Preliminary screening oxidative degradation methyl orange using ozone/ persulfate Nur Aqilah Razali, Che Zulzikrami Azner Abidin, Ong Soon An, Fahmi Muhammad Ridwan, Abdul Haqi Ibrahim, Siti Nasuha Sabri and Su Huan Kow E3S Web Conf., 34 (2018) 02038 Published online: 19 March 2018 DOI: 10.1051/e3sconf/20183402038