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.
Dirty Water: Oceanic Clues About Climate Change
Many scientists believe they can better understand today's climate patterns by comparing them to those from the past. One way to do this is by examining ancient sediment samples.
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...
The Semiconductor and Electronics Industry: Microchips, CFC's and the Ozone Layer
Because electronics manufacturing is set in sterile surroundings and requires the use of delicate components, it may be hard to imagine that is has global environmental consequences. But the industry's dependence on chlorofluorocarbons, or CFC's, ...
Biological Treatment Technologies: Bioremediation
While the term 'biological treatment' traditionally refers to sewage and wastewater facilities, a newer science known as bioremediation broadens the use of living organisms to concentrate or decompose contaminants. The goal of bioremediation is to ...
Introduction to Waste Stream Management: Gaseous Waste
Gaseous wastestreams present a unique set of challenges. Air pollutants can travel far from their point of origin, causing a variety of health and environmental problems. A range of treatments, including physical, chemical, thermal and biological,...
Pollution Prevention: Bridging Troubled Water: Alternative Pulp and Paper Bleaching Technology
Facing a lawsuit charging it with discharging toxic effluent in the water off the coast of northern California, Louisiana Pacific knew it needed to change the way its pulp mills operated. Even though it successfully met the mandates of the lawsuit ...
Pollution Prevention: Clearing the Air: Reformulated Gasoline
The oil industry has traditionally challenged many environmental regulations. So, in 1989, when California's South Coast Air Quality Management District proposed sweeping changes that would lead to the elimination of gasoline fueled cars in Souther...
Pollution Prevention: Clearing the Air: Case Study: Alternative Dry Cleaning Solvents
Like many other neighborhood businesses, such as the local bakery, auto body shop and photo finishing lab, dry cleaners nearly always have fewer than 20 employees. And yet, like these other small businesses, dry cleaners generate significant toxic ...