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No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

SIMULATED YIELD AND WATER DEMAND FOR CHILLI
PEPPER PRODUCTION IN THE DRY SEASONS IN FLOODAFFECTED CHAU PHU DISTRICT
Nguyen Van Tuyen, Pham Van Toan, Nguyen Huu Chiem,
Le Anh Tuan, Dang Kieu Nhan, Van Pham Dang Tri
Can Tho University
ABSTRACT
Storing flood water and subsequently using it for rice-based upland crop production in
the dry season is an issue for sustainable agriculture in the Mekong Delta of Viet Nam. An
on-farm trial, conducted in between August – December 2015 in the Chau Phu district of An
Giang province, was conducted to determine irrigation requirement and water use efficiency
of chilli pepper that could replace a rice crop in the dry season in the flood-prone areas for
higher water use efficience. Irrigation requirement and yields of chilli were simulated by
using the AquaCrop software (version 4.0) with various varieties for air temperatures and
water irrigation level. Results showed that simulated yield of chilli pepper was 6.13 ton per
hectare, and this simulated yield was similar to the practical harvesting yield of chilli pepper
(6.33 ton per hectare). This water volume accounted for 59% of output components of the
water storage. The study revealed that changes in rainfall and temperatures significantly
influence irrigation requirement and the yield of chilli pepper. Irrigation requirement is
expected to increase as the temperatures rise. Irrigation requirement is expected to increase
as the rainfall reduce. Further studies for other crops and ways of how to reduce pond
storage water losses by evaporation and seepage are necessary.
Keywords: chilli pepper, flood water storage, AquaCrop, An Giang province
1. INTRODUCTION
Further improving crop water use efficiency is a concerned issued to deal with
freshwater shortage from projected climate change and sea level rise [1]. Rain-water
capture and flood water storage are considered solutions. In Cambodia, farmers retained
floodwater in bunded areas and then used it to irrigate the rice grown in the dry season

around the Tonle Sap [2]. In Viet Nam, freshwater storage in forests, lakes, swamps or
canals for agricultural, domestic and industrial purposes have been studied [3]. In the
Vietnamese Mekong delta, flood water is abundant during the monsoon flood periods. A
question is whether or not storing flood water in a pond is feasible for upland crop
cultivation water in the dry season in the flood-affected Mekong delta, in terms of
technological and economical considerations. If the proposed solution is practically
feasible, it would contribute to improve flood water use efficiency and mitigate negative
flood impacts in upstream delta in the wet season as well as salinity intrusion downstreams
15


Nguyen Van Tuyen...

Simulated yield and water demand for chilli pepper production in...

in the dry season in the delta. The present study was conducted to determine the water
irrigation requirement and water use efficiency of chilli pepper grown in a paddy field
through using pond-retained flood water for irrigation in the dry season. The proposed
study will contribute to improving efficiency of natural floodplain resource management in
the Mekong Delta in the future. Chilli pepper (Capsicum frutescens L) is common planted
around the world because of its color, flavor, and nutritional value [4]. In addition, chilli
peppers can also be used in pharmaceutical processing industry [5]. To achieve the research
objectives the study focused on: (1) Simulation of chilli pepper yield; (2) Simulation of
irrigation requirement for chilli peppers in varieties.
2. MATERIALS AND METHODS
2.1 Experimental design
The study was conducted in a rice-dominant area area with partly flood-control
structure located, from August 2015 to December 2015, in the Vinh Thanh Trung
commune, Chau Phu Distrist, An Giang Province (10o29' north latitude and 105o12' east
longitude) (Figure 1).

The study area

Figure 1. Location map of the study site

The study used chilli pepper is one of target plants are being cultivated in the study
area. Chanh Phong chilli pepper variety was used for the study. Cropping duration was 90 –
100 days and the planting density was 50,000 plants/ha. An on-farm experiment consisted
of three plots measuring 600 m2 eachand a flood water-storing pond of 1,000 m2. A
sprinkler irrigation water system was appliedwith an irrigation rate of 6 mm/day [6].
2.2. Simulation of pepper yields
Using AquaCrop software version 4.0+ is summaried in Figure 2
The AquaCrop software version 3.1+ was applied to simulate crop water
requirement and yield (Figure2). Input data included soil parameters (texture, wilting point,
field capacity, saturated moisture, permeability coefficient), weather data (temperature,
precipitation, evaporation wind speed, sunshine hours, CO2 concentration), plant data
consisting of canopy cover, depth of roots, yield, crop production schedule were directly
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No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

collected in the field. The output consisted of water demand and yield generated by
AquaCrop software version 3.1+. The model was operated at a daily time step. Soil data,
temperatures, precipitation and evaporation were recoreded from the field, while wind,
sunshine and CO2 concentration data were collected from the nearest weather station.

Figure 2. The structure of

AquaCrop model with soil
components - plant –
atmosphere (Source: [7]).

Weather data during the experimentation are shown in Figure 3. Air temperature at the
study area ranged from 21.4○C to 35.0○C. The average sunshine was 7.05±2.53 hours per
day. The average wind speed was with 4.9 ± 1.42 m/s. The average humidity was
80.92±3.89 % [8]. The Figure 4 shows the parameters of humidity, sunshine hours and
wind speed.

Figure 3. Temerature, rainfall and reference evaportranspiration (ETo)
at study site (source: [8])

17


Nguyen Van Tuyen...

Simulated yield and water demand for chilli pepper production in...

