The efficiency of humic acid removal from water by low-cost activated carbons

Huminske kiseline su vrsta humusnih tvari te predstavljaju aktivan dio humusa. Prisutnost huminskih tvari u tlu povećava plodnost tla, poboljšava kemijska svojstava tla te neposredno utječe na plodnost biljaka, rast korijena te povećava otpornost biljaka na promjenu okolišnih uvjeta. Humusne tvari mogu nastati razgradnjom prirodne organske tvari u tlu i vodi pri čemu se najveći dio molekula prevodi u humin, od kojeg oksidacijskom razgradnjom nastaju huminske, a zatim fulvinske kiseline. Prisustvo huminskih kiselina u vodama je nepoželjno zbog njihove kemijske reaktivnosti s mnogim tvarima, čime njihova prisutnost dodatno smanjuje kakvoću vode. U ovom radu ispitana je mogućnost uklanjanja huminske kiseline iz vode protokom kroz kolonu primjenom ,,low-cost“ adsorbensa dobivenog iz aktivacije ljuske oraha. Uz navedeni adsorbens, uklanjanje huminske kiseline ispitano je i komercijalno dostupnim aktivnim ugljenom Cullar D. Učinkovitost uklanjanja huminske kiseline ispitana je u ovisnosti o početnoj masenoj koncentraciji huminske kiseline, vremenu adsorpcije, pH vrijednosti i masi adsorbensa.A type of humic acids with humic substances are an active part of humus. The presence of humic substances in the soil increased soil fertility, improved soil chemical properties and direct effects on plant fertility, root solution and increased plant resistance to changing environmental conditions. Humic substances can be formed by the decomposition of natural organic matter in the soil, leading to the transfer of most of the molecule to humin, of which oxidative degradation occurs to form humic and then fulvic acid. The presence of humic acids in water is undesirable because of their chemical reactivity with many substances, thus their presence further reduces the water quality. This paper investigates the possibility of removing humic acid from water by flowing through a column using a "low-cost" adsorbent obtained by the activation of a nut shell. In addition to said adsorbent, the removal of humic acid was also examined by the commercially available activated carbon Cullar D. The removal efficiency of humic acid was tested depending on the initial mass concentration of the humic acid, the adsorption time, the pH value and the mass of the adsorbent