Swine Wastewater: A Potential Aid in Oil Degradation

 by Ruby Ayala

A comparison of oil degradation rates among four different bacterial strains and indigenous    microorganisms, all of which used swine wastewater as a nitrogen source. Figure taken from Zhang et al. 2020

The swine industry plays an important role in the agricultural and economic development of a country (Shin et al., 2005). However, the swine wastewater that is accumulated in the pig farms can have severe consequences on aquatic environments if it is disposed of improperly. Swine wastewater is mainly comprised of pig urine, floor-washing water, and pig manure. Due to the high concentrations of organic matter, ammonia, and nitrogen present in the wastewater, Zhang and colleagues proposed swine wastewater could be a potential replacement of nitrogen source in the natural degradation of oil in soil. In this study, the oil degradation rates of native microorganisms and four different, introduced bacterial strains were compared to aid in the selection of the best oil degrading bacteria. Oil-contaminated soil treated with a combination of a sophorolipid-producing bacterial strain, an alkene-degrading bacterial strain, and swine waste revealed a higher percentage of oil degradation in just 40 days! On the other hand, swine wastewater added to soil with only native microorganisms degraded oil at a very poor rate, thus suggesting that additional microorganisms or genetic variants of a bacteria must be introduced to aid in the process of removing oil form soil. Using swine wastewater as as a source of nitrogen in soil remediation can be economically and environmentally beneficial because it can lessen the cost of repairing oil-contaminated soil and can allow for the swine wastewater to be recycled which also reduces environmental pollution. 

Original Article: Zhang, C., Wu, D. & Ren, H. (2020) Bioremediation of oil contaminated soil using agricultural wastes via microbial consortium. Sci Rep 10, 9188.

References cited: Shin, J.H., Lee, S. M., Jung, Y.J., Chung C.Y., and Noh, H.S. (2005) Enhanced COD and nitrogen removals for the treatment of swine wastewater by combining submerged membrane bioreactor (MBR) and anaerobic upflow bed filter (AUBF) reactor. Process Biochem. 40, 3769-3376.