Simultaneous biological removal of endosulfan (alpha+beta) and nitrates from drinking waters using wheat straw as substrate.
Nitrate and endosulfan (alpha+beta) removal was studied in an upflow biological denitrification reactor packed with wheat straw as carbon source and support particles for microorganisms. While almost complete nitrate elimination and between 65% and 70% endosulfan (alpha+beta) elimination occurred when the temperature was higher than 20 degrees C; below that value, nitrate removal efficiency decreased to about 10%. Nitrate, dissolved organic carbon (DOC), and endosulfan (alpha+beta) removal efficiencies decreased considerably at 1500 microg/l endosulfan concentration in the batch experiments. Although a high removal efficiency was observed for endosulfan (alpha+beta) and nitrate in the biological denitrification continuous reactor, the effluent water could not be used for drinking purpose because of the unacceptable levels of endosulfan (alpha+beta), colour and dissolved organic content. During the continuous study, 23.4% of the initial weight of wheat straw was lost and 24 g was consumed per gram of nitrogen removed. The results of the continuous study showed that 21.3% of the endosulfan removal was achieved by adsorption onto the wheat straw and 68.2% of the endosulfan removal occurred by biological activity and the remaining portion was detected in the effluent water.
Aslan
Sükrü
S
Department of Environmental Engineering, Cumhuriyet University, 58140, Sivas, Turkey. sukru.aslan@deu.edu.tr
Türkman
Ayşen
A
D000327:Adsorption; D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors; D004726:Endosulfan / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014908:Triticum; D018508:Water Purification / Q000379:methods*
D007306:Insecticides; D009566:Nitrates; D004726:Endosulfan; D010100:Oxygen