Figure 4. Average humidity, wind speed, sunshine hour at study site (source: [8])

Soil samples in the early cultivation were collected at 0 to 30 cm deep, physical and
chemical indicators of this early stage is presented in Table1.
Table 1. Physical characteristics of soil at study site
Depth

Clay

Silty

Sand

(cm)

(%)

(%)

(%)

Texture

1

0-10

41.40

55.20

3.40

Silty clay loam

2

10-20

47.30

49.50

3.20

3

20-30

45.60

50.60

3.80

OM (%)

PWP

FC

SAT

Ksat

(%)

(%)

(%)

(mm/ngày)

1.13

28.71

48.39

52.18

142

Silty clay loam

1.74

28.14

49.49

54.07

151

Silty clay loam

1.20

28.21

47.62

52.77

158

Layer

Notes: OM: Organic matter; PWP: Permanent wilting point; FC: Field capacity; SAT: Saturation.

In order to assess weather factors (temperature, prepicipation) to take form irrigation
requirement for chilli pepper crop, chilli pepper yields under various conditions were
simulated in Table 2.
Table 2. Impacting of factors are analysised in varieties.
Factors
Varieties

Notes
Temperature

Precipitation

1

unchanged

unchanged

2

unchanged

P=90%

3

P=10%

unchanged

Using 2015 as the base year

Average 10 years have probabilities to appear
1 time the highest temperatures and 1 time
the lowest rainfall.

4

P=10%

P=90%

5

unchanged

P=80%

6

P=20%

unchanged

7

P=20%

P=80%

Average 5 years have probabilities to appear
1 time the highest temperatures and 1 time

18

the lowest rainfall.


No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

3. RESULTS AND DISCUSSION
3.1 Simulated yield of chilli pepper
Soil physical characteristics in Table 1 were used as inputs of the model. The reference
parameter values of chilli pepper in Table 3 were calibrated to provide compatible between
simulation and actual result. [9]
Table 3. Calibrated parameters of chilli pepper (source: [10])
Parameters

Unit

Reference value

Calibrated

Water Productivity (WP)

g/m3

33.7

33.7

Reference Harvest Index (HIo)

%

48-52

48

Initial Canopy Cover (CCo)

plant/ha

50,000-100,000

50,000

Maximum Canopy Cover (CCx)

%

65-99%

80%

The calibrated parameters in Table 3 were high sensitive and they directly impact on
the simulated results. Actual water requirement of chilli peppers used as the input of the
model was shown on the Figure 5.
Figure 5. Actual irrigation
requirement of chilli pepper.

Simulated yield of chilli pepper in the 2015 Autumn-Winter cropping season
corresponding to irrigation water was presented on the Figure 5. Simulated yield was 6.13
ton per hectare, and this simulated yield was similar to the practical harvesting yield (6.33
ton per hectare).
3.2. Simulation of chilli irrigation requirement in varieties
Table 4. Irrigation requirement of chilli pepper
Varieties

Temperature

Precipitation

Irrigation requirement (m3/ha/crop)

1

Unchanged

Unchanged

6,519

2

Unchanged

P=90%

6,519

-

3

P=10%

Unchanged

7,169

13.4

4

P=10%

P=90%

7,396

13.4

5

Unchanged

P=80%

5,110

-21.6

6

P=20%

Unchanged

6,350

-2.59

7

P=20%

P=80%

5.945

-8,81

19

Difference (%)


Nguyen Van Tuyen...

Simulated yield and water demand for chilli pepper production in...

Table 4 showed distribution of air temperature with probabilities or exceedence P=10%
and precipitation with probabilities or exceedence P=90%, the highest irrigation
requirement of chilli pepper is 7,396 (m3/ha/crop). This results is different 13.4 % to
compare with irrigation requirement of chilli pepper in enough irrigation water condition.
4. CONCLUSION
The study revealed that changes in rainfall and temperatures significantly influence
irrigation requirement and the yield of chilli pepper. In addition, irrigation requirement is
expected to increase as the temperatures rise. Irrigation requirement is expected to increase
as the rainfall reduce.
REFERENCES
[1] Khem S., Goto A. and Mizutani M.- Determination of the potential land for securing doublerice cropping in the Cambodian Mekong Delta, based on a sub-area based modeling of flood
inundation, Paddy Water Enviro. 6 (3) (2008) 285-298.
[2] Fox J. and Ledgerwood J.-Dry-season flood-recession rice in the Mekong Delta: Two thousand
years of sustainable agriculture, Asian Perspect. 38 (1999) 37–50.

[3] Son N. T. -Water balance for Kien Giang river basis by IQQM model, Journal of Natural
science and Technichcal . Ha Noi National University. 25 (3S) (2009) 499–507.
[4] Mazourek M., Pujar A. Borovsky Y. Paran I. Mueller L. and Jahn M. M.-A Dynamic Interface for
Capsaicinoid Systems Biology, American Society of Plant Biologists.150 (2009) 1806–1821.
[5] Jolayemi A. and Ojewole J.-Comparative anti-inflammatory properties of capsaicin and ethylaacetate extract of capsicum frutescens linn in rats, African Health Sciences.. 13(2) (2013)
357–361.
[6] Tuan L. A. - Irrigation-Drainage. Can Tho University, 1997, 95-126.
[7] Steduto P., Hsiao T. C. Fereres E. and Nations U. -On the Conservative Behavior of biomass
water productivity, Irrigation Science. 61 (2006) 59–61.
[8] Hydro-Meteorological station in Chau Doc, Data of Hydrography and Meteorological station in
Chau Doc Station in 2015.
[9] Saadati Z., Pirmoradian N. and M. Rezaei, “Calibration and valuation of aquacrop model in
rice growth simulation under different irrigation managements. In CID 21st International
Congress on Irrigation and Drainage, 2011, 589-600.
[10] FAO, QuaCrop. Rome, Italy, 2011.
[11] Huy V. T. Application of AquaCrop to simulate rice yield due to climate change factors. Matter
thesis. College of environment and natural resource. Can Tho University, 2013.
Acknowledgement. The present study was part of the project on technical
development for agriculture in the Mekong delta adapting to climate change,
which was financially supported by JIRCAS-Japan.

