Due to the high cost of construction, there has risen need to find cheaper alternatives to partially
replace cement. Studies have been carried out on different materials such as wood ash and fly
ash in partial cement replacement. This research is however based on partial replacement of
cement using bone and coffee husks ashes.
Coffee is one of the crops majorly grown in Kenya for export. After processing, the husks are
normally disposed of and only a little amount is used as manure and as fuel when dried. This

Water is a basic need that is needed for all humanity. Throughout life water has been of core use
to humans and has always been adequately available for many generations. We can say that it is
because of this availability that has enabled the flourishing of humanity itself. The main sources
of water is water sheds and forests but due to civilization all this has been brought down in order
to accommodate more space. This sadly led to the decline of water. This is a problem that needs a

High fluoride concentration in drinking water causes widespread health problems to many
residents in the Rift Valley region of Kenya that encompass dental and skeletal fluorosis
(Kaseva, 2006). The excessive fluoride in groundwater is a serious water quality problem. The
WHO and national standard (ES 261:2001) permit only up to 1.5 mg/L of fluoride whereas the
concentration of fluoride in groundwater in the Rift Valley Region is much higher. Use of HAP
provides a potential method of fluoride removal through adsorption. Therefore, there is need to