The development of polypyrrole composites for wastewater treatment application

Polypyrrole composites were developed to use as ion-exchangers and surface adsorbents for wastewater treatment. The composites were prepared via chemical polymerization of pyrrole monomers using iron (III) chloride as an oxidant in aqueous solution. The reactions were carried out by varying amount and type of additives including carbon black, coconut fiber, rice husk, and rice straw. The morphology and chemical structure of the composites were characterized by using Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR), respectively. Thermal properties of the composites were also obtained by using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The efficiency of wastewater treatment by the composites was investigated. The composites were used as adsorbents for removing heavy metal (copper) and chemical oxygen demand (COD) in the synthetic wastewater. The results showed the composite containing 20% w/w carbon black significantly reduced both COD (approx. 70%) and amount of copper ions (approx. 40%). Moreover, the composite containing 80% w/w coconut fiber and 10% w/w carbon black efficiently removed copper ions (approx. 90%). However, it was found that the agricultural by-products were not the appropriate additives in the polypyrrole composites for COD removal, because they could also degrade to increase COD in the wastewater.