Article history:
– Received: Sep. 1.2016
– Accepted: Nov. 25.2016
– Email:
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No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

ISOLATION AND IDENTIFICATION OF CHLORPYRIFOSDEGRADING BACTERIA FROM RICE-UPLAND CROP SOIL
IN THE MEKONG DELTA
Truong Quoc Tat, Duong Minh Vien
Can Tho University
ABSTRACT
The aim of this study is to isolate the bacterial strains which degrade Chlorpyrifos from
rice-upland crop soils in the Mekong Delta. Twelve soil samples were taken at Cai Lay - Tien
Giang, Cho Moi - An Giang and Binh Tan-Vinh Long. Soil bacteria were enriched in mineral
salt medium solution containing 20 mg/L of Chlorpyrifos as the only carbon source for
bacterial growth. The results showed that one bacterial community was enriched and degraded
Chlorpyrifos. One bacterial strain (coded as BT_C8.9) that was isolated from this community
degraded 41.07 % of Chlorpyrifos after 30 culture days. According to the sequencing of 16S
rRNA gene, this bacterial strains was identified as Microbacterium sp. C8.9.
Keyword: Bacteria, Chlorpyrifos, degradation, isolate
1. INTRODUCTION
Application of the pesticide on agricultural crop is now a common practice and is an
important factor of integrated pest management (IPM) strategies. It adversely affects the
properties of the soil as well as it alters the pH of the soil required for microbial activities of
beneficial bacteria to act upon [1], [2]. Some of these pesticides persist in the soil to form
pollutants which may occasionally lead to surface and groundwater contamination. One of such
pesticides is Chlorpyrifos. It is a broad-spectrum organophosphate insecticide, which is widely
used to control insect pests on grain, cotton, fruit, nut, and vegetable crops, as well as lawns and
ornamental plants in Viet Nam. The environmental fate of Chlorpyrifos has been studied
extensively, and the reported half-life in soil varies from 10 to 120 days, with 3,5,6-trichloro-2pyridinol (TCP) as the major degradation product [3]. The manufacture and formulation
process of Chlorpyrifos also generate waste that contains the compound, and this has to be
treated by physicochemical or biological means [4]. If Chlorpyrifos is not degraded or
detoxified rapidly enough, the risk of their off-site migration may pose a health risk to human
[ref]. In soil, microorganisms play a very important role to promote the breakdown of

Chlorpyrifos. For example, Enterobacter strain B-14 could degrade Chlorpyrifos [5].
Alkaligenes faecalis DSP3 was isolated, which was capable of degrading Chlorpyrifos and 3, 5,
6-trichloro-2-pyridinol (TCP) [6]. Six Chlorpyrifos-degrading bacteria were isolated using
Chlorpyrifos as the sole carbon source by an enrichment procedure [7]. The main objective of
the present study involved the isolation and identification of Chlorpyrifos-degrading bacteria
from rice-upland crop soils in the Mekong Delta.
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Truong Quoc Tat...

Isolation and identification of chlorpyrifos...

2. MATERIALS AND METHODS
2.1 Materials
Soil samples: 12 soil samples were collected from 12 fields in the Mekong Delta. Among
them, 8 soil samples were collected from 8 fields in Vinh Long Province, 3 soil samples were
collected from 3 fields in An Giang Province, 1 soil samples were collected from 1 fields in
Tien Giang Province. Phosphate buffer used contain the following (in gram per liter): 23.99 g
of NaH2PO4 and 15.59 g of Na2HPO4. Mineral salt midium: 870 mL of Q-water, 25 mL of
buffer solution (35 g of Na2HPO4.2H2O, 4 g of KH2PO4 were mixed in 1 L of milli-Q water),
100 mL of mineral salt solution (10 g of (NH4)2SO4, 2 g of MgCl2.6H2O, 1 g of
Ca(NO3)2.4H2O were mixed in 1 L of milli-Q water) and 5 mL of trace metal solution. Tryptic
Soybean Agar (TSA): 30 g Tryptone Soya Broth and 15 g of agar were mixed in 1 L of milli-Q
water. Chlorpyrifos (Dr.Ehrenstorfer, 99.5%) of Accustandard.
2.2 Methods
2.2.1 Collection of soil
Collection of soil: 12 soil samples from the fields was collected as described aboved .
Soil was collected randomly from 0 - 20 cm depth. The samples were pooled together,
brought to the laboratory in polyethylene bags and kept in refrigerator at 4 oC to maintain

