Drinking Water Purification for Poultry

Construction (materials, technical sheet / cross-sections)

Filtration

Filters are used to remove (suspended) contaminants from the water, thereby increasing water clarity. Depending on the presence of fine or coarse particles, a coarse filter or a fine filter or a combination of the two types can be used.

1. Microfiltration (MF)

Microfiltration is a form of membrane filtration. With this technique, water, after oxidation, is forced under pressure through a membrane or fine mesh net, trapping virtually all particles between 0.1 – 20 micrometers.

2. Nanofiltration (NF)

In this technique, water is forced under pressure through a semi-permeable membrane. In this process, the membrane acts as an extremely fine filter that allows the water to pass through, but not the pollutants. With nanofiltration, micropollutants such as pesticides, dyes and divalent salts can be removed from water. If the water is too heavily polluted, pretreatment (e.g., de-ironing, softening, removal of suspended solids, etc.) is recommended.

Water purified by nanofiltration is generally suitable as drinking water. An advantage of nanofiltration is that, unlike reverse osmosis, nanofiltration allows dissolved salts (such as Na+) to pass through.

3. Reverse osmosis

Reverse osmosis (RO) is a form of membrane filtration. This technique is applied only to water where a very pure quality is desired. Usually, reverse osmosis is not used as a separate treatment but requires a pretreatment (such as, for example: de-ironing, softening, removal of suspended solids,…).

As already indicated, the techniques described do not stand alone and can be combined to form a “treatment train” depending on the composition of the untreated stormwater and the intended water quality.

4. Activated carbon filter

An activated carbon filter filters water through a one-time or continuous flow through the filter column. Activated carbon is an adsorbent composed of crushed grains of coal or peat and is highly porous. Through adsorption, the molecules adhere to the outer surface of the activated carbon. Activated carbon is a solid (non-soluble) which allows the undesirable substances to be easily removed from the water.

An activated carbon filter is not backwashed but must be replaced depending on the contamination of the water. If the water to be treated is contaminated by suspended particles, it is best to provide a rapid sand filter or other filter media for the activated carbon filter.

5. Sand Filter

In a sand filter, the water is passed through the filter material, causing the dirt particles/floating particles to remain in the grains and purified water to flow out of the sand filter. The sand filter consists of layers of loosely stacked filter material such as sand, gravel,… . This type of filter is usually part of a series of treatments as e.g. in de-ironing water or as pretreatment in reverse osmosis,…

This filtration process requires a regeneration process in which the rinse water is sent through the filter in the opposite direction, stirring up the filter material. The dirt particles are loosened more easily this way and can be disposed of.

Decontamination

1. Disinfection based on UV

Decontamination with a UV lamp is done in a tubular reactor with a mercury vapor lamp in the center protected by a quartz tube. Water flows between the quartz tube and the outer wall of the reactor. UV light has a wavelength between 100 and 400 nm. The smaller the wavelength, the greater the energy of the wave. Under the influence of this high energy, molecular bonds are broken whereby the DNA, RNA and enzymes of microorganisms are affected and they can no longer divide. This process destroys more than 99.9% of all pathogens (bacteria, fungi, viruses, etc.) in the water.

The effectiveness of UV does depend on the contact time and the amount of radiation. The amount of radiation from a UV lamp decreases over time (especially if it is switched on/off frequently), so the lamp should be replaced annually. Proper sizing of the UV lamp i.f. the required flow rate is necessary.

UV treatment is a localized treatment at the level of the lamp, has no after-effects in the drinking lines and also has no effect on biofilm in the lines.

2. Chemical-based disinfection.

Several disinfectants are available for treating water, ranging from the javel to the more expensive commercial mixtures.

3. Javel

Javel is a solution of sodium hypochlorite and water. It is easy to apply and fairly inexpensive. For disinfection, it is important that chlorine is present as “active chlorine. Active chlorine is the measure of the oxidizing power of a solution. The disinfectant has a broad spectrum of action, killing off bacteria, fungi, spores and viruses. However, javel will not break down the biofilm present in drinking lines.

4. Hydrogen peroxide

Hydrogen peroxide is a powerful oxidizing agent and has good activity against microorganisms. The product reacts with a large number of substances and can also be used as a post-dosing agent in the drinking water lines to the barn.

5. Ozone

Ozone is a very powerful oxidant. Its oxidizing action ensures the inactivation of microorganisms (bacteria, fungi and viruses). Ozone affects the cell membrane of bacteria as well as the RNA and DNA structure. When unstable ozone molecules come in contact with the cell wall of the bacteria, an oxidizing reaction occurs, the cell wall is perforated and the bacteria cannot survive as a result. In viruses, the protein envelope is compromised, making it impossible for the virus to reproduce.

Disinfection by ozone normally occurs optimally at pH 6, while faster ozone breakdown occurs at alkaline pH. After ozone treatment, a small amount of ozone is still present in the water, which can have an after-effect in the pipes. This aftereffect is limited in time. The half-life depends on the pH.

6. Electrolytic decontamination

Electrolysis is a chemical reaction that uses salt placed in solution. The dilute salt solution flows along a membrane and is exposed to an electric field. This membrane electrolysis creates anolyte at the positive electrode and catholyte at the negative electrode. Anolyte has strong disinfecting and sterilizing properties. Catholyte is an antioxidant and alkaline solution, usually applied as a cleaning agent or pH correction.

An installation by which electrolytic disinfection of water is performed comprises

– a filter

– A hydraulic cabinet: contains the electrolysis cell. This cell consists of two chambers separated by a ceramic membrane or diaphragm. One chamber contains the anode and the other the cathode.

– a softener (if needed)

– a saltshaker

– a storage vessel for the anolyte fluid