CHARACTERISTICS OF WASTEWATER FROM THE TOWN OF ZAPREŠIĆ

Otpadne vode sadrže razne štetne tvari koje onečišćuju vodu i kao takve ne smiju se ispuštati u prirodu, odnosno takva voda mora biti podvrgnuta adekvatnom procesu pročišćavanja. Najčešći način pročišćavanja otpadnih voda provodi se putem Uređaja za pročišćavanje otpadnih voda koji koristi kombinaciju mehaničkih, fizikalno – kemijskih i bioloških metoda. Mehaničkim procesom obrade otpadne vode uklanjaju se grube nečistoće i suspendirane tvari dok se daljnjom fizikalno-kemijskom obradom uklanjaju koloidne te anorganske tvari, a biološka metoda dizajnirana je za uklanjanje organskih tvari prirodnog porijekla. Cilj ovog završnog rada bio je provesti dvotjedno ispitivanje učinkovitosti pročišćavanja otpadnih voda pristiglih na Uređaj za pročišćavanje otpadnih voda grada Zaprešića. Dobiveni rezultati ukazuju na uspješno provedeno pročišćavanje pri čemu se u prvom stupnju obrade otpadnih voda količina štetnih tvari smanjila do 60%, a sekundarnom obradom moguće je uz pomoć aktivnog mulja smanjiti od 30% do 50% ukupnog dušika.Wastewater contains various harmful substances that pollute water and as such must not be discharged into nature, that is, such water must be subjected to an adequate purification process. The most common method of wastewater treatment is carried out through the Wastewater Treatment plant, which uses a combination of mechanical, physical-chemical and biological methods. The mechanical process of wastewater treatment removes coarse impurities and suspended substances, while further physical-chemical treatment removes colloidal and inorganic substances, and biological methods are designed for removing organic substances of natural origin. The target of this final work was to conduct a two-week test of the efficiency of wastewater treatment received at the Zaprešić City Wastewater Treatment Plant. The obtained results indicate a successful treatment, where in the first stage of wastewater treatment, the amount of harmful substances was reduced by up to 60%, and with the secondary treatment, it is possible to remove from 30 to 50% of the total nitrogen with the help of active sludge