the biological activity of the soil microbes..
2.2.2 Isolation of Chlorpyrifos-degrading Bacteria
Chlorpyrifos-degrading bacteria were isolated from the soil samples by the enrichment
culture technique on mineral salt medium, using Chlorpyrifos as the sole source of carbon
[8]. The enrichment preparation comprised of 90 mL phosphate buffer in 250 mL
Erlenmeyer’s flask. They were autoclaved at 121oC for 20 minutes before adding 10 g of
the soil sample. The flasks were incubated in a rotary shaker at 130 revolutions per minute
(rpm) and 30 oC for 1 hour. After shaking, 1 mL of the supernatant was inoculated in 24 mL
of mineral salt mideum containing 20 mg/L of Chlopyrifos, and the flasks were incubated
in a rotary shaker at 90 revolutions per minute (rpm) and 30 oC for 10 days.. This was
repeated from 4 to 5 times. After that, the experiment was set up in tube containing 4 mL of
mineral salt minimum and 20 mg/L of Chlorpyrifos to select bacterial community which
could degrade Chlorpyrifos.
Using bacterial communities could degrade Chlorpyrifos to isolate bacteria strain. 50
µL of the bacterial commnity was inoculated on TSA, and the incubated at 30 oC for 3 days.
Isolated Colonies were inoculated on tube containing 4 mL of mineral salt minimum and 20
mg/L of Chlorpyrifos. After 7 days, colony could grow which selected to set up in tube
containing 4 mL of mineral salt minimum and 20 mg/L of Chlorpyrifos to select bacterial
strain which could degrade Chlorpyrifos.
2.2.3 Chlorpyrifos Extraction and HPLC Analysis
After 30 days of incubation, 4 mL of the culture was taken from each flask and was
placed in centrifuge tubes. Extraction of Chlorpyrifos was done by using a solution of
Toluen (distilled) and Acetone (distilled) at a ratio of 2:1 and centrifuged at 3,000 rpm for
3 minutes. Concentration of Chlorpyrifos was determined on HPLC (High Performance
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No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

Liquid Chromatography) at 17.5 mins (Figure 1) . The C18 column ( 25 cm x 4.6 mm, 5
ratio 80:20. The flow rate was set at 1 ml/min and the UV detector was set at 20 nm.

peak of Chlorpyrifos

Retention time

Figure 1: Chromatogram of Chlorpyrifos

2.2.4 Identification of the Isolates
The one bacterial strain isolate was grown on TSA to extract DNA by CTAB 3 % [9].
After that, DNA product was amplified by PCR with 27F/1492R primers [10]. The forward
primer is, 5’ AGA GTT TGA TCC TGG CTC AG 3’ and the reverse primer id 5’
TACGGT TACCTTGTTACGACT 3’. Pre denaturation 95°C (5 minutes), 30 cycles:
Denaturation (95°C, 1 minute), Annealing (53°C, 30 seconds), Extension (72°C, 90
seconds), Final extension (72°C, 5 minutes) [10] and then use the sequence in a BLAST
search limited to a bacterial data base. Identify their unknown bacteria by examining the
top-scoring sequences from the BLAST search results.
2.2.5 Methods of processing, analysis and statistics data
Microsoft Excel (version) was used to calculate the percentage of decomposition and
graphed. Minitab 16 software was used to compare the differences between pairs of data
together.
3. RESULTS AND DISCUSSION
3.1. Enriched culture and identify Chlorpyrifos degradability of the bacterial
communities
The results of this study selected one bacterial community which degraded
Chlorpyrifos. After 30 days incubation, this bacterial community degraded 18.85 % of
Chlorpyrifos (Figure 2).
Thus, bacterial community (was coded as 8) was selected from rice - upland crop soil

in Vinh Long province. It could degrade Chlorpyrifos. So this community was used to
isolate bacteria strains.
23


Truong Quoc Tat...

Isolation and identification of chlorpyrifos...

Figure 2. Residue Chlorpyrifos after 30 days incubation with bacterial communities (n = 3,
standard error)

3.2. Identification of the Isolates
Bacterial strain was isolated from one bacterial community which was coded as 8.
After 30 days incubation, this bacterial strain could degrade 41.07 % of Chlorpyrifos
(Figure 3). Colony of this bacteria is circular, convex, entire, moderate and yellow (Figure
4a). This bacterial strain is Gram possitive (Figure 4b). It was sequenced and compared 16S
rRNA gene sequence segments with the NCBI database. The results showed that the
sequence of this bacterial strain sequences homologous about 98 % with 16S rRNA gene
segments of Microbacterium sp. (Accession number: JQKT01000007.1). So, It was
identified Microbacterium sp. C8.9.

Figure 3. Residue Chlorpyrifos after 30 days incubation with Microbacterium sp. C8.9
(n = 4, standard error)

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No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

(a)
(b)
Figure 4. (a) Colony morphology ;
(b) Gram staining of Microbacterium sp. C8.9
Figure 5. Agarose gel electrophoresis of PCR products
Notes: Lane M: 1kb DNA leadder; Lane 3: PCR products of Microbacterium sp. C8.9

