Reagent water treatment in Ukraine

Coagulation of impurities

Coagulation is the process of destruction of colloidal disperse systems as a result of a violation of the stability of their state. The process consists in increasing the size of particles due to sticking to sizes at which their colloidal properties are lost and precipitated. Coagulation is used to purify water from suspended and colloidal particles by adding coagulant solutions (aluminum salts, iron salts, etc.) to it. The use of the coagulation mechanism is advisable for the source water, if it exceeds the indicators of turbidity, color or content of organic matter and plankton.

Reagent softening

Water softening by reagent methods is based on its treatment with reagents that form sparingly soluble compounds with calcium and magnesium, followed by their separation in clarifiers, thin-layer sedimentation tanks, clarification filters. Lime, soda ash, sodium hydroxide, etc. are used as reagents. reagent softening of water is used at its high carbonate and low (or comparable) non-carbonate hardness, and also in the case when it is not required to remove salts of non-carbonate hardness from water.

Correction of acid-base balance

The acid-base balance of water is corrected in order to achieve the norm in terms of pH. The process is carried out by dosing acidifying substances (acids) or alkalizing reagents (alkalis) into water.

Correction of the acid-base balance is carried out in the following cases:

– if the pH value of natural water does not meet the established standards;

– if the reaction of water impedes the flow of other processes (for example, iron removal);

– if the water is prone to deposit formation or vice versa, aggressive;

– if the acid-base balance changes as a result of the use of other reagents.

Stabilization water treatment (scale inhibition)

Stabilization water treatment is carried out to prevent the processes of intensive scale formation on the heating surfaces of heat exchange and water heating equipment. The most commonly used reagents are based on organophosphorus compounds.

Removal of oxygen

Chemical deoxygenation is carried out by introducing special reagents (in particular, sodium sulfite and its modified analogues) into the make-up water of boiler equipment that absorb oxygen and prevent the process of oxygen corrosion. Such processing allows you to ensure the stable operation of boiler rooms with closed water circuits.

Water treatment with reagents, depending on the purpose of treatment, can be divided into several types:

  1. Water disinfection.
  2. coagulation of impurities.
  3. Reactive softening.
  4. Correction of acid-base balance.
  5. Stabilization water treatment (inhibition of corrosion and deposits).
  6. removal of oxygen.

Almost each of the above goals is achieved by dosing a special reagent (or successively several reagents) into the water.

Dosing is usually carried out using dosing stations (in some cases, preparation and dosing) of reagents, the main components of which are a supply tank and a dosing pump.

Water disinfection

For water disinfection, dosing of reagents containing active chlorine is most often used.

Sodium hypochlorite (NaClO) solution has received the widest application due to its availability and ease of use. The disadvantages of this reagent are the potential for the release of chlorine gas during storage, the formation of trihalomethanes and other harmful by-products.

В настоящее время все большую популярность приобретает способ обеззараживания воды диоксидом хлора (ClO2). This reagent works at reduced doses, does not form trihalomethanes and chloramines, destroys phenols (a source of unpleasant taste and odor), an effective oxidizer and disinfectant against all types of microorganisms, including cysts. The disadvantages include the mandatory receipt and place of application.