Luoana Florentina Pascu, Ladislau Andres, Smaranda Masu
COD and TOC reduction efficiencies
This study shows the wastewater efficient treatment process resulted with Fe-Al complex coagulation agent obtained from industrial waste. Coagulation agent prezented 24.5 – 28.0 g·L-1 Fe and 16.0 – 17.5 g·L-1 Al content. pH coagulation agent is in the range pH=1-2. The wastewater with high degree i.e. chemical oxygen demand (COD) = 25,000-30,000 mg O2·L-1, Total organic carbon (TOC) = 3,600 – 4,000mg C·L-1, dry matter = 9.55 – 10.45 g·L-1, etc. is resulted from printing house. Treated water samples with the optimal dose of coagulation agent based on iron-aluminium salts obtained from industrial waste prezented similar TOC and dry matter reduction efficiencies with samples treated with the optimal dose of ferric chloride. COD reduction efficiency in treated water samples with the optimal dose of coagulation agent based on iron-aluminium salts it was 10% greater vs. reduction efficiency obtained from samples water treated with classic coagulation agent, FeCl3. The advantage of the complex Fe-Al coagulation agent obtained from industrial waste was that it can be used for some wastewater of printing house in lower optimal dose, by 30%, vs. ferric chloride, coagulation agent. The complex Fe-Al coagulation agent obtained from industrial waste cost is much less than that of classical coagulation agents.