Clean Water Treatment

Archive for the ‘Other Water Info’ Category

The NSF/ ANSI (American National Standards Institute) standard, which pertains to each, is located in parentheses. For a more complete listing
please visit: http://www.nsf.org/

Adsorption (NSF/ANSI 42 & 53)
The physical process that occurs when a liquid, gas, dissolved or suspended substance sticks to an adsorbent medium.
Example: Carbon filters.

Distillers (NSF/ANSI 62)
Water is heated to the boiling point and the vapor is collected as it condenses.
This process leaves a majority of the contaminants behind. However, certain contaminants such as volatile organic chemicals may contaminant the water vapor, thus contaminating the water.

Reverse Osmosis (NSF/ANSI 58)
Uses pressure to force water over a semi-permeable membrane, separating solid contaminants like dirt and sediments, as well as dissolved solids like chemicals that have entered our water supply. Many reverse osmosis systems also integrate pre- and post-filters as well as the membrane.

Softeners (NSF/ANSI 44)
Water softening devices that are covered under the Standard 44 use action exchange resin which is coated with sodium chloride or potassium chloride that replaced the calcium and magnesium that is found in hard water.

Ultraviolet Treatment (NSF/ANSI 55)
Class A systems uses UV light to disinfect water.
Class B systems uses UV light to reduce the amount of heterotrophic bacteria present in the water.

Filter presses are classified by broad categories, which differentiate them from other forms of dewatering equipment. Filter presses require a specific amount of solids present in the total influent stream in order for the press to function effectively. If the press is not filled to capacity with solids, then the filter cake will not dry sufficiently.  Each press operations include the following steps:

1. Closing of the press is when the filter has been completely emptied. This presses is self-regulated through filtration.

2. Filling is the phase when the chamber is filled with sludge for filtration.

3. Filtration occurs when the chambers have been filled with sludge, causing a rise in pressure from the thick sludge. This pressure pushes the liquid purged by compressed air through the filter.

4. Filter opening is when the press disengages and the cake fall from the press.

5. Washing cleans the plates as they separate.

This complete process takes less than four hours from start to finish.

The right wastewater planning processes will involve the coordination of different techniques and institutional factors including environment legislative and engineering, public education. The planning process has to be able to direct a community through the selection, construction, operation, maintenance, and financing of a system, which meets the total needs of that community, complicated—yes.

The first step in this complicated process is to evaluate the overall community, including its current and possible future needs. Then issues and concerns of where the existing facilities are insufficient and areas where problems have and may occur must be identified. This would include such areas as growth and security. Then, examine and compare which  technologies, or combination of technologies, would best meet the community’s needs by addressing all these concerns.

Evaluating a community-wide plan involves comparing all feasible and cost-effective solutions to a baseline alternative such as expanding or upgrading existing systems. Other alternatives would include improving operations through maintenance, or constructing completely new systems.

Several communities have found that the best option is actually employing several methods such as decentralizing onsite systems and cluster systems in some sections of the community, and having centralized facility in another sections of the community. An integrated approach such as this reinforce land use planning and emphasizes the need for centralized and decentralized systems to be managed together by a central oversight agency.

Wastewater treatment systems have become more important in the past years because of the decrease of water availability. This has become more evident as an increasing number of communities impose outdoor watering restrictions, and restaurants charge for water. As municipal development and growth increases worldwide, several arid regions have started compensating for the lack of water in several ways. Large seawater desalination projects are being developed and improved upon. These systems have several disadvantages associated with them, they are extremely expensive to build, operate, and maintain and in some instances, the water produced is not recommended for agriculture use. Because of this, other solutions are need. One such solution is water reuse, or recycling. Water reuse, has been proven to reduce the cost of water by re-cycling municipal wastewater for industrial, irrigation, aquifer recharge, or other non-potable (water that is not suitable to drink) uses.

Wastewater has to be treated with a multiple step process before it can be reused with the traditional activated sludge process. Wastewater treatment systems produce a liquid effluent, which can be directly reused for either industrial or agriculture applications. This liquid effluent can also be reprocessed through reverse osmosis for a higher degree of purification.

Reverse osmosis uses pressure to force water through semi-permeable membrane removing all dissolved particles form the water. This system requires little energy to use. Reverse osmosis will eliminate dissolved solids, bacteria, and other organisms from water that filtration will not remove. However, this system is mostly used for
producing potable (suitable for drinking) water from salt-bearing water.

Nanofiltration is similar to the reverse osmosis process, but is not as fine a filtration process as reverse osmosis since the pore size of the membrane is larger. It removes
particles with a molecular weight greater than one thousand and is ideal for conditions that require a high organic and moderate inorganic removal. Nanofiltration is not recommended for salt removal.

Ultra filtration removes works similar to both Nanofiltration and reverse osmosis, however ultra filtration removes component from the water with a molecular weight of greater than 10,000 daltons, (A unit of mass equal to 1/12 the mass of carbon). The percentage of water purity depends on the permeability and thickness of the membrane as well as feed consumption, concentration, system pressure, velocity, and temperature.

Polymeric materials have several benefits including flexibility, resistant to kinks, and is easily cut and bent to fit the size or shape for any system. Polymeric material is leak resistant, and can handle up to 100 pounds per square inch (PSI) of water pressure. They are used as membranes in reverse osmosis, ultra filtration, and in Nanofiltration. However, polymeric materials are not heat resistant. Inorganic materials like ceramics, and carbon-based materials are commercially available which offer the same resistance as polymeric materials but are more heat resistant.

Microfiltration is the most widely used membrane filtration process for wastewater management systems. This system basically performs sterile filtration, by restricting passing of microorganisms and material approximately 10 to 10,000 angstroms, (one hundred-millionth of a centimeter), in size and larger.

Years ago, the only way to test well water meant simply looking at the water for signs of algae or discoloration. Today we have sophisticated technology to treat well water and laboratory testing to ensure its safety. In order to make an educated decision on which well water treatment system is right for you and your family, you should have a basic understanding of the technologies available.

Several companies employ reverse osmosis, which uses pressure to force water over a semi-permeable membrane, separating solid contaminants like dirt and sediments and certain chemicals from the water supply. However, smaller compounds can slip through the membrane. This has lead to many individuals searching for a better  technology.

More carbon filters sold in the United States than any other form of filtration device. You do not recharge carbon filters. They remove such contaminants as volatile organic chemicals (VOC), pesticides, herbicides, chlorine, benzene, trihalomethane (THM), radon, solvents, and other chemicals but will not remove healthy minerals. This is one reason why carbon filters are the number one filters sold in the U.S.

Water purification systems all work differently. In order to find the one that is right for you and your family, do some research on salt filters before making your finally decision.

Water purification is one of our nation’s biggest obsessions. We spend billions of dollars each year on bottled water and we invest in whole house water filtration systems. So, is all of this really necessary?

To answer this question, first let’s point out that the EPA has a list of set standards of approximately 90 contaminants found in our drinking water. Some of these, contaminants are lead and arsenic. Next, no matter how good the municipal water is, unfortunately, there have been several cases where municipal water was contaminated, and warnings to boil water for the communities. For these reasons, you can never be too safe where your drinking water is concerned.

There are several brands of water filters on the market, but only two main commercial methods for tap water filters. Salt filters are less expensive, but require frequent refills. They block the unwanted compounds from the water, and replace them with sodium. These sodium acids can corrode plumbing and appliances.

Carbon filters are considered safer for the environment and more effective. Carbon filters use a technology, which permit the filtration of chlorine, pesticides, and other contaminant but does remove the healthful minerals. If you want healthier safer water, then consider carbon filters.