Beryllium-containing wastewater is of high toxicity,but there are limited researches concerning its treatment.Beryllium smelting wastewater contains high concentrations of beryllium and ammonia.Biological aerated filters(BAF),which was inoculated with microorganisms,was used to treat beryllium smelting wastewater,and the mechanisms involved were investigated.Results show that BAF could remove beryllium and ammonia simultaneously.When influent concentrations of ammonia nitrogen and beryllium were 200 mg/L and 50~100 μg/L respectively,HRT was 24 h,the concentration ammonia was in the range of 1.8~10.0 mg/L,and beryllium concentration was less than 5 μg/L in the effluent.The removal of beryllium was mainly attributed to the microorganisms in BAF,and the maximum uptake of beryllium by microorganisms calculated by Langmuir equation was 684.9 μg/g.The beryllium removed by BAF was mainly combined to organic fraction.Moreover,large amount of beryllium accumulated inside the cell with limited biosorption by the external surface of microorganisms.Therefore,high removal efficiency of beryllium by BAF was observed.
Purpose:To investigate the concentration level of tertiary butylhydroquinone in rats after oral exposure,and then to evaluate the cytotoxicity of tertiary butylhydroquinone in the concentration range observed above.Methods:After a single gavage dose of 700 mg/kg,concentrations of tertiary butylhydroquinone in rat serum were quantified by liquid chromatography/mass spectrometry(LC/MS).Using MTT method,effects of tertiary butylhydroquinone on inhibiting proliferation of human normal hepatic cells HL7702 were studied,and changes of cell morpha were observed with inverted microscope.And then the cytotoxicity of tertiary butylhydroquinone in the concentration range in rat serum observed in vivo was evaluated.Results:Tertiary butylhydroquinone had inhibitory effect on the in vitro growth of HL7702 cells and changed the cell morpha.With the concentration of tertiary butylhydroquinone increasing from 0.01 mmol/L to 1.20 mmol/L,with the culture time increasing from 12 h to 24 h,the cytotoxicity grade increased from 0 to 4.When the culture time was 12,24,48 h,the LC50 values were respectively 0.63,0.34,0.16 mmol/L.After oral administration,concentrations of tertiary butylhydroquinone in rat serum were less than 0.12 mmol/L.Accordingly,the cytotoxicity grade in vitro was in the range of 0~2.Conclusions:Following oral exposure,the concentration level of tertiary butylhydroquinone in vivo can not result in high cytotoxicity in vitro.
To evaluate the toxicity of tertiary butylhydroquinone,a food antioxidant,the experiment was accomplished by serum pharmacology.After a single gavage dose of 700 mg/kg,the blood samples were taken at 0.08,0.25,0.50,24.00 and 48.00 h,and the serums were separated.Using MTT method,effects of tertiary butylhydroquinone and the serums containing tertiary butylhydroquinone and its metabolites on inhibiting proliferation of human normal hepatic cells HL7702 were respectively studied,and changes of cell morpha were observed with inverted microscope.The results showed that the serums containing tertiary butylhydroquinone and its metabolites had no significant inhibitory effect on the in vitro growth of HL7702 cells,although tertiary butylhydroquinone in the high concentration range significantly had inhibitory effect and changed the cell morpha.Therefore,tertiary butylhydroquinone is safe by oral exposure under the current standards.
The sorption of Cu(Ⅱ)by loess was investigated experimentally.In general,the measured results were fitted with the conventional Langmuir isotherm very well.However,the further applicability analysis showed that the parameters in Langmuir equation no longer keep their original physical meanings.The parameters in Langmuir equation are characterized more by the precipitation than the adsorption of Cu.
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