Purification of wet process phosphoric acid by decreasing iron and uranium using white silica sand.

Natural white silica sand as an adsorbent has been developed to reduce the concentration of iron and uranium ions as inorganic impurities in crude Egyptian phosphoric acid. Several parameters such as adsorbate concentration, adsorbent dose, volume to weight ratio and temperature, were investigated. Equilibrium isotherm studies were used to evaluate the maximum sorption capacity of adsorbent. Thermodynamic parameters showed the exothermic nature of the process and the negative entropy reflects the affinity of the adsorbent material towards each metal ion.

Effect of food preservatives on mother rats and survival of their offspring.

This work aimed to investigate the effect of food preservatives (sodium benzoate and sodium nitrite) on biochemical aspects of mother rats and survival of their offspring. Fifty pregnant albino rats (Sprague Dauley strain) were divided into 5 groups (10 rats each) and kept individually in wire cages. The first group was fed standard diet free from any additives (control group). The second and third groups were fed standard diet with added acceptable and high doses of sodium benzoate as a preservative. The fourth and fifth groups were fed on standard diet containing sodium nitrite at the same levels like that for benzoate in the second and the third groups. Animals were fed ad libitum during pregnancy. After delivery, the pups were measured anthropometrically (weight and length) and the mothers were sacrificed and their blood samples were taken from the hepatic portal vain. Serum was separated and subjected to biochemical analysis. The results indicated that sodium nitrite intake was associated with a significantly decreased food intake and lowered hemoglobin and hematocrit values (p<0.01 each) while their serum AST and ALP showed significantly higher values (p<0.01). Mothers receiving high dose of benzoate had significantly high ALT values (p<0.01). Both levels of benzoate and nitrite were shown to induce decrease in serum bilirubin and increased serum urea, while the high and acceptable doses of benzoate induced higher values of serum uric acid (p<0.01 and p<0.05, respectively), but did not induce a significant increase in serum creatinine. Pregnant rats which received acceptable and high doses of nitrite showed an increased mortality rate of their pups. The mean weight and length of live pups were lowered by food preservatives compared with controls.