dr.chao nokyoo - wepa-db.netdr.chao nokyoo director of inland water division water quality...

Dr.Chao NokyooDirector of Inland Water Division

Water Quality Management Bureau

Pollution Control Department

Ministry of Natural Resources and Environment

Thailand

1The 11th Annual Meeting of Water Environment Partnership in Asia (WEPA), Workshop and field Visit in Vientiane,

Lao P.D.R. (25-27 January 2016) at Vasana riverside Hotel, Vientiane, Lao P.D.R.

Content1. Swine Breeds in Thailand

2. Classification of Swine Farm

3. Pollution from Swine Farm

4. Wastewater from Swine Farm

5. Swine Waste Management in Thailand

5.1 Effluent Standard for Pig Farm

5.2 Good Agricultural Practices for Pig Farm

5.3 Institutional Mechanisms to Mitigate Pollution Problems

5.4 Swine Waste Treatment

5.4.1 Open ponds / lagoons

5.4.2 Manure to the crop farm or fishing feed

5.4.3 Biogas systems2

1. Swine Breeds in Thailand

• Although modern swine breeds was first introduced in the

1960s, and programs were put in place in the mid-1970s to

train farmers in modern production and farm management,

major changes in the Thai swine industry only began to

take place in the mid-1980s.

• The introduction of exotic pig breeds and evaporation shed

cooling has begun to move Thailand into industrial swine

production.

• The production of swine increased from just less than 11

million pigs in 1983 to over 16 million in 2001.

• The pace of expansion has been slowed by disease

problems that limit exports to high-value markets, and also

by the regulation of slaughterhouses in a way that

constrains growth in the sector. Burgeoning environmental

concerns have also been a factor.3

• The three largest pig-producing provinces, Nakorn

Pathom in the West, and Chachoengsao and

Cholburi in the East, cannot accommodate new

large-scale farms because of land constraints and

the high risk of spreading disease in already high

animal density areas.

• Therefore, new pig farms have expanded into

Ratchaburi (in the West), and Saraburi and

Lopburi (in the East).

• These provinces, particularly the latter two, have

abundant water resources.

• Another constraint is the increasing level of water

pollution caused by the farms situated near the

extensive river system in Nakorn Pathom and Chachoengsao.

4

• Before 1970, more than 70% of total pig

population was kept in backyard farm. Locally

contact farming. The biggest farm confined < 400

sows. No recording system was applied. Solid

floor with individual pen found incommon.

• From 1970 – 1990, the system developed to

modern farming, confinement and intensive. A

gestation crate, Taiwan design, was first used.

Breeding companies and other related business

expanded very fast. Herd book and white broad

were available, but no farm data analysis. Small

farm possessed 60% of total pig population. Big farm populated up to 5,000 sows in a single site.

5

• From 2000 – present, housing is equipped with evaporative

cooling system. Standard farming is controlled and certified

by the Department of Livestock Development.

• Big enterprises have expanded their business through

contact farming. Swine practitioner and farm consultants are

more popular.

• Environmental awareness becomes a hot issue.

• Farm biosecurity are more concerned. Farm owners are

better educated and some of them are replaced by new

generation.

• Pig Board has been established. Misused and off-label using

chemical, vaccines and drugs in pig farms are more often

seen. Minimal disease farms and Specific Pathogen Free

herds are available.

• Small and middle-size farms are less than 40% of total pig populations. 6

• Pig Populations

• In 2013, the standing populations of all-age pig were 9.51

million head. The annual production was 16.2 million

heads (Table 2). Farming system based on sheltered

accommodation with little outdoors pig keeping.

• The number of small and medium-size farms dramatically

decreased, but pig populations increased due to up-scale.

There were 210,978 households. The majority of these

household (94.15%) raised <50 pigs, while 0.11% were

big farm with >5,000 pigs.

• The number of breeder pigs was approximately 1.01

million heads, 46% of which owned by the two big

companies. Only 6.1% of standing populations are indigenous breed.

7

Source: FAO, LEAD Project and OAE

Form the study of the Department of Livestock

Development and the Pollution control

Department, total amount of pigs in Thailand is

10 million, which distribute over the parts of

country.

