This study was conducted to investigate the removal characteristics of PO4 3- -P contained in livestock wastewater using waste concrete. With small particle size, increased dosage and temperature of water, PO4 3- -P was well removed by waste concrete. PO4 3- -P was removed by adsorption reaction in low pH of the primary phase, but the crystallization reaction predominated for increasing pH with passed time. As a result of adapting the adsorption isotherm equation, PO4 3- -P removal was more affected by the crystallization reaction than the adsorption reaction. In the SEM micrograph, there was no evident change on the waste concrete surface. Particle size was plate-phase before reaction but appeared a dense form to progress in the crystallization reaction after reaction.
This study was performed to investigate the utilization of waste concretes for neutralization and removal of heavy metals in plating wastewater, because waste concretes have been known to be very porous, to have high specific surface area and to have alkaline minerals such as calcium.
The results obtained from this research showed that waste concretes had a buffer capacity to neutralize an acidic alkali system in plating wastewater. Generally, neutralization and removal rate of heavy metals were excellent in the increase of waste concrete amounts and a small size. Because a coefficient of correlation was high, it seemed that removal of heavy metals could be explained by Freundlich and Langmuir isotherms. If we reflected the adsorption capacity(k) and adsorption intensity(l/n) of Freundlich isotherm, we couldn`t consider waste concretes as a good adsorbent, But, we could know that waste concretes were capable of removing a part of heavy metals. In point of building waste debris, if waste concretes substituted for a valuable adsorbent such as actviated carbon, they could look forward to an expected economical effect.