Removal of alkalinity and metal toxicity from incinerated biomedical waste ash by using Bacillus halodurans

Abstract

Incinerated biomedical waste ash (IBWA) contains an abundance of polyaromatic hydrocarbons (PAHs), heavy/toxic metals and, is highly alkaline in nature. To tackle the problems that could be caused by these PAHs, heavy metals, or alkalinity, a disposal treatment must be given to IBWA before its landfilling or before putting it into use, to avoid disrupting the balance of the landfill site. This study is conducted to reduce the alkalinity and heavy metal leaching from IBWA using an alkaliphilic bacterium. Bacterium Bacillus halodurans strain (NCIM 5439) grew well at pH values of 8 − 11 pH, the temperature of 25-45 °C. When IBWA comes in contact with water or fluids, leachate generated is alkaline and is harmful in nature. Dumping of IBWA also caused an increase in the pH of groundwater as leachate generated from IBWA, can penetrate the environment. Leaching assessment of the IBWA is must be done to evaluate the hazardous capacity of the material due to alkalinity and heavy metals present in it. Bacterium Bacillus halodurans strain reduced the alkalinity and heavy metal concentration in IBWA and showed promising results and possible solution to the problem of leachate. U.S.EPA’s Toxicity characteristic leaching procedure (TCLP) test was performed to investigate its toxicity.

Keywords:

• Alkaliphiles
• Bacillus haloduran
• biosorption
• heavy metal
• incinerated biomedical waste ash
• SEM
• stabilization
• TCLP
• toxicity