Makkar Randhir S, Rockne Karl J
Department of Civil and Materials Engineering (m/c 246), University of Illinois, Chicago, 842 West Taylor Street, Chicago, Illinois 60607-7023, USA.
Environ Toxicol Chem. 2003 Oct;22(10):2280-92. doi: 10.1897/02-472.
Polycyclic aromatic hydrocarbon (PAH) contamination of the environment represents a serious threat to the health of humans and ecosystems. Given the human health effects of PAHs, effective and cost-competitive remediation technologies are required. Bioremediation has shown promise as a potentially effective and low-cost treatment option, but concerns about the slow process rate and bioavailability limitations have hampered more widespread use of this technology. An option to enhance the bioavailability of PAHs is to add surfactants directly to soil in situ or ex situ in bioreactors. Surfactants increase the apparent solubility and desorption rate of the PAH to the aqueous phase. However, the results with some synthetic surfactants have shown that surfactant addition can actually inhibit PAH biodegradation via toxic interactions, stimulation of surfactant degraders, or sequestration of PAHs into surfactant micelles. Biosurfactants have been shown to have many of the positive effects of synthetic surfactants but without the drawbacks. They are biodegradable and nontoxic, and many biosurfactants do not produce true micelles, thus facilitating direct transfer of the surfactant-associated PAH to bacteria. The results with biosurfactants to date are promising, but further research to elucidate surfactant-PAH interactions in aqueous environments is needed to lead to predictive, mechanistic models of biosurfactant-enhanced PAH bioavailability and thus better bioremediation design.
环境中的多环芳烃（PAH）污染对人类健康和生态系统构成严重威胁。鉴于PAHs对人类健康的影响，需要有效且具有成本竞争力的修复技术。生物修复已显示出作为一种潜在有效且低成本处理选项的前景，但对其缓慢的处理速率和生物可利用性限制的担忧阻碍了该技术的更广泛应用。提高PAHs生物可利用性的一种选择是在原位或异位生物反应器中直接向土壤添加表面活性剂。表面活性剂可提高PAH在水相中的表观溶解度和解吸速率。然而，一些合成表面活性剂的研究结果表明，添加表面活性剂实际上可能通过毒性相互作用、刺激表面活性剂降解菌或使PAHs螯合到表面活性剂胶束中而抑制PAH生物降解。生物表面活性剂已显示出具有许多合成表面活性剂的积极作用但没有其缺点。它们可生物降解且无毒，并且许多生物表面活性剂不会形成真正的胶束，从而促进与表面活性剂相关的PAH直接转移至细菌。迄今为止，生物表面活性剂的研究结果很有前景，但需要进一步研究以阐明水环境中表面活性剂与PAH的相互作用，从而建立生物表面活性剂增强PAH生物可利用性的预测性、机理模型，进而实现更好的生物修复设计。
