Naturally derived organic biochar as an alternative to commercially activated carbon in the oxygen removal of seafood processing wastewater

BACKGROUND

The seafood processing industries are tremendously increasing in numbers which eventually discharge a large quantity of wastewater with a high range of biochemical oxygen demand (BOD) and chemical oxygen demand (COD), directly into the aquatic environment. A high level of BOD and COD in wastewater pertains to a higher level of pollution which must be reduced to prevent hazardous impacts on ecosystems. The main objective of the research aimed to develop cost-effective biochar and to remove BOD and COD from processing wastewater using two natural biomasses: water hyacinth and sugarcane bagasse.

RESULTS

NaOH-treated and non-treated biochar for both water hyacinth as well as sugarcane bagasse were prepared through the process of pyrolysis carried out at 600 °C with three different residence times of 30, 45 and 60 min. The wastewater was initially analyzed for BOD and COD levels. The results showed that among all the groups of biochars, the water hyacinth NaOH-treated biochar pyrolyzed at 600 °C for 60 min exhibited significantly (P < 0.05) higher levels of reduction in BOD (86.6 ± 0.03%) and COD (94.3 ± 0.05%) at a residence time of 60 min in D2 (0.5 g (250 mL)⁻¹). The maximum removal efficiency was observed for water hyacinth NaOH-treated biochar pyrolyzed at 600 °C for 60 min.

CONCLUSION

The removal efficiencies of organic load revealed that the treated biochars exhibited a better reduction of nutrients. The biochar efficiencies when compared with those of activated carbon exhibited a higher removal level. The present research can be used to reduce BOD and COD levels in wastewater treatments. © 2024 Society of Chemical Industry (SCI).