Since conventional water treatment is not affordable in developing countries,looking for locally available and alternative treatment options is mandatory.Removal of fluoride and phosphate can be achieved by designing ...Since conventional water treatment is not affordable in developing countries,looking for locally available and alternative treatment options is mandatory.Removal of fluoride and phosphate can be achieved by designing appropriate filtration media from different materials such as sand,calcined clay,pumice,scoria and bone char.This study was designed to determine the removal efficiency of these locally available filter media with respect to detention time and pH.The filtration apparatuses(tank) were filled separately with stone,gravel with grain size 0.6-4.75 mm and 40 cm deep,sand(ES = 0.15—0.35 mm and UC = 1.5-3),calcined clay,pumice,scoria and bone char with grain size 0.25-0.5 inch.Water samples were prepared using glass bottles with fluoride concentrations of 6 and 8 mg/1 and phosphate concentration of 4 mg/1.Laboratory analysis was carried out before and after filtration to determine the removal efficiency of each medium.It was found that the highest removal of fluoride was achieved by bone char(89.65%),followed by pumice(82.4%).However,bone char has rather increased the concentration of phosphate by 63.8%.Sand was the most efficient media to remove phosphate,managing to remove by 70%.Therefore,it is an attractive option to use these locally available,environmental friendly and appropriate technologies for efficient removal of both fluorine and phosphate at the household or community water treatment level.展开更多
目的建立简便、灵敏的手性高效液相色谱法检查苄基依折麦布中的异构体杂质。方法以Chiralpak IC为固定相,正己烷-异丙醇（体积比90∶10）为流动相,流速为1.0 m L·min-1,检测波长为232 nm。结果通过对分离条件进行优化,苄基依折麦...目的建立简便、灵敏的手性高效液相色谱法检查苄基依折麦布中的异构体杂质。方法以Chiralpak IC为固定相,正己烷-异丙醇（体积比90∶10）为流动相,流速为1.0 m L·min-1,检测波长为232 nm。结果通过对分离条件进行优化,苄基依折麦布与其异构体杂质能达到良好分离。苄基依折麦布在质量浓度为1.0～12 mg·L-1内线性关系良好。平均回收率为99.8%,日内与日间精密度均小于3.0%。结论所建立的分析方法灵敏度高、重现性好,适用于苄基依折麦布中异构体杂质的检查。展开更多
文摘Since conventional water treatment is not affordable in developing countries,looking for locally available and alternative treatment options is mandatory.Removal of fluoride and phosphate can be achieved by designing appropriate filtration media from different materials such as sand,calcined clay,pumice,scoria and bone char.This study was designed to determine the removal efficiency of these locally available filter media with respect to detention time and pH.The filtration apparatuses(tank) were filled separately with stone,gravel with grain size 0.6-4.75 mm and 40 cm deep,sand(ES = 0.15—0.35 mm and UC = 1.5-3),calcined clay,pumice,scoria and bone char with grain size 0.25-0.5 inch.Water samples were prepared using glass bottles with fluoride concentrations of 6 and 8 mg/1 and phosphate concentration of 4 mg/1.Laboratory analysis was carried out before and after filtration to determine the removal efficiency of each medium.It was found that the highest removal of fluoride was achieved by bone char(89.65%),followed by pumice(82.4%).However,bone char has rather increased the concentration of phosphate by 63.8%.Sand was the most efficient media to remove phosphate,managing to remove by 70%.Therefore,it is an attractive option to use these locally available,environmental friendly and appropriate technologies for efficient removal of both fluorine and phosphate at the household or community water treatment level.
