肯尼亞是一個(gè)水資源匱乏的國家,人均年供水量不足1000m3。能夠獲得足夠降雨來維持農(nóng)業(yè)生產(chǎn)的區(qū)域不到全國的20%,而很大一部分人口集中在相對較小的地區(qū),留下大片干旱和半干旱地區(qū)無人居住。水資源來自五大水塔,分別源自Ewaso Nyiro、Tana River、Rift Valley、Athi River和Lake Victoria Basin。人口的快速增長,沒有得到相應(yīng)的經(jīng)濟(jì)擴(kuò)張的支持,導(dǎo)致了不可持續(xù)的自然資源的攫取,特別是森林儲備。這在大多數(shù)發(fā)源于森林保護(hù)區(qū)的河流的源頭都有毀滅性的影響。源頭水位下降,再加上過度開采,正導(dǎo)致一些河流干涸。地原的和人為的污染使得僅存水資源已有的極度短缺愈加嚴(yán)重。本研究的目的是調(diào)查肯尼亞淡水中潛在有毒元素(重金屬和微量元素)的濃度、分布、對消費(fèi)者健康構(gòu)成的風(fēng)險(xiǎn)、廢水的回收及相關(guān)風(fēng)險(xiǎn),以及植物在植物修復(fù)中的潛在應(yīng)用。由此,我們開展研究,測定了內(nèi)羅畢河地表水中重金屬和養(yǎng)分濃度及植物生物修復(fù)潛力,分析了來自Thika水處理廠的再生水用于灌溉的適宜性,評估了塔納河水的可持續(xù)利用及風(fēng)險(xiǎn)。28份水樣采自內(nèi)羅畢河2015年雨季和2016年旱季。對Cd、Cu、Cr、Zn...

【文章頁數(shù)】：106 頁

【學(xué)位級別】：博士

【文章目錄】：
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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