The Air Quality Act (AQA) Act No.39 of 2004 promulgated in 2004 follows the outdated Atmospheric Pollution Prevention Act (APPA) (Act No.45 of 1965). The legislative approach shifted from a source- based, end of pipe, command and control, guideline principle to ambient air quality management and improvement of compliance to standards through a consultative process. The AQA’s management framework incorporates a co-operative and integrated approach with government, communities and polluters to look at the holistic management of ambient air quality and the identified roles and responsibilities for all stakeholders. The AQA branched from the National Environmental Management Act (NEMA) 107 of 1998, which is the first piece of legislation formalizing the principles of the Integrated Pollution Waste Management (IPWM) Policy published in 2000 and the Bill of Rights. Government and Industry have a role to play in the implementation of the AQA. Government’s role covers the management and enforcement aspects, whilst industries’ role includes the management of air emissions and compliance reporting to improve the overall ambient air quality. The AQA’s industrial requirements range from compliance and reporting by ensuring emission licenses are in place, compliance with standards set by different spheres of government and the management of these emissions. The management of these requirements includes understanding the legislation, its implications and the provision of other financial, human and technological resources. Industry needs to consider the impacts of these legislative changes and how it may impact business as a whole. The aim of this study is to analyze the industrial perspectives of the AQA and its implementation through the use of a questionnaire. Open-ended questionnaires were administered to a total of forty industrial companies in the chemical, petrochemical, energy and mining sectors in the Gauteng, North West and Durban industrial areas. Industries were identified as those which have scheduled process certificates or companies that will be impacted by the impending changes as a result of the AQA. The overall outcome of the industrial responses revealed poor general knowledge of the principles, purpose and the reasons for the transition from APPA to AQA. Few industries had insight into the type of challenges they may face from the AQA’s listed control measures and the control measures that would apply to their particular industry. There is a general concern surrounding the government’s lack of support and the essential enforcement that is required to ensure ambient air quality compliance. These challenges and recommendations are discussed in the thesis. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009.

Metal–organic materials (MOMs), a type of porous crystalline structure composed of organic ligands jointed with metal ions, have captured the interest of scientists as potentially useful in gas sorption applications. Some of the most crucial avenues of investigation are in H2 storage (for use as a clean burning fuel source) and CO2 capture and sequestration (to remove the greenhouse gas from the environment). A major advantage of MOMs for such applications is their high variability in terms of physical dimensions and chemical moieties, based on composition and synthesis conditions, making them potentially customizable for specific application if necessary structural characteristics are known. Computational experimentation is an important avenue for determining such specifications as it allows examination of gas/MOM interaction at the molecular level. In this dissertation a number of MOM structure are computationally studied in order to elucidate gas sorption mechanisms. These systems were probed by classical simulation using grand canonical Monte Carlo with a carefully chosen set of intermolecular interaction parameters. While the focus of this work is specifically H2 and CO2 sorptive behavior, the insights gained from simulation extend beyond these specific applications. Addressed first are a series of MOMs with rht topology, which possesses asymmetric copper paddle-wheels and easily functionalized linkers. Beginning with a prototypical structure and then branching out into more chemically interesting variants revealed surprising gas sorption behavior about the metal paddle-wheels (with a definite preference for one copper over its counterpart). A synthetic strategy for controlling the preferred open-metal sorption site through the inclusion of electron rich functionality in the linker bodies, was also revealed. An additional MOM with similar composition components, exhibiting zyg topology, also showed this metal preference effect on the asymmetric paddle-wheels. A second class of MOMs, composed of square-pillared grids and known as the SIFSIX series (due to the inclusion of SiF62− as pillaring units) was also examined. These structures have been shown excellent results for CO2 sorption making the elucidation of the sorptive mechanisms of great interest. Six different structures were examined, probing the effects of linker length, metal selection, and interpenitration of unbonded scaffolds. The nature of the CO2-MOM sorption interactions were revealed through simulation and provided insights regarding the synergistic effect of pore dimensions and SiF62− functionality for specifying specific behavior (i.e. high selectivity vs. high uptake). A final MOM, composed of Y3+ ions and chemically complex linkers, was also examined. Disorder in the crystallographic data (e.g. single atoms with multiple positions) indicated the coexistance of notably different unit cells in the same system. Nevertheless, simulations revealed favored sorption sites in conjunction with results from physical experimentation.

The effect of inclusion of explicit polarization is investigated through several theoret- ical studies of crystalline porous materials herein. In addition to the use of Monte Carlo simulation for such studies, a robust molecular dynamics software is presented which is suitable for analyzing time dependent properties of gases or other molecules in porous materials and other condensed phase systems. Metal-organic frameworks (MOFs) are the main focus of the work included here, a relatively young class of materials originally in- troduced in the early 1990s. These are usually three dimensional crystalline nanoporous materials that exhibit unique properties such as gas separation, storage and catalysis. They are synthesized by the combination of a metal ion e.g. Cu2+ with an organic linker e.g. benzene dicarboxylate. They are a very popular topic of scientific research due to the diversity in possible structures and manifold utility – finding applications in electron transfer, sensing, drug release etc. Industrially, MOFs like HKUST-1 and others are on the global market for use in gas storage and separation in fuel cell and raw materials processing. These materials are often ideal candidates for computer simulation owing to their crystalline nature – a very large atomic system (that is, moles of particles) can be under- stood by only evaluating one or a few unit cells of the MOF, usually less than 5,000 atoms, and macroscopic properties such as gas sorption capacity and diffusion coefficients can be calculated through extrapolation of atomistic interactions in a mathematically infinite lattice. The software developed by the space group as of 2005, Massively Parallel Monte Carlo (MPMC), allows for sophisticated calculation of repulsion dispersion, electrostatic and polarization energies. In this work, Monte Carlo Molecular Dynamics (MCMD) is in- troduced, which can hybridize both methods to explore the phase space of a system with ease and better efficiency, as well as explore the effects of MOF flexibility and dynamic properties which to-date are rarely studied. Studies involving primarily CO2, H2 and CH4 will be presented, but other gases investigated include C2 H2 , C2 H4 , C2 H6 , N2 , H2 O and others. Metal-organic materials with a wide variety of composition and structure will also be presented. Finally, features of the software MCMD will be presented for use by future studies.