorption capacity and the treatability of various odor compounds and their properties, including the coefficient between octanol and water (LogK), solubility, molar refractivity (MR), dipole and volume, were also evaluated using the Pearson and Spearman correlation analysis. The results indicated that there were not significant correlations between the adsorption capacity and the properties of the odor compounds, while there were significant correlations between the treatability and LogK, MR and volume. The odor causing compound with a larger LogK, MR and volume was more suitable to be treated by PAC.
本研究旨在评估粉末状活性炭（PAC）吸附在处理不同结构的各种气味化合物方面的应用。通过两种等温模型（朗缪尔和弗伦德利希模型）拟合 14 种气味化合物在不同 PAC 剂量下的吸附性能，以评估吸附能力。结果表明，由于忽略了气味阈值，等温模型预测的吸附能力不适合评估气味化合物的处理能力。通过比较转折点处的残留浓度（气味化合物残留浓度和 PAC 剂量曲线向下趋势开始变平的点）和相应的阈值浓度，采用了一种新的评估方法。该评估方法考虑了各种气味化合物的不同阈值及其被 PAC 吸收的能力和成本。结果表明，只有硫气味化合物，包括二甲基二硫、二乙基二硫和二甲基三硫，不适合 PAC 处理。其他气味化合物可以通过 PAC 进行不同程度的处理。还使用 Pearson 和 Spearman 相关性分析评估了吸附能力与各种气味化合物处理能力及其性质（包括辛醇-水分配系数（LogK）、溶解度、摩尔折射度（MR）、偶极矩和体积）之间的相关性。结果表明，吸附能力与气味化合物的性质之间没有显著相关性，而处理能力与 LogK、MR 和体积之间存在显著相关性。具有较大 LogK、MR 和体积的致臭化合物更适合用 PAC 处理。