Sequence nucleotide of Microbacterium sp. C8.9
2 GGCGGTGTGTACAAGACCCGGGAACGTATTCACCGCAGCGTTGCTGATCTGCGATTACTA
62 GCGACTCCGACTTCATGAGGTCGAGTTGCAGACCTCAATCCGAACTGGGACCGGCTTTTT
122 GGGATTCGCTCCACCTCACGGTATTGCAGCCCTTTGTACCGGCCATTGTAGCATGCGTGA
182 AGCCCAAGACATAAGGGGCATGATGATTTGACGTCATCCCCACCTT-CCTCCGAGTTGAC
241 CCCGGCAGTATCCCATGAGTTCCCACCATTACGTGCTGGCAACATAGAACGAGGGTTGCG
301 CTCGTTGCGGGACTTAACCCAACATCTCACGACACGAGCTGACGACAACCATGCACCACC
361 TGTATACGAGTGTCCAAAGAGTTCTACATTTCTGCAGCGTTCTCGTATATGTCAAGCCTT
421 GGTAAGGTTCTTCGCGTTGCATCGAATTAATCCGCATGCTCCGCCGCTTGTGCGGGTCCC
481 CGTCAATTCCTTTGAGTTTTAGCCTTGCGGCCGTACTCCCCAGGCGGGGAACTTAATGCG
541 TTAGCTGCGTCACGGAAACCGTGGAATGGTCCCCACAACTAGTTCCCAACGTTTACGGGG
601 TGGACTACCAGGGTATCTAAGCCTGTTTGCTCCCCACCCTTTCGCTCCTCAGCGTCAGTT
661 ACGGCCCAGAGATCTGCCTTCGCCATCGGTGTTCCTCCTGATATCTGCGCATTCCACCGC
721 TACACCAGGAATTCCAATCTCCCCTACCGCACTCTAGTCTGCCCGTACCCACTGCAGGCT
781 GGAGGTTGAGCCTCCCGTTTTCACAGCAGACGCGACAAACCGCCTACAAGCTCTTTACGC
841 CCAATAATTCCGGATAACGCTTGCGCCCTACGTATTACCACGACTGCAGGCACGTAGTTC
901 ACCCGGCGCTTTTTCTGCAAGTACCGTCACTTTCGCTTCTTCCTTGCTAAAA-GAGGTAT
960 ACAACCCAGA-GGGCCGTCATCCCTCACGCGGGCGTGGCTGCATCAAG-CATGTAGCCCA
1018 TTGAGG-AGTAGTCACCCACTGCTAACCTCCCGTATGAAATCTAGGACCG

61

121
181
240
300
360
420
480
540
600
660
720
780
840
900
959
1017
1066

Thus, Microbacterium sp. C8.9 had Chlorpyrifos-degrading higher than its bacterial
community. This result was explained by active of the bacteria in their community which
had inhibited the activity of Microbacterium sp. C8.9.
4. CONCLUSIONS
This study was selected one bacterial community and Microbacterium sp. C8.9 was
isolated from rice - upland crop soil in Vinh Long province. Bacterial community and
Microbacterium sp. C8.9 was degraded Chlorpyrifos about 18.85 % and 41.07 %,
respectively.
REFERENCES
[1] Rehman G. K. M. M. and Motoyama N. – Determination of Chlorpyrifos residue in andosol
upland soils using methanol phosphoric acid extraction. J. Pesticide Sci, 25 (4) (2000) 387-391.

25


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Isolation and identification of chlorpyrifos...

[2] Malinowski H. – Impact of more important factors on the activity of insecticide used in forest
protection. I. Soil Insecticides, Sylwan, 144 (9) (2000) 90-100.
[3] Singh B.K., Walker A., Morgan A.J. and Wright D.J. – Effects of soil pH on the Biodegrading
of Bacterium. Applied Environmental Microbiology. 9 (2003) 5198-5206.
[4] Fulekar M.H. and Geetha M. – Bioremediation of Chlorpyrifos by Pseudomonas aeruginosa
using scale up technique. Journal of Applied Bioscience, 12 (2008) 657-660.
[5] Singh K., Brajesh K., Walker A., Alum J., Morgan W., Wright D.J. – Biodegradation of
chlorpyrifos by Enterobacter strain B-14 and its use in biodegradation of contaminated soils.
Appl. Environ. Microbiol. 70 (2004) 4855-4863.
[6] Yang L., Zhao Y.H., Zhang B.X., Yang C.H., Zhang X. – Isolation and characterization of a
chlorpyrifos and 3, 5, 6-trichloro-2-pyridino degrading bacterium. FEMS Microbiol. Lett. 251
(2005) 67-73.
[7] Yang C., Liu N., Guo X., Qiao C. – Cloning of mpd gene from chlorpyrifos-degrading
bacterium and use of this strain in bioremediation of contaminated soil. FEMS Microbiol.
Lett. 265 (2006) 118-125.
[8] Zhu J., Zheo Y. and Qiu J. – Isolation and Application of a Chlorpyrifos degrading Bacillus
licheniformis ZHU-1. African Journal of Microbiology Research, 4 (24) (2010) 2716-2719.
[9] Ihrmark K., Inga T.M., Bödeker K.C.M., Hanna F., Ariana K., Jessica S., Ylva S., Jan S.,
Mikael B.D., Karina E.C., Björn D.L. – New primers to amplify the fungal ITS2 region evaluation by 454-sequencing of artificial and natural communities. Article first published
online: 27 (2012) DOI: 10.1111/j.1574-6941.2012.01437.x.
[10] Xuan D.T., Guong V.T., Rosling A., Alström S., Chai B., Högberg N. – Different crop rotation
systems as drivers of change in soil bacterial community structure and yield of rice, Oryza
sativa. Biology and Fertility of Soils. 48 (2) (2012) 217- 225.

