Practical experience with combined carbon oxidation and nitrification in plastic media trickling filters

Heinemann, T. A.; Land, Greg; Watson, Richard S.

doi:10.2166/wst.1994.0761

Cited by 11 publications

(9 citation statements)

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“…The natural passage of air through voids present in the biofilm support media [25] has been shown to avoid oxygen limitation and in our trials dissolved oxygen concentrations in bulk leachate were maintained close to saturation even for the strongest leachates.…”

Section: Discussionsupporting

confidence: 54%

Aerobic biological treatment of landfill leachate

Matthews¹,

Winson²,

Scullion³

2006

WIT Transactions on Ecology and the Environment, Vol 92

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There is an ongoing need to treat leachates from landfills using approaches that avoid expensive installation and operating costs. Faced with such a problem, Powys County Council (Wales, UK) developed a treatment system based on practical experience. Leachate was re-circulated through aeration towers containing a biofilm supported on plastic media before being polished in reed/filter beds.Investigations were undertaken to evaluate the performance of these processes. Replicated model aeration towers (1/300 site scale) were used to establish treatment rates for pollutants in leachates of varying strengths; the effects of temperature and variations in pollutant concentrations were also evaluated. Data from these model experiments were corroborated with findings from pilot-scale plants (1/10 site scale) operating on landfill sites. Assessment of treatment performance was based on the degree of amelioration of standard chemical (ammoniacal-N and total organic carbon) parameters. A range of related parameters including nitrate, pH and redox potential were measured in support of these assessments.Model system experiments indicated treatment rates at 15 o C (883-1895 mg NH 3 -N m -3 h -1 ; 347-1600 mg TOC m -3 h -1 ) that were similar across a wide range of leachate concentrations (37-1880 mgl -1 ammoniacal-N; 130-5315 mgl -1 COD). Marked changes in the concentration of leachates did not affect treatment efficiency following a short lag effect. Process rates roughly halved with each 5 o C decrease in temperature below 15 o C, significant nitrification was maintained at temperatures of 0.5-1 o C. High variability in treatment capacity was observed for individual plastic media. Treatment rates in pilot scale plants were slightly higher but broadly consistent with those obtained in model systems.

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Section: Discussionsupporting

confidence: 54%

Aerobic biological treatment of landfill leachate

Matthews¹,

Winson²,

Scullion³

2006

WIT Transactions on Ecology and the Environment, Vol 92

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“…Published data from wastewater NTFs, indicates that this transition occurs at much higher organic carbon concentrations (. 20 mg sBOD 5 L 21 ) than those used in the current study (Wanner & Gujer 1985;Parker & Richards 1986;Daigger et al 1994). For the current study, it was probable that the low concentrations of organic carbon reaching the lower depths (3-5 mg sBOD 5 -L 21 ) still imposed inhibitory effects on nitrification.…”

Section: Nitrification Depth Profilementioning

confidence: 66%

“…Nitrification inhibition was most evident at the top of the NTF, which was an area of the filter that was exposed to the highest concentrations of organic carbon (Figures 3 and 4). has been reported by Wanner & Gujer (1985), Parker & Richards (1986), Daigger et al (1994), Metcalf & Eddy Inc. (2003 and Pearce (2004). Published data from wastewater NTFs, indicates that this transition occurs at much higher organic carbon concentrations (.…”

Section: Nitrification Depth Profilementioning

confidence: 74%

“…The effect would be to minimise the competition between heterotrophs and nitrifiers for DO via the vertical separation of heterotrophic populations from nitrifying populations. The partitioning of biological activity within the filter bed into vertical zones of carbon removal (predominantly heterotrophic) and nitrification (predominantly autotrophic) may be a function of bed depth and relative substrate availability, since ammonia and organic carbon concentrations are expected to change with depth (Daigger et al 1994). This study tested the hypothesis that during periods of increased organic carbon loads, heterotrophic bacteria dominate the top filter depths where the greatest concentration of organic substrate is introduced.…”

Section: Introductionmentioning

confidence: 99%

“…The lower depths of the filter would therefore be expected to receive filtrate lower in organic content than above and would favour the growth of nitrifiers (Daigger et al 1994;Metcalf & Eddy Inc., 2003). The filter depth at which most of the ammonia is removed will depend on the influent carbon concentrations, making bed depth and surface area crucial design parameters for NTFs.…”

Section: Introductionmentioning

confidence: 99%

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The impact of organic carbon on the performance of a high rate nitrifying trickling filter designed to pre-treat potable water

Akker

Holmes²,

Cromar

et al. 2010

Water Science and Technology

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The application of nitrifying trickling filters (NTFs) to potable water treatment is less well understood than their application to wastewater treatment, particularly regarding the effect of low ammonia substrate concentrations and organic carbon loading on filter performance. A large pilot-scale NTF was operated under conditions that simulated the raw water quality of poorly protected catchments typically found in SE Asia, with the objective of reducing the ammonia driven chlorine demand during disinfection. The efficacy of a high rate NTF to remove low concentrations of ammonia (0.5-5.0 mg NH(4)-N L(-1)) in the presence of high organic carbon (1-12 mg soluble biochemical oxygen demand (sBOD(5)) L(-1)) was investigated. Results demonstrated that 90 to 100% of nitrification was maintained only when the carbon load was less than 0.7 g sBOD(5) m(-2) d(-1) (<4 mg sBOD(5) L(-1)). Once the organic load was increased beyond 0.75 to 2.1 g sBOD(5) m(-2) d(-1) (4.5-12.1 mg sBOD(5) L(-1)), a linear decline in nitrification from 70 to 15% was observed within a timeframe of 8 to 10 d. The impact of high organic loads on the distribution of nitrification down the NTF was also investigated. Results confirmed that carbon loads greater than 0.95 g sBOD(5) m(-2) d(-1) (>5.5 mg sBOD(5) L(-1)), severely suppressed nitrification throughout the entire filter bed.

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