Development of national standards for the needs of the water industry on the examples of the aluminium polyoxycloride

Abstract

An important stage in conditioning of water before its supply is the use of coagulants, with polyaluminium chloride being one of such agents. Active application of this coagulant began late last century, and its global output has been consistently growing since. The purpose of the work was to create a new standart because of the need to ensure a uniform assessment of the quality of the proposed coagulants. The necessity of unification in the field of quality control processes of coagulants is shown. General requirements for quality control of aluminum polyoxychloride are formulated. In particular, the standard contains universal methods to determine impurities and main quality parameters (basic capacity, contents of aluminium oxide and chloride ions) in polyaluminium chloride; regulate pH, residual aluminium, chlorides and heavy metal ions for the whole concentration range of the active ingredient in the agent (i.e. the standard covers both dry and liquid products); avoid use of low-quality raw materials (including aluminium scrap) in the production of polyaluminium chloride; characterise high- and low-basic products (given a non-linear change in properties at different concentrations); regulate frequency of and conditions for checking polyaluminium chloride against declared parameters.