Research On Modified Steel Slag To Treat Organic Waste Water And Heavy Mental Waste Water

Organic waste water and heavy metal waste water are the problems faced by our cou ntry in the process of industrialization that can not be effectively degraded in the environ ment.If the problems are not properly handled and directly discharged,it will cause seri ous harm to the environment and human body.Generally,the prices of materials used to deal with such waste water are higher.As the solid wastes discharged from steelmaking process,the steel slag that has the basis for processing mate rials has certain porosity and ratio surface,even inexpensive and easy to buy.So the steel slag was chosen as the raw material in this study to carries on the research on t he organic waste water and the heavy metal waste water treatment.The converter steel slag was chosen as raw materials in this thesis.The chemical constituents,properties and structural characteristics of steel slag were analysed by using XRF,BET and SEM,and by comparing with the treatment effect of steel slag modification before and after treating phenol waste water and heavy metal Cr³⁺ and Pb²⁺ wastewater to find the best treatment condition and explore its reaction mechanism.The main conclusions are as follows:1.By comparing the non-modified steel slag,acid-modified steel slag,alkali-modified steel slag in different reaction time,steel slag adding quantity and solution pH,the optimum experimental conditions were obtained.At ambient temperature,when the phenol waste water concentration is 40mg/l and the oscillator speed is 150r/min and 100-200 mesh of steel slag,acid modified steel slag,alkali modified steel slag reaction time respectively is 60 min,70min,60 min and each property of steel slag adding amount property is 8g/l,6g/l,10g/l,the solution pH respectively is pH=4,pH=10,pH=9,that is the best experimental conditions for the treatment of steel slag in various properties.2.The optimum experiment condition is obtained by comparing the removal effect of the Cr³⁺,Pb²⁺ of heavy metal waste water in different reaction time,steel slag adding amount and solution pH value of the non-modified steel slag,acid-modified steel slag,alkali modified steel slag.At ambient temperature,when the concentration of heavy metal ions is 20mg/l,the oscillator speed is 200r/min,treatment of Cr³⁺ wastewater,100-200 mesh unchanged steel slag,acid-modified steel slag,alkali modified steel slag reaction time respectively is 50 min,40min,50 min,and the steel slag adding amount respectively is 3g/l,1.8g/l,2.6g/l,solution pH value >3,which are the best experimental conditions for all properties of steel slag.When Pb²⁺ waste water was treated,the best experimental conditions for all properties of steel slagare under the conditions for steel slag properties are 100-200 mesh non-modified steel slag,acid-modified steel slag,alkali modified and 100 min reaction time,2g/l of steel slag adding amount,solution pH value >3.3.The removal of phenol with non-modified steel slag is best,and the removal rate of phenol is up to 42% under the optimum experimental conditions.The removal of Cr³⁺ and Pb²⁺ with acid modified steel slag is best under the best experimental conditions.The Cr³⁺ removal rate is up to 99.2% and the Pb²⁺ removal rate is 98%.4.The treatment of phenol waste water with non-modified steel slag is more consistent with the two-level kinetic-equotion,and the acid and alkli modified steel slag comfirm to the first-level kinetic equotion.The adsorption process of Cr³⁺?Pb²⁺ waste water in steel slag is more consistent with the Langmuir isothermal adsorption model.The adsorption process of heavy metal waste water treatment by steel slag is mainly adsorption and chemical reaction.