Leaching of a low-grade lead and zinc oxide ore was studied by an organic reagent, citric acid. The quadratic mathematical models were developed for the relationship among the influential parameters and lead and zinc recoveries. Leaching rate was strongly affected by the interactive effects of factors. It was also found that the quadratic effects of stirring speed and linear<e...

hydrographically bolivian poopó lake is located in the basin of desaguadero river and it has over a dozen main tributary rivers and other smaller rivers with lower flow. the mine water discharge from the abandoned and current mining activities polluted these rivers by carrying heavy metals, dissolved and suspended solids which in turn polluted the poopó lake which is considered as an important ...

abstract heavy metals are the important pollution which there is in the aquatic ecosystems. today, with advances in technology have increased the pollution therefore it is important to assessment the risks. the aim of this study was acute toxicity effects of mercury chloride, lead chloride and zinc chloride in silver carp fish. in this study there were 5 treatments for lead chloride and mercury...

apart from the breast milk, infant formula and baby weaning food have a special role in infant diet. infants and young children are very susceptible to amount of trace elements. copper and zinc are two elements that add in infant food. lead and cadmium are heavy metals that enter to food chain unavoidably. dpasv is a benefit and applicable method for measurement of trace elements in food produc...

lead is a common toxic agent which impairs various organs functions of the body. the basis of this toxicity is believed to be the negative influence on enzymatic system of cells. in the past few years, increasing consideration has been given to interactions occurring between lead and some essential metals including se and zn. based on the finding that some trace elements could reverse the toxic...

in present study we determine the zinc and lead levels in human blood samples by differential pulse polarography under optimum experimental conditions (ph=7.5, scan rate=5mv/s and pulse amplitude=50mv) the polarographic reduction peaks of zn and pb were examinedin the -0.72 v and-0.15 respectively. the zinc and lead content can be determined by in comparison with their standard solutions. accor...