In-situ biological treatment (bioremediation) systems have now gained widespread acceptance for dealing with sites impacted by petroleum hydrocarbons. However, at many remediation sites, the need to pump groundwater to maintain gradient control still generates a stream of contaminated water requiring treatment, even if in-situ technologies are being employed.
This article originally appeared in the 06/01/2004 issue of Environmental Protection.
This is the second article in a two-part series on membrane elements and treatment systems. "Demystifying Membranes - Part I" was published in Environmental Protection's July-August 2003 issue and is accessible online at no charge under "Archives" at www.eponline.com. The first article compares the advantages and disadvantages of four types of membrane separation technologies. Part II clears up some common misunderstandings about the properties of membrane technologies.
- By Peter S. Cartwright, P.E.
This article originally appeared in the 05/01/2004 issue of Environmental Protection.
Fiberglass composites have become the material of choice in many water or wastewater treatment operations. For mild to severe corrosion service, they can often be the materials of choice for economy and durability.
- By J. Albert Rolston, PE, FAIChE
This article originally appeared in the 03/01/2004 issue of Environmental Protection.
Water treatment plants and pumping stations supported by variable-frequency drives (VFDs) may be unwittingly threatened with power system problems including interruptions, interference, downtime and even disruption of instrumentation and other sensitive equipment due to an elusive culprit called harmonic distortion, an undetected condition that has been said to cost between $16 to $40 billion in annual losses due to downtime, equipment failures and malfunctioning systems.
This article originally appeared in the 03/01/2004 issue of Environmental Protection.
Water utilities have been using free chlorine to disinfect drinking water for more than 100 years and have been measuring chlorine residuals for almost as long. Monitoring the product water ensures adequate chlorine is present for disinfection. It also helps the utility prevent taste and odor problems arising from overchlorination.
This article originally appeared in the 11/01/2003 issue of Environmental Protection.
The enormity of the problem facing the drinking water industry first surfaced in the United States in 1993, when Cryptosporidium, a single-celled parasite living in the intestines of warm-blooded animals, made its way into the drinking water in Milwaukee, leaving 403,000 people sick and 104 people dead.
This article originally appeared in the 09/01/2003 issue of Environmental Protection.
Implementation of a new Laboratory Information Management System (LIMS) has helped the Portland, Ore., Bureau of Water Works meet regulatory requirements while increasing laboratory throughput. Water quality laboratories across the country face the need to perform a higher volume of testing and improve data security in order to ensure the safety of the nation's water supply.
This article originally appeared in the 09/01/2003 issue of Environmental Protection.
Activated carbon is well known for its ability to remove organic compounds from water through a process known as adsorption, remove chlorine and chloramine through various chemical reactions and serve as a general filter media; however, its use for reduction of bromate is unclear.
- By Kimberly Thompson, Neal Megonnell
This article originally appeared in the 07/01/2003 issue of Environmental Protection.
Groundwater contamination has been an area of environmental concern for decades. Underground storage tank and process line leaks, product spills and intentional dumping have been the greatest contributors to the problem.
- By Duygo Tokat, Arturo A. Keller, PhD., Reid H. Bowman, PhD., Peter Herlihy, Michael J. Joy
This article originally appeared in the 07/01/2003 issue of Environmental Protection.
Drinking water professionals know that the quality of raw or finished water supplies may be adversely impacted by a number of contaminants, including petroleum products from leaking tanks or pipelines, insecticides and herbicides from agricultural runoff, pathogens from untreated sewage discharges and others.
This article originally appeared in the 07/01/2003 issue of Environmental Protection.
Methyl Tertiary Butyl Ether (MTBE) is a gasoline additive used to oxygenate and add octane to gasoline. Since the late 1970s, lead has been banned from use in automobile fuel use due to its toxicity to humans, leading to the problem of low oxygenation in gasoline that has caused exhaust to be more easily trapped in urban airsheds.
This article originally appeared in the 05/01/2003 issue of Environmental Protection.
While Asia's public and private sector stakeholders strive to achieve robust economic growth, they are faced with the daunting task of mitigating the effects of that growth on the environment and addressing a wide range of legacy environmental problems, particularly in the areas of water and wastewater management.
- By Doug Shuster, Kim Mihalik, Maria Gilpin
This article originally appeared in the 01/01/2003 issue of Environmental Protection.
Currently, the process of ozonation is being implemented in drinking water purification in treatment plants around the globe. Ozone is a potent agent in the disinfection of raw water. When raw water is pumped into the treatment plant, it carries many bacteria and viruses. The use of ozone eradicates these harmful pathogens.
This article originally appeared in the 11/01/2002 issue of Environmental Protection.
Isn't the number of remedial technologies that actually exist to remediate and protect groundwater amazing? Not only does industry have a wide selection of pump and treat options, there is a full array of in-situ technologies that engineers continue to conceive and refine.
- By Charles Cohen, Thomas E. Jamrok
This article originally appeared in the 09/01/2002 issue of Environmental Protection.
In today's chemically dependent society, it has been undeniably demonstrated that America's drinking water contains numerous industrial chemicals, pesticides, pharmaceuticals and compounds from the water treatment process itself.
- By Patrick J. Sullivan, Franklin J. Agardy, James J.J. Clark, PhD
This article originally appeared in the 09/01/2002 issue of Environmental Protection.
Bioremediation -- cleaning up soil and groundwater contamination with indigenous bacteria -- has been a holy grail for property owners and consultants, since it can eliminate active pumping systems, which include associated operations and maintenance, as well as treatment and disposal costs. However, the natural pace of unamended bioremediation or "leave-alone" natural attenuation tends to be too slow and uncertain to be practical.
- By Bryan W. Vigue, Stephen S. Koenigsberg, Ph.D.
This article originally appeared in the 05/01/2002 issue of Environmental Protection.