Objective To understand the contents of residual chlorine in the wastewater of 12 hospitals in the urban districts of Jinan. Methods Wastewater samples discharged from 12 hospitals were collected from June to September in 2003. The contents of residual chlorine in the wastewater samples were determined using iodometric titration method and the fecal coliform counts of the wastewater were determined. Results The contents of residual chlorine in the wastewater of 12 hospitals were 3.7 mg/L-128 mg/L with the average level of 27.6 mg/L. The result of the fecal coliform count in the wastewater was accorded with the National Hygienic Standard. Conclusion The contents of residual chlorine in the wastewater discharged from municipal hospitals in Jinan were too high, which might cause the secondary pollution to water environment.

Objective To study the determining method of trace amounts of Pb?Cd in nature water body. Methods Pb, Cd in nature water body were concentrated by on-line chelate resin, and concentration was determined by concentration-AAS. Results The Pb and Cd detection limit of the present method were 0.500,0.02 ?g/L respectively, RSD were 2.3%,1.7% respectively and the rates of recovery were 94%-104.4%. Conclusion Using on-line chelate resin concentration technic and atom absorption,the sensitivity will increase two order of magnitudes compared to concentration FAAS,the precision will be better than that of GAAS. The present method can be used for quick determination of trace Pb?Cd in nature water body.