Adsorption of micropollutants in wastewater using pulverized activate carbon - The influence of organic matter content and characteristics

Abstract: Wastewater is one of the biggest emission sources of organic micropollutants to the aquatic environment. Due to the negative effects of micropollutants on the receiving waters, advanced treatment steps are needed to reduce these emissions. Activated carbon is one promising approach. However, the adsorption of micropollutants to activated carbon is affected by the content of organic matter in the wastewater. This study aims to investigate how the adsorption capacity of activated carbon varies between different organic micropollutants, and how the adsorption is affected by the presence of organic compounds in different wastewaters. The adsorption of the micropollutants carbamazepine, mecoprop, sulfamethoxazole and diclofenac onto pulverized organic carbon (PAC) was tested in three wastewaters with different amounts of organic matter. Eight PAC doses were added ranging from 0 to 100 mg PAC/L and the remaining micropollutants in the water were measured after equilibrium was reached. The results were then normalized with three different measurements of organic content, DOC (dissolved organic carbon) and UVA254 (Adsorption of UV light at 254 nm) for filtered and raw water. Carbamazepine was adsorbed to the highest extent followed by diclofenac, mecoprop and sulfamethoxazole. A difference in adsorption between the three wastewaters was observed and DOC was observed to be a too broad measurement of organic matter to be used for normalization. The normalization with UVA254 of raw and filtered water superimposed the adsorption data from the different wastewaters equally well and they could potentially both be used as a parameter for PAC dosing in wastewater treatment plants.