BS EN 897:2012 pdf download
BS EN 897:2012 pdf download.Chemicals used for treatment of water intended for human consumption一Sodium carbonate.
3.3.7 Specific heat
3.3.8 Viscosity (dynamic) Not applicable.
3.3.9 Critical temperature
Not applicable.
3.3.10 Critical pressure
Not applicable.
3.3.11 Physical hardness
The hardness of solid sodium carbonate is given as 1 tp 2 on the Moh scale p4 hardness.
3.4 Chemical properties
Sodium carbonate reacts exothermically with acids with the formation of carbon dioxide, Sodium carbonate is slightly hygroscop.c and dissolution in water IS an exoihermic reaction.
4 Purity criteria
4.1 General
This European Standard specifies the minimum purity requirements for sodium carbonate 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 check the nabonal regutations in oxter to clarity whether it is of appropriate purity for treatment of water intended for human consumption, taking Into aOi1t raw water quality, required dosage, contents of other iinpunties and additives used w, the products not stated en this product standerd.
Limits have been given for rnpurities 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 leads to significant quantities of impurities, by-products or additive5 being present, this shall be notified to the user.
4.2 Composition of commercial product
The product shall contain not less than a mass fraction of 99 % of Na2CO3.
4.3 Impurities and main by-products
The product shall conform to the requirements specified in Table 1.
The concentration limits refer to pure Na2CO3.
B.1.3.4 Scandium (internal standard) solution, c(Sc) = 50 mg/.
Transfer 50ml of a scandium stock solution [c(Sc)= 1 000 mg/] and 10 ml nitric acid (B.1.3.1) to a 1 000 ml
volumetric flask. Make up to the mark with water and mix.
B.1.3.5 As, Cd, Cr, Ni or Pb elements stock solution, c(element)= 1 000 mg/l commercial solution.
B.1.3.6 Multi-element solution, C(As, Cd, Cr, Ni, Pb) = 100 mg/1
Transfer 10 ml of each stock solution (B.1.3.5) and 10 ml of hydrochloric acid (B.1.3.2) to a 100 ml volumetric flask,
make up to the mark with water and mix.
B.1.3.7 Argon, the pressure shall not be less than 700 kPa and the argon used may be compressed or liquefied gas.
B.1.4 Apparatus
Ordinary laboratory apparatus and glassware together with the fllowing:
NOTE All vessels (glassware, polyethylene (polyethene), polypropylene (polypropene) and polytetrafluorethylene (polytetrafluorethene) (PTFE) fasks) should be washed with hydrochlorie acld C(HCI) – 6 mol and water successively.
B.1.4.1 Inductively coupled plasma optical emission spectrometer (ICP/OES) ftted with a nebulizer for high salt concentration. This instrument can be simultaneous and/or sequential. The spectrometer parameters and operating conditions are given in Table B.2。
B.2.5 Procedure
B.2.&1 Test portion
Weigh, to the nearest 0.01 g. 2 g of the laboratory sample
B.2.5.2 Test solution
Transfer the test portion and 50 ml of water to a 250 ml conical flask. After dissolution, neutralize the solution with hydrochloric acid solution c(HCI) =8 moth Add 1 ml of potassium permanganate solution (50 gfI) and, with care. fivel mlportionsofsulfuricacid(p=1,84glniI).
Heat and keep boiling for 1 mm,
After cooling, dissolve the precipitate of manganese dioxide. dropwise, with the hy&oxytanhine hydrochloride solution (100 g/l). add 5 ml of potassium dichroniate solution (4q11). dilute to 100 ml witti water in a volumetric flask and mix.
B.2.5.3 Blank test solution
Prepare a blank test solution according to the instructions detailed in B.2.5.2 but omitting the test portion.
B.2.5.4 Calibration solutions
Just before use, prepare a series of soc calibration solutions containing 0 mg/i, 1 mg/I. 2.5 mg/i, 5 mg/I. 7,5 mg/i and lOmg/iot’Hg,
To 100 ml of those solutions add 1 ml of potassium pennanganate solution and with care five 1 ml portions of sulfuric acid and continue as described in B.2.5.2 for the test solution
B.2.5.5 Determination
Proceed with the calibration solutions, test solution and blank test solution as described in 4th paragraph of 4.7.1 in
EN ISO 12846:2012 beginning at “Transfer in a flask..
8.2.6 Expression of results
See 4.8 and 4.9 of EN ISO 12846:2012.
