Pilot plant studies on 2-methylisoborneol(2-MIB)removal in drinking water by biological activated carbon-sand filter(BACSF)were conducted in this paper.The biological activated carbon was chosen from a BAC filter of a...Pilot plant studies on 2-methylisoborneol(2-MIB)removal in drinking water by biological activated carbon-sand filter(BACSF)were conducted in this paper.The biological activated carbon was chosen from a BAC filter of an advanced treatment plant which has operated for 1 year.The results showed that the BACSF worked effectively when high concentrations of MIB in raw water especially in summer season.Most of the MIB was removed within 450 mm of the top packed media and the removal rate was 75.24%.The biomass on the surface of activated carbon increased to 103 nmolP/g carbon in August.In addition to MIB,turbidity,UV254 and DOC consumption value are also effectively removed by BACSF.The micro flocculation in combination with BACSF enhanced filtration test provided the evidence that the micro-flocculation made the contaminant in water forming the colloidal matter and it improved the BACSF removal ability of MIB.The optimum PACl dosage was 0.2 mg/L and the PACl contact time was 2-4 min.展开更多
Modeling of the roughness in micro-nano scale and its influence have not been fully investigated, however the roughness will cause amplitude and phase errors of the radiating slot, and decrease the precision and effic...Modeling of the roughness in micro-nano scale and its influence have not been fully investigated, however the roughness will cause amplitude and phase errors of the radiating slot, and decrease the precision and efficiency of the SWA in Ku-band. Firstly, the roughness is simulated using the electromechanical coupled（EC） model. The relationship between roughness and the antenna＇s radiation properties is obtained. For verification, an antenna proto- type is manufactured and tested, and the simulation method is introduced. According to the prototype, a contrasting experiment dealing with the flatness of the radiating plane is conducted to test the simulation method. The advantage of the EC model is validated by comparisons of the EC model and two classical roughness models （sine wave and fractal function）, which shows that the EC model gives a more accurate description model for roughness, the maxi- mum error is 13%. The existence of roughness strongly broadens the beamwidth and raises the side-lobe level of SWA, which is 1.2 times greater than the ideal antenna. In addition, effect of the EC model＇s evaluation indices is investigated, the most affected scale of the roughness is found, which is 1/10 of the working wavelength. The proposed research provides the instruction for antenna designing and manufacturing.展开更多
The capillary model was used to analyze the hydraulic conditions in the deep bed filtration process. The physicochemical interaction forces between the filter media and suspended particles and their influence on deep ...The capillary model was used to analyze the hydraulic conditions in the deep bed filtration process. The physicochemical interaction forces between the filter media and suspended particles and their influence on deep bed filtration process were also studied theoretically. Through the comparison of the hydraulic and physicochemical forces, the key influencing factors on the filtration process were proposed and investigated. Pilot study of the micro-flocculation deep bed filtration was carried out in the No. 9 Potable Water Treatment Plant of Beijing, and the experimental results of hydraulic head loss, particle distribution and entrapment were presented. The theoretical prediction was reasonably consistent with the experimental results under different conditions, which indicated that the regulation and control of micro-flocculation and deep bed filtration could be realized by the evaluation of the physicochemical interactions. Further theoretical and experimental research should be carried out to investigate the interaction mechanism and its application in the deep bed filtration and other cases.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.50678046)
文摘Pilot plant studies on 2-methylisoborneol(2-MIB)removal in drinking water by biological activated carbon-sand filter(BACSF)were conducted in this paper.The biological activated carbon was chosen from a BAC filter of an advanced treatment plant which has operated for 1 year.The results showed that the BACSF worked effectively when high concentrations of MIB in raw water especially in summer season.Most of the MIB was removed within 450 mm of the top packed media and the removal rate was 75.24%.The biomass on the surface of activated carbon increased to 103 nmolP/g carbon in August.In addition to MIB,turbidity,UV254 and DOC consumption value are also effectively removed by BACSF.The micro flocculation in combination with BACSF enhanced filtration test provided the evidence that the micro-flocculation made the contaminant in water forming the colloidal matter and it improved the BACSF removal ability of MIB.The optimum PACl dosage was 0.2 mg/L and the PACl contact time was 2-4 min.
基金Supported by National Natural Science Foundation of China(Grant Nos.51305322,51405364,51475348)
文摘Modeling of the roughness in micro-nano scale and its influence have not been fully investigated, however the roughness will cause amplitude and phase errors of the radiating slot, and decrease the precision and efficiency of the SWA in Ku-band. Firstly, the roughness is simulated using the electromechanical coupled（EC） model. The relationship between roughness and the antenna＇s radiation properties is obtained. For verification, an antenna proto- type is manufactured and tested, and the simulation method is introduced. According to the prototype, a contrasting experiment dealing with the flatness of the radiating plane is conducted to test the simulation method. The advantage of the EC model is validated by comparisons of the EC model and two classical roughness models （sine wave and fractal function）, which shows that the EC model gives a more accurate description model for roughness, the maxi- mum error is 13%. The existence of roughness strongly broadens the beamwidth and raises the side-lobe level of SWA, which is 1.2 times greater than the ideal antenna. In addition, effect of the EC model＇s evaluation indices is investigated, the most affected scale of the roughness is found, which is 1/10 of the working wavelength. The proposed research provides the instruction for antenna designing and manufacturing.
文摘The capillary model was used to analyze the hydraulic conditions in the deep bed filtration process. The physicochemical interaction forces between the filter media and suspended particles and their influence on deep bed filtration process were also studied theoretically. Through the comparison of the hydraulic and physicochemical forces, the key influencing factors on the filtration process were proposed and investigated. Pilot study of the micro-flocculation deep bed filtration was carried out in the No. 9 Potable Water Treatment Plant of Beijing, and the experimental results of hydraulic head loss, particle distribution and entrapment were presented. The theoretical prediction was reasonably consistent with the experimental results under different conditions, which indicated that the regulation and control of micro-flocculation and deep bed filtration could be realized by the evaluation of the physicochemical interactions. Further theoretical and experimental research should be carried out to investigate the interaction mechanism and its application in the deep bed filtration and other cases.
