The Papermaking Industry: Recycled Pulping
Approximately forty percent of the fiber in U.S. paper products is recycled, or secondary, fiber. Re-pulping fibers that have already been processed shortens them and weakens their bonding capacity, so secondary fiber is often mixed with virgin fib...
Chemical Treatment Technologies: Chemical Principles
Chemicals provide the building blocks for everything in our physical world. Uncontrolled, their misuse can result in tragedy. As a safeguard against potential dangers, treatment processes are being implemented to mitigate or eliminate the harmful ...
Chemical Treatment Technologies: Oxidation and Reduction: An Overview
While some metals can be readily precipitated, others cannot be until they are reduced. The clarified water resulting from these processes can then be discharged into a municipal wastewater treatment system.
Chemical Treatment Technologies: Precipitation and Toxicity
The electroplating industry uses many chemicals in the process of plating objects like golf clubs and water faucets with metals such as chromium and copper. Before the chemically-laden water used in the electroplating process can be released into s...
Chemical Treatment Technologies: Electrolysis
The oxidation/reduction process is applied by industries in several unique and environmentally beneficial ways. The most frequently used technique is electrolysis. This is especially common in the photographic processing industry.
Chemical Treatment Technologies: Innovative Oxidation Processes
To reduce the reliance on harmful chlorinated oxidizing agents, the EPA has conducted numerous demonstrations of the effectiveness of safer oxygen-based compounds. The performance of these oxidizers can be enhanced by the addition of powerful ultra...
Chemical Treatment Technologies: Ozonation
Traditionally, chlorine has been used as a disinfectant to kill viruses and bacteria in drinking water. However, chlorine has the disadvantage of reacting with organics in the water, producing potentially carcinogenic by-products. Ozonation, an ox...
Chemical Treatment Technologies: Water Treatment
The control of pH is critical in the treatment of both wastewater and drinking water. Through the Clean Water Act of 1972, the Environmental Protection Agency established standards for water quality and limits for the toxicity of effluents from ind...
Chemical Treatment Technologies: Oxidation, Reduction and Gaseous Wastes
Oxidation and reduction not only apply to liquid waste streams. A packed bed scrubber can be used to treat gaseous wastes, such as the hydrogen sulfide odors from a water treatment facility.
Introduction to Waste Stream Management: Solid Waste
Improper disposal of hazardous substances removed from both air and water treatment can become solid waste problems. Thermal treatments, like the reciprocating grate incinerator, can be used to eliminate most of the volume of solids. When large am...