厭氧生物溶出技術應用於重金屬污染底泥整治之探討

Anaerobic Bioleaching Process for Remediation of Metal-Contaminated Sediments

陳勝一(Shen-Yi Chen)

《土壤及地下水污染整治》 1卷2期 (2014/10) Pp. 127-139

https://doi.org/10.6499/JSGR.2014.0102.003

摘要

目前國內針對受污染水體底泥處理技術之研究極少，未來極需要此方面之技術，以處理浚渫後之大量底泥。但是，污染底泥量增加、處理費用升高，加上更嚴格管制要求，以致於未來底泥之處理與處置技術將必須脫離傳統方法並且重新調整，始能因應實際之需要。在以往的好氧生物溶出技術中需要提供反應系統足夠之氧氣，因此必須使用曝氣設備及能源，在提倡節能減碳之現代，將會使得好氧生物溶出技術於環境工程之實際應用受到限制。本文中首先針對兼性厭氧硫氧化菌在底泥中重金屬溶出作學理機制上之回顧與探討，以評估此環境生物技術於重金屬污染底泥整治之可行性；同時對於厭氧生物溶出技術之影響因子亦進行深入討論，此將可以提供未來應用厭氧生物溶出技術於重金屬污染底泥整治時之重要參考資訊。

關鍵字

底泥 ； 重金屬 ； 生物溶出 ； 兼性厭氧 ； 硫細菌

並列摘要

Since the amendment of the Soil and Groundwater Remediation Act in 2010, the sediments in the surface water bodies have been regulated by environment protection laws in Taiwan. This raised four important issues, namely contaminated sediment monitoring, contamination investigation and assessment, remediation assessment and execution, and the related controls. On the other hand, in the restoration strategies of river and lake, besides controlling pollution sources and building sewer systems, the contaminated sediment may need to be dredged from the rivers or lakes. The sediments dredged from contaminated rivers or lakes often contain substantial amount of heavy metals, and thus cannot be disposed of on the land and in water bodies without any treatment. To date, there are relative few studies on the detoxification and decontamination processes of heavy metals in aquatic sediments in Taiwan, and this is thus the focus of the current work. The removal of heavy metals from contaminated sediments is generally achieved by the oxidation and acidification carried out by leaching bacteria during the bioleaching process. Therefore, the oxidation and acid producing abilities of leaching bacteria play important roles in the bioleaching process. Bioleaching for the removal of metals from sediment and soil using chemolithoautrophic bacteria, such as sulfuroxidizing bacteria, is a well-known process. In addition to the well-known aerobic bacteria that are used for this, facultative anaerobic bacteria also play important roles in the bioleaching process. This biotechnology is environmentally friendly, and it may have lower operational costs and energy requirements than conventional physico-chemical methods. However, the anaerobic bioleaching of heavy metals from sediment, sludge and soil has received little attention to date. This article reviewed and evaluated the feasibility of applying the anaerobic bioleaching process for the remediation of metal-contaminated sediments in Taiwan. The anaerobic bioleaching process is carried out with the aid of facultative anaerobic sulfur-oxidizing bacteria, and in recent years has been developed for the recovery (removal) of heavy metals from mineral ores and soils. The theoretical mechanisms of metal solubilization from the contaminated sediment and the physiological characteristics of microorganisms involved in the anaerobic bioleaching process are first described in this article, and then the effects of the operational parameters on metal solubilization from sediment are discussed. In addition, the application of anaerobic and facultative anaerobic microorganisms in the bioleaching process and treatment of groundwater are also reviewed in this article.

並列關鍵字

sediment ； heavy metal ； bioleaching ； facultative anaerobes ； sulfur-oxidizing bacteria