Studies On The Preparation Of The Modified Rectorite And Removing Of The Compound Pollution

With the rapid development of farming,heavy metals and antibiotics overusing make the waste water from farm contain a lot of antibiotics and heavy mentals.Not only that,landfill leachate,animal fecal use and sewage irrigation process will produce compound pollution.The compound pollution waste water going into the environment will make some microbes be resistant to genes.These genes lead to some pathogens on drog resistance and then will be a threat to humans.Therefore,this paper choose tetracycline（TC）and lead ion（Pb（Ⅱ））as the research object,and studies the influencing factors of single and compound pollution.Adsorption method,photocatalytic method,biological method and comprehensive treatment method are used to treat TC-Pb（Ⅱ）composite pollution in waste water.The use of clay mineral material as adsorbent has been a hot spot in the treatment of waste water by adsorption.Rectorite,as a unique clay mineral in Hubei,is an inexpensive adsorbent and is widely used in wastewater treatment research.Most of the current research focused on the effect of rectorite on the adsorption performance in the calcination temperature range of100⁵00℃,and the effect of high temperature calcination on the structure and adsorption performance of the rectorite is less concerned.In addition,the study on the adsorption behavior and mechanism of rectorite under the high temperature calcination condition of TC-Pb（Ⅱ）was less.But the structure and properties of the clay mineral has an important impact.In this paper,sodium modified rectorite was selected as adsorbent and Pb（Ⅱ）and TC were selected as adsorbents.The effects of rectorite on the adsorption performance were studied.This paper studies the rectorite structure change rule under high temperature calcination and its effect on the performance of adsorption.Studing the adsorption behavior and mechanism of rectorite in the compound polluted environment provides a scientific basis for the application of wastewater treatment and rectorite.In this paper,Pb（Ⅱ）was selected as the adsorbent.The effects of rectorite on the adsorption performance were studied.The adsorption behavior and mechanism of rectorite in the complex polluted environment were studied.The application of waste water treatment and rectorite was studied.Provide a scientific basis.The main work of this paper was as follows:（1）After Calcining rectorite with high temperature（500¹000℃）,the effect of temperature on the structure of modified rectorite was studied.When the temperature rised to 800℃,the characteristic diffraction peak begined to disappear and the layered structure collapsed.The electronegativity of modified rectorite at 700℃was the largest.（2）The effects of time,pH,temperature and coexisting ions on the adsorption of Pb（Ⅱ）and TC on rectorite were studied.When adsorption of Pb（Ⅱ）,the adsorption was in accordance with Langmuir isothermal adsorption and quasi second order kinetics equation.After 3 h,the adsorption was balanced and the removal rate was 95%.The adsorption of Ca²⁺,Mg²⁺,Na⁺and K⁺on Pb（Ⅱ）adsorption was inhibited.The adsorption of K⁺to TC was more favorable than Na⁺.The adsorption rate of TC was significantly higher than that of Na⁺.At 25 h,the removal rate of TC was 88%.After adsorption,the structure of the modified rectorite layered structure was unchanged,the interlayer spacing increased.The characteristic diffraction peaks of Pb（Ⅱ）or TC appeared on the XRD pattern,and the half-width and peak area of C and O elements changed obviously.（3）The effects of pH,mixing ratio and time on the adsorption of Pb（Ⅱ）-TC on the modified rectorite adsorption were studied.In the coexistence system,the two promote each other,and can be described by quasi-second-order kinetics and Langmuir isothermal adsorption model.After adsorption,the structure of modified rectorite did not change,but the interlayer distance increased.And the absorption peaks of-NH₃ and-C=C-were observed on the FT-IR spectrum.The diffraction peaks of Pb（Ⅱ）and TC appear on XRD,and the half width and peak area of C,O and N elements changed.