提高改性粘土除藻效率的机理与方法研究

	提高改性粘土除藻效率的机理与方法研究
	刘扬1,2,3
学位类型	博士
导师	俞志明 ; 曹西华
	2016-05-20
学位授予单位	中国科学院大学
学位授予地点	北京
学位专业	环境科学
关键词	有害藻华改性粘土除藻效率机制方法
摘要	近年来人类活动造成的水体富营养化促进了有害藻华在世界范围内的爆发，对海洋生态健康、海洋渔业、水产养殖业和近海景观造成了严重威胁。利用粘土的絮凝作用防治有害藻华被认为是最有发展前景的方法之一，已经在日本、韩国和中国等国家和地区进行了大规模的应用并取得了良好的效果。但是粘土原土对藻华生物的絮凝效率较低。为了提高絮凝效率，我国科学家提出了粘土表面改性理论与方法，制备的PAC-MC大幅度的提高了除藻效率，为高效改性剂的筛选提供了依据。改性粘土去除有害藻华的主要依靠其絮凝作用，在絮凝过程中改性粘土表面性质影响其除藻效率。在应用改性粘土治理有害藻华时，首先要制备改性粘土悬浮液，研究发现，制备悬浮液的分散介质，如淡水和海水，对改性粘土除藻效率的影响较大。张雅琪(2013)的研究也发现，使用硫酸钠溶液制备的改性粘土悬浮液的除藻效率较低，因此，有必要对悬浮液性质对改性粘土除藻效率的影响开展研究，分析其影响机制，以进一步寻找提高PAC-MC除藻效率的原理与方法。本文中我们还研究了其他无机改性粘土(AC-MC和AS-MC)、有机-无机改性粘土和无机-氧化改性粘土的除藻效率，探索了进一步提高改性粘土絮凝效率的途径和方法。本研究的主要结果如下：悬浮液理化特征对PAC-MC除藻效率的影响及机理研究悬浮液中硫酸根离子是影响PAC-MC去除藻华生物效率的重要因素，除藻效率随硫酸根离子浓度变化呈现先降低后升高的“V”字形规律，去除悬浮液中的硫酸根离子是提高该改性粘土除藻效率的途径之一。无机改性粘土AC-MC和AS-MC的除藻效率及机理研究分散介质、改性比例、悬浮液pH、藻液pH和藻液EOM均影响无机改性粘土AC-MC和AS-MC的除藻效率。AC-MC和AS-MC不受海水分散介质的影响，对有害藻华具有较强的去除能力。进一步提高改性粘土除藻效率的其他方法探索研究 PAC-PAM复合改性和PAC-PDM复合改性土的制备方式、添加方式和分散介质均能影响其对藻华生物的除藻效率，而其中以复合改性粘土悬浮液的分散介质的影响最大。有机高分子-无机改性粘土在去除淡水藻华和海水藻华种存在巨大的差别。在淡水水域防治有害藻华有用的有机-无机复合改性粘土在海水体系条件下很可能失效。 1 mg/L有机小分子杀藻剂十六烷基三甲基溴化铵 (HDTMA)或2.5 mg/L十二烷基二甲基苄基溴化铵(DDBAB)能够有效灭杀球形棕囊藻，不受分散介质的影响；HDTMA或DDBAB在无机改性粘土喷洒之后或者喷洒之前添加时获得了较有效的除藻效果。单过硫酸氢钾复合盐进一步提高了无机改性粘土的除藻效率，制备的无机-氧化复合改性粘土体系大幅度的提高了对球形棕囊藻的除藻效率，添加无机-氧化复合改性粘土后球形棕囊藻的生长受到了显著的抑制。无机-氧化复合改性粘土体系所涉及的主要成分粘土、硫酸铝(AS)和单过硫酸氢钾复合盐对除藻效率均有显著的影响(p<0.01)，并且硫酸铝(AS)和单过硫酸氢钾在提高除藻能力上存在显著的交互作用(p<0.01)。
其他摘要	In recent years coastal water eutrophication caused by human activities promoted its happening worldwide and caused profound and deleterious effects on aquatic ecosystems, aquaculture, tourism and public health. The control of HABs and the mitigation of their effects using clay is a promising method worldwide and it has been fully implemented in the field, with good results reported in Japan, South Korea and China. However, natural clay was inefficient in the removal of algae cells. The clay surface modification theory was proposed to increase the removal efficiency and the polyaluminum chloride modified clay prepared significantly improved the removal efficiency. However, PAC-MC was found to be easily affected by seawater. It is necessary to study the effects of the environmental factors of seawater to the removal efficiencies of modified clays to further improve the efficiency. We also studied the removal efficiencies of AC-MC and AS-MC and analyzed their removal mechanism. We also introduced “bridging” effects, “killing” effects and “oxidation” effects into the flocculation process to explore the methods that could be used to further improve the removal efficiency. The main results were as follows. The effects of the properties of the clay suspension on the removal efficiency of PAC-MC The presence of sulfate ions in the PAC-MC suspensions was one of the factors that caused the DW and SW suspensions to have different abilities to remove harmful algal cells. Sulfate in the PAC-MC suspension showed a “V”-shaped effects and removing sulfate in modified suspension could improve the algae removal efficiency. The removal efficiencies of AC-MC and AS-MC We found the removal efficiency of AC-MC and AS-MC was influenced by dispersion medium, percentage of modifier in modified clay, suspension pH, algae pH and EOM in algae culture. AC-MC and AS-MC was little affected by the dispersion medium and showed strong abilities in removing algae cells. Exploratory studies on the methods that could further improve the algae removal efficiencies of modified clays The results showed that the removal efficiency of PAC-PAM modified clay or PAC-PDM modified clay was influenced by preparation methods, addition methods, and dispersion medium, among which the dispersion medium showed the most influences. Great difference may exist in removing freshwater and seawater HABs by organic macromolecule-inorganic modified clay. 1 mg/L Hexadecyl trimethyl ammonium Bromide (HDTMA) or 2.5 mg/L Dodecyl dimethyl benzyl ammonium bromide (DDBAB) can kill the Phaeocystis globosa effectively regardless of dispersion medium. Good removal effects were obtained when HDTMA or DDBAB and inorganic modified clay was added sepraterly. The results showed that KHSO₅ further improved the removal efficiency of inorganic modified clay and the inorganic-oxidation modified clay further improved the efficiency at which P. globosa was removed. Besides, the growth of P. globosa was significantly depressed by inorganic-oxidation modified clay compared with the addition of AS-MC. All the three components, clay, aluminum sulfate and KHSO₅, showed significant influences on the removal efficiency (p<0.01) and aluminum sulfate and KHSO₅ showed significant interactions on the removal efficiency(p<0.01).
学科领域	生态学 ; 环境科学技术
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/116964
专题	海洋生态与环境科学重点实验室
作者单位	1.中国科学院海洋研究所 2.中国科学院大学 3.青岛海洋科学与技术国家实验室
第一作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	刘扬. 提高改性粘土除藻效率的机理与方法研究[D]. 北京. 中国科学院大学,2016.

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