Multistage Hybrid Wetland Systems for Pig Wastewater Treatment

Transcription

1 Multistage Hybrid Wetland Systems for Pig Wastewater Treatment WEPA Group Workshop on Pig Wastewater Management in Asia Chiang Mai, Thailand 21 February 2017 Hayama Kazuyuki/ K.K. Satisfactory

2 Introduction Tusk Co., Ltd., The National Agriculture and Food Research Organization (NARO) and K.K. Satisfactory are jointly conducting a feasibility study Dissemination of hybrid subsurface flow constructed wetland systems in Vietnam under Model Project for Improvement of Water Environment in Asia commissioned by Ministry of the Environment, Japan. 2

3 Overview 3

4 Newly Constructed Wetland before operation 4

5 Wetland in operation after a few years 5

6 Types of constructed wetlands Free water surface (FWS) Sedge, cat-tail etc. Vertical subsurface flow Aerobic (oxidative) Reeds, reed canary grass etc. Horizontal subsurface flow Anaerobic (reductive) Reeds, reed canary grass etc. 6

7 Types of constructed wetlands and reed beds Surface flow Reed beds Subsurface flow Vertical Horizontal Hybrid 7

8 Hybrid System/ Vertical and Horizontal subsurface flow Vertical subsurface flow Aerobic (oxidative) Horizontal subsurface flow Anaerobic (reductive) C organic CO 2 N organic -> NH 4+ -> NO - 3 NO 3- N 2 8

9 Schematic diagram of a multi-stage hybrid wetland system Floating cover material (Supersol) Pig Wastewater 1 st V bed Aerobic 2 nd V bed Aerobic 3 rd H bed Anaerobic 4 th V bed Aerobic P Mixing Tank Safety Bypass gravel gravel gravel gravel P P P P recirculation 5 effluent n Sampling and flow measuring point Siphon P Pump 9

10 Influent and Effluent 10

11 Effluent 11

12 Safety bypass and floating material to avoid clogging Floating material (Supersol etc.) Surface partition for alternate drying Density 0.4 g cm -3 Reinforced safety bypass 12

13 Main design innovation Bypass structure for safety treatment Floating cover material on the bed surface Advantages Able to increase organic load per area without clogging Available just after construction while growing reed and earthworm Minimize the area and cost! 13

14 Multistage Hybrid Wetland Systems in Japan 14

15 Subsurface flow constructed wetlands in Japan as of August th Mar Secondary & nonpoint 4 th Nov Agr. Canal (nonpoint) 2 nd Nov Dairy S 7 th Pig liquid food 9 th Nov Pig urine 13 th June Dairy E 8 th Dairy 18 th June Household 20 th Aug Dairy Biogas liquid 19 th Nov Dairy Biogas liquid 17 th Dec Dairy AF 3 rd Aug Acid mine 6 th Aug Nov Potato starch P 1 st Nov Dairy K 11 th Dec Chicken egg 12 th May Dairy G 5 th May Dairy N 14 th Aug Cheese R 16 th Jul Domestic secondary 15 th Jan plastic bottle recycle Low High 15

16 Multistage Hybrid Wetland Systems at Pig Farm O in Hokkaido Pig farm O Oct Hokkaido Daily Mean Temp. in Hokkaido Annual : 5 to 7 C. Winter months : 8 to 6 C. Summer months : 18 to 21 C. Tokyo 16

17 Pig Farm O in Hokkaido Total bed area : 1,472m 2 Inflow rate : 12.2 m 3 /d Influent: BOD 2,299 mg/l NH 4 -N 1,157 mg/l sows 2,000-2,500 pigs Since

