Improving the efficiency of water resources management: decentralized grey water treatment

Summary

The established over the course of decades strategy of municipal wastewater treatment needs to be revised since it is not oriented toward water reuse (instead of effluent discharge into the receiving waters); it is not designed for nutrients removal and demands significant expenditures for the removal of xenobiotics. The centralized wastewater treatment does not provide for the qualitative solution of the given problem. Overseas the concept of separate collection and decentralized treatment of concentrated black water containing urea and faeces and grey water containing bath, shower and sink water, water from washing machines and dishwashers, kitchen water has been rapidly developed. Grey water contains much less (compared to black water and municipal wastewater) xenobiotics and pathogens and can be a source of water of different purity levels. This approach predetermines more sustainable municipal water supply, in particular, by avoiding meeting all the demands from a single drinking water source, all the more in cases when there is no need in high-quality water. In USA, Japan, Australia, Israel, some EU countries studies of different scales are carried out; in practice different schemes of nonpotable use of grey water after the required treatment have been implemented.

Key words

grey water , decentralized treatment , treatment process flow schemes , xenobiotics , water reuse