Environmental Impacts of Energy Sources and Implications of Renewables

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… Continue reading Environmental Impacts of Energy Sources and Implications of Renewables

 UV Disinfection Process

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,… Continue reading  UV Disinfection Process

Dechlorination with Sulfur Dioxide

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… Continue reading Dechlorination with Sulfur Dioxide

 Limitations

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… Continue reading  Limitations

Evaluating the Life Cycle Environmental Performance of Two Disinfection Technologies

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… Continue reading Evaluating the Life Cycle Environmental Performance of Two Disinfection Technologies

Quantitative Analyses Using the USEPA Model: TRACI

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… Continue reading Quantitative Analyses Using the USEPA Model: TRACI

Large‐Scale Implementation of Biopulping

On a large scale, decontamination and inoculation must be done on a continuous basis and not batchwise as in a laboratory trial (Figure 6.9). To achieve this, the FPL investigators built a treatment system based on two screw conveyers that transport the chips and act as treatment chambers. Figure 6.9 is an overview of the continuous process… Continue reading Large‐Scale Implementation of Biopulping

The Pulping Processes

Mechanical Pulping Mechanical pulping, as the name implies, relies on mechanical energy to convert wood to pulp. Current mechanical pulp manufacturing processes constitute several high‐energy grinding and refining systems, including refiner mechanical pulping (RMP) process, the thermomechanical pulping (TMP) process, the chemimechanical pulping process, and the chemithermomechanical pulping process (Someshwar and Pinkerton 1992; Smook 1992). Mechanical pulping… Continue reading The Pulping Processes

Application of LCA

LCA is a tool, which has been described in Sections 6.4 and 6.5, for evaluating the environmental performance of a process, product, or activity, starting from raw material extraction, through manufacturing, to use, and final disposal. This is known as a “cradle‐to‐grave” approach (Figure 6.3). Because of its holistic approach to system analysis, LCA is becoming an increasingly… Continue reading Application of LCA

Evaluating the Life Cycle Environmental Performance of Chemical‐, Mechanical‐, and Bio‐Pulping Processes

Introduction Pulp and paper manufacturing constitutes one of the largest industry segments in the United States in terms of water and energy usage and total discharges to the environment. More than many other industries, however, this industry plays an important role in sustainable development because its chief raw material – wood fiber – is renewable.… Continue reading Evaluating the Life Cycle Environmental Performance of Chemical‐, Mechanical‐, and Bio‐Pulping Processes