Why activated carbon filter for water treatment

See our data use policy for details. Let your search flow Search. What is a perspective? Executive Summary Activated carbon filtration is a commonly used technology based on the adsorption of contaminants onto the surface of a filter. Water analysis is required to choose the most adapted type of activated carbon.

Introduction Factsheet Block Body. Treatment principles Factsheet Block Body. Preparation of activated carbon Factsheet Block Body. Use of activated carbon units Factsheet Block Body. Combination of activated carbon with other processes Factsheet Block Body. Cost considerations Factsheet Block Body. Operation and maintenance Factsheet Block Body.

At a glance Factsheet Block Body. Library References. Zhangjiagang Beyond Machinery Co. URL [Accessed: Further Readings. In: Applied and Environmental Microbiology: Volume 61 , Organic Removal Organic Removal.

Case Studies. In: African Journal of Biotechnology : Volume 5 , In: Ed. SMET, J. Training Material. Awareness Raising Material. Important Weblinks. Comparte con otros. Subscribe to our newsletter Get the latest updates on trainings, new articles or perspectives related to SSWM delivered directly to your inbox! Two filters arranged in sequence ensure that any chemical that might get past the first filter is trapped by the second. When the first filter is used up, the second filter is moved to the first position and a new filter is placed in the second position.

Sample ports located before, between, and after the filters allow for testing of the water at each location see diagram on the next page.

Most systems also have a bypass switch that allows the water flow to bypass the system when needed for chlorination or certain plumbing activities. When the system is bypassed, the water entering the home is NOT being filtered. A point of use POU filter is installed in the water supply pipe just before the faucet where people get water. One example is an under-sink unit; water passes through the carbon filter and travels to a separate water tap, next to the main faucet.

Water from the separate tap will be GAC-treated, and water from the main faucet hot or cold will be untreated. An under-sink filter protects people from ingesting the chemical by treating the drinking or cooking water only from that tap. It will not protect people from inhaling the chemical while showering or bathing, prevent the chemical from being absorbed through the skin, or protect other water faucets.

The less soluble organic molecules are, the more likely they are to be adsorbed. Smaller organic molecules fit the smallest pores and are held the tightest. Concentration: The adsorption process can be affected by the concentration of organic contaminants. For example, with chloroform removal one AC filter may be more effective than another at filtering high concentrations of contaminants, and less effective at filtering low concentration of contaminants. Consult with the manufacturer to determine how an activated carbon filter will perform at different concentration levels for a specific chemical.

Water Temperature and pH: The rate of adsorption will usually be higher at lower temperatures and pH levels. Chemical reactions and chemical forms are closely related to water temperature and pH.

In most cases, organic chemicals are more adsorbable as temperatures and pH levels decrease. Length of Exposure: The length of time in which the contaminant is in contact with the AC filter also influences the adsorption process — the longer the length of contact, the greater the number of contaminants that will be removed.

A greater amount of active carbon and a slower flow rate will improve the effectiveness of the filtration process. Bed depth and flow rate are critical design parameters. Carbon filtration is often engineered to provide a specified residence time of water in contact with the carbon bed, referred to as empty bed contact time or EBCT.

Filtration Equipment Activated carbon filters are similar to those used in multi-media filtration , except without the air scour step in the backwash process. Fill in the form below to request a quote for our industrial water treatment services. This field is for validation purposes and should be left unchanged. Contact Us This device should meet certain guidelines concerning the application rate of water to the carbon, contact time between the water and the carbon, the type of carbon used, and the concentration of contaminant s to be removed.

Point-of-entry devices are installed where the water enters the house, so they treat all the water used in the home. Systems used should be vented to the outside atmosphere so as not to cause a build up of harmful vapors inside the home. There is no bypass option, although water can be diverted for outdoor use prior to treatment. The effectiveness of an activated carbon unit depends on the extent of contact between the carbon and the untreated water.

During operation of carbon filters it is possible for channels to form within the filter which will allow some of the water to pass through untreated. Since treatment depends on the carbon granules adsorbing the chemical contaminants, these channels decrease the contact time and the effectiveness of the carbon filter unit. A disadvantage of block carbon is that if it is unevenly compressed when manufactured, irregular flow patterns may affect contaminant removal.

There are two main procedures to determine how much a carbon filter can adsorb: the iodine test and the phenol test. The iodine number is defined as the amount of iodine in milligrams adsorbed by one gram of carbon under a certain set of conditions.

The larger the number, the more the carbon filter can adsorb. Phenol is another measure of effectiveness. The lower the phenol number, the better the carbon is at removing organics. When comparing home carbon devices, pay attention to these values. Please keep in mind that manufacturers tend to report the best removal rate for their product.

The values are frequently the amount the unit will remove at the beginning of use for a single contaminant at moderate concentrations. Units having a larger bed volume of carbon usually remove a greater quantity of contaminants. Some types of activated carbon will remove specific contaminants better than others.

Buyers need to examine as many products as possible and know exactly what contaminant they want the unit to remove. You will also need to know how much water is used in the home on an average day to adequately size the treatment system. Additionally, have both the raw water prior to treatment and the treated water retested after a unit is installed to ensure it is functioning properly. Keep a log book to record water test results, equipment maintenance and repairs. Most activated carbon filter units need to have the carbon changed periodically.