Assessing Bacterial Biofilm Capacity on Plastic-Derived Char for Agrochemical Wastewater Bioremediation

Abstract The application of pyrolysis is being extended to inorganic residues like plastics, which are considered an abundant residue nowadays. However, the sorbent capacity of plastic-derived char and its capacity to host biofilm formation that may be applied in bioremediation processes are unexplored. This study aimed to evaluate the char produced by pyrolysis of nonrecyclable post-consumer plastics to develop biofilm formation and its application in a real agrochemical effluent. The experimental design was set up in two phases: (i) adherence ability was measured with Ochrobactrum anthropi AD2 (with known adherence capacity) at optimal growth conditions on nonactivated or washed char, char activated with Na2CO3, and char activated with KOH; and (ii) biofilm formation ability in a real and polluted agrochemical wastewater on the surface of activated chars. The obtained results showed that O. anthropi AD2 biofilms were markedly influenced by the structural and surface characteristics of char, with the activated chars being more successful than nonactivated char. In the second phase, Na2CO3-activated char was the most efficient in the removal of copper, and it showed significantly higher microbial enumeration compared to KOH. The biofilm was composed of members of the Pseudomonas genus. This study suggests the potential of co-systems of biofilm-char as biotreatment of heavy metal-polluted wastewater.