pH值和Fe^(3+)浓度对硫酸铵溶解度的影响

Effect of pH Value and Fe^(3+) Concentration on Ammonium Sulfate Solubility

为探明pH和Fe^(3+)浓度对硫酸铵溶解度的影响,文中采用激光法测定了温度为293.15~353.15 K时硫酸铵分别在纯水、不同pH和不同Fe^(3+)浓度溶剂中的溶解度,引入经验方程计算出各条件下硫酸铵溶解度,对比了实测值与模型计算值,并探究了pH和Fe^(3+)对硫酸铵溶解度的影响机理。结果表明,激光法所测硫酸铵溶解度与文献值偏差较小,具有良好的可靠性和准确性;经验方程可较准确预测出温度为293.15~353.15 K时,硫酸铵分别在纯水、不同pH和不同Fe^(3+)浓度条件下的溶解度。硫酸铵在酸性溶剂中的溶解度随温度升高而逐渐增大,SO_(4)^(2-)会抑制硫酸铵在酸性溶剂中的溶解,导致硫酸铵在酸性溶液和Fe^(3+)溶液中的溶解度小于其在纯水中的溶解度。另外,Fe^(3+)会水解促使H;生成,降低溶液的pH,从而降低硫酸铵溶解度。相关研究成果可为硫酸铵结晶提供参考。

In order to reveal the effect of pH and Fe^(3+)concentration on ammonium sulfate solubility,laser method was adopted to measure ammonium sulfate solubility under pure water,various pH and Fe^(3+)concentrations in temperature of 293.15~353.15 K,respectively.Meanwhile,the ammonium sulfate solubility was calculated by empirical equation.Based on contrast of measured value and model calculation value,the influence mechanism of pH and Fe^(3+)concentration on ammonium sulfate solubility were revealed.Results showed that deviation between measured value and literature value was tiny thus the laser method has favorable reliability and veracity.As temperature in 293.15~353.15 K,the empirical equation could precise predict the ammonium sulfate solubility under pure water,various pH values and Fe^(3+)concentrations.As temperature increased,the solubility of ammonium sulfate in acid solution increased too.SO_(4)^(2-)could inhibit the solution of ammonium sulfate in acid solution,therefore the solubility of acid solution and Fe^(3+)solution were less than which in pure water.The Fe^(3+)would induce the generation of H;and decrease pH,thus the ammonium sulfate solubility decreased.The research results could provide references to ammonium sulfate crystallization.