• Central region has the highest pig farming,

approximately 42%. In this region, most of pig

farm is located in Ratchaburi and Nakorn

Phatom Provinces.

• 19% of pig farming are located in northeastern

region, mostly in Nakorn Rajasima and

Ubonrajatani Provinces.

• Eastern region has 15% of pig farming, mostly

located in Cholburi and Chachoeng sao

Provinces

• Northern region has 14% farming, mostly

located in Chiang Mai and Lumphun Provinces.

• Southern region distributes 10% in Chumporn

and Nakorn Sri thumaraya Provinces.

9

10

Pig32 %

2. Classification of Swine Farm

Livestock Unit Swine Number Swine Farm Size

> 6 to 60 > 50 to 500 Small Scale

> 60 to 600 > 500 to 5,000 Medium Scale

> 600 > 5,000 Large Scale

Note: 1 livestock unit = 500 kg. live weight

Source: Ministry of Natural Resources and Environment (MONRE)

11

Type of Swine Farm

• Type 1 Backyard farms - very small

• Type 2 Open housing farms - small /

medium

• Type 3 Close housing farms (with

evaporative cooling) – large

12

Type 1 Backyard farm - very small

13

Type 2 Open housing farm - small / medium

14

Type 3 Close housing farms - Large / very large(with evaporative cooling)

15

3. Pollution from Swine Farm

• Solid waste

– Bad Smell

– Insect16

• Wastewater

– Bad Smell

– Insect

17

18Source: Poon Thiengburanathum, Ph.D. (Biogas Technology Center, Chiang Mai University, Thailand

4. Wastewater from Swine Farm

19

Swine

Type

water uses

rate(l/Head/day)

wastewater

rate(l/Head/day)

BOD(mg/l)

COD(mg/l)

SS(mg/l)

TKN(mg/l)

Breeder 92 64 800 1,700 900 350

Fattener 48 24 3,500 7,400 4,700 700

Nursery 32 20 2,500 5,400 3,000 350

- Wastewater Discharge 40%

- Wastewater Treatment 70% (Efficiency 80%)

Source: Pollution Control Department, Thailand

Year

Farm scale

Number of PigNumber

of Farmer

Generation Rate ofWastewat

er (CM/day)

BOD Loading

(Kg.BOD/day)

Discharge Rate of

Wastewater

(Kg.BOD/day)

Breeder Nursery Fattener Total

2014

Large 407,782 1,051,721 2,432,155 3,891,658 249 105,504.19 277,765.51 48,886.73

Medium 222,164 583,597 2,205,788 3,011,549 2,633 78,829.35 225,840.84 39,747.99

Small 124,916 274,198 591,224 990,338 8,083 27,667.96 69,768.42 12,279.24

Very small 168,934 406,096 1,036,346 1,611,376 180,551 43,806.00 116,007.28 20,417.28

Total 923,796 2,315,612 6,265,513 9,504,921 191,516 255,807.50 689,382.05 121,331.24

Source of wastewater

Wastewater Percentage(%)

Discharge of wastewaterPercentage

(%)

(CM/day) (Kg.BOD/day)

Community 6,601,602 4.1 517,990 45

Industry 13,793,272 8.6 413,797 36

Swine Farm 124,284 0.1 140,802 12

Aqua culture 949,148 0.6 13,218 1

Paddy Farm 138,092,136 86.5 34,955 3

Fish stew - - 33,585 3

Total 159,560,443 100 1,154,346 100

22

Community

45%

Industry

36%

Swine Farm

12%

Aqua culture1%

Paddy3%

Fish stew3%

ชุมชน อุตสาหกรรม ฟาร์มสุกร เพาะเล้ียงสตัวน์ ้ า นาขา้ว ปลากระชงั

Wastewater Discharge of Thailand

• As a consequence of deterioration of water quality in cannel and

river in Thailand form point sources including municipalities and

industries, related organization have conducted management of

pollution released from these sources.

• However, agricultural activities cause high volume of

wastewater, which affect water quality, especially pig farms.

• Form the study of the Department of Livestock Development

and the Pollution control Department, total amount of pigs in

Thailand is 10 million, which distribute over the parts of country.

• It is estimated that wastewater form pig farm releases over

121,331 kg.BOD/day, generated from large, medium and small

pig farm, approximately 45%, 37% and 18%, medium and small

pig farm, respectively.

