| The strict standards have been developed in China in the water quality, due to the increasingly serious water environmental problem. It is urgent to develope high efficient and economic water treatment technology. Meanwhile, another environmental problem is the stacking of waste rubber tires, which is called “black pollution”. With the rapid development of automobile industry, a large amount of waste rubber tires are not treated timely, which has effect on the mankind life. Therefore, how to reuse, recycle and dispose the waste rubber tires has caused much concern. If the waste rubber is converted into rubber particles, the surface will become rough, and the surface area willincreasa. As a result, the particle size will be small, and the porosity of the particles will increase. Thus, it is expected to use the waste tire rubber particles in the filtering process of waste water treatment. In this paper, the waste tire rubber particles(WTRPs) are used to be adsorptive materials, The adsorption of ammonia nitrogen, phenol and phosphate onto WTRPs was studied. On this basis, the WTRPs were applied in biological aerated filter(BAF) for simulated wastewater treatment. The objectives are to recycle the waste rubber tires, and make WTRPs be the new filler material in water treatment technology.Firstly, the rubber particles wrer used as an adsorbent to remove ammonia-nitrogen from wastewater. The influence of contact time, pH value, dosage of rubbber particle, initial concentration of pollutant and temperature on the adsorption efficiency were investingated. The data were fitted by the adsorption isotherm, kinetic, and thermodynamics models. The results demonstrated that the equilibrium adsorption time was 6 h for ammonia-nitrogen, and the kinetic adsorption of rubber particle followed the pseudo-second-order kinetic model. When the PH value was 7.5, the ammonia nitrogen could be adequately adsorbed by the rubber particle, and a good fit with Langmuir isotherm. The best dosage of rubber particle was 0.1g, and the maximum adsorption was 1.31 mg/g. Since this adsorption was endothermic, which increased heat will produce positive adsorptive results. For the adsorption of phenol, it was studied some results. The results showed that the removal rate of phenol could be up to 86% at 25 oC when 0.1 g of rubber particles was added, the pH value of solution was 7, the initial phenol concentration was prepared as 20 mg/L and the contact time was 4 h. The relationship between the sorbed quantity of phenol and contact time could be well described with the pseudo-second-order kinetic equation. The sorption capacity of phenol increased with the initial concentration of phenol and decreased with the addition of rubber particles. The relationship between the sorption capacity and equilibrium concentration of phenol was well fitted with Langmuirisotherm model. Thermodynamics parameters of adsorption showed the enthalpy change of the adsorption was 5.932 kJ/mol and its entropy change was 0.0247 kJ/mol·K, the process occurring endothermic spontaneously. For the adsorption of phosphate, it was studied some results. The adsorption of onto WTRPs reached equilibrium at 14 h. The adsorptive amount of phosphate was up to maximum when the pH value of solution was 10.0. The adsorptive amount of phosphate per unit mass of WTRPs decreased with WTRPs dosage increasing. The kinetics of phosphate adsorption was well described by pseudo-second-order kinetic model while the adsorptive isotherm followed Freundlich model. It is shown that phosphate in water could be removed effectively by WTRPs.Secondly, this experiment studied on the waste tire rubber particles BAF for simulated wastewater treatment. It takes a few days to succeed in cultivating biofilm using of the method of continuous flow fllowing with soaking rubber particles and intermission cultivating, when the removal rates of CODCr, NH3-N and P gets to 55.30%, 50% and 91.90%, and the reactor runs stable. After a period of stable operation, it is concluded that the removal rate CODCr, NH3-N and P gets to 63.51%, 43.27% and 89.41% respectively. When the water temperature was 17-20 oC, the ratio of air to water was 5:1, hydraulic loading in the 0.208,0.312 and 0.312m3/m2 h, it was included sampling in 30,45,60 and 75 cm, found that the hydraulic load of 0.208m3/ m2 h., the pollutant can get a higher removal rate at 45 cm height. Therefore, the waste rubber particles could be used in the treatment wastewater, especially in the removal phosphate, it was provided the basis for the actual treatment of simulated wastewater. In running condition, the rubber particles size, surface properties of improvement, it is expected to become a new materials used in BAF. |
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