ABSTRACT
Heavy metal pollution from industrial wastewater is an important source. A method for heavy metals determination in industrial wastewater based on laser-induced breakdown spectroscopy (LIBS) technique was studied and the on-line monitoring system that used automatic graphite enrichment and spatial plasma confinement detection was developed and field demonstrated. The limits of detection (LOD) of heavy metal elements (Cd, Cr, Cu, Ni, Pb, Zn) could reach several µg/L. In Tongling, the on-line heavy metal monitor was field demonstrated. The calibration curves of copper and zinc were built on site, and then on-line monitoring was conducted. The measurement results of this monitor were compared with ICP-OES and had a good correlation. The results showed that the heavy metal monitor could be used for on-line detection of heavy metals in wastewater and had a good reliability.
ABSTRACT
A total of 300 male adult Wistar rats (180-220 g) were used. Animals were divided into four groups: control, vinyl chloride (VC) 10-, 100-, and 3000-ppm exposed groups. Seventy-five rats were used for each group. Inhalation exposure to VC was conducted 6 hr per day and 6 days per week. In the third, sixth, and twelfth month following exposure 8-30 rats of each group were killed. The others were under observation and sacrificed after 18 months. After exposure to VC, the organ and body weight ratio, such as the kidney, liver, spleen, and heart were increased, but those of the testis were decreased in the experimental groups in the sixth month. The differences between experimental groups and the control group were statistically significant (P less than 0.05 or P less than 0.01). The weights of testis were decreased and damage of testicular seminiferous tubules were found in rats by histopathological examination. Incidence of damage of testicular seminiferous tubules in the control, 10-, 100-, and 3000-ppm groups were 18.9, 29.7, 36.5, and 56.0%, respectively. There was an obvious dose-response relation between the concentration of VC and the incidence of testis damage, with a correlation coefficient of 0.993 (P less than 0.01). Statistically, the incidence of damage of testicular seminiferous tubules in rats in the 3000-ppm group and in 100-ppm group were significantly higher than that of the control group, respectively (P less than 0.001) and P less than 0.05).