• Since most pig farms are located along with water resources,

wastewater discharge from pig farm is taken into account as a

major cause of water pollution.

24

• Usually, wastewater form pig farm is varied on

characteristic of farming style. Characteristic of the

wastewater is widely depended on farm operation.

– Baud Concentration of wastewater is morally up

to 10,000 mg/l

– Separation of pig manure can reduce half of

wastewater concentration to approximately

1,500–3,000 mg/l with this high concentration,

the wastewater would definitely caress water

pollution.

• Whenever it is discharged into environment, either

low carrying capacity water resources on large

water bodies such as the Tha Chin or the

Bangpakong River.25

5. Swine Waste Management in Thailand

1.Effluent Standard

2.Good Agricultural Practices for Pig Farm

3.Institutional Mechanisms to Mitigate Environmental Pollution Problems

4.Swine Waste Treatment

26

5.1 Effluent Standard

• Livestock farming could cause environmental pollution through

wasted water, odor and flies. Among the major livestock farming

in Thailand, swine farming has been the one that cause serious

environment problems. At times, the problem is heightened by

the expansion of community towards farm areas and by farm

concentration and expansion of farms near the rivers.

• According to a figure from the Pollution Control Department

(PCD) in 1999, 23 percent of Biochemical Oxygen Demand

(BOD) loading in Tha Chin River was caused by swine farming

due to the high concentration of swine farms in the central region

along the Tha Chin River and lack of proper waste treatment. In

2000, water quality at Tha Chin River became critical as the level

of Dissolved Oxygen (DO) has dropped to near zero for most

parts of the river. There was the complaint that swine production

is a cause of water pollution in Bangpakong River in the Eastern

Region. Consequently, in 2001, PCD has added the swine farms in the regulated list.

27

Parameters Units

Maximum Permitted Values

Large Farm

Small /

Medium

Farm

Method for Examination

1. pH - 5.5-9 5.5-9 pH meter

2. Biochemical

Oxygen Demand

(BOD)

mg/l 60 100 Azide Modification, or Membrane

Electrode

3. Chemical Oxygen

Demand (COD)

mg/l 300 400 Potassium Dichromate Digestion ;

Open Reflux or Closed Reflux

4. Suspended solids

(SS)

mg/l 150 200 Glass Fiber Filter Disc, Dry

Evaporation

103-105 °C

5. Total Kjedahl

Nitrogen (TKN)

mg/l 120 200 Kjeldahl; Colorimetric or Ammonia

Selective Electrode

Table 1 : Effluent Standard for Pig Farm

28

Remarks : For large and medium farm will be effective on February 24, 2002.

Large farm is more than 600 Livestock Unit (LU.)

Medium farm is 60-600 LU.

Small farm is 6 - < 60 LU.

1 LU. = 500 kg.

Weight of breeding pig = 170 kg./head

Weight of fattened pig = 60 kg./head

Weight of nursling pig = 12 kg./head

Notification of the Ministry of Science, Technology and Environment issued under the Enhancement and

Conservation of the National Enviromental Quality Act, B.E.2535, published in the Royal Government Gazette, Vol.

118, Special Part 8, page 11-18, dated February 23, B.E.2544 (2001) effective since February 24, B.E. 2545 (2002)

and Notification of the Ministry of Science, Technology and Environment issued under the Enhancement and

Conservation of the National Enviromental Quality Act, B.E.2535, published in the Royal Government Gazette, Vol.

118, Special Part 8, page 11-17 dated February 23, B.E.2544 (2001) effective since February 24, 2545 B.E.(2002)

was revoked by a) and b)

Source : a) Notification of the Ministry of Natural Resources and Environment ,Effluent Standard for Pig Farm dated

November 7, B.E. 2548 (2005) published in the Royal Government Gazette, Vol. 122 Part 125 D, dated December

29, B.E. 2548 (2005)

b) Notification of the Ministry of Natural Resources and Environment issued under the Enhancement and

Conservation of the National Enviromental Quality Act. dated November 7, B.E. 2548 (2005) published in the Royal

Government Gazette, Vol. 122 Part 125 D, dated December 29, B.E. 2548 (2005)

