Omya Water & Energy omya.com. Omyaqua. Calcium Carbonate treatment of drinking water

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1 Omya Water & Energy omya.com Omyaqua Calcium Carbonate treatment of drinking water

2 Omya In Water Treatment Omya has over 40 years experience in water treatment, supplying a range of products to treat drinking water, as well as municipal & industrial waste waters. Omya Calcium Carbonate and dolomite products allow alkalinity adjustment and mineral content modification of soft and hard waters. Water mineralization with fine and course Calcium Carbonate 2

3 Omyaqua Omyaqua, available as both a micronized and granular Calcium Carbonate, is a key product of our water treatment range. It enables remineralization of soft water, replacing the minerals lost during treatment, or adding minerals not initially available in the water. Benefits Technical and economic benefits Broad product range High purity Calcium Carbonate Drinking water approved Flexible packaging Technical support Long-term availability 3

4 Omyaqua Means High Quality Water The qualities and characteristics of water are determined by the elements it comes into contact with during the water cycle. This includes the geological composition of the ground it passes through, as well as the properties of other water it encounters. ph Waters sourced from granite, basalt, or 9,0 sandstone regions, tend to be deficient in important minerals such as calcium and magnesium. These minerals are import- 8,5 ant for human health, irrigation, and for water stabilization (maintaining the calco-carbonic equilibrium). 8,0 AGGRESIVE WATER ph SCALING If water has a low mineral content (< 80 ppm as CaCO 3 ), it is referred to as 7,5 phs soft water, and often presents with low alkalinity. The combination of a low ph 7,0 and soft water results in the water having an aggressive and corrosive character. 6,5 SOFT WATER 5 15 HARD WATER M-alk and and CaH (ºF) SUEZ s degremont water handbook 4

5 Preventing water corrosion Corrosive water deteriorates pipes through an electro-chemical process, and that enables metals such as lead, copper, iron, aluminum and cadmium to dissolve into the water. These metals can have significant detrimental effects on human health. The physical deterioration of water distribution networks leads to an increase in leaks and reduces the service life of pipes and equipment significantly. It also makes operation and maintenance of water distribution networks far more expensive, less durable, and considerably less efficient. 5

6 The Calcite Contactor Process Calcite contactors are the most common method of increasing water hardness quickly, easily, and efficiently. However, the quality of the finished water depends significantly on the quality of Calcium Carbonate used. High quality water demands high quality Calcium Carbonate. Raw water Omyaqua Treated water Contains dissolved (aggressive) CO 2 called Carbonic Acid. Corresponding chemical equations: CO 2 + H 2 O H 2 CO 3 (Carbonic Acid) Carbonic acid dissolves the Calcium Carbonate (CaCO 3 ) and forms Calcium Hydrogen Carbonate, also called (Calcium Bicarbonate) Ca+(HCO 3 ) 2. Remineralized (stabilized) water is achieved by the formation of Calcium Bicarbonate Ca(HCO 3 ) 2. Hardness and alkalinity increases while CO 2 is decreased. Final water typically reaches a ph of > CaCO 3 + H 2 CO 3 Ca(HCO 3 ) 2 (Calcium Bicarbonate) * Granular Calcium Carbonate

7 Final ph adjustment Arrival of raw water Backwash Height of freeboard: Losens the material 25 % of the Omyaqua and avoids preferential layer height channels Eliminates the impuri- Frequency: every 800 hours or according to the water quality Cycle: air, air + water, water MODE operation OPERATION turbidity during MODE filtration and reduces Neutralization and minerali- BACKWASH ties retained during zation with Omyaqua Contact time of 20 to 45 minutes depending on the feed-water quality and selected Omyaqua product Refill on a regular base to maintain the empty bed contact time (EBCT) Omyaqua provides for stable phwithout ph peak Base of filter Sand or gravel (optional) Filter floor Calculating the required Omyaqua volume Number of m3 to be filled x density (see TDS/MSDS) of Omyaqua = tons of Omyaqua Calculating Omyaqua consumption Depending on the chemistry of the water, the theoretical consumption of Omyaqua is 2.3 grams per gram of CO2 neutralized Example: To neutralize 35 mg/l of CO2 and increase hardness by 8 F (4.5 dh /5.6 e), an estimated consumption of 80 mg/l of Omyaqua is required. In such cases, and for a Calcite Contactor station with a flow of 30 m3/h, operating 10 hours/day, approx. 8.8 tons Omyaqua per year is required. Depending on the EBCT and the final water quality requirements, a CO2 removal step may be required using a Degasser or Caustic Soda Dosing.

8 Omya advanced Remineralization Process (OARP) Omya Advanced Remineralization Processes (OARP) involve the generation of a concentrated Calcium Bicarbonate solution within a side stream, which can be used to dose into final water stream to increase the hardness and alkalinity content of the final water. Omyaqua Micronized Calcium Carbonate CO 2 Membrane Calcite Reactor Calcium Bicarbonate Solution Omyalime ph adjustment Omyaqua Suspension ph/alk/turb Desalinated Water Permeate/Distillate - H 2 O CaCO 3 CO 2 Ca 2+ HCO 3 The concentration of the initial Omyaqua micronized Calcium Carbonate suspension, the acid dosage and the contact time can all be controlled to obtain the desired concentration and qualities of the Calcium Bicarbonate solution before blending with the main product water flow to achieve the fi nal (drinking) water specification. Furthermore, the OARP process allows to follow different permeate flow patterns and therefore provides for an optimized remineralization process at changing plant-operating conditions. 8

9 High Quality & Performance Omyaqua provides for unique physical characteristics, including specific surface area and particle size distribution to obtain the best dissolution properties in the processes used. In addition, all Omyaqua products are characterized by their high purity: over 98%, with an insoluble content as little as 0.1%, making them ideally applicable for use within drinking water to achieve International Standards such as DIN EN-1018 and NSF-60. Benefits Premium quality water Cost optimized design Modular & flexible operation Zero product & backwash waste Drinking water approved 9

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11 Omyaqua the product Our Omyaqua remineralization products provide you with a range of technical and economic benefits Broad product range and multiple manufacturing locations allow for particle size selection adapted to your water quality and operational needs High purity with total calcium carbonate content > 98% Drinking water approved following international standards such as NSF-60 and/or EN-1018 Local products sourced from local/regional Quarries Flexible packaging which can be combined with our professional supply chain solutions Technical support experts are always on hand to ensure a trouble-free application of Omyaqua Long-term availability: sustainable mineral reserves managed by our global team of geologists and quarry managers Omyaqua : a micronized calcium carbonate product has been tailored with respect to its use in drinking water treatment. 11

12 09/2017 Omya Water & Energy Omya International AG CH-4665 Oftringen