Dirk ESSER Waste free wastewater treatment wetlands in France

Transcription

1 Waste free wastewater treatment wetlands in France Dirk ESSER

2 Short Biography Dirk ESSER, agricultural engineer from Germany Came to France in 1988 to do prost-graduate studies and research work with Cemagref, now IRSTEA (public research institute) Created SINT in 1991 to develop a new wetland system under license from Cemagref > Phragmifilter (excl. license until 2003), also known as French System, which are vertical flow filters, planted with common reeds (Phragmites), treating raw, unsettled sewage, thus producing NO WASTE sludge Associated partner of SINBIO ( and SYNTEA ( co-founder and treasurer of GWT

3 Lay-out of a typical Phragmifilter Fine gravel 1 st stage: 3 * 0.4 m² per person 1.2 m 2 /p.e. (100 g COD.m -2.d -1 on the total filter surface, max 0,7 m. d -1 on the filter in operation ) Three parallel filters feeding/resting :3-4d/7d Sand and fine gravel 2 nd stage: 2 * 0.4 m² per person 0,8 m 2 /p.e. Two parallel filters feeding/resting: 7d/7d

4 Panorama A typical Phragmifilter, working by gravity, before planting of reeds

5 The first stage of a Phragmifilter Vertical flow reed beds Non saturated, freely drained filter media (good oxygen transfer for aerobic degradation) First stage fed with raw unsettled sewage Build up of sludge layer cm / year

6 Feeding of the first stage of a Phragmifilter Needs a good distribution of the water and the waste water solids on the entire surface of the filter Can be achieved by gravity, if sufficient slope, NO ENERGY needed With the patented selfpriming siphon

7 Desludging after 8 to 15 years

8 Sludge quality The sludge retained on the first bed looks and smells like a compost Dry matter Organic matter

9 Montromant (200 p.e.), 500 m² of filter, near Lyons, built in 1994, one desludging Montromant August h composite samples Flow COD BOD 5 SS TKN N-NH4 TN TP % of nominal load m3/day mg/l mg/l mg/l mg/l mg/l mg/l mg/l Inflow 15, ,9 82,13% Outlow ,8 1, Waste free wastewater treatment wetlands in France

10 Les Breviaires (150 p.e.), near Paris, built in 1995, 375 m² of filter, no desludging Les Breviares December 2011 Spot sample COD BOD 5 SS TKN N-NH4 TN TP mg/l mg/l mg/l mg/l mg/l mg/l mg/l Inflow Waste 149 free wastewater 78 treatment Outlow 60 < 3 14 < wetlands 3 in France 1,2 39 5,9

11 Roussillon, 1250 p.e., 1550 m² of filter, south of France (mediterranean climate) built1998, one desludging Roussillon August h composite samples Flow COD BOD 5 SS TKN N-NH4 TN TP % of nominal load m3/day mg/l mg/l mg/l mg/l mg/l mg/l mg/l Inflow Waste 358 free wastewater 81 treatment 114,75% Outlow 45 < 3 4,4 wetlands 3,5in France 8

12 Waste free wastewater treatment wetlands in France

13 Some more recent references Nègrepelisse (Tarn et Garonne) seperative sewer, 4000 p.e., b m² of filter surface SW of France - Nègrepelisse April hour composite Flow COD BOD 5 SS TKN N-NH4 TN TP % of nominal load m3/day mg/l mg/l mg/l mg/l mg/l mg/l mg/l Inflow ,6 50,3 51,6 10,8 87,86% Outlow ,1 1 23,2 6,7 Waste free wastewater treatment wetlands in France

14 Some more recent references Sillé le Guillaume Sarthe built 2009, combined sewer, 4000 p.e m² of filter surface north west of France - oceanic climate Sillé Guillaume November hour composite COD BOD 5 SS TKN mg/l Waste free mg/l wastewater mg/l treatment mg/l Inflow 250 wetlands 210 in France Outlow < 30 < 3 2 <2

15 Some more recent references Les Halles - Rhône, near Lyons 2013, 800 p.e. about 2000 m² of filter surface : denitrification and P-removal with zero energy Les Halles July hour composite Flow COD BOD 5 SS TKN N-NH4 TN TP % of nominal load m3/day mg/l mg/l Waste mg/lfree wastewater mg/l treatment mg/l mg/l mg/l Inflow wetlands 89,4 in France 54 89,4 8,6 41,44% Outlow 48,3 < 30 < 3 3 < 3 0,6 19 1

