A Review of the Design and Performance of Vertical-flow and Hybrid Reed Bed Treatment Systems

1999 ◽  
Vol 40 (3) ◽  
pp. 1-9 ◽  
Author(s):  
Paul Cooper
Keyword(s):  
Oxygen Transfer ◽  
Alternative Methods ◽  
Horizontal Flow ◽  
Vertical Flow ◽  
Reed Bed ◽  
And Performance ◽  
Oxygen Transfer Capacity

The paper reviews the different options for the combination of vertical- and horizontal-flow beds used in hybrid reed bed/wetland systems. The design and performance of these systems are briefly described. The importance of the oxygen transfer capacity of the different arrangements to their performance and their size is discussed. Alternative methods for denitrification are briefly described.

Design of a Hybrid Reed Bed System to Achieve Complete Nitrification and Denitrification of Domestic Sewage

1999 ◽  
Vol 40 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Paul Cooper ◽  
Paul Griffin ◽  
Stuart Humphries ◽  
Adrian Pound
Keyword(s):  
Horizontal Flow ◽  
Vertical Flow ◽  
Total N ◽  
Reed Beds ◽  
Loading Rates ◽  
Flow Systems ◽  
Reed Bed ◽  
And Performance ◽  
Sludge Drying ◽  
Complete Nitrification

The design of vertical-flow (VF) reed beds is reviewed and the performance of the few worldwide existing hybrid systems, combining both horizontal- and vertical-flow beds, is assessed. Horizontal-flow (HF) beds are good for suspended solids removal and will remove BOD5 up to a set loading. Vertical-flow beds can achieve BOD5 removal at much higher loading rates and they are capable of complete nitrification as tertiary or secondary treatment systems. It is possible to achieve biological denitrification in horizontal-flow beds. By combining horizontal- and vertical-flow systems in the appropriate process sequence it is thus possible to produce a system which removes BOD5, TSS and achieves complete nitrification as well as substantial removal of nitrate and hence a lowered Total N. The paper discusses the possible process options for combining horizontal- and vertical-flow systems. One example of these systems will be described in more detail. This is a flexible hybrid system being built by Severn Trent Water. Designed to treat the flow for a small village with a population of 129 it will have vertical-flow beds followed by horizontal-flow beds. The design allows for flexibility such that the size of the vertical-flow and horizontal-flow stages can be altered (for experimental purposes) to allow the design arrangement to be stressed and performance evaluated with the intention of defining the optimum loading rates for each of the stages. The same site also has sludge drying reed beds for treating the primary sludge.

Compact vertical flow constructed wetland systems - first two years’ performance

2003 ◽  
Vol 48 (5) ◽  
pp. 15-23 ◽  
Author(s):  
C.M. Weedon
Keyword(s):  
Oxygen Transfer ◽  
Transfer Rate ◽  
Oxygen Transfer Rate ◽  
Oxygen Demand ◽  
Phosphate Removal ◽  
Normal Operation ◽  
Vertical Flow ◽  
Average Percentage ◽  
Load Rate ◽  
Reed Bed

In order to move towards optimising wastewater treatment performance by vertical down-flow reed beds, user and installer demands were applied to design, resulting in the “compact vertical flow reed bed” (CVF bed). Performance data are presented for the two years since commissioning a CVF bed and pond system serving eight residents. Particular emphasis was placed on investigating oxygen transfer rate and susceptibility to hydraulic overloading. Average percentage concentration reduction effected by single passage through the bed exceeded 97% for suspended solids and biochemical oxygen demand, and 90% for ammoniacal nitrogen and total Kjeldahl nitrogen. The occurrence of nitrification and denitrification (up to 58%) within the same bed was clearly indicated. Percentage ortho-phosphate removal averaged 92% over the first 17 months’ operation and thereafter fell to approximately 45%. Faecal coliform density underwent an almost four log reduction. Oxygen transfer rate within the reed bed was between 28-36 gO2/m2.d. Normal operation was maintained until six times dry weather hydraulic load rate was exceeded, at which point surface flooding occurred. The capacity of a single vertical flow reed bed to achieve effective treatment of domestic sewage was demonstrated, with no requirement for reduced load rates, promising substantial advantages over established approaches.

