To investigate the compositions and spatio‐temporal changes of chromophoric dissolved organic matter (CDOM) in a typical urban river in Taihu Basin, China, that has been treated with series of water quality mitigation measures, 180 water samples were collected from November 2011 to October 2012 and analyzed with fluorescence excitation–emission matrices combined with parallel factor analysis (EEMs–PARAFAC). Three humic‐like components (C1, C2, and C4) and two protein‐like components (C3 and C5) were identified. Fluorescent intensity showed more apparent temporal changes than spatial changes, and humic‐like substances were dominant. The C3, C4, and C5 components decreased from November 2011 to October 2012, indicating effective CDOM removal by the water quality mitigation measures. Significant positive correlations were found between fluorescent components (C3 and C5) and nutritional factors including TN, NH4+‐N, and NO3−‐N. Furthermore, changes of fluorescent components (C2) were found to be related to microbial phosphatase activities. The application of EEMs–PARAFAC presents a promising approach to track the compositions and spatio‐temporal changes of CDOM in urban rivers.

2014): Synthesizing attapulgitegraft-polyacrylamide flocculant and immobilizing microorganisms to treat low-ammonium water, Desalination and Water Treatment, Low concentrations of ammonium are difficult to remove from surface water through traditional adsorption, air stripping, and biological techniques. Hence, we flocculate attapulgite-graft-polyacrylamide (ATP-g-PAM) and immobilize cells in this study to purify low-ammonia surface water. ATP-g-PAM was synthesized by grafting the polymerization reaction of ATP and acrylamide (AM). In this process, FeSO 4 and NaHSO 3 acted as initiators. The optimum reaction conditions were as follows: 15% AM monomer, 2% ATP, 10.5 × 10 −4 mol/mol AM initiator concentration with a 1:5 molar ratio of FeSO 4 to NaHSO 3 , and 5 h reaction time. The ATP-g-PAM structure was characterized further by Fourier transform infrared spectra, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. Results indicated that AM monomers were successfully grafted onto the ATP surface. Pellets of ATP-g-PAM-bound nitrifying bacteria were manufactured for surface water treatment. The ammonia-nitrogen removal rate ranged from 14.9 to 33.9% for adsorption and flocculation and from 69.4 to 82.6% under cell immobilization. Post-treatment, ammonia-nitrogen was less than 0.8 mg/L. Therefore, ATP-g-PAM can be an ideal carrier material of microbial fixations in water and wastewater treatment because the double-action of adsorption and flocculation induced by ATP-g-PAM can supplement the removal of pollutants.