可持續(xù)發(fā)展的環(huán)境修復方法及土壤中石油烴遷移與傳遞研究.pdf

1、In recent years, there are increasing interests in integrating sustainability as adecision-making criterion for environmental remediation. Intemational initiativeshave been established to explore sustainable remediation

2、but there are knowledgegaps to be filled due to the specific challenges and problems in China. Improvedinsights into how to use the currently available frameworks to guide implementationof sustainable remediation in Chin

3、a are essential for improving risk assessment,remediation strategies and effective generation of previously contaminated land. Thisthesis explores the potential application of two remediation approaches includingsolvent

4、extraction and compost amendment for petroleum hydrocarbon contaminatedsoils in context of China and the United Kingdom (UK).
　　 Solvent extraction is a preferred approach for sites with high levels ofcontamination w

5、hich are not amenable for some more sustainable approaches such asbioremediation. This study provides new insights into the benefits of using integratedapproaches such as solvent extraction followed by biodegradation for

6、 remediatingcontaminated soils with high levels of total petroleum hydrocarbons (TPH > 140 000mg/kg) as most of the previous studies have been only focused on low concentrationcontamination(< 5000 mg/kg). The method allo

7、ws > 90％ of TPH to be removedwithin 15 min at room temperature, which is much more effective than previousreported solvent extraction method that required an extraction time ranging from 30min to 48 h and temperature ran

8、ging from 70℃ to 100℃. In addition, the issue ofsecondary pollution was addressed because gg％ of the solvent was recycled usingwater. This method also shows good performance for the long-term effectivenessbecause the res

9、idual contaminants (mainly asphaltene) after treatment are extremelyrecalcitrant, non-available to ecological receptors in soil, and may be left in placewithout creating additional environmental risks. The complementatio

10、n of solventextraction and biodegradation promoted the strength but circumvented the drawbacksof their individual application, and therefore should be encouraged at contaminatedsites for reducing remediation time, enhanc

11、ing efficacy, improving sustainability andrestoring previous contaminated sites especially with high concentration weatheredhydrocarbons.
　　 Adding mature compost to contaminated soils is a good alternative for reusi

12、ngwaste and remediating the degraded land. The influence of compost addition on thedegradation and bioavailability changes of polycyclic aromatic hydrocarbons (PAH)in both spiked and genuinely contaminated soils were inv

13、estigated in this study. Thequantified contribution of degradation and desorption/sorption to bioavailabilitychange has implication for future studies to bring bioavailability concept intoexposure assessment and to devel

14、op a more realistic and defensible remediationcriteria for petroleum hydrocarbon in soils. Results of conjoint analysis reinforced theimportance of incubation time and soil type (accounting for 92％) for PAHbioavailabilit

15、y change. The relationship between time, eleven readily accessible soilproperties, and the bioavailable concentration of 16 PAHs using machine leamingtechniques gained insights into their high nonlinear relationship and

16、provided a usefultool for the temporally prediction of bioavailability allowing a quick forecast of thebioremediation endpoint. Although the type and ratio of compost added were lessimportant for bioavailability change,

17、their interactions with other factors weresignificant. Results of multiple factor interactions implied that the compost additionshifted the equilibrium of soil-oil interaction (e.g. competitive sorption), however,knowled

18、ge about how to model the multi-phase partitioning of hydrocarbons in thesoil-compost-oil system and the contribution of each mass transfer process (e.g.biodegradation, desorption, volatilization, diffusion, and etc.) to