29

http://www.pcd.go.th/count/lawdl.cfm?FileName=3_8_water.pdf&BookName=%E0%B8%81%E0%B8%8E%E0%B8%AB%E0%B8%A1%E0%B8%B2%E0%B8%A2%E0%B9%80%E0%B8%81%E0%B8%B5%E0%B9%88%E0%B8%A2%E0%B8%A7%E0%B8%81%E0%B8%B1%E0%B8%9A%E0%B8%A1%E0%B8%A5%E0%B8%9E%E0%B8%B4%E0%B8%A9%E0%B8%97%E0%B8%B2%E0%B8%87%E0%B8%99%E0%B9%89%E0%B8%B3




• As for the odor problem, large swine farms often locate

over massive land spaces away from community. This

can reduce the conflicts on acerbic odors. For the smaller

scaled farms that have been operating for a long period

of time in swine communities, expanding civilization could

quickly catch up with their current locations, and cause

conflict between the farms and the community. In the

municipal district of Nakhon Ratchasima province in the

Northeastern region, complaints have frequently been

filed regarding the pollution from farms, restrained by

their limited lands, which have no pond of any kinds to

ameliorate toxic wastewater. The farms simply discharge

wastewater directly into public waterways, leading to

endless friction between farm owners and protests from

the community.

30

5.2 Good Agricultural Practices for Pig Farm

31

• REQUIREMENTS AND INSPECTION METHODS

33

• GUIDANCE ON GOOD AGRICULTURAL PRACTICES FOR PIG FARM

Recommendations for good agricultural practices for pig farm are aimed to

provide pig farmers to use as guidance on pig farming practices. The details of such recommendations are explained in Appendix A.

• The major government offices that are

responsible for establishing the rules and

regulation for environmental pollution results

from livestock production are

– Pollution Control Department (PCD), Ministry of

national resources and environment;

– Department of Livestock Development (DLD), Ministry

of Agriculture and Cooperatives; and Ministry of Public Health.

5.3 Institutional Mechanisms to Mitigate Pollution Problems

38

• The Enhancement and Conservation of National Environmental

Quality Act B.E. 2535

• Under the responsibility of Ministry of Natural Resources and Environment,

the National Environment Quality Act was first enacted in 1969 as a

comprehensive package for institutionalization of environmental policy and

planning. The act was amended in 1992 as the Enhancement and

Conservation of National Environmental Quality Act B.E. 2535 (NEQA), which

is dubbed the environmental constitution of Thailand.

• The new act put more emphasis on the conservation of natural resources and

environmental quality. The key provisions include the establishment of the

National Environmental Board (NEB), the measurement for environmental

protection which also includes Environmental Impact Assessment (EIA), the

measurement of pollution control, the environmental protection and the

statement on civil liability.

• NEB is a high-powered policy-making committee chaired by the Prime

Minister. NEB aims to coordinate the environmental protection efforts of

governmental agencies at the central level and with those of local

governments at the provincial level. The main powers of the NEB include the

submission of policies and plans to the Cabinet for approval, the prescription

of environmental standards, the approval of Environmental Quality

Management Plans and provincial action plans, the amendment,

improvement and enforcement of laws, and the monitoring of environmental compliance by government agencies and state enterprises.

39

• PCD has set the regulation for chanelization in respect of waste

dumping into water courses. This regulation is implemented to prevent

sedimentation which a navigational obstruction and to prevent

pollution effects on living resources. Regarding the livestock activities,

the effluent standard for pig farm is presented in Table 1

• The Energy Conservation and Promotion Act B.E 2535

• Another Act is the Energy Conservation and Promotion Act B.E 2535

(ECPA). Swine production is linked through the energy sector via

recovering and renewing use of methane to produce electricity. This

production could replace the conventional demand, thus reducing

potential required supply. ECPA has had appreciable impacts for

Thailand and provided quite a comprehensive window for supporting

projects in the energy sector that will yield other additional local and

global benefit.

40

• The Public Health Act B.E 2535

• The Ministry of Public Health plays a significant role on environmental

protection. The Public Health Act B.E 2535 has authorized Tambon

(sub-district) Administrative Office (TAO) to be an inspection office on

the environmental control in the sub-district level. Accordingly, TAO has

an authority to close the farm that violates the environmental

regulations, which lead to public health hazards.

