Based on the City of Hollywood’s experience, the use of 316L stainless steel should be evaluated carefully due to the potential for problems in the erection and construction of water treatment facilities that will be in contact with high chloride water and/or other corrosive chemistries. As with many membrane facilities, much of the stainless steel is exposed (not buried), which subjected it to atmospheric as well as water quality problems. Therefore, unless the quality control of the raw and reject water (chemical, physical and microbial) can be assured, 316L stainless steel may not be the appropriate material for engineers to specify.
Drinking water treatment professionals have long held fast to the belief that granular activated carbon (GAC) based on bituminous coal provides the best performance for their demanding application. That’s why, when an article in 1999 cited evidence that a lignite-based GAC outperformed a bituminous-based carbon, industry experts were surprised and more than a bit skeptical.
Fresno Discovers Big Difference Between Reagglomerated Carbon and Direct Activated Carbons
At the Procter & Gamble manufacturing plant in Greensboro, N.C., an Aquionics ultraviolet (UV) dechlorination unit was installed before two banks of reverse osmosis (RO) membranes. Trials that ran soon after the UV system’s installation showed a dramatic reduction in the RO membrane wash frequency—down from an average of eight cleanings per month to only two per month.
Reverse Osmosis Membranes Maintenance Costs Reduced
challenges are emerging in the industry that require new methods and product
developments. This article discusses additional test methods for the AC
ASTM, AWWA and EPA Standard Methods and New Test Methods for AC
Since the 1960s, municipalities and industries have used packaged water treatment plants to successfully and economically treat small water supplies. These packaged plants have offered a smaller footprint, lower capital cost and easy operation.
The future of safe drinking water lies squarely in the hands of the point-of-use (POU) water purification industry. Growing awareness among decision-makers and consumers is the force behind the increasing importance of the POU industry.
Membrane technology offers the possibility of managing total water resources. The spiral wound membrane element configuration is the most widely used due to its high packing density and relatively low price. This article will describe some technological advances in the area of innovative new membranes and application concepts for spiral wound membrane elements.
On November 26, 2001, the new arsenic standard was signed into law—lowering the acceptable level for the contaminant from 50 parts per billion (ppb) to 10 ppb. Approximately 4,100 municipal water systems serving nearly 13 million people nationwide are affected by the law and are required to meet compliance by January 2006. According to the U.S. Environmental Protection Agency (EPA), 97 percent of these systems are small systems serving fewer than 10,000 people each. The economic impact on these small systems is likely to be large. However, there currently are options available to small municipalities that may be more affordable than central treatment.
New POU Technologies May Be the Answer for Small Municipalities Facing High Costs
Part one of this article appeared in the February issue and described how nanofiltration, reverse osmosis and electrodialysis reversal are being run side-by-side at the Brackish Water Demonstration Facility in California.
The Diablo Canyon Power Plant at Avila Beach in California utilizes seawater for both cooling water and makeup water for steam generation. Ionics, Inc., Watertown, Mass., designed and built and now operates a complete water treatment system serving the high-purity water needs of this power plant. Over the past eight years, the seawater treatment section has demonstrated excellent long-term performance as a result of strong design, consistent maintenance and qualified operators.