RESUMO
The linear relationship between the concentration of either bovine serum albumin (BSA) or sodium alginate (SA) and the intensity of a resonance light scattering (RLS) spectrum was established by using Congo red and neutral red as the dye probes, respectively. Moreover, the linear relationship between the concentration of humic acids (HA) and UV absorbance was determined by using toluidine blue (TB) as the dye probe. The detection of concentration range and the pH value of three kinds of standard substances were optimized. The recovery rate of bi-and tri-element samples of the standard objects was investigated by means of the dye probe analysis method. The results show that, in the appropriate concentration range, the linear correlation coefficients between the concentration of BSA, HA, or SA and the intensity of its corresponding dye probe spectrum were all high, at 0.98. The recovery rates of the three kinds of standard objects in mixed samples were all greater than 95%, and the standard errors were all less than 0.11%. Based on qualitative analysis of the proteins, polysaccharides, and humic acids in the secondary water discharge samples of urban sewage obtained via UV and RLS spectra, the dominant pollutants were confirmed in the four kinds of secondary effluent. The relative deviations of the concentration of polysaccharides and proteins measured using the dye probe technique and the national standard method ranged were from 1.2% to 0.04%.