A wide range of technologies, some new and some more traditional, is being marketed and applied for arsenic treatment. Each of these technologies has specific properties impacting its suitability for any particular scale of application. While rare, the ability of a single water treatment technology to perform effectively across many treatment platforms is not unique.
Cross-platform viability of treatment technologies
Manganese greensand is a specially processed medium for iron, manganese, and hydrogen sulphide removal. This premium non-proprietary filter medium is processed from glauconitic greensand on which a shiny, hard finite thickness manganese oxide coating is formed and is firmly attached on every grain by a controlled process.
Over the years, water quality has noticeably deteriorated worldwide. This decline in water quality stems from the extreme demand on very limited natural resources. Various principles of filtration are used in many applications to improve the general quality of the water that is being treated. Along with screen filters, coagulation/filtration, neutralizing filters, oxidizing filters, clairifying filters and carbon filters are other treatment methods that may be used.
Various filter technologies stretch limited natural resources for drinking water
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.
Editor’s Note: Part 1 of this series provided a timeline for the development of a drinking water standard for arsenic. It also summarized the political and public reactions to the U.S. EPA decision to delay and withdraw the arsenic rule.
Part 2 dealt with human exposure and advances in knowledge concerning human health effects of exposure to arsenic.
Part 3 summarized early data on the occurrence of arsenic in U.S. waters.
Arsenic Removal Methods
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.
Only recently has a substantial amount of data become available on the concentrations of arsenic in United States drinking water supplies. Most of these data have been accumulated by the state regulatory agencies responsible for monitoring drinking waters. Since the arsenic standard has been 50 µg/L, some state agencies have recorded arsenic concentrations only in excess of that concentration. Others have been limited by the sensitivity of the analytical techniques and equipment used for the arsenic analysis. As a result, much of the available arsenic data are “below the limits of detection.
Occurrence of Arsenic in U.S. Waters
If you’ve seen it once, you’ve seen it a hundred times — customers who come to you looking for a home filtration system, unaware of what their specific needs are. While many consumers simply want a system that improves their water’s taste and aesthetic qualities, the majority are looking for a product that will make their water healthier. But as you know, “healthier” is a subjective term, and without knowing the issues that are present in the customer’s water, providing them with a system that fits their needs isn’t very easy to do.
How Culligan helps its dealers become better-educated consumers of drinking water
The National Academy of Sciences, National Research Council (NAS-NRC) report was released on September 11, 2001. It concluded that the existing health effects data on arsenic essentially were sound. In addition, their review of three new epidemiological studies indicated that the health risks posed by arsenic in drinking water were greater than previously believed. As a result, in October, well before its self-imposed deadline, EPA rescinded its March implementation ban and endorsed the 10 µg/L arsenic MCL.
The Development of Drinking Water Regulations
Understanding and reacting to the performance of a reverse osmosis (RO) system is necessary for continued successful operation. It is this interaction that allows us to quickly and correctly identify and correct issues that may arise.
Tending to System Maintenance is Necessary for Successful Operation