| Adsorption separation technology is considered as a promising wastewater treatment technology because of its advantages of low cost and high separation efficiency.However,its separation efficiency is limited by the difficulty in continuous particle adsorption process and the difficulty in applying to suspension system.In order to solve this problem,this paper proposes to use belt adsorption instead of particle adsorption,coupling air flotation technology with belt adsorption separation,and using dye as separation model to establish an efficient continuous gas-assisted belt adsorption separation method that can be directly applied to suspension wastewater system.The research content is as follows:(1)Firstly,the adsorption and desorption properties of the belt adsorbent on the Congo red dye were discussed by using the cheap polyester with rich functional groups such as hydroxyl and ester groups,and the effects of dye concentration,pH and ionic strength on the adsorption effect were further investigated.The results showed that the saturated adsorption capacity of the belt adsorbent was 460.83 mg/m~2,the adsorption equilibrium of the belt adsorbent could be reached within 120 min,and the adsorption rate reached 16%of the equilibrium adsorption rate within 5 min.With ethanol as the desorption agent,the desorption rate reached 24.76%within 5 min,the desorption equilibrium was reached about 10 min,and the desorption rate was26.79%.(2)Second,design and build the intermittent gas-assisted for belt adsorption separation plant,examines the Congo red initial concentration,pH,ionic strength,gas velocity and surfactant(CTAB),and other parameters on the intermittent gas absorption separation effect of the belt conveyor,to obtain the kinetic characteristics of the adsorption,further discusses the applicability of the method of suspending liquid waste water.The results showed that air flotation could significantly accelerate the adsorption and separation process.Under the optimized separation conditions,the gas-assisted belt adsorption could separate the Congo red wastewater of 30 mg/L,and achieve the removal rate of over 97%for the Congo red wastewater of 165 min.Using fine mud(sludge)containing 300 mg/L and Congo red containing 30 mg/L as simulated suspended wastewater,this method was used to treat these suspended wastewater directly.The removal rate of Congo red could reach 92.60%at 450 min,and the belt adsorbent could achieve good separation from the mother liquor of suspension.(3)Finally,under the condition of continuous feeding,carried out air flotation,belt adsorption,echoing off washing coupling process of the whole process of research,to obtain corresponding to each flow under continuous time needed for the steady state operation,on the basis of investigation and optimization of the initial concentration of Congo red,pH,ionic strength,gas flow rate,surfactant(CTAB)and feed flow rate of the whole flow of continuous gas help belt adsorption separation effect,and further examines the feasibility of the method is used for direct continuous suspension wastewater treatment and belt adsorbent recycling performance.All the results show that the implementation process of continuous gas-assisted belt adsorption separation process is feasible and efficient,in optimization of separation conditions,the small experimental separation device designed for 30 mg/L of Congo red simulated wastewater treatment,continuous processing is 20 mL/min,the removal rate of Congo red can reach more than 98%,and the continuous running 450 min,belt adsorbent about recycled after 30 times,of Congo red removal rate can reach 90.15%.Furthermore,the simulated wastewater with sludge concentration of 100 mg/L was further directly treated,and the continuous treatment capacity was 20 mL/min.The removal rate of Congo red was up to 87.63%,and the belt adsorbent could be well separated from the particles in the suspension. |
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