摘要
随着乙醇混合汽油的不断推广应用,乙醇将成为地下水中与苯、甲苯、乙苯及二甲苯的同分异构体(BTEX)共存的一种新型污染物。通过4个含水砂柱实验,研究了乙醇存在及其强化去除对含水介质渗透性能的影响。结果表明:在有限溶解氧与反硝化增强修复条件下,乙醇去除率达92%以上;生物过程对介质渗透能力影响程度随乙醇初始浓度、消耗速率与补充频率而变化:乙醇初始浓度接近1000mg/L和3000mg/L时,乙醇消耗快,补充频率高,渗透系数下降总体上有连续性,最大下降幅度达一个数量级(×10-1cm/s);乙醇初始浓度达到5000mg/L时,渗透性下降显著,可下降两个数量级,但乙酸的积累可影响生物活性,并使得渗透性变化出现反复;当不含乙醇时,汽油溶解组分对介质渗透性能的影响相对不明显。
Increasing use of ethanol blended gasoline will make ethanol a new contaminant along with benzene,toluene, ethylbenzene and xylene isomers（collectively denoted as BTEX）in groundwater. This study focuses on the effects of ethanol nitrate-enhanced bioremediation on permeability of porous media via four sand column experiments. Results showed that the removal rates of ethanol were greater than 92 % under limited dissolved oxygen and amended nitrate conditions. Effects of bioprocesses on permeability could vary with the initial concentration of ethanol, biodegradation rate and amendment frequency. For the initial concentration of ethanol near 1 000 mg/L or 3 000 mg/L,the permeability coefficient could continuously decrease one order of magnitude（×10-1 cm/s）comapred with the background value. The amendment frequency of ethanol was high because ethanol could be rapidly consumed within a short time. In the presence of the initial ethanol concentration up to 5000 mg/L, the permeability coefficient could decrease two order of magnitude. However, the slow consumption rate of ethanol and the low amendment frequency for ethanol would likely cause the permeability to be increasd. For comparison,dissolved hydrocarbons of gasoline without ethanol showed insignificant effect on permeability.
出处
《高校地质学报》
CAS
CSCD
北大核心
2010年第1期32-38,共7页
Geological Journal of China Universities
基金
国家自然科学基金(40672200)
教育部留学回国人员科研启动基金联合资助
关键词
乙醇混合汽油
含水介质
反硝化
增强修复
渗透性
影响
ethanol blended gasoline
porous media
denitrification
enhanced bioremediation
permeability
effect
