The Papermaking Industry: History of Papermaking
A variety of materials and methods is used to create paper, but the basic process still involves techniques that are centuries old: the moistening, separating and intertwining of fibers to form a sheet. Different kinds of fibers are used to make pa...
Biological Treatment Technologies: Biological Treatment, Wastewater and Sewage
Biological treatment is a major application of microbial technology used for treating municipal wastewater and sewage. One of the most important biological treatment processes is anaerobic digestion, in which anaerobic bacteria are placed in huge c...
Biological Treatment Technologies: Microorganisms and Metabolism
From the polar ice caps to the bottom of the sea, microorganisms that provide the backbone of biological treatment are becoming our greatest ally in the quest for a cleaner environment. The microbial kingdom is comprised of organisms ranging from s...
Chemical Treatment Technologies: Benign by Design, Biomonitoring, and Enforcement
The future of chemical treatment technology is striving to attain the reduction of waste at its source, and seeking to improve the monitoring of that which is discharged.
Thermal Treatment Technologies: Wet Air Oxidation
Wet air oxidation is a process in which organic matter in an aqueous solution can be oxidized and release heat, provided that oxygen is present under increasing pressure. With the passage of the Clean Water Act in 1972, and the requirements that it...
Thermal Treatment Technologies: Risks and Rewards of Thermal Destruction
Thermal destruction of hazardous wastes has much potential, but it has aroused much public concern, as well. Even the best such techniques are only safe and effective when they are controlled and done properly--something that is not always the case.
Physical Treatment Technologies: Electrostatic Precipitation
Particulate matter created as a result of burning coal may be too hot to draw through a baghouse. With an electrostatic precipitator, the hot, dirty stream of exhaust gas passes through a densely spaced series of plates. High voltage electricity c...
The Metal Plating and Finishing Industry: Electroplating: Metal Finishes and Application Processes
Once the part has been cleaned, it is ready to receive the electroplating. One way of plating large quantities of small workpieces at the same time is by barrel plating. In this process, large, plastic barrels are filled with quantities of workpie...
The Semiconductor and Electronics Industry: Obsolete Computers and the Environment
Throughout the 1960's and 70's, mainframe computers were expected to have long, useful lives. But with rapid advances in technology, and the phenomenal growth of the personal computer, yesterday's million-dollar computers are now only valuable as s...
The Metal Plating and Finishing Industry: Electroplating: Waste Treatment and Control
The processes of electroplating, anodizing and galvanizing produce several different wastestreams, including contaminated wastewaters, metallic sludges, and air emissions. In most plating shops, the bulk of the waste comes in the form of wastewater...