Leachability of heavy metals from fired clay bricks incorporated with cigarette butts

Although small in size, indiscriminate littering of cigarette butts (CBs) can cause serious environmental impact. Several trillion cigarettes produced worldwide annually lead to thousands of kilograms of toxic waste that will end up in the waterways. Most cigarette filters are made of cellulose acetate which is slow to biodegrade and can take up to 18 months or more to break down under normal litter conditions. CB filters release range of toxic chemicals as they deteriorate. Toxic chemicals and heavy metals trapped in the CB filters can be leached and so cause serious damage to the environment. This paper presents some of the results from a continuing study on recycling CBs into fired clay bricks. Fired clay bricks were manufactured with different percentages of CBs (0%, 2.5%, 5% and 10%) to determine the possible levels of heavy metals that can be leached from the manufactured bricks. Leaching of heavy metals from the fabricated clay bricks was tested to investigate whether the leachate values exceed the regulatory standards. Three types of leaching tests which are Australian Bottle Leaching Procedure (ABLP), the Toxicity Characteristics Leaching Procedure (TCLP) and Static Leachate Test (SLT) were carried out in this investigation to analyse eleven heavy metals: Arsenic (As), Selenium (Se), Mercury (Hg), Barium (Ba), Cadmium (Cd), Chromium (Cr), Lead (Pb), Silver (Ag), Zinc (Zn), Copper (Cu) and Nickel (Ni). The leachate results revealed trace amounts of heavy metals.