Biomass derived activated carbons in wastewater treatment – the aim of metallurgical industry

In the presented study, two commercial powder activated carbons (ACs) produced from low-cost biomass: coconut shells and wooden chips, were used in the adsorption process. The treated solution was wastewater obtained from production area of metallurgical industrial plant, which was analysed before and after the adsorption process using atomic absorption spectrometry (AAS). The adsorption process proceeded at two pH levels 7 and 9. The removed pollutants were Cd, Co, Cu, Ni, Sb, and Zn. Based on the adsorption results, the correlation between adsorption efficiency, pH and ACs properties was determined. The complicated composition of the tested wastewater causes that the adsorption mechanism did not have to be obvious due to the phenomena occurring in the multi-component system. Both ACs adsorbed ions efficiently, better results were obtained for AC derived from coconut shells. It was found that higher pH correlate with higher adsorption efficiency for every checked type of ions. AC with higher iodine number, mainly basic surface groups and higher micropores volume had better efficiency for adsorption Cd, Co, Cu, Ni and Zn. AC with higher surface area and presence of acidic surface groups only, had better efficiency in Sb adsorption process.