Abstract:Characteristic parameters of phenol were investigated at different ion concentration and pH values by three-dimensional fluorescence spectra method. In the meantime, the effect of fluorescence quenching brought by humic acid was also explored. Results showed that nine kinds of ions usually existing in natural water including Na+、Mg2+、Ca2+、K+、NH4+、Cl-、HCO3-、SO42-、HPO42- had no effect on the shape of spectra and fluorescence intensity of phenol. However, the presence of NO3- caused the changes of fluorescence intensity, which decreased with the increasing concentration of NO3-. The impact of pH was significant because phenol had different forms in acidic and alkali conditions. The fluorescence intensity remained unchanged in acidic condition; in contrast, only a weak fluorescence signal was found in the alkali condition.The latter phenomena can be explained by the ionization of hydroxyl. In addition, the presence of humic acid may cause the fluorescence quenching. Finally, Stern-Volmer equation was used to fit the quenching results, and good results had been obtained with relative coefficient of 0.9995.