Wastewater characteristics of the city of Zagreb

U radu su analizirane karakteristike otpadnih voda sjevernog i južnog Zagreba u svrhu određivanja opterećenja Centralnog uređaja za pročišćavanje otpadnih voda grada Zagreba, te utjecaj povećanja opterećenja priključivanjem otpadnih voda južnog Zagreba na uređaj. Pokazatelji karakteristika otpadne vode koji su određivani su: suspendirana tvar, isparni i žareni ostatak, KPK, BPK5, amonijak, nitrati, ukupan dušik, ortofosfati i ukupan fosfor. Vrijednost srednjeg dnevnog protoka otpadne vode sjevernog Zagreba iznosila je u prosjeku 10139 m3/h, a južnog Zagreba 1057 m3/h. U kanalizacijski sustav sjevernog Zagreba uvode se vode potoka zbog kojih su koncentracije onečišćenja u prosjeku veće u otpadnoj vodi južnog Zagreba, ali sjeverni Zagreb mnogo više pridonosi onečišćenjem nego južni Zagreb i to prosječno 6 puta više za KPK, BPK5, 4 puta za ukupni fosfor i ukupni dušik te 9 puta za suspendiranu tvar.Purpose of this thesis was to analyze wastewater characteristics of north and south Zagreb in order to determine load of Central wastewater treatment plant of the city of Zagreb and the influence of increased load device as south Zagreb wastewater is connected to the wastewater treatment plant. Wastewater characteristics that were analyzed were: TSS, VSS, ISS, COD, BOD5, ammonium, nitrates, total nitrogen, orthophosphate and total phosphorus. Daily flow of wastewater for north Zagreb was on average 10139 m3/h, and for south Zagreb 1057 m3/h. In sewage system of north Zagreb stream waters are introduced and this is the reason why pollutant concentrations are on average larger in wastewater of south Zagreb, although north Zagreb contributes much more with pollutants load and on average contributes 6 times more for COD, 4 times more for total phosphorus and 9 times for suspended particles then south Zagreb