The Study On The Adsorption Treatment Of Methylene Blue Dye Wastewater Using Maize Straw Particles

The treatment of printing and dyeing wastewater has become a serious problem in our country. At the same time, the pollution caused by a large number of agricultural solid wastes is becoming more and more serious. Therefore, the reasonable and effective utilization of agricultural solid waste to deal with the printing and dyeing wastewater has significantly development prospect and significance. As a great agricultural country, China has a large number of agricultural solid wastes, especially the straw waste that the main ingredient is cellulose. Agricultural solid waste can be made into adsorbent, and this adsorbent has rich sources and low cost, as well as a large adsorption capacity and biochemical degradation characteristics. Therefore, using crops straw (maize) as raw materials to develop cellulose biological adsorbent can effectively solve the problem of agricultural solid waste and wastewater treatment. This method has a positive effect on establishing a sustainable development and the environment friendly society in our country.To achieve the reutilization of maize straw (MS), MS particles are used as the adsorbent in this study to treatment the simulated wastewater include methylene blue (MB). A series of optimization condition experiments are carried out, at the same time, the adsorption isotherm and adsorption dynamics were investigated to research the adsorbent adsorption capacity, adsorption state, and adsorption strength and adsorption mechanism. The main conclusions are as follows:(1) The static experiment showed that the optimal adsorption conditions were particle size of MS0.1～0.2mm, the initial wastewater pH value6.0, the temperature of adsorption system20℃, and the adsorption time60min. Under the optimal conditions, while the initial simulated concentration of wastewater was200mg/L and the dosing quantity of adsorbent was0.20g/L, the decolorization rate could reach more than90%. Even when the initial concentration was300mg/L, the decoloring rate was still higher than80%. While the adsorbent dosage was small, it also showed a good adsorption performance, which indicated that this material had good application potential.(2) In the common two kinds of adsorption isotherm equation, Langmiur adsorption isotherm equation was better than the Freundlich adsorption isotherm equation for describing the adsorption equilibrium of MB onto MS particles. In the process of adsorption kinetics, the decision coefficient of the pseudo-second-order kinetic model was0.9917, which was better than the pseudo-first-order kinetic model. Adsorption equilibrium and kinetics studies showed that MB adsorption onto MS particles was mainly controlled by chemical action.(3) In the indoor dynamic adsorption treatment experiment of MB simulated wastewater, the results showed that the designed miniature adsorption column was suitable for the treatment of MB wastewater below300mg/L, and the advisable rate of flow is30ml/min. Results of the dynamic adsorption curve also showed that Thomas model is suitable to describe the up-flow adsorption process.