The design and performance of a nitrifying vertical-flow reed bed treatment system

1997 ◽  
Vol 35 (5) ◽  
pp. 215-221 ◽  
Author(s):  
Paul Cooper ◽  
Mark Smith ◽  
Henrietta Maynard
Keyword(s):  
Nitrate Solution ◽  
Treatment System ◽  
Vertical Flow ◽  
Biological Filter ◽  
Ammonium Nitrate Solution ◽  
Reed Bed ◽  
And Performance ◽  
Long Term Performance ◽  
Term Performance

The paper describes the design, construction and the monitoring of a vertical-flow Reed Bed Treatment System (RBTS) which achieves tertiary nitrification of the effluent from a biological filter, treating the sewage flow from a population of about 200 people. It treats the flows from toilets, kitchen laboratories and a saline wastewater. The RBTS system takes effluent from an old biological filter and produces a nitrified effluent from a two-stage intermittently-dosed system. The paper shows the long-term performance of the system over a 4 year period and also describes experiments to assess the nitrification performance using a step-feed of ammonium nitrate solution. The system shows a removal of 8-13 g NH4-N/m3 of bed day. The design basis is shown and the operational features described.

The design and performance of a vertical flow reed bed for the treatment of high ammonia, low suspended solids organic effluents

1997 ◽  
Vol 35 (5) ◽  
pp. 197-204 ◽  
Author(s):  
Michael Morris ◽  
Robert Herbert
Keyword(s):  
Suspended Solids ◽  
Cod Removal ◽  
Vertical Flow ◽  
Ammoniacal Nitrogen ◽  
Influent Concentration ◽  
Infiltration Rates ◽  
Processing Wastes ◽  
Coarse Substrate ◽  
Reed Bed ◽  
And Performance

A design approach for vertical flow constructed wetlands based on selection of not only bed size, but also substrate characteristics, configuration, plant species/variety and management is piloted in a trial system to treat sugar beet processing wastes. In the beet processing season these wastes are hot, low in suspended solids and relatively high in ammoniacal nitrogen. The pilot system consists of a small, coarse substrate first stage followed by a larger, fine substrate second stage. Results in the beet processing season show 87.3% COD removal, 87.7% TSS removal and a 79.5% reduction in ammoniacal nitrogen. Treating larger volumes of cooler stored wastes out of season, the mean removal efficiencies were 73.9% for COD, 88.0% for TSS and 93.4% for ammoniacal nitrogen. TSS removal m−2 was found to be independent of influent concentration and temperature, whilst COD removal m−2 was found to be independent of temperature, but not influent concentration. Removal of ammoniacal nitrogen appeared to be dependent upon influent concentration and, in particular, upon temperature. Infiltration rates were shown to be negatively correlated to length of dosing cycle. Simple models of substrate permeability based on substrate particle size distribution are seen to be inadequate for describing infiltration rates in vertical downflow systems, even those treating low strength wastes.

The design, operation and performance of a municipal hybrid reed bed treatment system

2003 ◽  
Vol 48 (5) ◽  
pp. 119-126 ◽  
Author(s):  
S. O'Hogain
Keyword(s):  
Treatment System ◽  
Septic Tank ◽  
Vertical Flow ◽  
Max Planck ◽  
Operational Characteristics ◽  
Monitoring Study ◽  
Pump Sump ◽  
Reed Bed ◽  
And Performance ◽  
Final Effluent

The first Irish municipal application of a hybrid reed bed treatment system (RBTS) was designed and constructed at Colecott, County Dublin. The hybrid design for Colecott RBTS was based on modifications to the Max Planck Institute Process (MPIP). The constituent parts of the design were a septic tank, a pump sump, two stage vertical flow beds, a secondary settlement tank, a horizontal reed bed, an outlet chamber and outfall pipe. The population at the time of design was 48, but with future development in mind 60 was used as the population equivalent (pe). Construction and operational characteristics are outlined. Results of a two year monitoring study are presented, showing good performance and producing a final effluent with 88% BOD removal, 89% COD removal and 99% SS removal. Percentile compliance with EU discharge standards were BOD 60%, COD 100%, SS 100% with 50% for nitrogen and 0% for PO4. Surface water input increased flows to twice the average, resulting in increased maintenance visits without affecting results. The ability to deal with the excess inflow is demonstrated by the system. The method of distribution to the primary vertical beds was satisfactory while that on the secondary vertical beds was not.

Reed bed treatment systems for sewage treatment in the United Kingdom - the first 10 years’ experience

1995 ◽  
Vol 32 (3) ◽  
pp. 317-327 ◽  
Author(s):  
P. Cooper ◽  
B. Green
Keyword(s):  
Root Zone ◽  
Sewage Treatment ◽  
Horizontal Flow ◽  
Water Industry ◽  
Soil Systems ◽  
Design Changes ◽  
Flow Systems ◽  
Group A ◽  
Reed Bed ◽  
The Uk

