Targeted testing of activated carbons for advanced wastewater treatment

• Novel test method for selection and quality control of powdered activated carbon.
• Inexpensive and fast photometric quantification of target pollutants in test solution.
• Selectivity of activated carbon for one of two groups of organic micro-pollutants.
• Good correlation of micro-pollutant removal in the test solution and in treated wastewater.

Powdered activated carbon (PAC) is a promising agent for the adsorptive removal of organic micro-pollutants (OMP) from wastewater treatment plant (WWTP) effluents. Reliable and predictive test methods are required for the selection and for the quality control of PAC. In the present investigation, a pragmatic test method using indicative target OMP and photometric analyses was developed. Eight different PAC were compared according to the test method and according to removals of individual OMP in WWTP effluent. The test method allowed identification of the PAC with the highest and the lowest removals of benzotriazole and elucidated differences of the PAC with regard to removals of individual OMP. In WWTP effluent both positive and negative correlations between OMP removals with different PAC were observed: Some PAC removed diclofenac, carbamazepine and metoprolol to a comparatively greater extent while other PAC are comparably more efficient for benzotriazole, methylbenzotriazole and acesulfame adsorption.