Laboratory investigations were carried out to establish conservative estimates of the contaminant removals obtained by the recharge of local secondary effluents through a sand dune. In the preliminary study, suitabili...Laboratory investigations were carried out to establish conservative estimates of the contaminant removals obtained by the recharge of local secondary effluents through a sand dune. In the preliminary study, suitability of unchlorinated wastewater as opposed to the chlorinated wastewater and the development of headlosses were investigated with respect to the development of anaerobic conditions. In the main laboratory study, a 5 m high Plexiglass sand box column was investigated for conservative predictions. The average removals of BOD, COD, and TOC were over 65%, 65%, and 55%, respectively. The COD was primarily removed in the first 200 cm of the column. The effluent had a residual TOC of 1.66 mg/L and consisted of humic substances. The average removal of microbial indicator organisms： Total Coliform （TC） and Coliphage were over 85% and 66%, respectively. The product water contained only nominal amounts of TC （Average - 21.5 MPN/100 ml） and Coliphage （Average - 6 PFU/100 ml）. The porous media largely remained unaffected by the recharge operation. The changes were mainly seen in the upper 26 cm of the column.展开更多
文摘Laboratory investigations were carried out to establish conservative estimates of the contaminant removals obtained by the recharge of local secondary effluents through a sand dune. In the preliminary study, suitability of unchlorinated wastewater as opposed to the chlorinated wastewater and the development of headlosses were investigated with respect to the development of anaerobic conditions. In the main laboratory study, a 5 m high Plexiglass sand box column was investigated for conservative predictions. The average removals of BOD, COD, and TOC were over 65%, 65%, and 55%, respectively. The COD was primarily removed in the first 200 cm of the column. The effluent had a residual TOC of 1.66 mg/L and consisted of humic substances. The average removal of microbial indicator organisms： Total Coliform （TC） and Coliphage were over 85% and 66%, respectively. The product water contained only nominal amounts of TC （Average - 21.5 MPN/100 ml） and Coliphage （Average - 6 PFU/100 ml）. The porous media largely remained unaffected by the recharge operation. The changes were mainly seen in the upper 26 cm of the column.
