Chemical BacComber Scale and Bacteria Control Comparison Between BacComber and Chemical Treatment Chemical BacComber Descaling and fouling Cannot perform descaling on existing scale present in the cooling system. Chemical and other deposit will build up over period of time. Ability to remove existing scale in the cooling system. No chemical and other deposit could build up due to descaling effect and absence of chemicals. Scale control principle and side effect Use chelating agents such as phosphate to prevent formation of hard calcite scale. Phosphate promote growth of bacteria and algae. Overdose causes calcium phosphate which inhibits heat transfer. Uneven coverage due to under-dosing can cause localized corrosion attack ULF waves used to form water cluster to reduce the formation of calcium carbonate. Scales that may form is non-sticking aragonite soft scale instead of the surface adhering calcite hard scale. Scale control effectiveness For effective scaling control, usually TDS is controlled at below 1000 ppm. Control of scale at higher TDS level not recommended. Scale control is effective even at high TDS level of up to 3000 ppm. However, maximum TDS limit must be within authority sewerage discharge control limit. Bacteria control principle and side effect Use biocide to control bacteria Chemical dosage is based on certain assumed cycle of concentration, which is difficult to control. Scale controlling agent such as phosphate promotes bacteria growth which may be out of control when biocide dosage is low. Most biocides are highly corrosive and will corrode the metal members in the cooling system. Environmentally unfriendly Uses copper and silver ions to control bacteria and alter the DNA to prevent bacteria multiplying. In addition, the ULF treatment controls and enhances the overall bacteria control effectiveness. Non-corrosive and environmentally friendly. Bacteria control effectiveness Bacteria control effectiveness varies with the dosings. Effectiveness depends on the other chemicals introduced during treatment. Ineffective in controlling bacteria that are under the chemical deposits, scales and in the biofilm. Effective and continuous control of bacteria in the water. Effective in controlling bacteria in biofilm and under the scale and deposits. The descaling effect of BacComber system will remove the bacteria under the scale, deposit, biofilm and inhibit their growth. NOTE: The Copper & Silver Ions was the 1st generation system & was obsoleted many years back. The latest 3rd generation that has started to commission in 2011 is ULF+Emitters system.

Comparison Between BacComber and Chemical Treatment: Corrosion, algae, slime control and cost effectiveness Chemical BacComber Corrosion control principle and side effect Using corrosion inhibitor such as phosphate to control corrosion. Phosphate is nutrient to bacteria and algae. Hence can promote bacteria and algae growth, microbial induced corrosion. Using ULF wave to generate water cluster to reduce the formation of iron oxide and in addition, promote the formation of corrosion protection magnetite layer instead of non-protective hematite when iron oxide is formed. Corrosion control effectiveness Excessive biocide can cause severe corrosion. Excessive chemical can cause pitting or under-deposit localized corrosion. Absence of chemicals, hence no "created" corrosion problems. Algae and slime control Effective in algae control but subject to environment conditions. Excessive phosphate will promote algae growth. Slime and biofilm control effectiveness vary between dosing. Very effective in slime / biofilm control because of descaling effect. Water saving Heavy water consumption due to heavy bleed off to control the desired cycle of concentration or to maintain the TDS level. Drained off water cannot be recycled due to chemical content. Great water saving, because of ability to maintain higher cycle of concentration compared with chemical treatment. Water saving cost can be more than the treatment cost. Water can be recycled as it does not contain chemicals. Further saving can be achieved if recycled. Energy saving Well treated system can maintain the energy consumption. Unable to remove the existing scale and deposit hence cannot further reduce energy consumption. Very effective in descaling the existing scales hence further reduce the energy consumption. Energy cost saving usually more than treatment cost. For new cooling system, low energy consumption level can be maintained. Economy Recurring perpetually One time investment with a payback time not between 16 to 24 months. Safety, health hazard, environment and ISO 14000 consideration Environmentally unfriendly, cost of handling and storage of chemical is high. Dangerous to be handled and stored by staff. Very safe, environmentally friendly, no health hazard, no handling and storage cost.