Maggie Chetty

By Emmanuel Kweinor Tetteh, Sudesh Rathilal, Maggie Chetty, Edward Kwaku Armah and Dennis Asante-Sackey

Fresh water quality and supply, particularly for domestic and industrial purposes, are deteriorating with contamination threats on water resources. Multiple technologies in the conventional wastewater treatment (WWT) settings have been adopted to purify water to a desirable quality. However, the design and selection of a suitable cost-effective treatment scheme for a catchment area are essential and have many considerations including land availability, energy, effluent quality and operational simplicity. Three emerging technologies are discussed, including anaerobic digestion, advanced oxidation processes (AOPs) and membrane technology, which holds great promise to provide integrational alternatives for manifold WWT process and distribution systems to mitigate contaminants and meet acceptable limitations. The main applications, basic principles, merits and demerits of the aforementioned technologies are addressed in relation to their current limitations and future research needs in terms of renewable energy. Hence, the advancement in manufacturing industry along with WWT blueprints will enhance the application of these technologies for the sustainable management and conservation of water.

Part of the book: Water and Wastewater Treatment

By Edward Kwaku Armah, Maggie Chetty, Jeremiah Adebisi Adedeji and Donald Tyoker Kukwa

Lignocellulosic biomass has gained increasing recognition in the past decades for the production of value-added products (VAPs). Biomass feedstocks obtained from various sources, their composition, and pretreatment techniques employed for delignification into bioenergy production are discussed. The conversion processes of biomass into VAPs involve various methods. Notable among them are biochemical conversions; namely, anaerobic digestion and ethanol fermentation, and thermo-chemical conversions; namely, pyrolysis and gasification which are considered in this chapter. Microalgae can adapt to changes in the environment, producing biomass that serves as a precursor for a variety of biomolecules, such as proteins, which find their application in pharmaceutical, cosmetic, and biofuel industries. Suitable strains of freshwater microalgae biomass contain high levels of lipid which can be harnessed for bioenergy production. Hence, the advancement in the conversion of biomass into VAPs could help scientists and environmentalists for sustainable use of biomass in future developments.

Part of the book: Biotechnological Applications of Biomass

By Edward Kwaku Armah, Maggie Chetty, Jeremiah Adebisi Adedeji, Donald Tyoker Kukwa, Boldwin Mutsvene, Khaya Pearlman Shabangu and Babatunde Femi Bakare

The quality of freshwater and its supply, particularly for domestic and industrial purposes are waning due to urbanization and inefficient conventional wastewater treatment (WWT) processes. For decades, conventional WWT processes have succeeded to some extent in treating effluents to meet standard discharge requirements. However, improvements in WWT are necessary to render treated wastewater for re-use in the industrial, agricultural, and domestic sectors. Three emerging technologies including membrane technology, microbial fuel cells and microalgae, as well as WWT strategies are discussed in this chapter. These applications are a promising alternative for manifold WWT processes and distribution systems in mitigating contaminants to meet acceptable limitations. The basic principles, types and applications, merits, and demerits of the aforementioned technologies are addressed in relation to their current limitations and future research needs. The development in WWT blueprints will augment the application of these emerging technologies for sustainable management and water conservation, with re-use strategies.

Part of the book: Promising Techniques for Wastewater Treatment and Water Quality Assessment

By Donald Tyoker Kukwa and Maggie Chetty

Microalgae are unicellular, eukaryotic organisms which possess unique qualities of replication, producing biomass as a precursor for biofuels, nutraceuticals, biofertilizer, and fine chemicals including hydrocarbons. Microalgae access nitrates and phosphates in wastewater from municipalities, industries, and agricultural processes to grow. Wastewater is, therefore, culture media for microalgae, and provides the needed nutrients, micronutrients, inorganic and organic pollutants to produce microalgae biomass. Suitable strains of microalgae cultivated under mesophilic conditions in wastewater with optimized hydrodynamics, hydraulic retention time (HRT), luminous intensity, and other co-factors produce biomass of high specific growth rate, high productivity, and with high density. The hydrodynamics are determined using a range of bioreactors from raceway ponds, photobioreactors to hybrid reactors. Carbon dioxide is used in the photosynthetic process, which offers different growth stimuli in the daytime and the night-time as the microalgae cultivation technique is navigated between autotrophy, heterotrophy, and mixotrophy resulting in microalgal lipids of different compositions.

Part of the book: Biotechnological Applications of Biomass