18 1 st summer (July 2010) at Pig farm O

19 2 nd summer (July 2011) at Pig Farm O

20 Schematic diagram at Pig Farm O Piggery slurry Solid liquid separation Liquid P 1 In 1st Vr 572m 2 Reed Pumice L 10-50mm ALC 50mm~ recirculation P 2 2nd Vr 446m 2 Reed Pumice M 5-10mm Pumice L 10-50mm recirculation Lagoon reservoir 700m 3 P P 3 3rd V 184m 2 Reed Pumice S 1-5 mm Pumice M 5-10mm Pumice L P P 4 P 4th H 195m 2 Pumice M 5-10mm Pumice S 1-5 mm P 5th V 75m 2 Floating cover (Supersol) 5 Reed Pumice S 1-5 mm Pumice M 5-10mm Pumice L out P 6 n Sampling point Siphon P Pump P Recirculation pump Vr: Vertical flow with recirculation, V: Vertical flow, H: Horizontal flow 20

21 Samples taken from Pig Farm O In Out Pig farm O Item unit Influent Effluent rate % BOD mg/l % COD mg/l % SS mg/l % TN mg/l % TP mg/l % Coliform i/l % 21

22 Operating costs US$/year Cost comparison between activated sludge* CAPEX OPEX 1,200 70,000 Capital costs 1,000 US$ 1, Activated sludge Hybrid WS 3/4 60,000 50,000 40,000 30,000 20,000 10,000 Activated sludge Hybrid WS 1/ ,000 4,000 6,000 8, ,000 4,000 6,000 8,000 Pigs Pigs *swine wastewater treatment, under the condition that the influent and effluent BOD conc. is the same. *From the open database of Livestock Indusrtry s Environmental Improvement Organization (LEIO), Japan *1US$ = 108JPY 22

23 Multistage Hybrid Wetland Systems in Vietnam 23

24 Multistage Hybrid Wetland Systems in Vietnam Thai Nguyen Province/ May 2015~ Hai Duong Province/ May 2013~ 24

25 Phuoc Tien Pig Farm in Thai Nguyen Province Total bed area : 1,868m 2 Inflow rate : 180 m 3 /d 4,000 pigs/year Since

26 Layout of MSHWS at Phuoc Tien Pig Farm 1 st Bed (V) 2 nd Bed (V) 26

27 Influent and Effluent sampled at Phuoc Tien Pig Farm/TSS QCVN 62-MT:2016/BTNMT A: wastewater as being discharged into water resources used for the purpose of domestic water supply B:wastewater as being discharged into water resources not used for the purpose of domestic water supply 27

28 Influent and Effluent sampled at Phuoc Tien Pig Farm/BOD 5 QCVN 62-MT:2016/BTNMT A: wastewater as being discharged into water resources used for the purpose of domestic water supply B:wastewater as being discharged into water resources not used for the purpose of domestic water supply 28

29 Influent and Effluent sampled at Phuoc Tien Pig Farm/COD QCVN 62-MT:2016/BTNMT A: wastewater as being discharged into water resources used for the purpose of domestic water supply B:wastewater as being discharged into water resources not used for the purpose of domestic water supply 29

30 Influent and Effluent sampled at Phuoc Tien Pig Farm/T-N QCVN 62-MT:2016/BTNMT A: wastewater as being discharged into water resources used for the purpose of domestic water supply B:wastewater as being discharged into water resources not used for the purpose of domestic water supply 30

31 Influent and Effluent sampled at Phuoc Tien Pig Farm/Coliforms QCVN 62-MT:2016/BTNMT A: wastewater as being discharged into water resources used for the purpose of domestic water supply B:wastewater as being discharged into water resources not used for the purpose of domestic water supply 31

32 Advantages of subsurface flow constructed wetland Inexpensive (esp. in terms of operation cost) Labor-saving High flexibility in response to changes in wastewater level and amount Purification capability with a smaller area than that for the surface flow type All-year-round purification even in cold regions during winter Fewer pests, mosquitoes, flies, etc. 32

33 Thank you very much! Contact: Tusk Co., Ltd./Mr. Ietsugu/ The National Agriculture and Food Research Organization (NARO) /Mr. Kato/ K.K. Satisfactory/Mr. Hayama/ 33