The current study was carried out to examine the heavy metals （Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and As） concentration in GW （groundwater） samples in the vicinity of distillery spent wash evaporation ponds and RGW （...The current study was carried out to examine the heavy metals （Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and As） concentration in GW （groundwater） samples in the vicinity of distillery spent wash evaporation ponds and RGW （reference groundwater） samples collected 2 km to 3 km away from the source. The study examines the potential health risk caused by consumption of heavy metals to local inhabitants living around distillery spent wash evaporation ponds. HM （heavy metals） concentration was determined by AAS （atomic absorption） and the results were compared with permissible limits of PEPA （pakistan environmental Protection Agency） and WHO （World Health Organization）, set for industria effluents and drinking water. The health risk assessment such as CDI （chronic daily intake） and HQ （hazard quotient） were determined on the sources ofHM concentration. The cm of heavy metals in GW were found in following decreasing order Fe, Zn, Mn, Ni, Co, Cu, Cr, Cd, Pb and As. The HQ indexes of HM in the GW samples near the distillery spent wash evaporation ponds was in the order As, C, Ni, Cu, Mn, Zn, Pb and Cr. The results showed that the distillery spent wash is the cause for the change in HM contents of the study area.展开更多
Highly precise and reliable determination of heavy metals in soil micro-arthropod tissues remains a challenge because of the small size of the animals and their typical low abundance in metal-contaminated agricultural...Highly precise and reliable determination of heavy metals in soil micro-arthropod tissues remains a challenge because of the small size of the animals and their typical low abundance in metal-contaminated agricultural soils. The present study sought to develop a method for cadmium （Cd） determination in soil micro-arthropods by optimizing the sample digestion procedure, reducing sample weight, modifying sample pre-treatment and validating the methodology with field samples. The optimized digestion conditions comprised a sample mass of 50-150 μg, digestion reagent of nitric acid：hydrogen peroxide （3：1）, digestion temperature of 105 ℃, digestion period of 3 h and digestion volume of 30 μL. Defecation of the standard Collembola Folsomia candida （92 h） and the indigenous Collembola Onychiurus yodai （42 h） and ultrasonic cleaning of F. candida increased the accuracy of Cd determination. The recovery of Cd using the refined procedure was 98.9% and the limits of detection and quantification were 0.002 and 0.008 μg L-1, respectively. The within-batch precision values were 〈 3%. The Cd concentrations in the tissues of the Collembola Isotorna sp. collected from a range of metal-contaminated fields determined by the improved method were consistent with the Cd concentrations in the field soils. The results indicate that the optimized method can be used for more accurate or reliable determination of Cd concentrations in soil micro-arthropod tissues.展开更多
文摘The current study was carried out to examine the heavy metals （Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and As） concentration in GW （groundwater） samples in the vicinity of distillery spent wash evaporation ponds and RGW （reference groundwater） samples collected 2 km to 3 km away from the source. The study examines the potential health risk caused by consumption of heavy metals to local inhabitants living around distillery spent wash evaporation ponds. HM （heavy metals） concentration was determined by AAS （atomic absorption） and the results were compared with permissible limits of PEPA （pakistan environmental Protection Agency） and WHO （World Health Organization）, set for industria effluents and drinking water. The health risk assessment such as CDI （chronic daily intake） and HQ （hazard quotient） were determined on the sources ofHM concentration. The cm of heavy metals in GW were found in following decreasing order Fe, Zn, Mn, Ni, Co, Cu, Cr, Cd, Pb and As. The HQ indexes of HM in the GW samples near the distillery spent wash evaporation ponds was in the order As, C, Ni, Cu, Mn, Zn, Pb and Cr. The results showed that the distillery spent wash is the cause for the change in HM contents of the study area.
基金supported by the National High Technology Research and Development Program of China (No. 2012AA101402-2)the National Natural Science Foundation of China (Nos. 41271264, 41325003)
文摘Highly precise and reliable determination of heavy metals in soil micro-arthropod tissues remains a challenge because of the small size of the animals and their typical low abundance in metal-contaminated agricultural soils. The present study sought to develop a method for cadmium （Cd） determination in soil micro-arthropods by optimizing the sample digestion procedure, reducing sample weight, modifying sample pre-treatment and validating the methodology with field samples. The optimized digestion conditions comprised a sample mass of 50-150 μg, digestion reagent of nitric acid：hydrogen peroxide （3：1）, digestion temperature of 105 ℃, digestion period of 3 h and digestion volume of 30 μL. Defecation of the standard Collembola Folsomia candida （92 h） and the indigenous Collembola Onychiurus yodai （42 h） and ultrasonic cleaning of F. candida increased the accuracy of Cd determination. The recovery of Cd using the refined procedure was 98.9% and the limits of detection and quantification were 0.002 and 0.008 μg L-1, respectively. The within-batch precision values were 〈 3%. The Cd concentrations in the tissues of the Collembola Isotorna sp. collected from a range of metal-contaminated fields determined by the improved method were consistent with the Cd concentrations in the field soils. The results indicate that the optimized method can be used for more accurate or reliable determination of Cd concentrations in soil micro-arthropod tissues.
