Arsenic Removal from Water by Adsorption on Modified Cocoa Husks

Danas mnogo ljudi u svijetu konzumira vodu za piće u kojoj se nalazi arsen u povišenim koncentracijama. Također postoji i nekoliko lokacija u istočnoj Hrvatskoj gdje je arsen prisutan u povišenim koncentracijama. Dugoročna izloženost višim koncentracijama arsena negativno djeluje na ljudsko zdravlje, a u novije vrijeme istraživanja koja su provedena o utjecaju arsena na ljudsko zdravlje povezuju povišenu koncentraciju arsena s pojavom karcinoma. Iz toga razloga sve je veći interes za istraživanjem različitih metoda kojima se arsen može učinkovito ukloniti. Jedna od najčešće primjenjivanih metoda za uklanjanje arsena je adsorpcija. Metoda adsorpcije se koristi zbog jednostavnosti, učinkovitosti te ekonomičnosti. Cilj ovog diplomskog rada bio je promaći ekološki prihvatljivu metodu i optimalne uvjeta pri kojima se arsen najučinkovitije uklanja. Ispitana je mogućnost uklanjanja arsena iz vode za piće postupkom adsorpcije. Kao adsorbens u radu je korištena sirova i modificirana ljuska kakaovog zrna. Učinkovitost uklanjanja arsena ispitana je u ovisnosti o pH vrijednosti, vremenu adsorpcije, masi adsorbensa te početnoj koncentraciji arsena.Today, many people in the world are consuming drinking water that contains arsenic in elevated concentrations. There are also several locations in eastern Croatia where arsenic is present in elevated concentrations. Long-term exposure to higher concentrations of arsenic has a negative effect on human health and more recent research on the impact of arsenic on human health has linked elevated arsenic levels to higher incidence of various cancer. For this reason, there is a growing interest in researching various methods in which arsenic can be effectively removed. One of the most commonly used methods for arsenic removal is adsorption. The adsorption method is used for its simplicity, efficiency and economy. The aim of this thesis was to promote an environmentally friendly method and optimal conditions under which arsenic is most effectively removed. The possibility of removing arsenic from drinking water by adsorption was tested. Raw and modified cocoa shell was used as an adsorbent in the work, and for needs of this testing, a modification of the cocoa shell was made. Arsenic removal efficency was observed depending on four parameters; pH values, time adsorption, adsorbent mass and initial arsenic concentration