Bioremediation of fibreboard sludge by using bacteria and fungi

Abstract

Sludge produced from the fibreboard industry releases hazardous substances that may damage the environment as well as human health via inhaled air, drinking water, and food consumed. Correspondingly, the aim of this study was to focus on the bioremediation to treat industrial wastewater sludge produced from Evergreen Fibreboard, Parit Raja, Batu Pahat, Johor by using bacteria (Sphingobacterium spiritivorum) and fungi (Aspergillus brasiliensis). Three stages of the investigation were performed, which are the collection of raw materials, the preparation of microbes, and sample analysis, including the determination of COD and heavy metals including Chromium (Cr), Copper (Cu), Arsenic (As), Lead (Pb) and Zink (Zn). From the Chemical Oxygen Demand (COD) test, Aspergillus brasiliensis shows higher potential for sludge bioremediation as 61 mg/L COD was reduced in 14 days compared to the Sphingobacterium spiritivorum which only 31 mg/L was reduced. Meanwhile, the leaching result for heavy metals shows that Zn had the highest concentrations and As was the lowest for 14 and 28 days. Inoculation of Aspergillus brasiliensis shows the lowest leaching concentration for heavy metal elements such as Cr, Cu, As, Pb and Zn compared to Sphingobacterium spiritivorum. The reduction concentrations of these elements are 13%, 22%, 17%, 33% and 6%, respectively. The result shows that the fungi strain has the highest capability to absorb metals compared to the bacteria strain. Indigenous microorganisms in sludge have the lowest potential to reduce COD and heavy metals. However, a combination with the other method such as physical and chemical processes would be recommended to improve the results in the future.