Assessing Technical and Economic Feasibility of Complete Bioremediation for Soils Chronically Polluted with Petroleum Hydrocarbons

Abstract

Petroleum hydrocarbons are highly persistent in the environment and represent a significant risk for humans, biodiversity, and the ecosystems. Frequently, hydrocarbon-contaminated sites remain polluted for decades due to a lack of proper decontamination treatments. Although bioremediation techniques have gained attention for being environmentally friendly, cost-effective and applicable in situ, their application is still limited. Each polluted soil has particularities, therefore, the bioremediation approach for a contaminated site is unique. Bioremediation cost studies are usually based on hypothetical assumptions rather than technical or experimental data. The research aims of this study were to clean-up chronically hydrocarbon-polluted soils using aerobic and anaerobic bioremediation techniques and to carry out an economic evaluation of the most promising bioremediation treatments. The results showed that aerobic biostimulation with vermicompost and aerobic bioaugmentation plus air venting were the most effective treatments, degrading 78% and 73% of total petroleum hydrocarbons (TPH) in chronically hydrocarbonpolluted soils after six weeks, respectively. In contrast, no significant degradation of hydrocarbon was observed by anaerobic biostimulation treatments with lactate and acetate. An economic evaluation of the aerobic treatments were carried out. This analysis revealed that the cost of treating one cubic meter of soil by biostimulation is US$ 59, while bioaugmentation costs US$77. This study provides a clear structure of costs for both aerobic bioremediation approaches based on projections made from these lab-scale incubations. These values represent the first step towards a better understanding of the feasibility of such treatments at larger scales, which is crucial to move on industrial bioremediation of soils chronically polluted with petroleum hydrocarbons.

Economic Evaluation of Bioremediation of Hydrocarbon-Contaminated Urban Soils in Chile

“…Economic assessment was made based on the results of bioremediation of five treatments to clean-up chronically hydrocarbon-contaminated soils, based on bioaugmentation, biostimulation or combination of both technologies [52]. The first approach was bioaugmentation, with the addition of five hydrocarbonoclastic strains (named as BA).…”

“…Our results showed that biostimulation-based treatments have lower costs than their counterparts using bioaugmentation. Specifically, the comparison between all bioaugmented treatments and BE1 revealed that the last treatment, though effective in hydrocarbon biodegradation [52], showed a significant reduction in direct material costs, provision and covering assets. This highlights the properties of compost, which is the mature product of composting, a bioprocess that transform solid organic substrates into relatively stable, organic-rich material via microbial communities [60].…”

“…The analysis presented here was based on the bioremediation of chronically contaminated soils, such as those currently present at Las Salinas, in which there is no evidence of persistent degradation processes over time. Therefore, the economic assessment was based on the addition of compost, the addition of hydrocarbon-degrading microorganisms as well as a mixture of both approaches, for which experimental results were previously published [52]. In this study, the bioremediation was addressed by five treatments.…”

“…Calculations for culture volume added for bioaugmentation was determined on the basis that each strain reaches a density of 10 6 CFU g −1 , value that is 10-fold higher than those levels of cell density of hydrocarbon-degrading microorganisms at which bioremediation will be negligible [55]. Based on bacterial counts made in preliminary laboratory experiments [52], each strain requires one jacketed reactor, except for Acinetobacter sp. AA64, which requires two.…”

Vozmozhnosti spektral`ny`x metodov analiza v issledovanii nefteshlamov

“…Кроме того, эффективное обезвреживание нефтеотходов и ликвидация амбаров-накопителей по-прежнему остается актуальной задачей нефтехимических предприятий. С одной стороны, это связано с высокой устойчивостью нефтешламов к разрушению, особенностями их состава и свойств, которые постоянно меняются под воздействием погодных условий и процессов, протекающих в них [15][16][17]. С другой стороны, нефтеперерабатывающие предприятия при обращении с нефтеотходами должны минимизировать их количество, разрабатывать собственные экономически доступные и технически осуществимые технологии для вовлечения отходов в ресурсооборот.…”