Abstract | Važnost vode za život na Zemlji dobro je poznata, međutim unatoč tome vode u prirodi se svakodnevno onečišćuju različitim štetnim tvarima porijeklom iz antropogenih izvora. Najveća prijetnja dolazi iz industrije gdje industrijske otpadne vode, ukoliko se prije ispuštanja ne obrade, ozbiljno narušavaju kakvoću vodnih ekosustava. Otpadne vode iz industrije te rudarenja visoko su opterećene teškim metalima koji ugrožavaju sve žive organizme. Iz toga su razloga istraživanja sve više usmjerena na razvijanje postojećih metoda obrade voda te pronalaženje prirodnih lako dostupnih materijala koji su ekonomski i ekološki prihvatljivi. U ovome završnom radu provedeno je uklanjanje cinka iz vodene otopine koncentracije 100 mg Zn/L kemijskim taloženjem uz neutralizaciju različitim taložnim sredstvima do pH područja 7,0-7,5; 8,0-8,5 i 9,0-9,5, a potom sorpcijom na biosorbensima (koštice maslina, trešanja i višanja). Već u prvom stupnju obrade kemijskim taloženjem uz neutralizaciju do pH=9,0-9,5 postignuta je izvrsna učinkovitost uklanjanja (≥ 99,55 %), s ostatnom koncentracijom cinka ispod maksimalno dopuštene (2 mg/L), dok je pri pH=7,0-7,5 i pH=8,0-8,5 za postizanje graničnih koncentracija trebalo provesti drugi stupanj obrade sorpcijom na biosorbensima. |
Abstract (english) | The importance of water for life on Earth is well known, but despite this, water in nature is polluted daily by various harmful substances originating from anthropogenic sources. The biggest threat comes from industry where industrial wastewaters, if not treated before discharge, seriously endanger the quality of water ecosystems. Wastewater from industry and mining is highly contaminated with heavy metals which are harmful for all living organisms. Therefore, research is increasingly focused on developing existing water treatment methods and finding natural, easily available materials that are economically and environmentally acceptable. In this thesis, the removal of zinc from contaminated water containing 100 mg Zn/L was carried out by chemical precipitation with neutralization using different precipitating agents to a pH range of 7.0-7.5; 8.0-8.5 and 9.0-9.5, followed by sorption on biosorbents (olive pits, cherry pits and sour cherry pits). Excellent removal efficiency (≥ 99.55%) was achieved already in the first stage of treatment by chemical precipitation with neutralization to pH=9.0-9.5, with the remaining zinc concentration below the maximum allowed (2 mg/L). At pHs 7.0-7.5 and 8.0-8.5, in order to achieve the discharge limit, it was necessary to perform second treatment stage by sorption on biosorbents. |