• Public subsidy to mitigate environmental problems.

• To induce more farms to treat their waste properly, some government

agencies such as Department of Livestock Development (DLD),

National Energy Policy Office (NEPO) and Department of Agricultural

Extension (DAE) have provided partial funding for construction the

waste treatment system such as biogas digester and multi-level pond.

The amount provided by the governmental funds for installing of waste

water treatment system ranged from 20,000 to more than 150,000 baht

per farm, approximately 40-60 percent of the total installation cost. By

1999, NEPO has subsidized 10 swine farms build power generation to

turn swine waste into bio-gas and electricity (NaRanong, 1999). 41

• The Biogas Dissemination Program in Livestock

Farms: Medium and Large Size Farms.

• The NEPO has also cooperated with the Biogas Advisory Unit (BAU),

Chiang Mai University (CMU) on subsidizing the farm to inspect the

bio-gas system. The program was called "The Biogas Dissemination

Program in Livestock Farms: Medium and Large Size Farms." In this

program, NEPO will subsidize up to 38 percent of the construction

cost and low cost loan as well as loan facilitation will be sought to

assist the farm owners. The subsidy was tied to the condition of

complete construction of BAU design and specification. (Intarangsi

and Kiatapakdee, 2001)

• The loan from commercial banks

• As the governmental sources are limited and insufficient to support

all the farmers who need to construct the water treatment system,

some farmers use their own funds or the loan from commercial

banks or Bank of Agriculture and Agricultural Cooperatives (BAAC)

to build these facilities.42

• Scaling-Up and Environmental Control

• As the livestock sector has been more industrialized, livestock farms

tend to be larger in size. Since most of the large farm belongs to big

businesses, they tend to be under more closely scrutiny by the

community and the local authority. Also, they tend to face a more

stringent standard than medium and small farms. Moreover, the

authority tend to have the enforcement policy that is bias against the

large farms.

• Swine production is probably the least environmental friendly

livestock production. As a result, the PCD has set the regulation to

control its sewage. As stated earlier, most attention has been paid to

large farms, both in regulation and enforcement. According to data

from PCD, all pig farms of sizes greater than 500 have invested in

certain type of water treatment, while some small-scale farms (12.7

percent) have no sewage treatment system at all.

43

• In terms of treatment techniques (Table 2) employed by farm of different

size, all of the large scale farms (with 5,000 pigs or more) use pond

system or solid-liquid system to treat their sewage. Medium-scale and

small-scale farms tend to equip the reception pond (which consist of only

one pond and therefore not very effective in treating the sewage, as the

water that is spilled-over to the drainage would still be very polluting.

Interestingly, according to the PCD data, only small and medium farms

use biogas digesters. It is possible that large farms do not find this

technique cost-effective. As most of the large farms are new farms settled

in land-ample areas, they have enough land to build a pond system

instead.

• It is not clear whether pollution from swine increases or decreases with

farm size. While it is most likely that pollutant per animal is lower for large

farms-as all of them have system of treatment ponds compare with the

less efficient reception pond, in some cases, the higher volumes of

sewage created by large farms could provide more pollutant per area than

a smaller farm. Therefore absorptive capacity is also an important issue.

• In this respect, however, there have been more evidences of serious

pollution created by concentrated smaller farms in certain rivers than a

sole problem in certain area created by a large farm 44

Treatment Techniques

Farm Size

Average 1-500 501-5,000 5,000 up

Pond system (2-10 ponds) 42.0% 36.6% 38.2% 100%

Solid-liquid system + holding pond 7.0% 3.6% 8.8%

Biogas digester 6.0% 9.1% 2.9% 0.0%

Reception pond (1 pond only) 37.0% 34.5% 44.0% 0.0%

No treatment at all 7.0% 12.7% 0.0% 0.0%

TOTAL 100.0% 100.0% 100.0% 100.0%

Table 2 : Treatment Techniques Employed in Swine Farm

45

• Enforcement Problems

• Although number of rules and regulations on wastewater

management are announced and some incentives are offered to the

livestock farms in investing in waste treatment technology, there has

been a lack of enforcement.

