Erratum Water Science and Technology 72 (12), 2122-2131: Efficient visible-light photocatalytic degradation of sulfadiazine sodium with hierarchical Bi7O9I3 under solar irradiation, MengMeng Xu, YaLei Zhao and QiShe Yan, doi: 10.2166/wst.2015.433 - Xu, MengMeng (Water science and technology : a journal of the International Association on Water Pollution Research, 2016)