Comparative Study On Adsorption Of Methylene Blue Printing And Dyeing Wastewater By Attapulgite And Its Three Modification Tests

Under the great situation of China's booming economy,the people's livingstandards have been greatly improved,and people have put forward higher demand for the color of clothing,so a variety of printing and dyeing wastewater will be produced.Printing and dyeing wastewater has the characteristics of high chroma,high concentration of pollutants and low biodegradability.There are still many technical challenges in terms of treatment and resource utilization.This paper relies on the national key research and development project-"Technology and Demonstration of Advanced Treatment and Degradation of Low-Salt Wastewater in Textile Industry" to carry out adsorption test of methylene blue printing and dyeing wastewater.Some scholars have suggested that the modified attapulgite as an adsorbent can greatly improve its adsorption rate,among which thermal modification,acid modification and magnetization modification are common modification methods.According to the literature review,there are few studies on the treatment of printing and dyeing wastewater by modified attapulgite.Therefore,the adsorption effect of the original soil and three modified soils on methylene blue printing and dyeing wastewater is tested and compared.In this paper,based on the theoretical basis,the thermal modification,acid modification and magnetization modification schemes of attapulgite are designed,and the modification test of attapulgite is carried out.Secondly,the characterization and analysis of attapulgite before and after modification are compared to compare its structure and The difference in performance;then the adsorption test was carried out to investigate the relationship between the calcination temperature,acid type,acid concentration,recombination rate,adsorption time,attapulgite dosage,initial concentration of methylene blue printing and dyeing wastewater and adsorption rate of attapulgite.Furthermore,the optimal modification method is obtained.Finally,the orthogonal test is used to obtain the primary and secondary order and optimality of the five factors affecting the temperature,adsorption time,p H value,initial concentration and dosage of the optimal modification method.Combination and best point.IV conclusion as below:(1)Analyze the structure and properties of attapulgite after attapulgite,thermal modification,acid modification and magnetization modification by SEM,XRD,FT-IR,TGA,etc.The morphological structure of the attapulgite has changed.For example,the surface is smooth and rough,the internal impurities are removed,the pores are dredged,the iron oxide is attached to the surface,and the specific surface area is increased,thereby improving the adsorption performance.The position and intensity of the diffraction characteristic peaks were compared and analyzed to analyze the effect of the modification on the attapulgite.According to the characteristic absorption peak,the internal structure changes are analyzed.(2)Thermally modified attapulgite: The adsorption curve will increase first and then decrease as the calcination temperature increases.That is,when the calcination temperature is 400 ° C,the adsorption effect is optimal.(3)Acid-modified attapulgite: The adsorption effects of different kinds of acids are: hydrochloric acid,nitric acid,sulfuric acid.As the acid concentration increases,the adsorption curve of attapulgite decreases.When the volume fraction of the three acids is 10%,the adsorption effect is excellent.(4)Magnetized modified attapulgite: The adsorption curve will increase first and then decrease as the recombination rate increases.When the recombination rate is20%,the adsorption effect is optimal.(5)The adsorption rate will increase with the increase of adsorption time,and then tend to be gentle;the adsorption rate increases with the increasing dosage of attapulgite,and then tends to be gentle;the adsorption rate is high and low,and methylene blue printing and dyeing wastewater The initial concentration is inversely proportional.(6)Study on the adsorption law of attapulgite original soil and three modified attapulgites on methylene blue printing and dyeing wastewater,and obtain three optimal modification methods: magnetization modification(20% recombination rate),thermal modification(500 ° C calcination),acid modification(10% by volume of hydrochloric acid solution).(7)Through orthogonal test,the thermal modification(400 °C calcination),acid modification(10% volume fraction of hydrochloric acid solution)and original soil are obtained,and the order of influence on the adsorption rate is: initial concentration,investment Add amount,temperature,p H value,adsorption time.The magnetization modification(20% recombination rate)affects the primary and secondary order of adsorption rate: dosage,initial concentration,p H value,temperature,and adsorption time.(8)Through the orthogonal test,the optimal combination and the best point are as follows: the temperature is 25 ° C,the adsorption time is 8 h,the p H value is 13,the initial concentration is 250 mg / L,and the dosage is 1.0 g.This paper broadens the application field of modified attapulgite adsorption technology,and verifies the feasibility of using modified attapulgite to adsorb methylene blue printing and dyeing wastewater.It is expected that in the subsequent research process,a new adsorbent for attapulgite with low cost and good adsorption effect can be obtained,which provides basic data for the treatment and resource utilization of printing and dyeing wastewater.