| In 21 century for our country, development of economic has been rapidly increased, the pace of urbanization has been distinctively accelerated。 Smelting, electroplating, mining and other traditional industries enter the stage of industrialization。However, emissions of heavy metals for these industries have serious influence on soil and water and threat health development for environment and human beings。How to remove heavy metals in water media to alleviate the shortage of water resources? How to absorb heavy metals in soil to avoid to contaminate groundwater? How to select chemical reagents to treat contamination in soil and water? Conditions, effects, and mechanism for heavy metals contamination remediation have been a series of crucial problems。As a new and high-efficient green water treatment agent, potassium ferrate possesses advantages of oxidation, flocculation, and sterilization。In recent years, based on serious situation of heavy metal contamination, potassium ferrate is the first time to apply to soil remediation and has optimistic prospects。Based on flocculation adsorption performance of colloid Fe(OH)3 generated by potassium ferrate oxidation, this study prepares and simulates wastewater and polluted soil to research the ability for potassium ferrate to remove and absorb heavy metal Cu through 4 flocculation experiments。 The main purposes for this study are as follows:(1) To investigate removal effect of Cu2+ based on influence of flocculation pH and time and dosing quantity under only polyaluminium chloride in simulated environment;(2) To research removal efficiency of Cu2+ depend on oxidation pH, flocculation pH, oxidation time, flocculation time, dosing quantity under individually cast potassium ferrate in simulated environment;(3) To study removal effect of Cu2+based on oxidation pH, flocculation pH, oxidation time, flocculation time, dosing quantity under individually cast polyaluminium chloride and potassium ferrate under combination of polyaluminium chloride and potassium ferrate;(4) To explore adsorption efficiency of Cu2+depend on pH, absorption time, dosing quantity under potassium ferrate in soil。The conclusions are as follows:(1) The best conditions of Cu2+ removal for polyaluminium chloride are flocculation of pH=7, flocculation time of 30 min, and PAC dosing quantity of 50 mg/L corresponding to Cu2+ removal rate reached 83.1%,83.89%, and 78.56%, respectively;(2) The best conditions of Cu2+ removal for potassium ferrate are oxidation of pH=9, flocculation of pH=8,15 min of oxidation time,30 min of flocculation time and potassium ferrate dosing quantity of 15 mg/L corresponding to Cu2+ removal rate reached 90.3%,93.5%,77.38%, 80.54%,80.24%, respectively;(3) The best conditions of Cu2+ removal for polyaluminium chloride with potassium ferrate assistance are:oxidation of pH=9, flocculation of pH=8, 15 min of oxidation time,30 min of flocculation time, polyaluminium chloride dosing quantity of 40 mg/L and potassium ferrate dosing quantity of 15 mg/L corresponding to mentioned conditions, removal rates of Cu2+ are 93.1%, 94.2%,89.7%,91.21%,90.04%,91.47%, respectively;(4) The optimal Cu2+adsorption conditions for potassium ferrate in soil S are as follows:after 35 hours for pH stabilization, the value of pH is 7.14 and adsorption rate is 59.36%<= Optimal adsorption time is 14days, While the best mass rate (potassium ferrate:Cu2+) is 25/1 o Under this circumstance, adsorption rates for Cu2+could reach 50.94%and 63.23%;(5) The optimal Cu2+adsorption conditions for potassium ferrate in soil H are as follows:after 30 hours for pH stabilization, the value of pH is 7.08 and adsorption rate is 72.56%。Optimal adsorption time is 10 days, While the best mass rate (potassium ferrate:Cu2+) is 15/1。 Under this circumstance, , adsorption rates for Cu2+could reach 64.78% and 72.64%。... |
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