Hydrocarbon Bioremediation: Scaling Up from Lab to Field for Petroleum-Contaminated Soils

Abstract

Abstract Previous degradation tests done at a lab scale displayed good results in TPHs degradation using the combination of vermicompost, nutrients addition, and microbial inoculation; this work was a scaling-up experiment for testing and optimizing the use of biopiles for bioremediation of TPHs polluted soils. In this scaling up experiment, based on previous bioremediation trials, three 500 kg pilots of polluted soil was prepared, and respective treatments were implemented: including control soil (CT) maintained at 40% field capacity, bioaugmentation and vermicompost treatment (BAVC), and a combined application of BAVC along with bioelectrochemical snorkels (BESBAVC). The bacterial consortia for bioaugmentation was inoculated at the start of experiment and at day 30 and water was added at same amount in CT pilot. The pilots were sampled in triplicate at 0 (before and after inoculation), 7, 30, 60, and 90 days, and extractable petroleum hydrocarbons (EPHs), chemical and biochemical soil properties were assessed. With natural attenuation ~ 15% of EPHs losses after 90 days occurred, attributed due to direct volatilization. With BAVC increased EPHs removal up to 90.3% of the initial amount at 90 days was noted. No statistically significant difference between BAVC and BESBAVC was restored. The BES snorkel application for the remediation of emerging pollutants is an innovative and budding technology, due to its capacity to enhance the pollutant removal capacity. However, it is highly dependent on the combination of provided aerobic and anaerobic conditions and requires higher water levels to support the process.