Simultaneous removal of organic and inorganic pollutants from synthetic road runoff using a combination of activated carbon and activated lignite

Road runoff presents a unique case when it comes to selecting adsorbents for the simultaneous removal of organic and inorganic pollutants. In this study, a series of rapid small-scale column tests (RSSCTs) were conducted to investigate the performances of granular activated carbon (F300) and granular activated lignite (HOK) in removal of the ubiquitous pollutants methyl tert-butyl ether (MTBE), naphthalene, and zinc (Zn²⁺). F300, HOK, and a combination of both materials were studied in RSSCTs. The experimental data were fitted with the Thomas and Yan models. In the experiments, naphthalene was efficiently removed by both F300 and HOK. Expectedly, both F300 and HOK showed high naphthalene removals. Further, F300 showed a higher selectivity towards MTBE than Zn²⁺, while HOK had a significantly higher selectivity towards Zn²⁺, while the lowest selectivity towards MTBE. Although the adsorption capacity of MTBE was reduced from 19.9 mg/g to 11.6 mg/g, a combination of HOK and F300 drastically increased the adsorption capacity of Zn²⁺ by three times from 1.13 mg/g to 3.36 mg/g. Hence, the combination of F300 and HOK offers a promising solution for removal of organic and inorganic pollutants from road runoff.