Treatment of Coking Wastewater Using Sorption Processes

Adsorption is one of the basic surface phenomena involving saturation of the adsorbent surface with adsorbate molecules located near the adsorbent-adsorbate interface. The processes that are accompanied by the accumulation of adsorbate molecules on the surface are different from absorption, which is related to absorbing molecules into the whole mass and requires diffusion into the interior. If both processes can occur simultaneously, this phenomenon is called sorption. The aim of the present study was to characterize the sorption properties of selected sorbents and to assess the possibility of their application to support the treatment of coking wastewater from ammonium nitrogen, phenol, and TOC. The scope of the study included the examinations of sorption properties of selected sorbents (coal dust, coke dust, biochar), physicochemical tests of coking wastewater after biological treatment, as well as the examinations aimed to determine the dose of adsorbents and time needed to establish the equilibrium state of the process. The results obtained were analyzed for the effect of dose and contact time on the pollutant removal efficiency. The literature describes the efficiency of ammonium nitrogen removal from wastewater using chemical processes. However, there is a lack of studies on the removal of ammonium nitrogen, phenol, and TOC from industrial (coking) wastewater. The conducted study aimed to develop an alternative solution to the currently used conventional methods of removing high concentrations of pollutants from wastewater.