• DLD is one of the inspection offices and is expected to be a key

institution to enforce the environmental protection law. Ironically,

DLD's main job is on the extension program and serves as support

unit for livestock farmers. To act as an inspection office might cause

some conflicts between the department and the farmers which will

lead to the difficulty while working with the farm owners.

Consequently, DLD may not be able to act efficiently as an inspection

agency. Thus, the more effective enforcement and implementation of

existing laws are needed to achieve responsible environmental

management

46

5.4 Swine Waste Treatment

5.4.1 Open Ponds / Lagoons


5.4.3 Biogas System

1) Fixed Dome System 3) Covered Lagoon System

2) Plastic Bag System 4) Channel Digester System

47

5.4.1 Open Ponds / Lagoons

48


49

5.4.3 Biogas System


53

Source: Poon Thiengburanathum, Ph.D. (Biogas Technology Center, Chiang Mai University, Thailand

1) Fixed Dome System

• It is a small biogas system for livestock

wastewater treatment

• Promoted by Department of Agricultural

Extension (DOAE) and Energy Policy and Planning Office (EPPO), Ministry of Energy

62

5.4.3 Biogas System

• System is composed

of wastewater filling

chamber, digester

unit, effluent tank and sludge drying beds

63Source: Nipatphan Kulpredarat, DVM, Ph.D.(Department of Livestock Development, Thailand

Item Phase,

Year

No. of

Farms

Digester

Volume,

m3

CH4

Produced,

m3/year

CH4

Produced,

tCO2e/year

Treatmen

t for

Swine,

heads

1 1, Year

1998-

2000

263 6,056 637,350 8,967 27,965

2 2, Year

2001-

2004

887 45,464 4,773,720 67,166 220,405

Fixed Dome System Construction Record


Case Study for Fixed Dome System

Donkeaw Farm is a small pig

farm with 250 sows and 500

piglets. Discharged

wastewater 20 m3/day with

BOD 10,000 to the open

ponds

Problem :

• The unpleasant smell and

nuisance flies

• Complaint from neighbors to

the local government65Source: Nipatphan Kulpredarat, DVM, Ph.D.(Department of Livestock Development, Thailand

Results :

1) Health – No bad smell and flies

2) Economic - Produced biogas was piped to all

neighbor houses for cooking gas. Each family

can save for 70 USD per year

3) Social issue - Good relationship between farm and neighbors


2) Plastic Bag System

System had been developed by DEDE for small livestock farms

Concept

1) ease for construction, installation and operation

2) good performance and promptness for extension

3) acceptable price for farmers

Selected system was Bag Digester, made from PVC sheet with prefabricated at the workshop

Two model; DEDE1 treating capacity of 10 m3

wastewater/day DEDE2 treating capacity of 2 m3

wastewater/day


Case Study for Plastic Bag System

• DEDE had promoted the DEDE1 and DEDE 2 systems to nationwide for small livestock farms

• Project extended to swine, dairy cow, beef cow, horse, and layer chicken farms

• Typically, system was composed of wastewater collecting tank, bar screen, bag digester, post treatment ponds and sludge drying beds


Construction site survey

Photo courtesy from Thai Environment and Energy Development Co., Ltd.

70

Layout and Earth Work Preparation


71

Bag Filter Installation

Photo courtesy from Thai Environment and Energy Development Co.,Ltd.

72

Finishing Bag Filter Installation


73

Wastewater Collecting Tank


74

Sludge Management Unit


Sludge Removal Pit Sludge Drying Beds

75

Post Treatment Ponds


76

Parameter Influent, mg/l

Effluent after

DEDE2, mg/l

(Treatment

Efficiency, %)

Effluent after

Post Treatment

Ponds, mg/l

(Treatment

Efficiency, %)

Total Treatment

Efficiency, %

pH (no unit) 7.0 7.2 7.9 -

BOD5 767 127 (83.4) 66 (48.0) 91.4

TCOD 4,258 1,445 (66.1) 298 (79.4) 93.0

TKN 288 439 (-) 173 (60.6) 39.9

TSS 1,599 537 (66.4) 115 (78.6) 92.8

Wastewater Characteristics for Plastic Bag System

Parameter

Treatment Efficiency after

DEDE1, %

Treatment Efficiency after

DEDE2, %

TCOD 72-88 78-82

BOD5 76-92 83-91 77

Source : DEDE Prototype monitoring data

Benefit to farm :

