Kinetics of COD removal from a synthetic wastewater in a continuous biological fluidized bed

Kargı, Fikret; Kapdan, İlgi Karapinar

doi:10.1007/bf00417638

Cited by 7 publications

(1 citation statement)

References 14 publications

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“…To minimize introduction of pathogens into the laboratory environment, researchers often use synthetic wastewaters in laboratory treatment studies (Cao et al, 1992; Chen et al, 1995; Kargi and Karapinar, 1995; Kuai and Verstraete, 1998; Noto et al, 1998; Raj and Murphy, 1998; Rodgers, 1999; Romanski et al, 1997; Yoo et al, 1999). Laboratory chemicals were combined to develop a synthetic wastewater with characteristics similar to typical septic tank effluent (Brooks et al, 1984; Crites and Tchobanoglous, 1998; Kristiansen, 1981; Piluk and Hao, 1989; Rock et al, 1984; USEPA, 1977, 2002).…”

Section: Methodsmentioning

confidence: 99%

Nitrogen Removal in Laboratory Model Leachfields with Organic‐Rich Layers

2005

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Septic system leachfields can release dissolved nitrogen in the form of nitrate into ground water, presenting a significant source of pollution. Low cost, passive modifications, which increase N removal in traditional leachfields, could substantially reduce the overall impact on ground water resources. Bench-scale laboratory models were constructed to evaluate the effect of placing an organic layer below the leachfield on total N removal. The organic layer provides a carbon source for denitrification. Column units representing septic leachfields were constructed with sawdust-native soil organic layers placed 0.45 m below the influent line and with thicknesses of 0.0, 0.3, 0.6, and 0.9 m. Using a synthetic septic tank effluent, NO(3)-N concentrations at 3.8 m below the influent line were consistently below 1 mg L(-1) during 10 months of operation compared with a NO(3)-N concentration of nearly 12 mg L(-1) in the control column. The average total N removal increased from 31% without the organic layer to 67% with the organic layer. Total N removal appeared limited by the extent of organic N oxidation and nitrification in the 0.45-m aerobic zone. Design modifications targeted at improving nitrification above the organic layer may further increase total N removal. Increased organic layer thicknesses from 0.3 m to 0.9 m did not significantly improve average total N removal, but caused a shift in residual nitrogen from organic N to ammonia N. Results indicate that addition of a layer of carbon source material at least 0.3 m thick below a standard leachfield substantially improves total N removal.

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