Several on-site greywater treatment systems are under development including biofiltration, whose efficiency is influenced by the filter media. Therefore, the main objective of this study was to evaluate the influence ...Several on-site greywater treatment systems are under development including biofiltration, whose efficiency is influenced by the filter media. Therefore, the main objective of this study was to evaluate the influence of the type of filter media and their grain size in the removal of organic and microbial pollutants from greywater. Hence, three types of local filter media of different grain size were used for the pre-treatment of greywater. Their removal potential and clogging time were evaluated and compared. The results indicated that the type of filter media and the grain size have an influence on the elimination of organic and microbial pollution from greywater. Indeed, sand of 1 - 2 mm in size obtained the highest removal efficiencies of organic pollutants (67.35% and 78.04% for COD and BOD5 respectively) and microbial indicators (2.07, 1.77 and 2.27 log. units for E. coli, fecal coliforms and enterococci respectively). Although media of fine texture enhanced the removal efficiencies, they experienced significant clogging problems. To overcome these limitations while enhancing the removal efficiency, 1) pre-treatment stage with coarse materials followed by a treatment with finer materials or 2) the use of a combination of fine and coarse materials should be considered.展开更多
The latent heat of condensation is lost to the atmosphere; hence it is not utilized to increase distillate output of single basin solar stills. This difficulty was overcome by attaching an additional basin to the main...The latent heat of condensation is lost to the atmosphere; hence it is not utilized to increase distillate output of single basin solar stills. This difficulty was overcome by attaching an additional basin to the main basin. The performance of the double basin solar still was also increased by attaching vacuum tubes to the lower basin; hence the lower basin possessed a higher tempera- ture throughout the day. The latent heat of condensation of the bottom basin was also utilized to increase distillate. But the distillate output of the compared with that of the proposed a novel approach to of the double basin solar still top basin was even lower bottom basin. This paper increase the distillate output attached with vacuum tubes by introducing different sensible energy storage materials like pebbles, black granite gravel and calcium stones to increase the basin area. Experiments were conducted in climate conditions of Mehsana （23.6000° N, 72.4000° E） Gujarat from April to September 2013 with a constant water depth of 2 cm in the top basin with and without the use of basin materials. The results showed that the distillate output of basin material with calcium stones is greater （74%） compared with that of black granite gravel and pebbles. The integration of vacuum tubes with solar still greatly increases the distillate output of the solar still by providing hot water at the lower basin.展开更多
文摘Several on-site greywater treatment systems are under development including biofiltration, whose efficiency is influenced by the filter media. Therefore, the main objective of this study was to evaluate the influence of the type of filter media and their grain size in the removal of organic and microbial pollutants from greywater. Hence, three types of local filter media of different grain size were used for the pre-treatment of greywater. Their removal potential and clogging time were evaluated and compared. The results indicated that the type of filter media and the grain size have an influence on the elimination of organic and microbial pollution from greywater. Indeed, sand of 1 - 2 mm in size obtained the highest removal efficiencies of organic pollutants (67.35% and 78.04% for COD and BOD5 respectively) and microbial indicators (2.07, 1.77 and 2.27 log. units for E. coli, fecal coliforms and enterococci respectively). Although media of fine texture enhanced the removal efficiencies, they experienced significant clogging problems. To overcome these limitations while enhancing the removal efficiency, 1) pre-treatment stage with coarse materials followed by a treatment with finer materials or 2) the use of a combination of fine and coarse materials should be considered.
文摘The latent heat of condensation is lost to the atmosphere; hence it is not utilized to increase distillate output of single basin solar stills. This difficulty was overcome by attaching an additional basin to the main basin. The performance of the double basin solar still was also increased by attaching vacuum tubes to the lower basin; hence the lower basin possessed a higher tempera- ture throughout the day. The latent heat of condensation of the bottom basin was also utilized to increase distillate. But the distillate output of the compared with that of the proposed a novel approach to of the double basin solar still top basin was even lower bottom basin. This paper increase the distillate output attached with vacuum tubes by introducing different sensible energy storage materials like pebbles, black granite gravel and calcium stones to increase the basin area. Experiments were conducted in climate conditions of Mehsana （23.6000° N, 72.4000° E） Gujarat from April to September 2013 with a constant water depth of 2 cm in the top basin with and without the use of basin materials. The results showed that the distillate output of basin material with calcium stones is greater （74%） compared with that of black granite gravel and pebbles. The integration of vacuum tubes with solar still greatly increases the distillate output of the solar still by providing hot water at the lower basin.
