The incidence of by-products (THMs) disinfection in drinking water

The paper presents some aspects related to the incidence of trihalomethanes (ThMs) disinfection by-products, in drinking water obtained from various natural resources: surface water (rivers, barrier lakes) and groundwater (bank infiltration water, deep groundwater). In order to set up the quality of drinking water and its compliance with the enforced legislation, a number of 27 DWTPs was investigated. The romanian water companies which are included in the analytical investigation program were: Timisoara, Deva, Drobeta – Turnu severin, Botosani, Brasov, Turda, Satu Mare, Bistrita – Nasaud, Oradea, Galati, Cernavoda, Tulcea. according to the nature of raw water and the pollution context, the applied treatment technologies for water potabilisation are based
on classical methods: chlorine disinfection or aeration/pre-chlorination – sand filtration – disinfection for groundwater and pre-chlorination (optionally) – coagulation flocculation – settling – sand filtration – final disinfection for surface water. The performed analyses emphasised the compliance of ThMs content with the imposed concentration by law 458/2002 and law 3 /2004 (ThMs = 00 µg/l) for almost all samples, with three exceptions: Saveni-Botosani (ThMs = 2 µg/l), Santamarie Orlea-Deva (ThMs = 545 µg/l), Oradea (ThMs = 40.44 µg/l).