Removal Of Pb²⁺ From Water By Using Co-TiO₂ Aerogel And Fe₂O₃/Hydrilla Materials

With the growing contradictions between environmental pollution and the ecological civilization construction,there has been a concern about the pollution problems caused by wastewater containing lead and coking wastewater.The lead wastewater,which is mainly discharged by metallurgical industry,has a great harm to human bodies and even leads to death.Adsorption,among methods of treatment,is the most traditional and effective one.Most traditional adsorbents,however,have disadvantages of small adsorption capacity,high cost and low selectivity.Therefore,a more effective and environmental adsorbent at a low cost has always been a hotspot of environmental research.Aiming at this,the thesis designed the experiment to synthesize two absorbents used to absorb Pb2+ in water body.The specific conclusions are as follows:(1)Hydrilla/Fe2O3(HZ/Fe2O3)material was prepared through biotemplating,and studied by XRD,SEM,and BET to discuss the influence exerted by solution concentration,PH,time on absorption property.The adsorption capacity could reach 186 mg/g.The isotherm of the material was closely consistent with the Langmuir isotherm,and was monolayer adsorption.(2)Co-TiO2 aerogel was prepared through reflux method,and studied by XRD,SEM,and BET to discuss the influence exerted by solution concentration,PH,time on absorption property.The adsorption capacity could reach 197 mg/g.The isotherm of the material was closely consistent with the Langmuir isotherm,and was monolayer adsorption.Meanwhile,the coking wastewater is mainly from coal tar industry.The water body contains a lot of highly toxic material such as phenols,cyanides and ammonium salt,which are harmful for human bodies.Besides,with the features of odour,foam,high chroma,the wastewater is difficult to be treated,and the common treatment has the disadvantages of high energy consumption,high cost,low effluent and instability.For the problems,the thesis applied photocatalysis technology to the treatment of coking wastewater and obtained satisfactory effects.The problems in common treatment have also been concerned.Specifically,the thesis made a deep treatment tothe coking wastewater through photocatalysis technology:(1)In the condition of 6‰catalyst dosing ratio,pH of 6,illumination of 6h and lighintesity of 10.3mW/cm2,the removal rate of COD in coking wastewater reached 93%,the same rate of NH3-N was 92%.Through the deep photocatalysis treatment,the contents of COD and NH3-N were 278 mg/L and 10.5 mg/L respectively,which means the water reached the standard of the landscape water quality;(2)With amplification experiment,the water quality can reach the recycling standard of factories and the problems of odour,foam and chroma have been solved.