
Keywords: اکسیژن موردنیاز شیمیایی; WAS, waste activated sludge; WWTPs, wastewater treatment plants; VFAs, volatile fatty acids; PEH, protease/EDTA-2Na hydrolysis; EH, EDTA-2Na hydrolysis; PH, protease hydrolysis; TAH, thermal alkaline hydrolysis; COD, chemical oxygen demand; BOD, biologica