Application of Composite Construction and Demolition Debris in Heavy Metals Removal From Industrial Wastewater

Abstract

The utilization of construction and demolition debris in industrial wastewater treatment by sorption of Co2+ and Ni2+ ions was investigated. Selected waste composites are cost-effective and locally available; still their sorption characteristics and application are not sufficiently investigated. The samples of concrete, facade, ceramic materials and asphalt were characterized in terms of min- eral and surface composition, radioactivity, and stability at different pH values, as well as pH values of suspension and filtrate and electrical conductivity of the filtrate. The sorption capacities were determined in batch experimental conditions in one- and multi-component solutions. Characteriza- tion showed different crystal structures and mineralogical compositions of components. The results of gamma spectrometry confirmed the radiological safety of samples. Based on stability testing re- sults, waste materials are suitable for further utilization and do not pose any risk to the environment. The overall sorption results suggested that cement-based materials, in addition to high affinity for the tested ions, represent a sorbent that binds contaminants firmly enough, reduces their mobility and bioavailability, and are suitable for removing Co2+ and Ni2+ ions from wastewaters.

Ispitivano je korišćenje građevinskog i ruševnog otpada u tretmanu industrijskih otpadnih voda sorpcijom jona Co2+ i Ni2+. Odabrani kompoziti otpada su isplativi i dostupni na lokalnom nivou; još uvek nisu dovoljno istražene njihove sorpcione karakteristike i primena. Uzorci betona, fasada, keramičkih materijala i asfalta su okarakterisani u pogledu mineralnog i površinskog sastava, radioaktivnosti i stabilnosti na različitim pH vrednostima, kao i pH vrednosti suspenzije i filtrata i električne provodljivosti filtrata. Kapaciteti sorpcije određivani su u serijskim eksperimentalnim uslovima u jednokomponentnim i višekomponentnim rastvorima. Karakterizacija je pokazala različite kristalne strukture i mineraloški sastav komponenti. Rezultati gama spektrometrije potvrdili su radiološku sigurnost uzoraka. Na osnovu rezultata ispitivanja stabilnosti, otpadni materijali su pogodni za dalju upotrebu i ne predstavljaju nikakav rizik po životnu sredinu. Ukupni rezultati sorpcije sugerišu da materijali na bazi cementa, pored visokog afiniteta za ispitivane jone, predstavljaju sorbent koji dovoljno čvrsto vezuje zagađivače, smanjuje njihovu mobilnost i bioraspoloživost i pogodni su za uklanjanje jona Co2+ i Ni2+ iz otpadnih voda.