The Chemical Oxygen Demand Modelling Based on a Dynamic Structure Neural Network

In many semiarid and arid countries, water is now becoming an increasingly limited resource and managers are forced to take into account sources of water that may be used economically and efficiently to encourage further development. Simultaneously, with the population increasing at a high rate, the requirement for increased production of food is apparent. The prospective for irrigation to increase both the agricultural productivity and living standards of the poor has long been acknowledged. Irrigated agriculture occupies nearly 17% of the total arable land in the world but the yield from this land includes about 34% of the world total. This perspective is even more distinct in arid areas like the Near East Region, where only 30% of the cultivated land is irrigated but it yields around 75% of total agricultural production. In the same area, more than 50% of the food necessities are imported and the increased rate in demand for the food surpasses the rate of an upsurge in agricultural production (Tunney et al., 2000).

The fashion industry contributes 20% of industrial water pollution  With a high water footprint, massive chemical use and atmospheric, water and greenhouse gas (GHG) emissions, dyehouse operations are the most environmentally damaging component of the apparel supply chain2.Global brands are responding by requiring manufacturers to treat wastewater and reduce effluent. Paradoxically, conventional water treatment systems generate toxic sludge, trading water pollution for solid, chemical discharge that is landfilled and emits GHG – mostly methane.

Introduction Every year in South Africa an estimated R500m is spent on chemicals used in the treatment of drinking and waste water. Most of this money is allocated on the basis of tenders issued and contracts awarded. The evaluation of tenders is generally undertaken by a team of people from various disciplines within the awarding organization and the decisions they make can have a significant effect on the quality of water or waste that is produced and also on the finances of the organization for which they work. It is obvious therefore that these decisions – which chemicals to use, how much to use, how much should be paid, who is the most professional supplier – are important ones and ones that should be taken whilst in possession of the most factual and impartial information. This guide aims to provide those decision-makers, and other users of water treatment chemicals, with specific and useful information about water treatment chemicals. It is a chemistry text book aimed specifically at those people who have to make informed decisions but who have not had a formal education in chemistry or whose chemistry education has not been specific in detail relevant to water treatment chemicals. It does not, however, aim to be a comprehensive chemistry textbook and chemicals not used in water treatment are not discussed; nor are properties that are irrelevant to the water treatment application of the chemical. The guide is designed to serve as a reference book with each chapter being self contained and specific. It will be easily understood by those readers that do not have a formal chemistry education and hopefully will provide some useful additional insight and information to those that The guide is divided into ten chapters and includes an appendix at the end that contains various useful equations. The contents of each chapter are listed below.

Conventional wastewater treatment technologies improve the quality of wastewater discharged into the environment and restrain polluted waters from contaminating other available clean water resources. However, these treatment technologies do not make wastewater fit for further beneficial uses in communities closer to the points of generation. Innovative and advanced technologies that can further improve the quality of wastewater are needed to overcome this limitation of conventional technologies, and to promote widespread adoption of recycle and reuse practices. Advanced treatment processes can be biological processes, physicochemical processes, or a combination of both (hybrid processes). Biological processes to remove nutrient pollutants such as nitrogen and phosphorus, provide the platform for further wastewater treatment to reusable quality. Physicochemical processes such as deep-bed filtration, floating media filtration, and membrane filtration, play a major role among treatment technologies for water reuse. Membrane filtration has significant advantages over other processes since they produce high quality effluent that requires little or no disinfection with minimum sludge generation. The hybrid processes attempt to obtain the benefits of both biological and physicochemical processes in one step.

This book provides an overview of the most studied AOPs, some of which are largely implemented for water remediation. The fundamental principles, kinetic modeling, water quality impact on process performance, byproduct formation, economics, examples of research and pilot studies, full-scale applications and future research needs are discussed for each advanced oxidation process.