While high concentrations of arsenic are found mostly in the Western region of the United States, parts of the Midwest and New England show levels of arsenic
that exceed the newly approved U.S. Environmental Protection Agency (EPA) standard of 10 parts per billion (ppb). Individuals not willing to wait for their water system's compliance with the arsenic standard currently are looking for treatment systems to use in their homes. POU and even point-of-entry (POE) treatment systems are an attractive solution for these individuals. The process should begin with a basic understanding of arsenic contamination and the element's chemistry, a complete water quality analysis of the application-specific water and the knowledge of available technologies.
Thanks to a new membrane filtration system, National Raisin Company, Fowler, Calif., not only has been able to cut its wastewater costs, but it also has opened up a potentially lucrative source of additional income.
Water works engineers are now turning to a new generation of pneumatic valve actuators that are capable of executing the instructions of electronic control systems with the necessary precision to accurately control effluent flow. Surprisingly simple but rugged in construction, this new breed of actuators also is meeting the need to reduce downtime, as some of the first ones to debut in 1981 are still in operation without needing a spare (new) part.
Reverse Osmosis - Anion-Filtration Water Plant Run by a Single Automation Platform with Fieldbus Communications
A new 3.0 mgd water treatment plant on North Carolina's Cape Hatteras is believed to be the first in the United States to apply Foundation fieldbus for device-level control communications. The plant, built by the Dare County Water Department near the famous Cape Hatteras Lighthouse, has been operating without a problem since startup more than two years ago. Fieldbus has been widely applied in all process industries including electric power generation, an industry also cautious to adapt new technology.
A study published as part of the EPA's Environmental Technology Verification (ETV) Program verifies the performance of a Fyne Process membrane filtration plant tested on high organic-laden surface water in Barrow, Ark. The plant was able to remove significant levels of organics--precursors to disinfection byproducts such as trihalomethanes (THM) and haloacetic acids (HAA)--producing water that easily met the disinfection byproduct standards set by the EPA's stringent Stage 1 D/DBP Rule.
Occasionally, height is an issue in a filtration system's housing design. A few years ago, Eden Equipment Company of Huntington Beach, Calif., was approached by a client with just this issue. Due to the client's specific requirements for their system, Eden's original ideas and drawings for this horizontal vessel needed to be redesigned. In addition to the height restrictions on their system, they also needed a design that could withstand a Seismic Zone 4 earthquake.
The AQUA 2000 Project is a build-own-operate-transfer (BOOT)
project, delivered and operated by Vivendi Water Australia. It includes the
construction and operation for 25 years of a water treatment scheme for the
Coliban Water Authority in Victoria, located in southeastern Australia.
Products in Action
On average there are 50 to 75 significant desalination projects per year in the United States with an average capacity of approximately 1 million gallons per day. The majority of these projects utilize membrane processes such as nanofiltration (NF) or reverse osmosis (RO).
In the late 1990s, one western Pennsylvania sewage treatment plant (STP) sought to process Class B biosolids on-site, eliminating the expense of hauling liquid off-site and significantly decreasing associated labor costs. At the same time, the plant needed to achieve higher cake solids and provide strict odor control. In addition, the selected equipment also had to be able to greatly enhance process efficiencies at not just the one plant, but its sister facility as well. Fortunately, USFilter offered a fairly simple solution to meet the STP's seemingly complex needs.
Robert W. Mau and Dean Clemons
Ann Arbor, a densely populated university town of 180,000, has been seeing an increase in urban redevelopment pressure in recent years as developable land has become scarce and land values have risen. The city of Ann Arbor has worked closely with the County Drain Commissioner’s office to use this redevelopment as an opportunity to improve the quality of stormwater flowing into the county drains.