Differences in bacterial N, P, and COD removal in pilot-scale constructed wetlands with varying flow types

2020 ◽  
Vol 318 ◽  
pp. 124061
Author(s):  
Luping Zeng ◽  
Ran Tao ◽  
Nora Fung-yee Tam ◽  
Wenda Huang ◽  
Longzhen Zhang ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Pilot Scale ◽  
Cod Removal

A model for organic matter removal in free water surface constructed wetlands

1998 ◽  
Vol 38 (1) ◽  
pp. 369-377 ◽  
Author(s):  
C. Polprasert ◽  
N. R. Khatiwada ◽  
J. Bhurtel
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Water Surface ◽  
Oxygen Demand ◽  
Free Water ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Cod Removal ◽  
Model Parameters ◽  
Free Water Surface

This study was conducted to determine performance of free water surface (FWS) constructed wetlands located in the tropics in the removal of organic matter and to assess the importance of biofilm bacteria in the overall kinetics of organic matter (or chemical oxygen demand, COD) removal. Because constructed wetlands normally contain both biofilm and suspended bacteria, a kinetic model incorporating the activities of these two bacteria groups, dispersion number and hydraulic retention time, was employed. The model parameters essential for the calculation of COD removal in FWS constructed wetlands were determined from the experiments and some from the literature. The model was found satisfactory in predicting COD removal efficiencies in a pilot-scale FWS constructed wetland unit treating a domestic wastewater.

Assessment of clogging in constructed wetlands by saturated hydraulic conductivity measurements

2019 ◽  
Vol 79 (2) ◽  
pp. 314-322 ◽  
Author(s):  
F. Licciardello ◽  
R. Aiello ◽  
V. Alagna ◽  
M. Iovino ◽  
D. Ventura ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Hydraulic Conductivity ◽  
Constructed Wetlands ◽  
Spatial Scales ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Test Method ◽  
Conductivity Measurements ◽  
Multiple Spatial Scales ◽  
Ks Values

Abstract This study aims at defining a methodology to evaluate Ks reductions of gravel material constituting constructed wetland (CW) bed matrices. Several schemes and equations for the Lefranc's test were compared by using different gravel sizes and at multiple spatial scales. The falling-head test method was implemented by using two steel permeameters: one impervious (IMP) and one pervious (P) on one side. At laboratory scale, mean K values for a small size gravel (8–15 × 10−2 m) measured by the IMP and the P permeameters were equal to 19,466 m/d and 30,662 m/d, respectively. Mean Ks values for a big size gravel (10–25 × 10−2 m) measured by the IMP and the P permeameters were equal to 12,135 m/d and 20,866 m/d, respectively. Comparison of Ks values obtained by the two permeameters at laboratory scale as well as a sensitivity analysis and a calibration, lead to the modification of the standpipe equation, to evaluate also the temporal variation of the horizontal Ks. In particular, both permeameters allow the evaluation of the Ks decreasing after 4 years-operation and 1–1.5 years' operation of the plants at full scale (filled with the small size gravel) and at pilot scale (filled with the big size gravel), respectively.

Effect of plants and filter materials on bacteria removal in pilot-scale constructed wetlands

2005 ◽  
Vol 39 (7) ◽  
pp. 1361-1373 ◽  
Author(s):  
Gabriela Vacca ◽  
Helmut Wand ◽  
Marcell Nikolausz ◽  
Peter Kuschk ◽  
Matthias Kästner
Keyword(s):  
Constructed Wetlands ◽  
Pilot Scale ◽  
Filter Materials ◽  
Bacteria Removal

Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal
Keyword(s):  
Removal Rate ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Pilot Scale ◽  
Cod Removal ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Removal Mechanism ◽  
Term Operation ◽  
Fixed Bed Reactors

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.

scholarly journals Innovative Effluent Capture and Evacuation Device that Increases COD Removal Efficiency in Subsurface Flow Wetlands

