GB/T 35937-2018Performance test methods for household and similar drinking water purifiers (English PDF)

1 Scope

China's national performance test methods for household drinking water purifiers. It specifies the terms and definitions and the test methods, covering the test conditions and equipment, the visual inspection, the structural performance test and the hygiene safety test. Domestic water treatment is a large consumer market in China and one where claims outrun evidence: a purifier is sold on what it is said to remove, and nobody buying one can verify any of it. A test method standard is therefore the whole basis of the category. The tests have to answer three separate questions, and the standard separates them. Does the unit work as a piece of plumbing - does it hold pressure, deliver flow, and survive being connected to a mains supply. Does it remove what it claims, at the claimed rate, until the claimed capacity is reached. And does it add anything: a purifier is a wetted plastic assembly holding stagnant water between uses, and a device that leaches or grows biofilm is worse than the water it treats.

This standard specifies the terms and definitions and test methods for drinking water treatment equipment for household and similar purposes (referred to as "water treatment equipment"). This standard applies to the performance test of drinking water treatment equipment for household and similar purposes.

2 Normative references

The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this standard.

GB 4706.1 Household and similar electrical appliances - Part 1. General requirements

GB 5749 Standards for drinking water quality

GB/T 5750 (all parts) Standard examination methods for drinking water

GB/T 6682 Water for analytical laboratory use - Specification and test methods

GB/T 17218 Hygienic safety evaluation for chemicals used in drinking water treatment

GB/T 17219 Standard for safety evaluation of equipment and protective mater

GB/T 22090 Cold and hot water dispenser

3 Terms and definitions

The following terms and definitions apply to this document. follows.

a) The water treatment equipment unit shall be installed on a shelf or platform off the ground. Set the equipment unit to be tested step by step in accordance with

4 Test methods...

Appendix A

(Informative) Preparation of contaminant liquid A.1 Residual chlorine purification test A.1.1 Preparation of residual chlorine contaminant liquid The preparation of the residual chlorine contaminant liquid is carried out as follows:

a) Residual chlorine standard stock solution [rho(Cl2) =

2.0 mL of 10% (effective chlorine) sodium hypochlorite (NaClO) solution to a 100 mL volumetric flask, USE the purified water to make the volume reach to the mark.

b) Residual chlorine contaminant liquid [rho(Cl2) =

2.0 mg/L]. PIPETTE

1.00 mL of residual chlorine standard stock solution, TRANSFER it into a volumetric flask, USE purified water to make the volume reach to 1000 mL, PREPARE it before use. A.1.2 pH adjustment The pH of the contaminant liquid is adjusted by dropwise addition of a 6 mol/L sodium hydroxide (NaOH) solution or a 6 mol/L hydrochloric acid (HCl) solution. A.1.3 Adjustment of the total dissolved solids The TDS value of the contaminant liquid is adjusted by adding sodium chloride (NaCl) or pure water. A.1.4 Adjustment of other indicators Other indicators are adjusted as required by Table 6.

Note. In order to ensure the specific content of free residual chlorine, the test water may need to be pre-chlorinated and dechlorinated. A.2 Hydrogen sulfide and phenol purification test A.2.1 Preparation of contaminant liquid A.2.1.1 Hydrogen sulfide The preparation of the hydrogen sulfide contaminant liquid is carried out as g/mL), in a volumetric flask, USE pure water to make its volume reach to 100 mL.

b) Iron contaminant liquid [rho(Fe) =

4.0 mg/L]. PIPETTE

4.00 mL of iron standard stock solution, TRANSFER it to a volumetric flask, USE pure water to make its volume reach to 1000 mL, PREPARE it before use. A.3.1.2 Manganese The preparation of the manganese contaminant liquid is carried out as follows:

a) Manganese standard stock solution [rho(Mn) =

1.0 mg/mL]. WEIGH 0.2291 g of anhydrous manganese chloride (MnCl2, first grade), USE pure water to dilute it to 100 mL.

b) Manganese contaminant liquid [rho(Mn) =

1.5 mg/L]. PIPETTE