| At present, surface water arsenic pollution occur frequently, it has became urgent environmental problem serious threat to people’s life and property security. Because the surface water of arsenic pollution incident has a large volume, concentration change in a range, the processing time is pressing and other characteristics. The actual application technology used for removeing arsenic in surface water only coagulation precipitation and adsorption method. But in practice, coagulation precipitation technology existing the problem of arsenic sediment in the secondary pollution and sediment of the follow-up processing.For adsorption method, it has the advantages of convenient operation and no secondary pollution. This method has broad prospects for development.This study to resolve the question of a surface water with arsenic, choose commonly used adsorption materials as adsorbent. Activated alumina on adsorption dynamics, adsorption isotherm, thermodynamics and various factors (temperature, particle diameter, pH, ion effect, etc) test research has studied. The research for the activated alumina used in water treatment of arsenic pollution to provide a theoretical basis. At the same time, through put the activated alumina materials into adsorption bag, builded mobile adsorption device, simulation emergency adsorptive arsenic system. Test analysis the device moving speed and the initial concentration, adsorption dose and adsorption bag length to the parameters such as the effects of arsenic, and dimension analysis to remove of arsenic are discussed. In order to get the parameters on the influence of adsorption efficiency arsenic experience formula for mobile adsorption in addition to the practical application of arsenic provide certain theoretical basis and technological parameters. The main research results are as follows:(1)Through the experience concluded that the optimal arsenic materials, active alumina, activated carbon, zeolite, fly ash and hematite fee landry equation in the K value of0.48,0.32,0.03,0.03and0.06. K value represents the absorbent adsorption capacity of the size, explain that alumina had best effect.(2) Activated alumina adsorption As (Ⅲ) and As (Ⅴ) balance time was24h, adsorption procedure which conform to pseudo-second-order kinetics equation, particle size spread within rate is the rate of reaction control factors. The equilibrium adsorption increased concentration with the initial rise. By the theory of Langmuir equation get single saturated adsorption capacity of71.94mg/g and79.37mg/g. Adsorption process for spontaneous exothermic reaction, adsorption temperature to rise. Activated alumina adsorption As (Ⅲ) and As (Ⅴ) the adsorption average free energy, adsorption heat, enthalpy change are low, adsorption process that on physical adsorption.(3)The smaller size of activated alumina adsorption As (Ⅲ) and As(Ⅴ) of the greater the adsorption capacity. The remove effect was good when pH between5.5and8.5. Temperature and solubility of adsorption effect was small, raised temperature to adsorption. Activated alumina adsorption As(Ⅴ), PO43-have great influence as removal rate decreased by80%and50%respectively, S2-and not significantly affect the result. Relatively AA adsorption As (Ⅲ), almost not affected by these ion influence.(4) Static adsorption adsorption test proved the operation speed of1.71m/min conditions, adsorption bag outside diameter<800mm, each layer activated alumina reach balance between adsorption. Mobile adsorption adsorption test proved that the running speed of the1.71m/min-3.8m/min, the initial concentration of0.14mg/L-1.34mg/L, adsorption dose for7.5kg and15kg and adsorption bag length was200mm and500mm, no difference between each layer concentration, to achieve the best effect of the pilot test.(5)The speed to the whole process of the removal rate the impact is not big, removal rate were above87%, the adsorption rate to a certain extent. In the early operation within20h, running with greater speed, the faster absorption rates. The speed to affect adsorption rate as time increases gradually decreased. The initial concentration has a significant influence on the removal rate, the removal rate raised with the concentration. The concentration of1.34mg/L than0.14mg/L high removal rate20%. Adsorption dose for7.5kg and15kg, removal rate was about64%and87%respectively. The adsorption rate and adsorption dose removal influence were relatively large, absorb dose large removal efficiency and absorption rates were relatively large. In adsorption dose the same condition, the adsorption bag length of200mm and500mm remove law completely consistent. (6) The experimental results indicate that the removal rate and water volume, the initial concentration, sampling from the surface of the distance and device is inversely proportional to the total length, and total quality, and adsorbent sampling time, operation speed and water depth is proportional to the factors. |
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