1) Produced biogas for DEDE 2 and DEDE1 range from 16-

22 m3/day and 1.1-3.2 m3/day, respectively. Average

methane content is 60%

2) Dry sludge (2.7% N, 3.2% P, 0.25% K) used as organic

fertilizer


3) Covered Lagoon System (CL)

First Covered Lagoon came to Thailand in year 1996 by

large scale agro-industry firm for the swine farm

wastewater treatment

System is an earth pond covered with HDPE or PVC

plastic sheet

Required most construction area because the design

long retention time

Low construction cost, quick startup and less concrete structure

79

Source: Nipatphan Kulpredarat, DVM, Ph.D.(Department of Livestock Development, Thailand

• There are many plants constructed in Thailand but no an

official record about the number of constructions

• Estimation that there are 150 to 200 medium- to large-

scale swine farms nationwide with CL

• From site surveys - overall system efficiency is 60 - 70 %

• Design hydraulic retention time (HRT) is between 40-60 days


HDPE thick 1.0 mm

HDPE thick 0.3 mm

Gas Collector Pipe HDPE

Depth 4 - 6 meter

Free Board 1 m


Gas Pipe Generator

Gas start to producingNo Gas


4) Channel Digester System (CD)

• Channel digester is a biogas system that collects produced biogas

in PVC plastic dome

• System had been developed since 1995 by Energy Research and

Development Institute (ERDI) under the Project “Biogas System

Promotion in Medium and Large Scale Livestock Farms”

• Project had been supported by Energy Policy and Planning Office

(EPPO), Ministry of Energy

• Aim of the Project is to promote the biogas system in medium and

large scale livestock farms (mainly in pig farms), to produce and use the biogas as the renewable energy

Photo Source : Energy Research and Development Institute

83

Channel Digester Flow Diagram

Wastewater Collecting Tank

Sand Trap

Sludge Removal Pit

Sludge Drying Beds

Influent from Farms

Effluent

Sludge


Channel Digester Structure

Bottom withConcrete Lining

RC Structure

PVC orHDPE Dome

85


Channel Digester System Aerial View


Item Phase, Year No. of

Farms

Digester

Volume,

m3

CH4

Produced,

m3/year

CH4

Produced,

tCO2e/year

Treatment

for Swine,

heads

1 1, year 1995-

1998

6 10,000 1,600,000 22,512 60,000

2 2, year 1997-

2003

14 46,000 10,000,000 140,700 276,000

3 3, year 2002-

2008

249 280,000 50,566,000 711,463 1,864,000

2,200,000

Channel Digester System Construction Record


Case Study for Channel Digester System

Pisit Farm is a medium pig farm with 3,000 fattening pigs

Daily discharged wastewater is about 72 m3/day with BOD 4,500 mg/l

Wastewater system was comprised of collecting

tank, sand trap, channel digester (HRT = 8 days)

and two series of earth pond for post treatment (Total HRT = 60 days)

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Parameter

Influent,

(mg/l)

Effluent after

Channel

Digester,

(mg/l)

Effluent after

Post Treatment

Pond,

(mg/l)

Discharged

Standard,

(mg/l)

pH (no unit) 7.0 7.2 7.1 5.5-9.0

BOD5 4,544 530 13 100

TCOD 17,046 3,359 50 400

TKN 1,196 1,021 23.3 200

TSS 8,110 2,610 22 200

Wastewater Characteristics for Channel Digester System


Channel Digester System Efficiency at Case Study Farm

Parameter

Channel

Digester,

%

Post

Treatment

Pond, %

Overall

Efficiency,

%

BOD5 88.3 97.5 99.7

TCOD 80.3 98.5 99.7

TKN 14.6 97.7 98.1

TSS 67.8 99.2 99.7

Benefit to farm :

1) Electricity produced from biogas generator 285 kWh/day from 238 m3 biogas2) Dry sludge for organic fertilizer ingredient 150 kg per day 90

dr.chao nokyoo - wepa-db.netdr.chao nokyoo director of inland water division water quality...

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