Article history:
– Received: Sep. 7.2016
– Accepted: Nov. 30.2016
– Email:

26


No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

TREATMENT OF TANNERY WASTEWATER BY
INTERMITTENT CYCLE EXTENDED AERATION SYSTEM
Truong Trong Danh, Nguyen Dinh Tri, Nguyen Tan Phong
Ho Chi Minh City University of Technology (VNU HCM)
ABSTRACT
A continuous-flow sequencing batch reactor known as the intermittent cycle extended
aeration system – sequencing batch reactor (ICEAS – SBR) was used to investigate the
treatability of the tannery wastewater. A model made from poly acrylic with a capacity of
20 liters was utilized to evaluate COD and nitrogen removal while the loading rate
increased up to 2.0 kg COD/m3.day. The polyvinyl alcohol (PVA) media was used to
compare with the non-media condition. At the loading rate of 1.5 kg COD/m3.day with or
without media, the removal efficiency was 83.57% and 79.17% COD, 54.01% and 43.33%
TKN, 51.48% and 41.72% TN, respectively. It proved that PVA media helped increasing
the removal efficiency. However, because of high concentration of the influent suspended
solid and low C/N ratio input, the removal efficiency was not quite high.
Keywords: ICEAS, PVA, tannery wastewater
1. INTRODUCTION

Tannery wastewater is a source of many environmental impacts. Tannery productive
cycle includes a series of chemical treatments using several different chemicals such as
surfactants, acid and metal organic dyes, natural or synthesis tanning agents, sulphonated
oils, salts, etc. [1]. Due to a wide range of chemicals and their low biodegradability, the
biological treatment of tannery wastewater is difficult and complicated. It is stated that
sequencing batch reactor (SBR) is an effective system for COD removal in tannery
wastewater [2]. Moreover, a low effluent nitrate concentration could be obtained in suitable
COD/TKN ratio condition [3].
A modification of the SBR process is the intermittent cycle extended aeration system –
sequencing batch reactor (ICEAS – SBR), which is operated on the principle of continuous
influent as in the conventional activated sludge process, but has intermittent effluent
withdrawing which is similar to the SBR system. ICEAS – SBR offers the advantages of
easy operation and flexibility [4]. Many research proved ICEAS – SBR having high
removal efficient in sewage wastewater [5-7], but its treatability in high concentration
wastewater is not studied thoroughly.
On the other hand, the moving bed is usually used in order to enhance treatability of the
system. The moving bed sequencing biofilm batch reactor (MBSBBR) is a combination of
the SBR process and the moving bed batch reactor (MBBR) process. Some studies pointed
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Treatment of tannery wastewater by intermittent...

that MBSBBR saw higher treatability than SBR [8-9]. This process is proved flexible,
reliable and easy-to-operation (no clogging problems, little suspended solid in the reactor,
easy to settle or decant) [10]. Similarly, the combination of ICEAS – SBR and MBBR,
intermittent cycle extended aeration system – moving bed sequencing batch reactor (ICEAS
– MBSBR), would have these advantages too. In this study, polyvinyl alcohol (PVA) gel

was used to carry the bacteria with an effective surface area 2,554 m2/m3. It is claimed that
bacteria which is growing inside the beads do not slough off in clusters and are protected
from predation in the micro-scale pores of the PVA gel [11]. PVA gel traps the bacteria
inside, it may boost the COD and nitrogen removal by increasing the bacteria concentration
and creates the anoxic condition inside the gel. The objective of this study is to investigate
the treatability of tannery wastewater by ICEAS with PVA used as biomass carrier.
2. MATERIALS AND METHODS
2.1. Raw wastewater, seed sludge
Raw tannery wastewater was collected at the first sedimentation tank (after the
coagulation and flocculation) of wastewater treatment plant of Dang Tu Ki Company
located at Le Minh Xuan Industrial Park, Binh Chanh District, Ho Chi Minh city.
Compositions and properties of wastewater were represented as pH: 6.7 – 8.0; COD: 2,000
– 2,500 mg/L; SS: 850 – 1,000 mg/L; NH4+-N: 400 – 500 mg/L; TN: 500 – 600 mg/L; TP:
1 – 2 mg/L. The ICEAS influent was used at the suitable dilution ratio raw tannery
wastewater. Seed sludge was taken from wastewater treatment plant of VISSAN Company,
Binh Thanh District, Ho Chi Minh city. Seed sludge was light brown, well-settled with SVI
being 92 and MLVSS/MLSS ratio being 0.70.
2.2. Reactor and operation
A 20-litre polyacrylic reactor were manufactured with dimensions 500 x 80 x 500 (L x
W x H) (mm). A baffle was installed to divine the reactor to 2 parts: the pre – reactor and
the main reactor with the ratio 1:4 (Figure 1). With the implementation of the baffle, the
mixing between the pre – reactor and the main reactor generated during the decanting phase
could be prevented. In addition, this baffle could eliminate the mixing in the reactor during
the settle phase while the inlet is flowing in. An air pump and several diffusers provided
required air and the DO was kept remaining 4 – 5 mg/L in the aeration phase. A mixing was
used to create the anoxic condition with DO < 0.5 mg/L.
The reactor was operated at a hydraulic retention time (HRT) of 12 hours and a 40
L/day continuous flow. The cycle time was 8 hours including 7 hours for reacting, 0.5
hours for settling and 0.5 hours for decanting phase. The reacting phase consisted 2 hours
of aeration then 3 hours of mixing and then 2 hours of aeration. All items in the process

operated automatically and were controlled by timers.
The study was operated at different organic loading rates (OLRs): 0.5; 1.0; 1.5; 1.5 and
2.0 (with PVA) (kg COD/m3.day). The mixed liquor suspended solid (MLSS) concentration
of the seed sludge was approximately 3000 mg/l; pH in the tank varied from 6.5 to 7.5. In
the second part of the study, PVA gel was added to 10% reactor volume (2 L).
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Scientific Journal Of Thu Dau Mot University

Figure 1: Schematic structure of ICEAS reactor.

