Introduction to Waste Stream Management: Block Flow/Mass Balance Analysis
The first step in controlling wastes is understanding where and how they are generated. Engineers and environmental managers use a tool called a block flow diagram to make sense of complex industrial processes. They also use a technique called mas...
Introduction to Waste Stream Management: Treatment Technologies and Pollution Sources
The approved EPA treatment technologies for solid, liquid and gaseous wastestreams can be categorized into four groups: physical, chemical, biological and thermal. Knowing which type of treatment to use and when to use it requires understanding the...
Introduction to Waste Stream Management: Overview and History of Pollution and Environmental Awareness
While pollution has always been part of the industrial process, environmental accountability is relatively new. The founding of the Environmental Protection Agency and the introduction of basic measures to standardize emissions and treatment of liq...
Introduction to Waste Stream Management: Liquid Waste
In the past, some of the major sources of water pollution have been landfills, underground storage tanks, and untreated effluent. Under the Clean Water Act, the EPA sets industry-specific discharge limitations for water pollutants. Treatment metho...
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...
The Semiconductor and Electronics Industry: Microchip Fabrication and the Environment
Semiconductor fabrication requires an ultra-pure environment. Delicate components are washed and rinsed at each stage, making this a water intensive process. Semiconductor manufacturing is also a chemical intensive industry. Many companies are ac...
The Semiconductor and Electronics Industry: Microchip Design and Production
The complex circuitry of a microchip appears flat and one dimensional but, in reality, it can have as many as twenty layers. The starting point for what ends up looking like a miniature electronic city is pure silicon, grown from seed crystals. As...
The Metal Plating and Finishing Industry: Electroplating: Cleaning and Preparation
Preparation of the metal surface is the first step in the electroplating process. In order for solutions to properly contact the workpiece, that workpiece must be free of any oil or dirt. The choice of cleaning methods varies, depending on the typ...