www bzfxw com BRITISH STANDARD BS EN 1209 2003 Chemicals used for treatment of water intended for human consumption — Sodium silicate The European Standard EN 1209 2003 has the status of a British Sta[.]
BS EN 1209:2003 BRITISH STANDARD Chemicals used for treatment of water intended for human consumption — Sodium silicate `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - The European Standard EN 1209:2003 has the status of a British Standard ICS 71.100.80 12&23 800 °C 3.3.7 Crystallisation point An accurate crystallisation point of a sodium silicate solution can not be measured By reducing the temperature of the solution the viscosity increases A precipitate of variable composition will form, depending on the molecular ratio and concentration of the sodium silicate 3.3.8 Specific heat Not known 3.3.9 Viscosity (dynamic) Solution: 70 mPa s to 90 000 mPa s at 20 °C depending on molecular ratio SiO2: Na2O and concentration Powder: 3) 100 kPa = bar `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295 EN 1209:2003 (E) not applicable 3.3.10 Critical temperature Not applicable 3.3.11 Critical pressure Not applicable `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - 3.3.12 Physical hardness Not applicable 3.4 Chemical properties Sodium silicate reacts as follows: with acids by exothermic reaction, to form a gel; with 2- or 3-valent ions, to form insoluble silicates; with carbon dioxide (CO2), to form a gel or precipitate Purity criteria 4.1 General ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ This European Standard specifies the minimum purity requirements for sodium silicate used for the treatment of water intended for human consumption Limits are given for impurities commonly present in the product Depending on the raw material and the manufacturing process other impurities may be present and, if so, this shall be notified to the user and when necessary to relevant authorities NOTE Users of this product should satisfy themselves that it is of appropriate purity for treatment of water intended for human consumption, taking into account raw water quality, required dosage, contents of other impurities and additives used in the products not stated in the product standard, and other relevant factors Limits have been given for impurities and chemical parameters where these are likely to be present in significant quantities from the current production process and raw materials If the production process or raw materials lead to significant quantities of other impurities by-products or additives being present, this shall be notified to the user 4.2 Composition of commercial product The commercial product varies in composition according to 3.1.4 The active matter content expressed as silica in percent by mass % (m/m) shall be within ± % of the manufacturer's declared values NOTE % (m/m) The active matter content in commercial products varies in the range of 20 % per cent by mass % (m/m) to 65 The sodium content expressed as Na2O varies from % by mass % (m/m) to 30 % (m/m) 4.3 Chemical parameters and indicator parameters The product shall conform to the requirements specified in Table Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295 EN 1209:2003 (E) 5.2.2.2 Determination of sulfate (SO42-) 5.2.2.2.1 General The method applies to products of sulfate (SO42-) content between mg to 250 mg 5.2.2.2.2 Principle Distillation reduction of the sulfate in the test portion with hydriodic acid in presence of ion dihydrogeno phosphate, then titration of hydrogen sulfide with a mercury (II) chloride standard volumetric solution 5.2.2.2.3 Reagents 5.2.2.2.3.1 Hydriodic acid, concentrated 5.2.2.2.3.2 Sodium dihydrogenophosphate 5.2.2.2.3.3 Acetic acid, concentrated 5.2.2.2.3.4 Diphenylthiocarbazone (dithizone), solution in acetone, 0,1 % (V/V) 5.2.2.2.3.5 Sodium hydroxide solution, c (NaOH) = mol/l 5.2.2.2.3.6 Mercury (II) chloride standard volumetric solution, c (1/2 HgCl2) = 0,0005 mol/l 5.2.2.2.3.7 Reduction solution In a round-bottomed flask fitted with a reflux condenser introduce 400 ml of the hydriodic acid (5.2.2.2.3.1), 100 ml of the acetic acid (5.2.2.2.3.3) and 10 g of the sodium dihydrogeno phosphate (5.2.2.2.3.2), then mix well Heat the flask and allow the nitrogen to pass the solution until the brown