Surface Clogging in an Intermittent Stratified Sand Filter

Soil Science Society of America Journal - Tập 68 Số 6 - Trang 1827-1832 - 2004
M. Rodgers1, J. Mulqueen1, Mark G. Healy1
1Dep. of Civil Engineering National Univ. of Ireland Galway Ireland

Tóm tắt

Accumulation of biomass and deposition of suspended solids at the surface of a sand filter can lead to clogging of the filter media. A laboratory intermittent sand filter column, which included three sand strata, was operated for a period of 806 d before failure occurred through surface clogging. Upon dismantling the column, the cause and effects of the surface clogging were investigated. The main mechanism responsible for sand clogging appeared to be biomass buildup. Maximum loss on ignition of filter media samples was 2.35%, and it occurred in the upper 0.01 m of the sand. There was a reduction in field‐saturated hydraulic conductivity in the top 0.01 m of the upper sand stratum from a value of 1.9 × 10−3 ± 1.7 × 10−4 m s−1 (for virgin sand with an effective size, d10, of 0.45 mm) to 3.5 × 10−5 ± 7.5 × 10−6 m s−1 The soil‐water characteristic curve, which relates the volumetric water content (θv) to the soil suction, also reflected the changes in the filter media due to clogging. The water‐holding capacity greatly increased as biomass accumulated in the filter media. Scanning electron microscopy (SEM) confirmed the existence of a clogging organic layer on the surface of the top sand layer.

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Tài liệu tham khảo

Bouwer E.J., 2000, Biofilms II: Process analysis and applications, 123

British Standards Institution., 1990, Classification tests

British Standards Institution., 1990, Chemical and electro‐chemical tests

British Standards Institution., 1990, Compressibility, permeability and durability tests

Brooks R.H., 1966, Properties of porous media affecting fluid flow, ASCE J. Irrig. Drain. Div., 92, 61, 10.1061/JRCEA4.0000425

Byrne E., 1979, Chemical analysis of agricultural materials

Christopherson S.H., 2001, On‐Site Wastewater Treatment: Proc. of the 9th Natl. Symp. on Individual and Small Community Sewage Systems, 207

Craig R.F., 1997, Soil mechanics

10.2134/jeq1974.00472425000300040005x

10.1002/9780470172759

Geo‐Slope International., 2002, Seep/W for finite element seepage analysis. v. 5. User's guide

Gill P.E., 1981, Practical optimization

10.1061/(ASCE)0733-9372(1990)116:4(711)

Gross M., 1985, Proc. of the 4th Natl. Symp. on Individual and Small Community Sewage Systems, 295

10.2134/jeq2004.7130

10.2134/jeq1995.00472425002400010012x

Kropf F.W., 1977, Equilibrium operation of subsurface absorption systems, J. Water Pollut. Control Fed., 17, 2007

10.1016/S0273-1223(97)00066-8

10.1016/S0273-1223(97)00090-5

10.2134/jeq1987.00472425001600020016x

10.1061/(ASCE)0733-9372(1987)113:3(550)

10.1128/AEM.58.5.1690-1698.1992

10.2136/sssaj1980.03615995004400050002x

10.2134/jnrlse.1998.0013

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Soil Science Society of America Journal

Tập 68 Số 6

1827-1832

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