RESUMEN
Leaching characteristics and influencing factors of the typical sulfa antibiotics-sulfadiazine and sulfamethoxazole were studied by soil column experiments. The results showed that the leaching rate increased and the residues of sulfa antibiotics in soil column decreased as the soil profile depth increased. The residual concentration of sulfa antibiotics in column filled with 0-20 cm profile soil was 2 times higher than that with 40-60 cm profile soil. The concentration of sulfa antibiotics in the leachate was higher, while the residual concentration in the soil column was lower under a higher leaching velocity. The concentration of sulfa antibiotics in the leachate was close to 500 microg.L-1 when the leaching velocity was 2 mL.min-1, while the concentration of sulfa antibiotics in the leachate was between 100-200 microg.L-1 when the leaching velocity was 1 and 1.5 mL.min-1. The concentrations of sulfa antibiotics in the leachate and soil column increased as the concentration of leaching solution increased. The concentration of sulfa antibiotics in the leachate was close to 0 microg.L-1 when the concentration of leaching solution was 250 microg.L-1 and 125 microg.L-1. When the concentration of leaching solution was 500 microg.L-1, the concentration of sulfa antibiotics in the leachate was close to 500 microg.L-1 and the residue concentration in the soil column was 2 to 3 times higher than that with lower concentration of leaching solution. The results in this research may provide a scientific basis for water irrigation with anibiotics.
Asunto(s)
Suelo/química , Sulfadiazina/química , Sulfametoxazol/química , Antibacterianos/química , Contaminantes del Suelo/química , Contaminantes del Agua/químicaRESUMEN
Soil samples were collected from 18 sites at a relocated lead accumulator factory in the Southwest region, China. Among the 15 sample sites, profile soil samples at 0-20 cm, 20-40 cm and 40-60 cm were taken. Soil lead contents were analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Characteristics of Pb in topsoil and soil profiles collected from different sampling sites were discussed. Results showed that: (1) The total Pb contents in topsoil (0-20 cm) ranged from 18.18 to 52,332.50 mg x kg(-1). The maximum content greatly exceeded the national standard (HJ 350-2007). The Pb concentration in different workshops followed a decreasing order: the fourth workshop > the second workshop > waste lead storage pit > sewage works > the third workshop > the fifth workshop > the first workshop > the original fourth workshop > the packing workshop > the office area. (2) Results of profile distribution showed that soil depth had no significant effect on Pb content. Lead can be highly accumulated at different depths of the soil, which was quite different from natural soils. (3) Hakanson's potential ecological risk index evaluation showed that there was widespread ecological risk in the soil of the plant, and serious ecological risk existed in some workshops where a large number of lead was enriched. Therefore, the site must be restored in order to reuse it.