Bioremediation of piggery slaughterhouse wastewater using the marine protist, Thraustochytrium kinney VAL-B1

Abstract

Industrial wastewaters from pig slaughtering plants (PSPs) generated in the slaughtering process could have an environmental impact, if discharged to a receiving water body without any treatment. In this study, a Chilean Thraustochytrid (TH) strain, a class of marine protist, was used for the bioremediation of piggery slaughterhouse wastewater (SWW). According to the physicochemical analysis of the residue, it was characterized by an initial chemical oxygen demand (COD) of 9610 mg L−1, 18,625 mg L−1 of oil and grease, 1639 mg L−1 of total nitrogen, 149 mg L−1 of total phosphorus, and 82.41 mg L−1 of total iron. Growth studies were conducted to evaluate the growth and biomass production of the strain on residue-based media and its subsequent bioremediation ability. After 5–7 days of fermentation, the results showed that COD of the medium supernatant was reduced by 56.29% (4200 mg L−1), while oil and grease had a significant decrease about 99% (18 mg L−1), and the content of total nitrogen, total phosphorus, and total iron were also decreased by 63.27% (602 mg L−1), 97.55% (3.65 mg L−1) and 60.35% (30.88 mg L−1), respectively. With these results, it was concluded that VAL-B1 can be used for the bioremediation of industrial wastewater from PSPs, and therefore THs could contribute to regulate the environmental pollution.