2.3. Analytical methods
The samples were collected at the influent and effluent positions of the reactor. The
parameters of wastewater such as pH, COD, SS, TKN, NH4+-N, NO2--N, NO3--N, TN were
analyzed according to Vietnam National Standards and Standard Methods for the
Examination of Water and Wastewater (APHA, Eaton DA, and AWWA) at the Laboratory
of Environmental Engineering, Faculty of Environment and Natural Resources, Ho Chi
Minh City University of Technology (HCMUT). Biomass concentration was assessed at the
last days of each organic loading rate.
3. RESULTS AND DISCUSSION
Table 1: Some average constituent values in different OLRs
Constituent (mg/l)
(Average)
COD influent
COD effluent
TKN influent
TKN effluent

NO3- influent
NO3- effluent
TN influent
TN effluent
COD/NH4+ in ratio

0.5
252
23
55
16
0.15
15.73
56
35
5.25

Organic loading rate (kg COD/m3.day)
1.0
1.5
1.5 (PVA)
506
767
752
83
161
123
116
195
194

58
110
89
0.4
0.39
1.09
8.71
1.12
2.44
117
196
195
72
114
95
5.01
4.51
4.50

2.0 (PVA)
1014
235
249
136
0.48
0.83
248
137
4.67

Figure 2 shown the COD removal efficient in different OLRs. The COD removal
efficient reduced when the OLR increased. In the OLR 1.5 kg COD/m 3/day, it could be
seen the PVA gel helped to increase the COD removal efficient. It helped to reduce the
COD effluent by 23% (from 161 to 123 mg COD/L, Table 1). However, the media only had
a minor role in the COD removal.
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Treatment of tannery wastewater by intermittent...

Figure 2: COD removal efficient in different OLRs (0.5; 1.0; 1.5 and 1.5; 2.0 with PVA gel).

Figure 3: TKN removal efficient in different OLRs (0.5; 1.0; 1.5 and 1.5; 2.0 with PVA gel).

Figure 4: TN removal efficient in different OLRs (0.5; 1.0; 1.5 and 1.5; 2.0 with PVA gel).

Fig. 3 and 4 represented the TKN and TN removal efficient. When the OLR increased,
the TKN removal efficient decreased, similar to the COD removal, whereas the TN removal
efficient increased. It could be explained as: High COD and TKN influent had negative
effects on the aerobic sludge, so it leads to the declined of the COD and TKN removal
efficient. However, their negative effects on the anaerobic sludge were not much.
Moreover, the higher COD influent was a reason of the increase of TN removal efficient
according by the following equation:
CH2O + 0.711 NO3- + 0.069 NH4+ + 0.232 HCO3- + 0.011 H+
 0.429 C5H7NO2 + 0.798 CO2 + 0.161 N2 + 0.635 H20 [12]

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However, it saw a decline in TN removal during the OLR 2.0 kg COD/m 3/day. The
NO3- effluent in this OLR was still lower than the previous OLR (this meant that
denitrification efficient in this OLR still increased) but the NO3- proportion in TN was too
low. So, that was the reason why, in the OLR 1.5 and 2.0kg/m3/day, we assumed that TN
removal efficient was equal to the TKN removal efficient and these two declined when the
OLR increased. So that, since the denitrification efficient in the OLR 1.5 and 2.0kg/m3/day
was too high while the TKN efficient was low, the aeration time should be increased
whereas the mixing time should be decreased.
On the other hand, PVA gel helped to increase the TN and TKN removal efficient too.
However, the gel only contributed a small role (reduced TKN effluent from 110 to 89 mg
TKN/L, TN effluent from 114 to 95 mg TN/L).
The low initial C/N ratio (6.3) was not relevant to NH4 removal [13]. Since the
COD/NH4+ ratio average of this research is in the range of 4.5 – 5.25, so the average TKN
removal efficient was not high (from 43% to 54%). However, in the OLR 0.5 kg
COD/m3/day, the average TKN removal efficient was 71%, it could be explained as a small
TKN amount was adsorbed in the sludge and helped to boost the TKN removal efficient.
Furthermore, since the influent suspended solid was quite high (900 mg/l), inorganic solid
was accumulated in the reactor and it lead to the decline of COD and nitrogen removal.
In order to enhance the performance, initial C/N ratio should be increased by adjusting
the external carbon source (for example: methanol or acid acetic) and resolve the high
influent suspended solid problem. In addition, this experiment used the diluted raw
wastewater, it needs to have another experiments using the non – diluted raw wastewater.
4. CONCLUSIONS
The experimental study indicated when the OLRs increased, the COD and TKN
removal efficient reduced while the TN removal efficient increased. The operation time

should be adjusted in the OLR 1.5 and 2.0kg/m3/day by increasing the aeration time and
reducing the mixing time. It shown that PVA gel helped to boost the COD and nitrogen
removal but the difference between the media and non – media condition was not much.
Hence, comparing price and its effect, PVA is not worthy. Moreover, because of the low
initial C/N ratio and high influent suspended solid, COD and nitrogen removal was not
quite high. So external carbon source should be used and the coagulation and flocculation
should be improved for better treatment efficiency.
REFERENCES
[1] Di Iaconi C., Lopez A., Ramadorai R., Di Pinto A.C. and Passino R. – Combined chemical and
biological degradation of tannery wastewater by a periodic submerged filter (SBBR), Water
Res. 36(9) (2002) 2205–2214.
[2] Ganesh G., Balaji G., Ramanujam R.A. – Biodegradation of tannery wastewater using
sequencing batch reactor - Respirometric assessment, Bioresource Technology 97(15) (2006)
1815–1821.