16 Phragmifilters in the French overseas French Guyana departments and territories Mayotte New Caledonia

17 Efficiency and outflow concentrations for the two stages (from Epur Nature database) Phragmifilter Mean Median SD percentile percentile percentile percentile Nb COD % 91,57 94,32 7,40 83, , , ,69 74 BOD5 % 97,37 Mean 98,29 Median 3,09 SD 95,28 percentile 96,61 percentile 97,22 percentile 97,75 Nb 74 SS COD % mg/l 96,65 97,72 50,27 3,24 41,00 93,05 28,89 95,59 62,60 73,00 96,28 91,40 97, TKN BOD5 % mg/l 89,61 92,71 7,91 11,86 5,00 81,98 9,09 88,65 10,40 15,70 89,09 19,70 90, TP % 32,26 36,69 24,85-2,10 21,04 25,94 31,05 19 SS mg/l 8,37 7,00 6,45 11,00 15,96 17,70 74 TKN mg/l 6,86 3,00 11,52 6,86 11,27 21,51 20 TP mg/l 5,70 5,70 3,05 6,94 10,25 10, Mean Median SD percentile percentile percentile percentile Nb COD % 78,77 81,31 13,48 64,48 72,00 73,66 77,29 62 BOD5 % 86,33 89,95 13,49 70,50 80,75 84,84 86,92 61 Mean SD 80 percentile 90 percentile 95 percentile Nb SS % 84,63 86,09 9,99 71,76 78,18 79,61 81,40 61 TKN % COD 59,28 mg/l 51,69 126,53 21,34 40,83 76,89 43, ,95 224,8 47,63 312, TP % SS 23,82 mg/l 25,36 31,61 13,24 18,75 20,15 20, , , TKN mg/l 19,69 14,55 25,2 38,6 46,3 11 Efficiency and outflow concentrations for the first stage

18 Development of waste free wastewater treatment wetlands in France Around 3200 treatment wetlands in France, serving communities from 40 to 4000 people (500 designed by SINT between 1992 and 2007) Founding of SINT from Molle et al. (2005)

19 Activated sludge extended aeration 35 % Municipal WWTP in France (19300 plants in 2012) according to water agency data base Lesavre, 2012 Other activated sludge systems : 7% RBC 2 % Sand filters 1 % Waste free wetlands 12% Aerated % ponds 2 % Trickling filters 9% Facultative ponds 24 %

20 Other applications : treating wastewater from a mountain refuge in the Italian Alps

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23 Extra light weight patented self priming siphon, brought to the site by helicopter

24 And treating wastewater in 2000 m altitude for a tourist site in the French Alps

25 Other applications : treating wastewater from a motorway service area

26 Phragmifilters are well adapted to highly variable wastewater loads of motorway facilities and tourist sites

27 Treating high strength wastewater from agrofood industries with activated sludge plus wetlands Reed bed filters for polishing, clarification and sludge treatment

28 Upgrading of trickling filters with Phragmifilters INFLOW Grid trap Return sludge from secondary clarifier primary settlement Sprinkler Sludge withdrawal Feeding device Trickling filter Recirculation pump OUTFLOW Parshall flume Flow measurement Secondary settlement Sludge return valve Sludge return pump

29 Frequent problems of trickling filters INFLOW Bad settlement due to hydraulic overloading Grid trap Return sludge from secondary clarifier Sludge withdrawal primary settlement Feeding device Trickling filter Sprinkler No nitrification due to high organic loads Too frequent sludge removal OUTFLOW Parshall flume Flow measurement Secondary settlement Recirculation pump Sludge return valve Sludge return pump

30 And how to resolve them INFLOW Flow regulation at the outflow of the Phragmifilter OUTFLOW Return sludge from secondary clarifier Sludge withdrawal Parshall flume Flow measurement primary settlement 80 % BOD 5 removal 50 % NH 4 removal sludge removal every 8 to 12 years Feeding device Trickling filter Secondary settlement Sprinkler Good nitrification due to low organic loads Recirculation pump Sludge return valve Sludge return pump COST SAVINGS DUE TO THE REUSE OF EXISTING ASSETS!

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33 Possible configurations WSP + Phragmifilters Phragmifilters + WSP 1 st Phragmifilters + WSP + 2 nd Phragmifilters 1 st + 2 nd Phragmifilters + WSP with recirculation To increase treatment capacity To improve effluent quality To improve effluent quality To improve effluent quality

34 A cheaper alternative to improve the effluent quality of ponds : the rock filter Aerated if nitrification is required Waste free wastewater treatment wetlands in France

35 Advantages of keeping ponds in Phragmifilter configurations Ponds provide some treatment of total P and N, especially during summer (when receiving waters are most fragile) Ponds can be used to provide storage and treatment for storm water overflow in combined sewers Ponds can provide good pathogen removal, if required

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