肯尼亚的淡水污染，风险评估和植物修复潜力

发布时间：2023-03-29 00:10

　　肯尼亚是一个水资源匮乏的国家,人均年供水量不足1000m3。能够获得足够降雨来维持农业生产的区域不到全国的20%,而很大一部分人口集中在相对较小的地区,留下大片干旱和半干旱地区无人居住。水资源来自五大水塔,分别源自Ewaso Nyiro、Tana River、Rift Valley、Athi River和Lake Victoria Basin。人口的快速增长,没有得到相应的经济扩张的支持,导致了不可持续的自然资源的攫取,特别是森林储备。这在大多数发源于森林保护区的河流的源头都有毁灭性的影响。源头水位下降,再加上过度开采,正导致一些河流干涸。地原的和人为的污染使得仅存水资源已有的极度短缺愈加严重。本研究的目的是调查肯尼亚淡水中潜在有毒元素(重金属和微量元素)的浓度、分布、对消费者健康构成的风险、废水的回收及相关风险,以及植物在植物修复中的潜在应用。由此,我们开展研究,测定了内罗毕河地表水中重金属和养分浓度及植物生物修复潜力,分析了来自Thika水处理厂的再生水用于灌溉的适宜性,评估了塔纳河水的可持续利用及风险。28份水样采自内罗毕河2015年雨季和2016年旱季。对Cd、Cu、Cr、Zn...

【文章页数】：106 页

【学位级别】：博士

【文章目录】：
摘要
Abstract
Chapter 1: Introduction
    1.1 Background information
    1.2 Key water sources in Kenya
        1.2.1 Mau complex water catchment area
        1.2.2 Aberdares water catchment area
        1.2.3 Mount Kenya water catchment area
        1.2.4 Mount Elgon
        1.2.5 Chyulu Hills
    1.3 Threats to water resources in Kenya
    1.4 Heavy metals and their associated risks
        1.4.1 Manganese
        1.4.2 Lead
        1.4.3 Aluminium
        1.4.4 Arsenic
        1.4.5 Cadmium
        1.4.6 Chromium
        1.4.7 Nickel
        1.4.8 Copper
    1.5 Risk assessment of fresh water resources
        1.5.1 Enrichment factor (EF)
        1.5.2 Geo-accumulation index (Igeo)
        1.5.3 Contamination factor (CF)
        1.5.4 Pollution load index (PLI)
        1.5.5 Potential ecological risk index (RI)
        1.5.6 Waste water recycling potential and associated risks
    1.6 Restoration of fresh water resources
Chapter 2: Assessment of macrophyte, heavy metal, and nutrientconcentrations in the water of the Nairobi River, Kenya
    2.1 Introduction
    2.2 Materials and method
        2.2.1 Study area
        2.2.2 Sampling sites
        2.2.3 Sample collection
        2.2.4 Sample analysis
        2.2.5 Quality assurance and quality control
        2.2.6 Statistical analysis
    2.3 Results
        2.3.1 Heavy metal and nutrient concentration
        2.3.2 Interaction among heavy metals and nutrients
        2.3.3 Probable sources of pollution
        2.3.4 Relationship between macrophytes distribution and the Nairobi River self-purification
    2.4 Discussion
    2.5 Conclusion
    2.6 Recommendation
Chapter 3: Health risk assessment by consumption of vegetablesirrigated with reclaimed waste water: A case study in Thika (Kenya)
    3.1 Introduction
    3.2 Materials and methods
        3.2.1 Study site
        3.2.2 Sampling and preparation of vegetable samples
        3.2.3 Sampling and preparation of water and sludge samples
        3.2.4 Digestion of sludge
        3.2.5 Digestion of vegetables
        3.2.6 Sample analysis and quality assurance
    3.3 Data analysis
        3.3.1 Daily intake of heavy metals
        3.3.2 Target hazard quotient (THQ)
    3.4 Results and Discussion
        3.4.1 Heavy metals in waste water
        3.4.2 Heavy metals in sludge
        3.4.3 Heavy metals in vegetables
        3.4.4 Dietary intake of metals (DIM)
        3.4.5 Target hazard quotient (THQ)
    3.5 Conclusion
Chapter 4: Sustainable use and risk assessment of Tana River waterresource in Kenya
    4.1 Introduction
    4.2 Materials and method
        4.2.1 Study area
        4.2.2 Water sampling
        4.2.3 Sample analysis and quality assurance
        4.2.4 Water pollution assessment using water quality index (WQI)
        4.2.5 Health risk assessment
    4.3 Results and discussion
        4.3.1 Heavy metal and nutrient concentration in the water
        4.3.2 Water quality index
        4.3.3 Hazard quotient and index
    4.4 Multivariate statistical analysis
        4.4.1 Correlation between heavy metals and nutrients
        4.4.2 Factor analysis
        4.4.3 Hiearachical cluster analysis
    4.5 Conclusion
Chapter 5 Conclusion
References
Acknowledgements
Education background and publication



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