Pesticides: Chemistry, Manufacturing, Regulation, Usage and Impacts on Population in Kenya

Pesticide use in Kenya plays a critical role in socio-economic development because its economy depends heavily on agriculture, which contributes to 30% of the GDP and accounts for 60% of export earnings. For agriculture and public health vector control, the country relies on pesticides, most of which (95%) are formulated products imported from China, India and Germany as the top exporters. In this chapter, we present the chemistry, manufacturing, importation and regulatory processes regarding pesticides in Kenya as well as their usage and impacts. All the various categories, organochlorine, organophosphate, carbamate, pyrethroid, neonicotinod insectides, as well as fungicides, herbicides and biopesticides, which are used in the country, are considered. A total of 1,447 and 157, which include formulations and active ingredients, respectively, for use in agriculture and public health sectors, with sufficient information on their usages and toxicities, are listed on the Pest Control Products Board (PCPB) database that is available to the public. A significant number of studies have been conducted in major agricultural regions, which have characterized pesticides, their toxicities, the types of crops and pests, the usage and human and environmental health risk indices, since the 2000, but the reports have not made any impacts on pesticide regulation, as some of the very toxic active ingredients, belonging to the WHO Class I and II, are still reported by farmers. However, a recent call from NGO’s made an impact in government and parliament, and a bill was introduced in 2020 with the aim of banning some of the toxic ones that have already been withdrawn from the EU market

Effect of Immobilizing Bacillus megaterium on the Compressive Strength and Water Absorption of Mortar

The world’s growing population and industrialization have led to increased construction activities. This has increased the amount of waste aggregates which can be recycled in construction and cut the cost of infrastructure development. This study, therefore, reports the experimental findings for the effect of immobilizing Bacillus megaterium on the compressive strength and water absorption of laboratory prepared test mortar. Bacterial solution used in this work had a concentration of 1.0 × 107 cells/mL. The impact of recycled mortar impregnated with bacteria was studied after curing the specimens in water, saturated lime water, and 1.5% sulfuric acid. Compressive strength for test specimens cured in the three media was determined at the 2nd, 7th, 28th, and 56th day of curing. SEM analysis was done for mortars cured in acidic media and saturated lime water after curing for 28 days. The test results indicated that curing in water and saturated water improved the compressive strength, while the acidic medium lowered it. Recycled mortar is, therefore, an ideal material for immobilizing Bacillus megaterium before introduction into fresh concrete/mortar. The use of recycled mortar is a good strategy to reduce wastes from construction activities, save on the cost of construction materials, and enhance environmental conservation

Adsorption of Heavy Metals in Contaminated Water Using Zeolite Derived from Agro-Wastes and Clays: A Review

Due to climate change and anthropogenic activities such as agriculture, mining, and urbanization, water contamination has become a very real modern problem. Modern solutions such as activated carbon, reverse osmosis, and ultrafiltration, among others, have been employed in the decontamination of water. These methods are, however, expensive to set up and maintain and therefore have proved a challenge to implement in developing countries. Zeolite materials exhibit excellent structural properties, such as high ion exchange capacity, porosity, and relative surface area, which make them attractive to water decontamination processes. However, conventional zeolites are expensive, and recent research has focused on utilizing low-cost materials such as agro-wastes and clays as raw materials for the synthesis of zeolites. This review aims to discuss the role of low-cost zeolites in their removal of heavy metals and the feasibility of agro-wastes and natural clays in the synthesis of zeolites. Recent research studies based on the synthesis of zeolites from clays and agro-wastes and their application in heavy metal removal have been reviewed and discussed. Agro-wastes such as rice husk ash and sugarcane bagasse ash and layered silicate clays such as kaolinite and smectites are particularly of interest to zeolite synthesis due to their high silica to alumina ratio. Zeolites synthesized through various methods such as hydrothermal, molten salt, and microwave irradiation synthesis have been discussed with their effect on the adsorption of various heavy metals