A semicircular section tubular photoreactor has been constructed, characterized and applied to the treatment of groundwater contaminated with As（V） by means of the SORAS （solar oxidation and removal of arsenic） te...A semicircular section tubular photoreactor has been constructed, characterized and applied to the treatment of groundwater contaminated with As（V） by means of the SORAS （solar oxidation and removal of arsenic） technique, using ferrous and citrate salts. The solar concentrator was built with recyclable waste materials： glass tubes from fluorescent lamps and 6-inch diameter PVC pipes cut in half and covered by aluminum foil. The reactor concentrates solar radiation up to 2.8 times its natural intensity. Batch irradiation experiments followed by controlled agitation （shear rate = 30-33 s^-1; 20 min agitation period） showed that the photoreactor accelerates the formation of settleable floccules （Dp 〉 0.5mm）, compared with a fluorescent lamp glass tube alone and a 2 L PET （polyethylene terephthalate） bottle. Irradiation times necessary for floccule formation in the photoreactor, the fluorescent lamp tube and the PET bottle were 15 min, 25 min and 60 min, respectively. Continuous flow experiments using a photoreactor with a photo-collection area of 0.9 m^2 and a hydraulic retention time （equal to the irradiation time） of 15 rain showed that immediate formation of floccules of good settleability occurs when the solution is subjected to moderate agitation （33 s^-1）. An efficiency of 98.36% for As（V） removal was obtained with a final concentration of 16.5 ktg/L in decanted waters. In accordance to these results, the photoreactor is able to treat approximately 130 L/m^2 within a 5-h period with UVA irradiation intensities of 50-70 W/mE.展开更多
文摘A semicircular section tubular photoreactor has been constructed, characterized and applied to the treatment of groundwater contaminated with As（V） by means of the SORAS （solar oxidation and removal of arsenic） technique, using ferrous and citrate salts. The solar concentrator was built with recyclable waste materials： glass tubes from fluorescent lamps and 6-inch diameter PVC pipes cut in half and covered by aluminum foil. The reactor concentrates solar radiation up to 2.8 times its natural intensity. Batch irradiation experiments followed by controlled agitation （shear rate = 30-33 s^-1; 20 min agitation period） showed that the photoreactor accelerates the formation of settleable floccules （Dp 〉 0.5mm）, compared with a fluorescent lamp glass tube alone and a 2 L PET （polyethylene terephthalate） bottle. Irradiation times necessary for floccule formation in the photoreactor, the fluorescent lamp tube and the PET bottle were 15 min, 25 min and 60 min, respectively. Continuous flow experiments using a photoreactor with a photo-collection area of 0.9 m^2 and a hydraulic retention time （equal to the irradiation time） of 15 rain showed that immediate formation of floccules of good settleability occurs when the solution is subjected to moderate agitation （33 s^-1）. An efficiency of 98.36% for As（V） removal was obtained with a final concentration of 16.5 ktg/L in decanted waters. In accordance to these results, the photoreactor is able to treat approximately 130 L/m^2 within a 5-h period with UVA irradiation intensities of 50-70 W/mE.
