A Study On The Preparation And Wastewater Treatment Application Of Iron Manganese Composite Oxides

With the rapid development of heavy industry and light industry in21stcentury, industrialwastewater pollution has become a serious threat to human health; it even destroys theecological environment which human beings rely on to survive. The traditional physical,chemical and biochemical methods cannot effectively dispose the remnants of pollutants inindustrial wastewater. Therefore, seeking for a low-cost, efficient and economic modernprocessing technology is an urgent difficult task for current environmental problems. Thisthesis uses the method of oxidation reduction precipitation, first mixes up potassiumpermanganate and ferrous sulfate, then compounds FeMnO through advanced methods suchas constant temperature heating, depositing, centrifuging, drying and roasting. The thesisanalyzes the characteristics of the FeMnO including area per unit volume, particle sizedistribution, morphology and its chemical features in order to discuss the adsorptionmechanism.The analysis results of the characteristics show that particles of FeMnO have larger area perunit volume and higher free energy which determines the strong adsorption performance ofFeMnO; the torispherical, random and small particle size arrangement of these particles andtheir natural reunion phenomenon embody its own adsorption properties; The zero pointcharge in the pH=8, illustrates that under the condition of weak base, FeMnO surface withpositive charge can enhance its adsorption effect; FeMnO has wide absorption band, whichproves that the product not only contains MnO2, Fe (OH)3, but also may contain iron oxide. Itis illustrated that FeMnO has a strong adsorption performance. Through the research of the Congo red simulated wastewater adsorption by FeMnOtreatment, the results show that the FeMnO plays its good adsorption properties only in theappropriate pH range; increase of the adsorbent dosing can enhance the adsorption effect incertain conditions, but if increasing too much adsorbent dosing, it could inhibit its adsorptionperformance; with the increase of adsorption time, when adsorption equilibrium is reached,the adsorption quantity do not change anymore. FeMnO adsorption can adsorpt Congo redsimulated wastewater in a wide temperature range; it may because the adsorbent adsorptioncapacity is saturated, the decolorization rate changes only in a small range with the increase ofinitial mass concentration of Congo red simulated wastewater; Chloride ion do not have anyinfluence on the adsorption effect of Congo red simulated wastewater by FeMnO; however,when adding the sulfuric acid ion, the adsorption effect of Congo red simulated wastewater byFeMnO has great changes, it is obvious that visible sulfuric acid ion has a strong inhibitoryeffect on the adsorption of Congo red simulated wastewater by FeMnO. By using two kindsof adsorption isotherm–Langmuir and Freundlich, the thesis fits the adsorption process ofCongo red simulated wastewater and the results show that the Langmuir adsorption isothermcan better conform to the adsorption process of Congo red simulated wastewater. By usingprimary Lagergren quasi kinetics, secondary Lagergren quasi kinetics and Elovich model tofit the adsorption process of Congo red simulated wastewater in the experiments of this thesis,the results show that the correlation coefficient in primary quasi kinetics model is0.9909,which well explains the adsorption process of Congo red simulation wastewater.Through the research of the wastewater containing cadmium adsorption by FeMnOtreatment, the results show that the adsorption rate is maximum when the pH=8, and onlyonly under the condition of appropriate pH, adsorption effect will be the best; because of theheating effect of the adsorption process, temperature has a certain influence on the adsorptionof wastewater containing cadmium by FeMnO, elevated temperature in heat absorptionprocess can be helpful for adsorption while lowering temperature in exothermic process may also be helpful for adsorption; as the extension of adsorption time, when adsorption potentialis saturated, the adsorption quantity will not change anymore, then it reaches a status ofadsorption equilibrium; appropriate adsorbent dosage can enhance the adsorption effect ofFeMnO. Through fitting adsorption isotherm and dynamic model in the adsorption process ofwastewater containing cadmium by FeMnO, the results show that the Freundlich adsorptionisotherm can better fit the experimental data; the correlation coefficient in secondary quasikinetics model is0.9909, which can well explain the process of adsorption.This thesis conducts an exploratory research on the treatment of adhesive wastewater byFeMnO and has the following findings: pH has important influence on the adsorption process,when pH is greater than8, the absorption rate of FeMnO begins to fall, this may because thesolution contains a large number of H+, Fe3+adhered on the adhesive surface when the pH <8,this can accelerate the flocculate coagulation; when the pH of the solution is greater than8, asultra high basicity destroys the stability of Fe(OH)3colloid, it forms the Fe(OH)3precipitationin the solution, which reduces the adsorption rate of adhesive wastewater; the best time forFeMnO to treat adhesive wastewater is5h; the additive amount of adsorbent affectsadsorption effect mainly due to the influence of the hydroxide colloid in FeMnO, which playsan vital role in the adsorption effect.In this paper, the preparation of FeMnO processed Congo red simulated wastewater,wastewater containing cadmium, adhesives wastewater, discussed the pH, temperature,adsorption time, adsorbent dosage, initial concentration on the adsorption effect of the impactthe situation, and the use of adsorption isotherms and kinetics model fit the data, depthadsorption mechanism.