In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic compounds have frequently been detected, sometimes at high concentrations, particularly at sites abandoned by chemical manufacturing enterprises. With the redevelopment of sites and changes in land-use type associated with these sites, substantial amounts of contaminated soils now require remediation. Since China is a developing country, soil remediation warrants the usage of techniques that are suitable for addressing the unique challenges faced in this country. Land shortage is a common problem in China; the large numbers of contaminated sites, tight development schedules, and limited financial resources necessitate the development of cost-effective methods for land reclamation. Mechanical soil aeration is a simple, effective, and low-cost soil remediation technique that is particularly suitable for the remediation of large volatile organic compound-contaminated sites. Its effectiveness has been confirmed by conducting laboratory studies, pilot tests, and full-scale projects. This study reviews current engineering practice and developmental trends of mechanical soil aeration and analyzes the advantages and disadvantages of this technology for application in China as an emerging soil remediation market. The findings of this study might aid technology development in China, as well as assist other developing countries in the assessment and implementation of costeffective hazardous waste site soil remediation programs.
研究了氧气和震荡条件对酿酒酵母高浓度乙醇发酵的影响.结果表明,震荡是提高发酵液乙醇浓度和产率的最重要因素.与静止培养相比,在不通气情况下震荡培养使乙醇浓度提高了69%(从75.8 g L-1提高到128.1 g L-1),在通气条件下乙醇浓度提高了68.7%(从85.2 g L-1提高到to 143.8 g L-1).在最优条件下,两次补料,经54 h发酵,发酵液中乙醇浓度达到143.8 g L-1,乙醇产率与理论产率的比值为0.471 g/g(即92.20%).经分析,通气和震荡条件提高了发酵液中酿酒酵母的生物量和细胞活力.图5表1参12 相似文献