藻类对重金属污染水体的生物修复

Bioremediation of Heavy Metal Contaminated Water by Algae

重金属对水体的污染已成为全球性的环境问题,利用藻类生物修复重金属污染水体,因其有效、低廉和环保引起了国内外的广泛重视,并且取得了一定的成效。本文介绍了藻类修复重金属废水的应用概况,总结了多年来在藻类对重金属离子的吸收途径、耐受机理、生物吸附机制、模型解释及影响因素等方面的研究成果,同时指出了当前在这些方面尚存的不足,并就今后继续筛选、利用生物技术培育对重金属高耐受、高富集性藻类,进一步探求修复机理以及野外应用方面的研究。

Heavy metal pollution in aqueous system is a significant world-wide problem. Heavy metal ions which are present as ions in wastewater are toxic and can be readily absorbed into the human body through the food chain in aquatic ecosystem. The prevention o! heavy metal contamination in aquatic environments is often performed by conventional methods. However, these methods have many disadvantages, such as incomplete metal removal, toxic sludge generation and cost inefficiency. Metal uptake by microorganisms has been studied for some years. Researches indicate that algae have the abilities to accumulate trace metals. Based on findings, technologies of bioremediation of heavy metal contaminated water by algae in living and nonliving form have been developed and got more and more attention around worldwide for its costeffective and environmental friendly characteristics. Some of the technologies in heavy metal removal, such as High Rate Algal Ponds and Algal Turf Scrubber, have been justified for some practical application in China and abroad and limitations of these methods in large scale still exist. As an innovative clean-up technology, it mainly depends on th mulation abilities of algae, and the former is dominated in the whole Studies suggest that the constituents of algae cell wall such as alginat e biosorption and bioaccuprocess of bioremediation. e and fucoidan which have key functional groups are chiefly responsible for biosorption of heavy metal ions. Cell storage and extracellular polysaccharides play important role in heavy metal detoxification of algae. In order to quantification of metal-biomass, interactions, several adsorption models are also discussed for algae so that we can evaluate their potential for metal uptake. Although a number of studies using different types of algae have proved that bioremediation is a more effective method for heavy metal removal than the conventional methods. However, there still exist some deficiencies in mechanism and application of bioremediation. So, further investigation is still needed to elucidate the process of bioremediation and optimize the maximum efficiency of removal, which is expected to lead to its large scale exploitation in our country.