EFFECT OF PYROLYSIS TEMPERATURE ON PROPERTIES OF SLUDGE FROM WASTEWATER TREATMENT PLANT IN NIGERIA

Abstract

Physicochemical properties, nutrients, structural and morphological characteristics of biochar derived from sludge collected from Lower Usuma Dam Wastewater Treatment Plant in Nigeria at different pyrolytic temperatures were investigated. Results showed significant variations in physicochemical and nutrient levels of biochar with temperature. Hydrogen ion concentration, ash and volatile matter levels were directly proportional to temperature, while biochar yield, moisture and organic content were indirectly proportional to temperature. Nitrogen, nitrate, ammonium ion and chlorides all decrease with temperature, while sulphate and phosphate of the biochar increase with temperature. Elemental analysis results indicated essential macro elements (Ca, Mg, K, Na), essential micro elements (Al, Zn, Fe, Mn) all increased with temperature due to the ability of the samples to concentrates by gradual loss of carbon, hydrogen and oxygen (CHO). X-ray diffraction result revealed the presence of CaCO3 and SiO2 in all the samples with Brunauer-Emmett – Teller surface area and pore volume decreasing greatly with pyrolytic temperature. There was similarities in the spectra of all the biochar disregarding temperature differences, although biochar obtained at the highest temperature (700oC) were found to have more spherical round edges with almost even surface than others.Keywords: Sludge, pyrolysis, physicochemical, biochar, water treatment plant.