BS EN 890:2012 pdf download

BS EN 890:2012 pdf download.Chemicals used for treatment of water intended for human consumption – Iron (WI) sulfate solution.
5.2.2.2 Iron (II) ( F. (II))
The Fe (II) content is expressed as C,., (see B.1.2.5.3).
5.2.2.3 Insoluble matters
The percentage mass fraction of the insoluble matiers shall be determined in accordance with the method described in B.3,
5.2.2.4 Free acid
The free acid shall be determined In accordance with the method described In B.4.
5.2.3 Chemical parameters
5.2.3.1 Preparation of sample solution
52.3.1.1 General
Oxidation and wet digestion is used to bring the samples into a stable solution.
5.2.3.1.2 Principle
Oxidation with hydrogen peroxide (H202) followed by digestion with hydrochloric acid (HCI).
5.2.3.1.3 Reagents
All reagents shall be of a recognized analytical grade and the water used shall conform to the grade 3 specified in
EN ISO 3696.
5.2.3.1.3.1 Hydrochloric acid (HCI), solution, mass fraction 30 %.
5.2.3.1.3.2 Hydrogen peroxide (H202), solution, mass fractIon 30%.
5.2.3.1.4 Apparatus
Ordinary laboratory apparatus and glassware together with the following.
5.2.3.1.4.1 Analytical balance.
5.2.3.1.4.2 Graduated cylinder, capacity 50 ml.
5.2.3.1.4.3 Round flask with reflux condenser.
5.2.3.1.4.4 Hot plate.
5.2.3.1.4.5 Volumetric flask, capacity 200 ml.
5.2.3.1.5 Procedure
Dissolve with 20 ml of water 20.0 g of the iron solution. Add 5 ml hydrogen peroxide solution (5.2.3.1.3.2) to iron (lll).sanlples. After addIng 50 ml hydrochionc acid (5.2.3.1.3.1) boil the solution for 15 mm by using a reflux condenser (5.2.3.1.4.3). Cool down the solution, transfer to a 200 ml volumetnc flask (5.2.3.1.4.5) and fill up to the mark with water. This is the sample solution.
52.3.2 Arsenic
The arsenic content shall be determined by hydride generation atomic absorption spectrometry (see B.5).
A.1 Origin
A,1.1 Raw materials
The product is manufactured from an iron source, typically won (II) sulfate or an iron oxide, which is reacted with a combination of sulfuric acid and an oxidising agent, such as nitric acid, oxygen, hydrogen peroxide or air, at elevated temperature or pressure.
&1.2 Manufacturing process
Iron (Ill) sulfate is produced by the action of sulfuric acid on a variety of won salts or ores in combination with an oxidation process as required.
A.2 Quality of commercial product
The three types of iron (Ill) sulfate solution specified in Table 3 reflect the quality of commercially available products. Figures Al to A.3 show the maxrum concentrations of trace metals that would be added to the raw water by the addition of products corresponding to the purity levels specified in Table 3. It can be seen that the concentrations of metal added are well below the parametric values given in the EU Directive 98)83/EC (see (1J) at typical product doses Furthermore, the figures overstate the concentration of metals that would be present in the treated water since a substantial proportion of the trace metals will be incorporated ri the sludge. Users of this product should select an appropriate grade and type to enable theni to achieve treated water quality targets taking into account raw water characteristics, required dosage. process plant conditions and other relevant factors.
The maxnium alowed percentage of mass fraction of insoluble matter in the product presented in Table 2 (i.e. 0.5 %) does not affect adversely the water quality. On the contrary, insoluble matter in the product improves the coagulation process and might therefore enhance the treatment.
B.1 Determination of iron (II) sulfate
B.1.1 Total iron
B.1.1.1 General
This method applies to the products at the supply concentration.
B.1.1.2 Principle
Iron is reduced by tin ()) chloride and is subsequenty titrated with ceric sulfate.
B.1.1.3 Reagents
All reagents shall be of a recognized analytical grade and the water used shall confom to the grade 3 in
accordance with EN ISO 3696.
B.1.1.3.1
Hydrochlorie acid, HC concentrated, density ρ= 1.19 g/ml.
B.1.1.3.3
Mercury (1I) chloride, saturated solution c(HgCl2) = 0,27 mol/.
B.1.1.3.4
Ferroin indicator (Le. 1,10-phenantroline ferrous sulfate) solution, 1 % W/v in water.
B.1.1.3.5 Ceric sulfate, (Ce(S04)2= 0,1 mol/.
B.1.1.4 Apparatus
Ordinary laboratory apparatus and glassware.