淄博地下水中生物降解作用的水化学判别

环境调查研究表明，大武地下水水源地上游邻近的石化厂区出现严重的地下管道石油污染物持续泄漏现象。堠皋－柳杭地段地下水环境在成为集中污染地段的同时，水文地球化学环境也发生了迥然的变化：地下水中电子接受体溶解氧，ＮＯ３＾－末检出，ＳＯ４＾２－呈低值分布。这与地下水中存在微生物降解烃污染物的作用有关。其作用类型包括需氧降解，脱硝降解，脱硫降解以及有Ｆｅ＾３＋参与的降解作用。然而由于该地段需氧降解、脱硝降解、脱硫降懈以及有F3+参与的降解作用。然而由于废地段需氧降解、脱硝降懈难以进行，导致了生物降解污染物的速度降低 其研究意义是提高地下水中电子接受体的浓度．增强微生物的活性，以促进生物降解速度，将有利于含水层中这类污染物的清除。

HYDROCHEMICAL IDENTIFICATION OF BIODEGRADATION IN THE GROUNDWATER

The Dawu Well Field is one of the largest karst-fractured groundwater sources in the east of zibo City, Shandong Province and It is the most important resource for the urban water supply in Zibo City. However, data from 35～ 56 monitoring wells in the Well Field indicated that groundwater was seriously polluted by petroleum products. Maximum concentration of organic contaminants up to 77.34 mg/1 was detected in the water supply wells located at the Liuhang-Hougao zone in the went part of Dawu Well Filed. A series of environmental investigations during the recent years showed that serious leaking of petroleum contaminant occurred in the subsurface of petrochemical factory areas in the upriver of Dawn Wel1 Field forming a major source of groundwater contamination by petroleum hydrocarbons. Since the Hougao and Liuhang zones are seriously polluted, hydrochemical environment has changed greatly in the past ten years (1987 to 1996). Concentrations of nitrate and sulfate in the groundwater oontaminated by pe trochemicals were reduced from 29.04 to <0.4mg/l and 113.59 to 51.23 mg/l respectively. On the other hand, concentrations of bicarbonate and ammoniumion, were increased from 298.79 to 426.84 mg/l and < 0.04 to 0.43 mg/1. Dissolved oxygen was almost not detected. Comparing with the zones seriously polluted, concentrations of nitrate and sulfate in the ground water of Xixia wells located in the east of Dawa Wel1 Field were increased from 15.75 to 21.71mg/1, and 38.90 to 55.23mg/l in the past ten years. And concentration of bicarbonate changed from 237.97 to 215.81 mg/l. These changes of hydrochemical characteristics suggested that some microbial processes have graded organic materials in the groundwater leading to a decrease in the concentrations of electric acceptors and an increase in concentration of bicarbonate near the zones seriously polluted. These microbial processes included biodegradations with oxygen, nitrate and sulfate ere. However, the hydrogeochemical conditions of the Hougao and Liuhong aquifers are characterized by absences of nitrate and dissolved oxygen and the low concentration of sulfate. The subsurface environmental conditions would reduce the rate of biodegradation beeaL1se of the absence of the electric acceptors. Therefore, the results of this research have demonstrated that： 1. The microbial processes could be evaluated through the hydrochemical data of groundwater. 2. Biorestoration method to renovate aquifers contaminated with petroleum productions in Zibo city is feasible. 3. To enhance the activities of micro-organisms in the subsurface water, increasing the concentrations of electric acceptors, such as nitrate, probably is a effective biorestoration method.