The role of nematodes in low rate percolating filter sewage treatment works

Woombs, Mark; Laybourn‐Parry, Johanna

doi:10.1016/0043-1354(86)90104-1

Cited by 14 publications

(6 citation statements)

References 29 publications

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“…On the contrary, a metazoan population was developed in the SMBR (Figures 6d, 6e, and 6f). Traditionally, they have been considered as predators, which consume microorganisms, but their effect is not as clear as that of protozoa (Woombs and Laybourn‐Parry, 1986). Moreover, suggested that the presence of the metazoa population plays a significant role in removing accumulated sludge from the membrane surface.…”

Section: Resultsmentioning

confidence: 99%

Submerged Membrane Bioreactor at Substrate‐Limited Conditions: Activity and Biomass Characteristics

Delgado

Villarroel

Cabrera

2010

Water Environment Research

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A pilot‐scale membrane bioreactor was operated for advanced treatment of secondary effluent from a wastewater treatment plant. The performance and biomass characteristics were evaluated under two different hydraulic retention time (HRT) values (7.5 and 15 hours). The system was operated successfully without biomass purge and, after an initial phase, evolved until reaching a constant mixed‐liquor volatile suspended solids (MLVSS) concentration, which resulted in the same value of carbon utilization rate (0.067 ± 0.004 kg COD kg−1 MLVSS d−1) for both HRTs. Respiration tests (maximum and endogenous oxygen uptake rates) confirmed a low microbial activity, which approached constant values (0.132 ± 0.001 and 0.064 ± 0.007 g O2 g−1 MLVSS d−1, respectively), regardless of the HRT. The sludge morphology and bound and supernatant extracellular polymeric substances also were assessed. Membrane performance was characterized by a stable behavior occurring simultaneously with a high level of biodegradation in the microcolloidal and soluble fraction.

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Section: Resultsmentioning

confidence: 99%

Submerged Membrane Bioreactor at Substrate‐Limited Conditions: Activity and Biomass Characteristics

Delgado

Villarroel

Cabrera

2010

Water Environment Research

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“…Biomass and density are expressed per unit area of media sampled by the method of Woombs & Laybourn-Parry (1986 where W = the greatest width (m); L = the length (pm); w = the live weight (g).…”

Section: Iii) Biomass Determinationsmentioning

confidence: 99%

“…The majority of freeliving species appear to be bacterivores, and studies on soil microcosms indicate that the presence of bacterial grazers, such as nematodes or amoebae, has the effect of increasing the rate of nutrient cycling (Coleman et al, 1977). Studies on sewage treatment plants suggest that in filter-beds nematodes play a role in the bio-oxidation of sewage by virtue of their grazing activity on the bacterial community (Woombs & Laybourn-Parry, 1986).…”

Section: Introductionmentioning

confidence: 99%

“…The maximum daily process load at Caton was 0.778 kg BOD m -2 and at Carnforth 0.247 kg BOD m -2 . Two specimens of rock media were randomly removed from the surface and at depths of 7.5, 15, 30, 45, 90, 135 and 180 cm from a series of medium filled baskets placed one above the other in a metal mesh well sunk into one of the filter beds at each site as described by Woombs & Laybourn-Parry (1986).…”

Section: Introductionmentioning

confidence: 99%

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The temporal and spatial distribution of nematodes in percolating filters

Laybourn‐Parry

Woombs

1988

Hydrobiologia

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The spatial and temporal distribution of nematodes in two low rate percolating filter bed sewage treatment plants at Carnforth and Caton, Lancashire, were investigated. Nematodes were abundant reaching densities up to 900 cm-2 of media surface. Numbers decreased down the bed and species composition displayed spatial differences with bed depth. Eight orders of nematode were represented, members of the sub-family Diplogasterinae and Rhabditinae were particularly common. A seasonal pattern of abundance was clearly apparent; two peaks occurred, one in May and a second during the winter months. Lowest numbers corresponded with periods of highest temperature. The demise of the nematodes in the spring was related to the sloughing of the surface film on the media.

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“…While bacteria play a key role in pollutant transformation and removal, microfauna (consisting of protozoa and micrometazoa), as the main consumers of various particles in wastewater, also affect the treatment performance through their predation (Curds 1982;Woombs and Laybourn-Parry 1986) and excretion of compounds stimulating bacterial growth (Ratsak et al 1996;Shen et al 1990) and promoting bacterial flocculation (Curds 1982;Pauli et al 2001). Insight into microfauna community composition is of great significance for a holistic understanding of activated sludge ecosystems.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of the microfauna community in a full-scale municipal wastewater treatment plant experiencing sludge bulking

et al. 2013

European Journal of Protistology

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We investigated the dynamics of the microfauna community in activated sludge, with special reference to sludge bulking, in two parallel municipal wastewater treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that microfauna community structures were highly correlated with the sludge volume index (SVI) (p < 0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p < 0.01) and hydraulic retention time (HRT) (p < 0.05) were also related to microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SVI (p < 0.001) and decrease in water temperature (p < 0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking.

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The role of nematodes in low rate percolating filter sewage treatment works

Cited by 14 publications

References 29 publications

Submerged Membrane Bioreactor at Substrate‐Limited Conditions: Activity and Biomass Characteristics

Submerged Membrane Bioreactor at Substrate‐Limited Conditions: Activity and Biomass Characteristics

The temporal and spatial distribution of nematodes in percolating filters

Dynamics of the microfauna community in a full-scale municipal wastewater treatment plant experiencing sludge bulking

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