Sorption of dexamethasone in waste sludge

Humani i veterinarski farmaceutici se danas proizvode i koriste u sve većim količinama te samim time dospijevaju u okoliš. Zbog svojih fizikalnih i kemijskih svostava mnogi od njih prolaze kroz sve prirodne filtre i postrojenja za obradu otpadnih voda i tako dospijevaju u podzemne i površinske vode čime može doći do zagađenja izvora pitke vode. S obzirom da su farmaceutici prepoznati kao potencijalna opasnost za ljude i okoliš, javlja se potreba za sve većim ispitivanjem farmaceutika, ali i nalaženjem analitičkih metoda njihovog određivanja kao i metoda njihova uklanjanja iz okoliša. Jedan od mogućih procesa koji bi se mogao koristiti za uklanjanje farmaceutika iz okoliša je sorpcija. Stoga su u ovome radu određivani koeficijenti sorpcije farmaceutika deksametazona na otpadni mulj, u svrhu ispitivanja običnog i toplinski obrađenog neutralizacijskog mulja, nastalih kao proizvodni otpad u procesu neutralizacije sulfatno kisele kupke, kao mogućih sorbensa za uklanjanje farmaceutika iz okoliša. Za određivanje preostalog deksametazona u vodi nakon sorpcije korištena je UV/VIS spektrofotometrija, a uzorci su analizirani na valnoj duljini 242 nm. Linearnom regresijom primjenom lineariziranih modela Freundlichove, Langmuirove i Dubinin- Radushkevichove izoterme određeni su koeficijenti sorpcije deksametazona na otpadni mulj. Također su ispitani utjecaji temperature i pH vrijednosti na proces sorpcije.Human and veterinary pharmaceuticals are now manufactured and used in more increasing quantities and therefore get in the environment. Because of their physical and chemical properties, many of them go through all of the natural filters and plants for waste water treatment and then reach the groundwater and surface water ,which can lead to pollution of drinking water sources. Since the pharmaceuticals are identified as a potential danger to people and the environment , there is a need for increased testing of pharmaceuticals, but also finding the analytical methods of their determination and methods of their removal from the environment. One of the possible processes which may be used for removal of pharmaceuticals from the environment is sorption. Therefore, in this paper are determined sorption coefficients of pharmaceutical dexamethasone to sewage sludge, in order to test an ordinary and heat-treated neutralization sludge, which occurred as production waste in the process of neutralization of acid sulphate baths, as well as potential sorbent for the removal of pharmaceuticals in the environment. To determine the residual dexamethasone in water after the sorption is used UV/VIS spectrophotometry, and the samples were analyzed at wavelength 242 nm. Sorption coefficients of dexamethasone were determined using the linear regression of linearized Freundlich, Langmuir and Dubinin- Radushkevich sorption models. It was also determined the effect of temperature and pH on sorption process