Geochemical Evaluation for the Hydrocarbon Potential of Source Rocks in the Anza Basin

Anza basin is located in the extensional arm of the central African rift system in the North-Eastern part of Kenya. Cretaceous sedimentary rocks were sampled from the four wells namely, Chalbi-3, Sirius-1, Ndovu-1 and Kaisut-1. Anza basin occurs on a fault block within a Paleocene-Cretaceous rift basin. The methodological approach used for the evaluation of source rocks included petrophysical and geochemical methods to ascertain their potential. Well sections with a higher shale-volume ratio were sampled for geochemical screening to determine the organic richness and thermal maturity of potential source rocks, respectively. Source rock with organic richness ≥ 0.5% were evaluated further for their petroleum potential using Rock-Eval pyrolysis to determine their thermal maturity, organo-facies and in-situ generated hydrocarbons present in sedimentary facies. The geochemical evaluation of rock samples from the drilled wells’ sections of Chalbi-3 and Sirius-1 confirmed both oil and gas potential. Gas Chromatography and Mass Spectrometry (GCMS) were used to characterize the biomarker signatures and oil-oil correlation of Sirius-1 samples. A predictive model was developed to integrate the petrophysical and geochemical data to reveal hydrocarbons’ potential in the Anza basin.

Microbial and Physical Chemical Indicators of Groundwater Contamination in Kenya: A Case Study of Kisumu Aquifer System, Kenya

Safe water of adequate quantity, and dignified sanitation, is vital for the sustenance of a healthy and productive human population. In the recognition of this, the United Nations formulated the Sustainable Development Goal No. 6 to ensure access to safe water and sanitation by all by 2030. Actualization of this Goal requires information on the existing status of water resources and sanitation levels. Knowledge on contamination of groundwater is essential to prevent risks to human health. The objective of this study was to determine groundwater contamination in Kisumu, Kenya. A total of 275 water samples were collected from 22 sites within the informal settlements between December 2016 and December 2017. The samples were analysed for bacterial contamination and physical chemical quality. Thermal tolerant coliform bacteria enumeration was used as a proxy to bacteria contamination, and the pH, turbidity, dissolved oxygen, conductivity, salinity and temperature were used as physical chemical indicators of contamination. The results indicate that groundwater in Kisumu hosed coliform bacteria and therefore didn’t comply with contamination limits for domestic water proposed by WHO and local KEBS standards. The results further indicated that the levels of bacteriological contamination vary with water type, shallow well having the highest bacterial loads. The study concluded that there were potential risks to human health due to high content of coliform bacteria. The study attributed the contribution to pit latrines that were present in virtually all compounds. The pit latrines are located close to the water points. The study recommended the definition of minimum distance between the pit latrines and shallow wells to minimize contamination. The low income dwellers should be educated on simple ways of treating drinking water contaminated by microbial to minimize enteric infections.

东非维多利亚湖流域气候、社会经济和健康因素对人类遭受霍乱的影响

在非洲东部地区,霍乱疫情事件的历史可追溯到1836年。如今霍乱已经成为维多利亚湖流域,这一世界上最为贫困和人口增长最快的地区之一的流行病。通过对维多利亚湖流域一些站点的降水、气温和水文特征的分析,研究者发现霍乱疫情与厄尔尼诺现象有密切联系。同样,如果连续两季的气温持续高于正常水平(Tmax),而在第二个高温季之后温度稍微降低,往往会引发一场霍乱疫情。维多利亚湖流域居民的健康保障体系和社会经济系统不足以帮助他们应付霍乱的爆发,因而更容易受到气候波动和气候变化的影响。本报告认为,在较低社会经济状况和缺乏足够卫生保障体系的条件下,维多利亚湖流域地区居民更容易受气候引起的霍乱的影响。在评价社区的适应能力方面,该报告的结论是:长期的贫困使这里的居民更容易遭受霍乱等流行病。