Evaluation of the treatability of various odor compounds by powdered activated carbon

• Published in: Water research (Oxford) 2019-06, Vol.156, p.414-424
• Main Authors: Huang, Xin, Lu, Qiang, Hao, Haotian, Wei, Qunshan, Shi, Baoyou, Yu, Jianwei, Wang, Chunmiao, Wang, Yan
• Format: Article
• Language: English
• Subjects: Adsorbate properties; Adsorption; Odor compounds; Powdered activated carbon; Treatability
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2019.03.043

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 (LogKw), 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 LogKw, MR and volume. The odor causing compound with a larger LogKw, MR and volume was more suitable to be treated by PAC. [Display omitted] •The adsorption performance of 14 odor compounds onto PAC were studied.•Adsorption isotherm models were not reliable to evaluate the odor treatability.•A new method was employed to evaluate the odor compounds treatability by PAC.•The method takes into consideration of threshold value, adsorption limits and cost.•Odor treatability was related with its LogKw, volume and molar refractivity.