colour disappears The reduction solution is ready for use 5.2.2.2.4 Apparatus Ordinary laboratory apparatus and glassware and the following: 5.2.2.2.4.1 5.2.2.2.5 Distillation apparatus (see Figure 1) Procedure Weigh, to the nearest 0,01 g, a test portion of the laboratory sample (m) containing between µg to 250 µg of sulfate ion into the distillation apparatus (5.2.2.2.4.1) and add 10 ml of the reduction solution (5.2.2.2.3.7) Heat the distillation tube and allow nitrogen to pass this mixture (2 to bubbles per minute) The formed hydrogen sulfide is absorbed in an absorber tube, containing the sodium hydroxide solution (5.2.2.2.3.5) and two to three drops of the dithizone solution (5.2.2.2.3.4) Continue the distillation for 15 Titrate the solution in the absorber with the mercury (II) chloride standard volumetric solution (5.2.2.2.3.6) until a faint pink colour occurs Carry out a blank distillation and the titration value as obtained shall be subtracted from the result of the determination 12 Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295 `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - All reagents shall be of a recognized analytical grade and the water used shall conform to grade specified in EN ISO 3696 EN 1209:2003 (E) 5.2.2.2.6 Expressions of results The sulfate content of the sample, C3, expressed in milligrams per kilogram of silica is given by the following equation: either in milligrams of (SO42-): C3 = V ×4,8×10 m or, in milligrams of (H2SO4): C3 = V ×4,9×10 m or, in milligrams of (Na2SO4): C3 = V ×7,1×10 m where V is the volume, in millilitres, of the mercury (II) chloride standard volumetric solution used in the titration; m is the mass, in milligrams, of the test portion 13 `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295 `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - EN 1209:2003 (E) Figure — Distillation apparatus 5.2.2.3 5.2.2.3.1 Determination of fluoride General The method applies to products of fluoride content less than 150 mg/kg of SiO2 5.2.2.3.2 Principle Distillation of hydrofluoric acid in the test portion respectively hexafluorosilicic acid with water vapour 14 Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295 EN 1209:2003 (E) Reaction of the ion fluor with alizarin-3-methylamine-N,N-diacetic acid dihydrate by formation of a blue coloured complex The absorbance of this complex is measured by molecular absorption spectrometry at a wavelength of 578 nm NOTE 5.2.2.3.3 The disturbance by ions chloride can be prevented by adding silver sulfate into the distillation tube Reagents All reagents shall be of a recognized analytical grade and the water used shall conform to grade specified in EN ISO 3696 5.2.2.3.3.1 Sulfuric acid, concentrated 5.2.2.3.3.2 Sulfuric acid, solution at 58 % (V/V) 5.2.2.3.3.3 Silver sulfate 5.2.2.3.3.4 Complexometric reagent Dissolve 1,100 g of alizarin-3-methylamine-N,N-diacetic acid dihydrate in 100 ml of water and add 10 ml of a sodium hydroxide solution at a concentration of mol/l in a 000 ml volumetric flask Adjust this mixture with acetic acid to pH 5,0 and make up to the volume with water and mix well (Solution A) Dissolve in water 1,000 g of cerium nitrate, 100 g of sodium acetate and 100 ml of acetic acid into a 000 ml volumetric flask Make up to the volume with water and mix well (Solution B) The stability of the solution B is maximum four weeks 5.2.2.3.4 Apparatus Ordinary laboratory apparatus and glassware and the following: 5.2.2.3.4.1 Distillation apparatus (see Figure 2) 5.2.2.3.4.2 Spectrometer, fitted with a filter ensuring maximum transmission at 578 nm 15 `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295 `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - EN 1209:2003 (E) Key Heater Double necked flask, capacity 000 ml Inlet tube for air Distillation tube with steam inlet Condensor Determination flask, capacity 100 ml Switch Counterbalance adjustable NOTE The counterbalance is adjusted in a way that the determination flask filled with 90 ml and funnel switches off the heater automatically Figure — Distillation apparatus 16 Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295 EN 1209:2003 (E) 5.2.2.3.5 5.2.2.3.5.1 Procedure Distillation Fill the flask (2) with 660 ml of the sulfuric acid (5.2.2.3.3.2) and start heating Allow passing air in an rate of 100 ml/min to 200 ml/min through the sulfuric solution Weigh to the nearest 0,01 g, a maximum of g of test sample with an amount of fluoride ion of about 70 µg Add ml of water and ml of the sulfuric acid (5.2.2.3.3.1) Put the distillation tube slowly into flask (2) and close the apparatus with the condensor (5) The distillation lasts 20 to 30 min, the temperature will rise from 130 °C to 160 °C After automatically switching off, another ml to 10 ml are distilled When distillation is finished carefully complete the volume of flask (2) with approximately 100 ml of water after cooling 5.2.2.3.5.2 Spectrometric measurements Fill up the determination flask (6) with water to 100 ml, add 2,5 ml of the solution A and 2,5 ml of the solution B of the complexometric reagent (5.2.2.3.3.4) and mix well Adjust the spectrometer to zero absorbance against water Allow to stand for 30 and carry out the spectrometric measurements using the spectrometer set up at the maximum of absorbance (wavelength to 578 nm) in cells of cm to cm optical path length Carry out a blank determination on a mixture of 100 ml of water and 2,5 ml of the solution A and 2,5 ml of the solution B of the complexometric reagent (5.2.2.3.3.4) and mix well 5.2.2.3.6 Calculation The amount of fluoride ion is taken from a calibration curve It is useful to calibrate the scale of the spectrometer with the values of the curve 5.2.2.4 Determination of antimony (Sb), arsenic (As), cadmium (Cd), chromium (Cr), cyanide (CN-), lead (Pb), mercury (Hg), nickel (Ni) and selenium (Se) 5.2.2.4.1 Principle The elements antimony, chromium, lead, mercury, nickel, selenium are determined by atomic absorption spectrometry Arsenic, cadmium and cyanide are determined by molecular absorption spectrometry NOTE When preparing the sodium silicate for analysis, it is important to ensure that the metals are effectively dissolved The concentration of the solution should be sufficient to permit adequate sensitivity in analysis of the metals and appropriate steps should be taken to compensate for any matrix interference caused by the concentration of sodium silicate 5.2.2.4.2 Reagents All reagents shall be of a recognized analytical grade and the water used shall conform to grade specified in EN ISO 3696 5.2.2.4.2.1 Hydrochloric acid, concentrated (ρ = 1,18 g/ml) 17 `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295 EN 1209:2003 (E) 5.2.2.4.3 Procedure 5.2.2.4.3.1 Test solution Weigh, to the nearest 0,001 g, 2,5 g (m) of the laboratory sample, add approximately 20 ml of water and ml of the hydrochloric acid (5.2.2.2.2.1) dissolve and make up to 100 ml with water 5.2.2.4.3.2 Determination Determine the content of metals in the test solution (5.2.2.2.3.1) by using the following methods: antimony (Sb): in accordance with EN ISO 11885 (ICP/OES); arsenic (As): in accordance with EN 26595; cadmium (Cd): in accordance with ISO 5961; chromium (Cr): in accordance with ISO 9174 (AAS); cyanide (CN): in accordance with ISO 6703-1; lead (Pb): in accordance with ISO 8288 (AAS); mercury (Hg): in accordance with EN 1483 (FAAS); nickel (Ni): in accordance with ISO 8288 (AAS); selenium (Se): in accordance with ISO 9965 (AAS) These methods will provide an interim result (y) expressed in milligrams per litre which needs to be corrected to give the final concentration according to the equation in 5.2.2.4.3.3 5.2.2.4.3.3 Expression of results From the interim results (y) determined (see 5.2.2.4.3.2), the content, (C4) of each substance in the laboratory sample, expressed in milligrams per kilogram of silica is given by the following equation: C4 = y×V ×100 m×C1 where y is the interim result (5.2.2.4.3.2); V is the volume, expressed in millilitres, of the test solution (5.2.2.4.3.1) (= 100 ml); m is the mass, expressed in grams, of the test portion; C1 is the concentration, expressed in percent by mass, of silica (see 5.2.1) 18 `,,,,`,,`,,,,,,,``,`,,,``,``-`-`,,`,,`,`,,` - Copyright British Standards Institution Reproduced by IHS under license with BSI - Uncontrolled Copy Document provided by IHS Licensee=Bureau Veritas/5959906001, 11/08/2004 00:44:49 MST Questions or comments about this message: please call the Document Policy Group at 303-397-2295