利用高效离心萃取机处理含酚废水,考察温度、相比、流量、碱液浓度对废水处理效果的影响,确定该含酚废水处理的最佳操作条件。两级逆流萃取最佳操作条件为:温度为70℃,相比(O/A)为1∶3,总流量为500 m L/min;三级逆流反萃取最佳操作条件...利用高效离心萃取机处理含酚废水,考察温度、相比、流量、碱液浓度对废水处理效果的影响,确定该含酚废水处理的最佳操作条件。两级逆流萃取最佳操作条件为:温度为70℃,相比(O/A)为1∶3,总流量为500 m L/min;三级逆流反萃取最佳操作条件为:温度为70℃,相比(O/A)为20∶1,总流量为250 m L/min。经过处理,酚的萃取率达到了99.44%,余水中酚的质量浓度降至18.05 mg/L。利用该工艺方法处理含酚废水,不仅提高了废水处理效率,同时也解决了现有设备存在的一系列问题,大大减少了废水处理成本。展开更多
Phosphorite ore is a potential resource of rare earths （RE） as well as phosphate; therefore, the recovery of RE from wet-process phosphoric acid （WPA） is promising. This study investigated the influence of rotatio...Phosphorite ore is a potential resource of rare earths （RE） as well as phosphate; therefore, the recovery of RE from wet-process phosphoric acid （WPA） is promising. This study investigated the influence of rotational speed, extractant concentration, flow ratio and phase contact time on the centrifugal extraction of RE from WPA and the separation of RE from impurities. The results indicate that higher rotational speed, higher extractant concentration and larger flow ratio are beneficial to the extraction of RE and impurities from phosphoric acid. It is found that the phase contact time for efficiently extracting RE and that for iron are of great difference, which provides an effective method for separating RE from iron using the non-equilibrium extraction process in centrifugal contactors. Compared with equilibrium extraction, the separation factor βRE/Fe is enhanced from 0.07 to 17.6.展开更多
Isotopic and chemical compositions of pore water(PW) are highly relevant to environmental and forensic study. Five lake water(LW)samples and five sediment samples were collected to investigate the effects of pore size...Isotopic and chemical compositions of pore water(PW) are highly relevant to environmental and forensic study. Five lake water(LW)samples and five sediment samples were collected to investigate the effects of pore sizes of sediments on PW chemistry and stable isotopes and determine mechanisms controlling their variations. Six pore water fractions were extracted from different-sized pores in each sediment sample at six sequential centrifugal speeds for chemical and isotopic analysis. The sediments consisted mainly of quartz, feldspar, and clay minerals. The hydrogen and oxygen isotopic compositions of PW are mainly controlled by the overlying LW, although the lag effect of exchange between overlying LW and PW results in isotopic differences when recharge of LW is quicker than isotopic exchange in PW. Identical isotopic compositions of PW from sediments with different pore sizes indicate that isotopic exchange of water molecules with different pore sizes is a quick process. The ratio of average total dissolved solid(TDS) concentration of PW to TDS concentration of LW shows a strong relationship with adsorption capacity of sediments, demonstrating that remobilization of ions bound to sediments mainly causes a chemical shift from LW to PW.Concentrations of Ca^(2+), Mg^(2+),and Cl^-in PW remain unchanged,while concentrations of Na^+,K^+,and SO_4^(2-) slightly increase with decreasing pore size. Chemical differences of PW from sediments with different pore sizes are governed by ion adsorption properties and surface characteristics of different-si zed particles.展开更多
文摘利用高效离心萃取机处理含酚废水,考察温度、相比、流量、碱液浓度对废水处理效果的影响,确定该含酚废水处理的最佳操作条件。两级逆流萃取最佳操作条件为:温度为70℃,相比(O/A)为1∶3,总流量为500 m L/min;三级逆流反萃取最佳操作条件为:温度为70℃,相比(O/A)为20∶1,总流量为250 m L/min。经过处理,酚的萃取率达到了99.44%,余水中酚的质量浓度降至18.05 mg/L。利用该工艺方法处理含酚废水,不仅提高了废水处理效率,同时也解决了现有设备存在的一系列问题,大大减少了废水处理成本。
基金the National High Technology Research and Development Program of China (No.2006AA06Z126) for the financial aid
文摘Phosphorite ore is a potential resource of rare earths （RE） as well as phosphate; therefore, the recovery of RE from wet-process phosphoric acid （WPA） is promising. This study investigated the influence of rotational speed, extractant concentration, flow ratio and phase contact time on the centrifugal extraction of RE from WPA and the separation of RE from impurities. The results indicate that higher rotational speed, higher extractant concentration and larger flow ratio are beneficial to the extraction of RE and impurities from phosphoric acid. It is found that the phase contact time for efficiently extracting RE and that for iron are of great difference, which provides an effective method for separating RE from iron using the non-equilibrium extraction process in centrifugal contactors. Compared with equilibrium extraction, the separation factor βRE/Fe is enhanced from 0.07 to 17.6.
基金supported by the National Natural Science Foundation of China(Grants No.41672225 and 41222020)the Program of the China Geology Survey(Grant No.12120113103700)the Fundamental Research Funds for the Central Universities(Grant No.2652013028)
文摘Isotopic and chemical compositions of pore water(PW) are highly relevant to environmental and forensic study. Five lake water(LW)samples and five sediment samples were collected to investigate the effects of pore sizes of sediments on PW chemistry and stable isotopes and determine mechanisms controlling their variations. Six pore water fractions were extracted from different-sized pores in each sediment sample at six sequential centrifugal speeds for chemical and isotopic analysis. The sediments consisted mainly of quartz, feldspar, and clay minerals. The hydrogen and oxygen isotopic compositions of PW are mainly controlled by the overlying LW, although the lag effect of exchange between overlying LW and PW results in isotopic differences when recharge of LW is quicker than isotopic exchange in PW. Identical isotopic compositions of PW from sediments with different pore sizes indicate that isotopic exchange of water molecules with different pore sizes is a quick process. The ratio of average total dissolved solid(TDS) concentration of PW to TDS concentration of LW shows a strong relationship with adsorption capacity of sediments, demonstrating that remobilization of ions bound to sediments mainly causes a chemical shift from LW to PW.Concentrations of Ca^(2+), Mg^(2+),and Cl^-in PW remain unchanged,while concentrations of Na^+,K^+,and SO_4^(2-) slightly increase with decreasing pore size. Chemical differences of PW from sediments with different pore sizes are governed by ion adsorption properties and surface characteristics of different-si zed particles.
