Comparative evaluation of bioremediation techniques on oil contaminated sediments in long-term recovery of benthic community health

• Published in: Environmental pollution (1987) 2019-09, Vol.252 (Pt A), p.137-145
• Main Authors: Lee, Changkeun, Hong, Seongjin, Noh, Junsung, Lee, Junghyun, Yoon, Seo Joon, Kim, Taewoo, Kim, Hosang, Kwon, Bong-Oh, Lee, Hanbyul, Ha, Sung Yong, Ryu, Jongseong, Kim, Jae-Jin, Kwon, Kae Kyoung, Yim, Un Hyuk, Khim, Jong Seong
• Format: Article
• Language: English
• Subjects: Benthic community; Oil spill; PAH-Degrading bacteria; PAH-Vulnerable bacteria; Restoration; Semi-field experiment
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2019.05.100

While various bioremediation techniques have been widely used at oil spill sites, the in situ efficiency of such techniques on recovering the benthic communities in intertidal areas has not been quantified. Here, the performance of several bioremediation tools such as emulsifiers, multi-enzyme liquid (MEL), microbes, and rice-straw was evaluated by a 90-days semi-field experiment, particularly targeting recovery of benthic community. Temporal efficiency in the removal of sedimentary total petroleum hydrocarbons (TPH), reduction of residual toxicity, and recovery of bacterial diversity, microalgal growth, and benthic production was comprehensively determined. Concentrations of TPH and amphipod mortality for all treatments rapidly decreased within the first 10 days. In addition, the density of bacteria and microphytobenthos generally increased over time for all treatments, indicating recovery in the benthic community health. However, the recovery of some nitrifying bacteria, such as the class Nitrospinia (which are sensitive to oil components) remained incomplete (13–56%) during 90 days. Combination of microbe treatments showed rapid and effective for recovering the benthic community, but after 90 days, all treatments showed high recovery efficiency. Of consideration, the “no action” treatment showed a similar level of recovery to those of microbe and MEL treatments, indicating that the natural recovery process could prevail in certain situations. [Display omitted] •Residual hydrocarbons and amphipod toxicity rapidly decreased within 10 days.•Quick recovery found for most of the bacteria, but some remained incomplete at >90 d.•Microphytobenthos community took more than 90 days to recover against oil exposure.•Combination of microbe treatments were effective for recovering the benthic community.•“No action” showed comparable recovery to others, indicating prevailing natural recovery. “Among various bioremediation techniques tested, the microbes was rapid and effective in restoring benthic community health.”