Reuse of wastewater treatment distillate after vacuum distillation in the aluminum casting process

Namen diplomskega dela je najti primerno tehniko za čiščenje kondenzata, ki smo ga dobili z vakuumskim uparjanjem odpadne tehnološke vode v podjetju LTH Castings. Preučili smo vpliv onesnaženosti vstopne vode iz nevtralizacijskega rezervoarja na kakovost kondenzata. Na začetku so prikazane analize kondenzata, ko so bile na uparjalnik vezane odpadne vode iz procesov tlačnega litja, mehanske obdelave ter pranja ulitkov. Proti koncu izvajanja diplomskega dela pa je bil proces nadgrajen tako, da so se na uparjanje prevezale samo odpadne vode s pralnih strojev. Ugotovili smo, da je to smiselno, saj je kakovost kondenzata pralnih vod boljša, ker le-ta ne vsebuje hladilno-mazalnih emulzij in emulgiranih minearalnih olj. Na fakulteti smo preizkusili razpoložljive tehnike za naknadno čiščenje kondenzata. Analize kondenzata in vstopne vode smo opravljali sami, paralelno smo pa vzorce pošiljali v zunanje laboratorije. Zaradi uporabe različnih vrst kemikalij pri izdelavi in proizvodnji aluminijevih ulitkov imamo opravka z odpadno vodo kompleksne sestave. Pri delu smo dobili najboljše rezultate ob predhodnjem redčenju kondenzata v poskusu adsorpcije na aktivno oglje, ampak v industriji to ni smiselno izvajati, zato nismo prišli do konkretnejših rezultatov. Prišli smo do zaključkov, ki nam bodo v pomoč pri nadaljnjem delu na tem projektu. Ugotovili smo tudi, da bi bilo smisleno pred uporabo novih kemikalij v procesu, narediti pilotni test, da se ugotovijo možne posledice nove kemikalije na kakovost kondenzata.The purpose of thesis is to find the suitable technique for wastewater treatment distillate that was obtained with vacuum evaporation of wastewater at company LTH Castings. The effect of inlet wastewater pollution out of neutralization reservoir on distillate quality was studied. The analysis of distillate with wastewater from die casting process, machining and castings washing were performed firstly. The process was modified with taking wasterwater for evaporation only from castings washing machines. The distillate quality of washing water was improved, because no coolant emulsions and emulsified mineral oil was contained. Available techniques for subsequent distillate treatment were tested at the faculty. Analysis of distillate and inlet wastewater were done at the faculty. Additionaly the samples were send to external laboratories for references. Composition of wastewater is complex, because different sorts of chemicals are used in aluminium die castings process and manufacturing. The best results were obtained in preliminary distillate dilution in activated carbon adsorption. Unfortunately this technique is not suitable for industry thus no definite results were achieved. The conclusions are going to be beneficial for further research at the project. Additionaly, pilot test should be performed before using new chemicals in the process for possible consequences on distillate quality