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 418 ◽  
Author(s):  
Pedro Cisterna-Osorio ◽  
Verónica Lazcano-Castro ◽  
Gisela Silva-Vasquez ◽  
Mauricio Llanos-Baeza ◽  
Ignacio Fuentes-Ortega
Keyword(s):  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Cod Removal ◽  
Discharge Device ◽  
The Impact ◽  
Real Scale ◽  
Conventional Device

The objective of this work is to evaluate the impact of innovative modifications made to conventional effluent capture and discharge devices used in subsurface flow wetlands (SSFW). The main modifications that have been developed extend the influence of the capture and discharge device in such a way that the SSFW width and height are fully covered. This improved innovative device was applied and evaluated in two subsurface flow wetlands, one on a pilot scale and one on a real scale. To evaluate the impact of the innovative device with respect to the conventional one in the operational functioning of subsurface flow wetlands, the elimination of chemical oxygen demand (COD) was measured and compared. The results show that for the innovative device, the COD removal was 10% higher than for the conventional device, confirming the validity and effectiveness of the modifications implemented in the effluent capture and discharge devices used in SSFW.

Pig Wastewater Treatment in Water Hyacinth Ponds

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2381-2384 ◽  
Author(s):  
C. Polprasert ◽  
S. Kessomboon ◽  
W. Kanjanaprapin
Keyword(s):  
Wastewater Treatment ◽  
Water Hyacinth ◽  
Loading Rate ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Small Scale ◽  
N Removal ◽  
In Series

Small-scale and pilot-scale experiments were conducted on pig wastewater treatment in water hyacinth (Eichhornia crassipesl ponds. The main objectives were to evaluate the treatment performance of the water hyacinth ponds and to determine suitable operating conditions. From the experimental results obtained, the optimum organic loading rate was found to be 200 kg COD/(ha.d), while the hydraulic retention times were proposed to be 10-20 days. The % COD removal in the small-scale water hyacinth ponds were 74-93, while for the pilot-scale ponds the % COD removal were 52-72 because of fluctuations in the influent wastewater characteristics and occasional insect attacks on the water hyacinth leaves and stems. Similar results were obtained for N removal. Although the water hyacinth ponds were found to be feasible for pig wastewater treatment, at least one polishing pond in series should be provided to polish the water hyacinth pond effluents before discharging into the environment.

Performance assessment of pilot horizontal sub-surface flow constructed wetlands for removal of diesel from wastewater by Scirpus grossus

2013 ◽  
Vol 68 (10) ◽  
pp. 2271-2278 ◽  
Author(s):  
Israa Abdulwahab Al-Baldawi ◽  
Siti Rozaimah Sheikh Abdullah ◽  
Nurina Anuar ◽  
Fatihah Suja ◽  
Mushrifah Idris
Keyword(s):  
Constructed Wetlands ◽  
Suspended Solids ◽  
Flow System ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Surface Flow ◽  
Total Petroleum Hydrocarbon ◽  
Physical Parameters ◽  
Contaminated Water ◽  
Development Technology

One of the appropriate development technology options for the treatment of wastewater contaminated with diesel is constructed wetlands (CWs). Throughout 72 days of exposure, sampling was carried out for monitoring of physical parameters, plant growth and the efficiency of total petroleum hydrocarbon (TPH) removal, as an indication for diesel contamination, to assess the pilot-scale performance. Four pilot CWs with a horizontal sub-surface flow system were applied using the bulrush of Scirpus grossus. The CWs were loaded with different diesel concentrations of 0, 0.1, 0.2 and 0.25% (Vdiesel/Vwater). The TPH removal efficiencies were 82, 71, and 67% at the end of 72 days for diesel concentrations of 0.1, 0.2, and 0.25% respectively. In addition, the high removal efficiency of total suspended solids and chemical oxygen demand (COD) were 100 and 75.4% respectively, for a diesel concentration of 0.1%. It was concluded that S. grossus is a potential plant that can be used in a well-operated CW for restoring 0.1% diesel-contaminated water.

Sign in / Sign up

Export Citation Format

Share Document