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胞外聚合物对微藻砷毒性富集和形态转化的影响【字数:7133】

2024-11-02 13:14编辑: www.jxszl.com景先生毕设

目录
摘 要 III
关键词 III
Abstract IV
引言
1 水体砷污染概述 1
1.1 水体砷污染源 1
1.2 砷的形态及分析方法 1
2 微藻胞外聚合物概述 2
2.1 EPS的定义 2
2.2 EPS的特性 2
2.3 EPS的结构和功能 2
2.4 EPS的提取方法 3
3 胞外聚合物对微藻砷毒性效应的影响 4
4 胞外聚合物对微藻砷富集和形态转化的影响 5
5 总结与展望 6
致谢 7
参考文献 8
胞外聚合物对微藻砷毒性、富集和形态转化的影响
摘 要
砷是自然界中广泛存在的一种元素,近年来,水体中砷污染日益严重,如何高效地修复水体中砷污染是当前亟需解决的问题。生物吸附法因其具有经济、安全、无二次污染等特点被作为研究的热点。微藻作为广泛分布于水环境中的水生生物,被认为是一种具有潜在价值的生物吸附剂,并且能够参与水环境中砷的积累、形态转化。微藻分泌的胞外聚合物(EPS)对重金属具有良好的吸附能力,为水环境中重金属的去除提供了强有力的选择。本文阐述了近年来国内外水体砷污染及微藻EPS的研究进展,包括水体砷污染来源、砷形态分析方法、微藻EPS的结构与功能、微藻EPS的提取方法与特性;总结了EPS对微藻砷毒性效应的影响,以及EPS在微藻砷富集、形态转化过程中的作用,讨论其可能的影响机制,为探讨微藻对水体As污染的耐受机制及治理应用研究积累科学依据。
EFFECT OF EXTRACELLULAR POLYMERIC SUBSTANCES ON TOXICITY, ACCUMULATION, AND SPECIATION TRANSFORMATION OF ARSENIC IN MICROALGAE
ABSTRACT
Arsenic (As) is an element that widely exists in nature. In recent years, As pollution in wa *51今日免费论文网|www.51jrft.com +Q: #351916072
ter is becoming more serious. It is urgent to effectively remediate As pollution in water. Biosorption is a hot spot because of its economy, safety and no secondary pollution. Microalgae are widely distributed in the aquatic environment. They are considered as potential biosorptive agents and can participate in the accumulation and transformation of arsenic in the water environment. Extracellular polymeric substances (EPS) secreted by microalgae has good adsorption capacity for heavy metals, which provides a choice for the removal of heavy metals in water environment. In this paper, the research progress of As pollution and microalgae EPS domestically and abroad in recent years is summarized, including the source of water As pollution, the methods of As speciation analysis, structure and function of microalgae EPS, extraction methods and characteristics of microalgae EPS. We also summarized influences of EPS on the toxic effect of microalgae arsenic, roles of EPS in the process of microalgae arsenic accumulation and speciation transformation, and discussed the possible influence mechanism, in order to study the tolerance mechanism of microalgae to As pollution in water. This review may accumulate scientific basis for the application research in the remediation of As pollution.
KEY WORDS:extracellular polymeric substances (EPS); microalgae; arsenic; toxic effects; accumulation; speciation
砷是自然界中普遍存在的一种类金属元素,其在生态系统中能够通过氧化还原、生物转化等方式发生形态变化,产生毒性效应,对生态系统安全和人类健康构成危害[1]。近年来,水体砷污染日趋严重,如何高效修复水环境砷污染备受关注。传统的砷污染修复方法包括化学沉淀法、膜分离法、离子交换树脂法、电化学法等存在二次污染的风险或者成本高等缺点[2]。因此,操作简单、经济高效、生态友好的生物修复技术在环境领域逐渐受到重视。胞外聚合物(Extracellular Polymeric Substances,EPS)是生长代谢过程中产生的大分子有机物,微藻亦能分泌出一类胞外聚合物,其在废水处理、矿物冶金、医药生物、食品加工、生态修复等方面有重要应用[3]。研究表明,微藻EPS中含有羟基、羧基、氨基、巯基等带负电的官能团,对重金属有良好的吸附能力,对环境中重金属的去除具有重要作用[4]。目前,国内外对EPS介导微藻与砷的相互作用有较深入的研究,但对其进行总结、归纳的文章较少,因此,本文综述EPS对微藻砷毒性效应的影响,以及EPS在微藻砷富集、形态转化过程中的贡献机制,为EPS在水体砷污染的生物修复中的应用奠定基础。

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