PAPERMAKING SLUDGE AS ABSORBENT FOR REMOVAL OF HYDROPHOBIC SUBSTANCESFROM WATER SURFACES

The invention comprises preparation, description of obtaining and application of papermaking sludge as absorbent for the removal of hydrophobic substances, e.g. plant oil, mineral oils, hydraulic oils, fats, fuels, nonpolar organic chemicals, etc. as well as floating dust, e.g. coal dust, wood dust from water surfaces. By drying papermaking sludge containing more than 20 % ash (on dry substance) down to a moisture content less than 10 %, a degree of absorption of hydrophobic substances from water surface of about 95 % to 99 % can be achieved. The adsorbent is prepared in a way to float on water. It floats on water surface as such in the case of cellulose fibre content above 52 % and when cellulose fibres are released from inorganic matrix. When the content of cellulose fibres is less than 52 % or they are not released from inorganic matrix, the absorbent needs to be packed into small cushions or cylinders to enable levitation of the material on water surface. Sawdust or crushed styropore can be added into small cushions or cylinders. In case dust is to be collected from water surface, zeta potential of the dust must be neutralised, which is achieved by using biodegradable, environmentally nonhazardous hydrophobic substances, e.g. alkyl esters of fatty acids, etc. A hydrophobic substance is dispersed within a dust cloud and then an absorbent is applied, which binds to itself about 95 % floating dust. Izum vključuje pripravo, opis pridobitve in uporabe papirniškega mulja kot absorbcijskega sredstva za odstranjevanje hidrofobnih snovi, npr. rastlinskega olja, mineralnih olj, hidravličnih olj, maščob, goriv, nepolarnih organskih kemikalij, itd. in plavajočega prahu, npr. premogov prah, lesniprah z vodnih površin. S sušenjem papirniškegamulja, ki vsebuje več kot 20 % pepela (glede na suho snov) do stopnje vlažnosti, ki je manjša od10 %, lahko na površini vode dosežemo cca. od 95 % do 99 % stopnjoabsorbcije hidrofobnih snovi z vodnih površin. Absorbent je pripravljen na način, da plava na vodi. Ob vsebnosti celuloznih vlaken nad 52 % in če so celulozna vlakna sproščena iz anorganske matrice, absorbent plava na vodni površini kot tak. Če je vsebnost celuloznih vlaken nižja od 52 %, ali le ta niso sproščena iz anorganske matrice, je potrebno absorbent pakirati v blazinice oz. valje, da se omogoči lebdenje materiala na vodni površini. V blazinice ali valje je mogoče dodajati žaganje ali drobljenstiropor. V kolikor se z vodne površine pobira prah je potrebno nevtral