Author: Muhammad Ahmad

What Is “Best Available Control Technology”? Best available control technology (BACT) is a pollution control standard mandated by the Clean Air Act: …an emission limitation based on the maximum degree of reduction of each pollutant subject to regulation under this Act emitted from or which results from any major emitting facility, which the permitting authority,…

A sensitivity analysis was conducted on each system to determine which parameters had the most influence on the results and to pinpoint opportunities for reducing the environmental burden of the system. In general, parameters associated with increasing the system efficiency and reducing the fossil fuel usage had the largest effects. Additionally, for the biomass systems,…

Figure 6.14 shows the net emissions of the three GHGs quantified for these studies: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The biomass IGCC system has a much lower GWP than the fossil systems because of the absorption of CO2 during the biomass growth cycle. Sensitivity analyses demonstrated that even moderate amounts of soil carbon…

A series of LCAs was conducted on biomass, coal, and natural gas systems to quantify the environmental benefits and drawbacks of each. All those evaluations were conducted in a cradle‐to‐grave manner to cover all processes necessary for the operation of the power plant including raw material extraction, feed preparation, transportation, waste disposal, and recycling. We…

Like chlorination, UV disinfection systems demand energy supplies. One of the most important factors that can contribute to achieving sustainable development is the requirement for a supply of energy resources that is itself fully sustainable. Effective and efficient utilization of energy resources calls for such resources to be readily available at reasonable cost utilized for…

A UV disinfection system transfers electromagnetic energy from a mercury arc lamp to an organism’s genetic material, the chromosomes which contain DNA and RNA. When UV radiation penetrates the cell wall of an organism, it destroys the cell’s ability to reproduce. In the disinfection process, UV radiation, generated by an electrical discharge through mercury vapor,…

In the past decade, concerns over chlorine toxicity and protection of fish and wildlife have led to a dramatic growth in the practice of dechlorination to remove all or part of the chlorine residual and halogenated organics remaining after chlorination. Dechlorination also reduces or eliminates toxicity harmful to aquatic life in receiving waters. Sulfur dioxide…

Although chlorine disinfection is a largely reliable and effective process, it has certain limitations. For examples, chlorine reacts with certain chemicals in the wastewater, leaving only the residual for disinfection. Wastewater components that readily combine with chlorine include reduced iron and sulfur compounds, ammoniated‐nitrogen, organic nitrogen, tannins, uric and humic acid, cyanides, phenols, and unsaturated…

With increasing emphasis on promoting a sustainable ecological future and concern over introducing toxic chemicals in water, disinfection process design is leaning toward technologies that destroy pathogens while balancing the effects of the disinfected wastewater aquatic biota or on a drinking water supply. Since ultraviolet (UV) irradiation is not a chemical additive, it does not…

The tool for the reduction and assessment of chemical and other environmental impacts (TRACI) is described along with its history, the research and methodologies it incorporates, and the insights it provides within individual impact categories. TRACI, a stand‐alone computer program developed by the US Environmental Protection Agency (USEPA), facilitates the characterization of environmental stressors that…