The UK Water Industry first became interested in Reed Bed Treatment Systems for sewage in 1985. Early problems were experienced with soil-based horizontal-flow systems of the Root Zone type. The problems were overcome by national co-ordination of a development programme and international co-operation by an EC Expert Contact Group. A number of different types of systems have now been developed and the systems are now being accepted. The paper reviews the development of these systems for secondary and tertiary treatment and nitrification and mentions development of systems for other forms of treatment. The design changes made to overcome the problems are described. These include the gradual move to the use of gravel-based systems because of the difficulty experienced with over-land flow in the soil systems. The sizing of the systems is described together with performance data for the original horizontal-flow and the more recently developed vertical-flow systems. Treatment at secondary and tertiary levels is illustrated and the potential for nitrification. Early problems with reed growth have been overcome by planting with port-grown seedlings. After 10 years the process is generally accepted by the Water Industry as an appropriate treatment for villages and there are now between 200 and 300 systems in operation.

Nitrogen removal in a combined system: vertical vegetated bed over horizontal flow sand bed

2001 ◽  
Vol 44 (11-12) ◽  
pp. 137-142 ◽  
Author(s):  
S. Kantawanichkul ◽  
P. Neamkam ◽  
R.B.E. Shutes
Keyword(s):  
Loading Rate ◽  
Low Cost ◽  
Oxygen Demand ◽  
Nitrogen Loading ◽  
Horizontal Flow ◽  
Vertical Flow ◽  
Combined System ◽  
Cost Treatment ◽  
Pig Farm ◽  
Farm Wastewater

Pig farm wastewater creates various problems in many areas throughout Thailand. Constructed wetland systems are an appropriate, low cost treatment option for tropical countries such as Thailand. In this study, a combined system (a vertical flow bed planted with Cyperus flabelliformis over a horizontal flow sand bed without plants) was used to treat settled pig farm wastewater . This system is suitable for using in farms where land is limited. The average COD and nitrogen loading rate of the vegetated vertical flow bed were 105 g/m2.d and 11 g/m2.d respectively. The wastewater was fed intermittently at intervals of 4 hours with a hydraulic loading rate of 3.7 cm/d. The recirculation of the effluent increased total nitrogen (TN) removal efficiency from 71% to 85%. The chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN) removal efficiencies were 95% and 98%. Nitrification was significant in vertical flow Cyperus bed, and the concentration of nitrate increased by a factor of 140. The horizontal flow sand bed enhanced COD removal and nitrate reduction was 60%. Plant uptake of nitrogen was 1.1 g N/m2.d or dry biomass production was 2.8 kg/m2 over 100 days.

scholarly journals Reference evapotranspiration for Londrina, Paraná, Brazil: performance of different estimation methods

2017 ◽  
Vol 38 (4Supl1) ◽  
pp. 2363
Author(s):  
Rodrigo Dlugosz da Silva ◽  
Marcelo Augusto de Aguiar e Silva ◽  
Marcelo Giovanetti Canteri ◽  
Juliandra Rodrigues Rosisca ◽  
Nilson Aparecido Vieira Junior
Keyword(s):  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Global Radiation ◽  
Alternative Methods ◽  
Estimation Methods ◽  
Performance Indices ◽  
Excellent Performance ◽  
Study Region ◽  
Temperature Radiation ◽  
And Performance

Aiming at assessing the performance of alternative methods to Penman-Monteith FAO56 for estimating the reference evapotranspiration (ETo) for Londrina, Paraná, Brazil, the methods temperature radiation, Hicks-Hess, Hargreaves-Samani (1982), Turc, Priestley-Taylor, Tanner-Pelton, Jensen-Haise, Makkink, modified Hargreaves, Stephens-Stewart, Abtew, global radiation, Ivanov, Lungeon, Hargreaves-Samani (1985), Benavides-Lopez, original Penman, Linacre, Blaney-Morin, Romanenko, Hargreaves (1974), McCloud, Camargo, Hamon, Kharrufa, McGuiness-Bordne, and Blaney-Criddle were compared to that standard method recommended by FAO. The estimations were correlated by linear regression and assessed by using the Person’s correlation coefficient (r), concordance index (d), and performance index (c) using a set of meteorological data of approximately 40 years. The methods modified Hargreaves, Stephens-Stewart, Abtew, global radiation, Ivanov, Lungeon, Hargreaves-Samani (1985), Benavides-Lopez, original Penman, and Linacre should be avoided, as they did not present excellent results. The methods McCloud, Camargo, Hamon, Kharrufa, McGuinness-Bordne, Blaney-Criddle, Hargreaves (1974), Romanenko, and Blaney-Morin were classified as very bad, not being recommended. In contrast, the methods temperature radiation, Hicks-Hess, Hargreaves-Samani (1982), Turc, Priestley-Taylor, Tenner-Pelton, Jensen-Haise, and Makkink presented excellent performance indices and can be applied in the study region.

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