Use of adsorption and membrane filtration for decolorization and decomposition of same industrial wastewater

Izpusti barvil iz tekstilnih obratov so sporni tako z okoljskega kot estetskega vidika. Zakonodaja in vedno večja okoljska osveščenost ter vedno večja paleta barvil, ki se nahajajo na tržišču, so nas spodbudili, da iščemo čim boljše postopke za čiščenje odpadnih voda. Kot dobra tehnološka postopka čiščenja te vrste odpadnih voda sta se izkazala adsorpcija in membranska filtracija. Najbolj znan in uporabljen adsorbent je aktivni ogljik, ki ga odlikuje velika specifična površina. Nekatere glavne prednosti membranskih procesov so, da sta koncentracija in separacija snovi, ki jih želimo filtrirati, doseženi brez spremembe agregatnega stanja, brez uporabe kemikalij in termične energije. Cilj tega dela je, poiskati alternativo cenovno dragemu aktivnemu ogljiku, ter izkoristiti, reciklirati zavržen material iz bližnje okolice, ki je cenovno ugoden, lahko dostopen in ki ima določene adsorpcijske sposobnosti. Pri delu smo uporabili šest različnih adsorbentov: grobo in fino žagovino, ki smo jo dobili pri lokalnem mizarju, odpadno blato iz Centralne čistilne naprave v Ljubljani, sami smo pripravili adsorbent iz oglja za žar, prašnato aktivno oglje proizvajalca Merck in odpadni pepel iz Termoelektrarne-toplarne Ljubljana. Merili smo, kako se obarvanost in koncentracija barvalne raztopine spreminjata z uporabo različnih adsorbentov, z različnimi količinami adsorbentov in pri različnih kontaktnih časih.Dye discharges are problematic from both environmental and esthetic point of view. The legislation in force, the increasing environmental awareness, and the widening range of dyes available on the market have prompted us to look for the most efficient wastewater treatment possible. Adsorption and membrane filtration have proven as efficient wastewater treatment measures. The best-known and the most often used adsorbent is activated carbon, characterized by great specific surface area. One of the main advantages of membrane processes is that concentration and separation can be obtained without any changes in physical state and without the use of either chemicals or thermal energy. The present thesis aims at finding an alternative to the costly use of activated carbon, by utilizing recycled waste material from the environment, which is characterized by low price, easy accessibility, and specific adsorption characteristics. Six different adsorbents were used, i.e. coarse and fine sawdust obtained from a local carpenter, sludge biomass from the central wastewater treatment plant in Ljubljana, an adsorbent made by ourselves from grill charcoal, powdered activated carbon produced by Merck, and waste ashes from the thermal power and heating plant in Ljubljana. We measured the changes in colorization and concentration of the coloring solution ensuing from the use of various adsorbents, varying quantities of adsorbents, and different contact times