Removal of dissolved organic matter in water-hyacinth waste-water treatment lagoons
Secondary treatment of domestic wastewater in water hyacinth lagoons was evaluated under experimental conditions to assess the role of the roots' bacterial biofilm in the removal of dissolved organic matter (DOM). Research was conducted to (1) quantify removal rates by the biofilm as a function of bulk DOM concentration, (2) formulate an analytical model of DOM removal incorporating biofilm activity, and (3) test the model response to variable organic loads in a pilot-scale plant. Removal of DOM by the biofilm was quantified in continuous-flow water hyacinth tanks at ten concentrations ranging from 45 to 330 g COD m {sup {minus}3} . Total DOM removal in the denitrifying, acetate-based experimental system was measured and partitioned into two fractions associated with the activity of biofilm and suspended bacteria. Calculated DOM removal by the biofilm was adjusted for the release of organic compounds by debris decomposition. Values of DOM removal were used to calculate oxygen transfer rates from the water hyacinth roots. A model of DOM removal in water hyacinth lagoons was formulated. The model, composed of four differential equations, was solved at steady-state conditions and the validity of its simulation results was tested in pilot-scale tanks. Hydraulic detection times ranging from 2 to 28 days were evaluated using biofilm density and concentrations of DOM and particulate organics as monitoring parameters of the model response. The observed decrease of suspended bacterial biomass along the tank was correctly simulated by the model, but predictions of effluent concentrations were not always consistent. Predicted values of biofilm bacterial mass were similar to those measured in the tanks, except when large algal populations were present in the film.
- Research Organization:
- Texas A and M Univ., College Station, TX (United States)
- OSTI ID:
- 5117434
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ORGANIC MATTER
BIODEGRADATION
WASTE WATER
WASTE PROCESSING
BACTERIA
DENITRIFICATION
ECOLOGICAL CONCENTRATION
MATHEMATICAL MODELS
MONITORING
REMEDIAL ACTION
WATER HYACINTHS
WATER POLLUTION
WATER TREATMENT
AQUATIC ORGANISMS
CHEMICAL REACTIONS
DECOMPOSITION
HYDROGEN COMPOUNDS
LILIOPSIDA
LIQUID WASTES
MAGNOLIOPHYTA
MANAGEMENT
MATTER
MICROORGANISMS
OXYGEN COMPOUNDS
PLANTS
POLLUTION
PROCESSING
WASTE MANAGEMENT
WASTES
WATER
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)
560300 - Chemicals Metabolism & Toxicology