Effect and Ecological Assessment of Microbial Remediation

In situ biological purification technology has been widely used in the engineering of environmental pollution treatment, since it is a more convenient and effective approach, with low cost. Therefore, the potential risk to the safety of biological agents should be seriously taken into consideration. The efficient aerobic denitrifying bacteria strain HF3, which is isolated and cultured in a low-nitrogen medium in order to remove nitrogen under oligotrophic conditions, has been used for bioremediation treatment, with effective and reliable ability in removing the nutrients of aquatic environments. Different to other biological agents, the efficient strain used for biological purification was cultured from raw water, and was isolated among indigenous bacteria. It is, therefore, the inferior species, and pathogenic bacteria had been excluded during the isolation. In addition, non-native application of the efficient strains which had a high environmental risk could be avoided during the application. In this chapter, we discuss the safety of the efficient strain HF3 by three aspects: biological safety on drinking water quality, ecological safety on indigenous microorganisms, and toxicological safety on aquatic animals. The results showed that the efficient aerobic denitrifying bacteria strain HF3 had no significant effect on the microbial community, and had no toxicity on mice, luminescent bacteria, or zebrafish. The efficient strain HF3 could be inactivated without any influence on the inactivation efficiency. The results suggest that the biological agent used for bioremediation treatment is safe and poses no risks to the urban drinking water supply, which could provide theoretical guarantees for the security of a wider range of application. It is important to reveal the effect and ecological assessment of microbial remediation. Therefore, in this chapter, we describe the effect and ecological assessment of the microbial remediation process.