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[3] Carucci A., Chiavola A., Majone M. and Rolle E. – Treatment of tannery wastewater in a
sequencing batch reactor, Water Sci. and Technol. 40(1) (1999) 253–259.
[4] Khararjian H. A., Callaway W. H., Cardinal P. and Meany J. – Intermittent cycle extended
aeration system (ICEAS R) for small wastewater treatment plants, Water Sci. Technol. 22(3–4)
(1990) 323–330.
[5] Chen A. C., Chang J. S. , Yang L. and Yang Y. H. – Nitrogen Removal from Sewage by
Continuous Flow SBR System with Intermittent Aeration, Environmental Technology 22(5)
(2001) 553–559.

[6] Lee H., Brereton J. A., Mavinic D. S., Fiorante R. A., Oldham W. K. and Paisley J. K. –
Nutrient Removal with Methanol as a Carbon Source Full-Scale Continuous Inflow SBR
Application, Environmental Technology 22(10) (2001) 1223–1235.
[7] Li Hongjing, Chen Yinguang, Gu Guowei, Liu Yandong – Phosphorous Removal in
Intermittent Cycle Extended Aeration System Wastewater Treatment Plant - Effect of
Temperature, Proceedings of the 2nd International Conference, Shanghai, 2008, pp.2970–2973.
[8] Kwannate Sombatsompop, Anusak Songpim, Sillapa Reabroi, Prapatpong Inkongngam – A
comparative study of sequencing batch reactor and moving-bed sequencing batch reactor for
piggery wastewater treatment, Maejo International Journal of Science and Technology 5(02)
(2011) 191–203.
[9] Jun-WeiLim, Poh-EngLim, Chye-EngSeng – Enhancement of nitrogen removal in moving bed
sequencing batch reactor with intermittent aeration during REACT period, Journal of Chemical
Engineering 197 (2012) 199–203.
[10] Giuseppe Pastorelli, Roberto Canziani, Luca Pedrazzi and Alberto Rozzi – Phosphorus and
nitrogen removal in moving-bed sequencing batch biofilm reactors, Water Sci. and Technol.
40(4–5) (1999) 169–176.
[11] Meta Levstek, Igor Plazl – Influence of carrier type on nitrification in the moving-bed biofilm
process, Water Sci. and Technol. 59(5) (2009) 875–882.
[12] C. P. Leslie Grady Jr., Glen T. Daigger, Nancy G. Love, Carlos D. M. Filipe. Biological
Wastewater Treatment 3rd Edition, IWA publishing, London, UK, 2011, pp.88.
[13] Ying-Chih Chiu, Li-Ling Lee, Cheng-Nan Chang and Allen C. Chao – Control of carbon and
ammonium ratio for simultaneous nitrification and denitrification in a sequencing batch
bioreactor, International Biodeterioration & Biodegradation 59(1) (2007) 1–7.

Article history:
– Received: Sep. 3.2016
– Accepted: Nov. 29.2016
– Email:

32

No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

THE EFFICIENCIES OF SMALL SCALE BIOGAS DIGESTERS
IN PIG MANURE TREATMENT IN THE MEKONG DELTA
Nguyen Thi Thuy Nghiem1, Tran Van Khai2, Nguyen Thanh Phong1
1
Hoa Sen University, 2 Asian Power Corporation
ABSTRACT
Biogas digester for treatment of pig manure was rapidly gaining interest in both
farmers and scientists in the Mekong delta. The largest advantage of anaerobic digestion is
energy recovery. Biogas collected from biogas digester is used as a substitute for fossil
fuels to produce heat; whereas digestion can be used as a fertilizer or soil conditioner. Due
to animal husbandry and biogas digester development, abundant effluence produced
courses environmental problems. There are increasing concerns about manure treatment
ability of the biogas digesters. However, many different models of biogas digester are
available on the market and therefore it is unknown which one can treat pig manure
efficiency. The study was conducted in four different models of biogas digester:
polyethylene (PE), high density polyethylene (HDPE), fixed dome and composite models. In
average, the reduction of TSS, BOD5, COD and oDM of HDPE system were 73%, 63%,
79% and 61% respectively. The results also showed that fixed dome model was the most
efficient in pig manure treatment compared to other models.
Keywords: biogas, digester, anaerobic, BOD5, COD, oDM, TSS, PE, HDPE,
fixed dome and composite
1. INTRODUCTION
The animal husbandry has increased in Viet Nam recently. The development of the
animal husbandry courses environmental pollution (Thanh, 2003). Most of animal manure

is not treated and discharged directly to the water bodies. The polluted water is harmful for
humans and animals. In fact, the manure creates environmental problems such as
greenhouse gas emissions and unpleasant odours.
The treatment for the manure is essentially. Biogas digester was widely used for pig
manure treatment. The treatment based on the activities of microorganisms that transform
organic substances into biogas (Appels et al., 2008). Biogas is used as renewable energy
source, and nutrients in the residue can be recovered in agriculture as fertilizer or soil
conditioner (Møller et al., 2009). In addition, biogas digester is attracting attention as an
effective method to reduce GHG emissions according to Kyoto protocol (Møller et al.,
2009). Actually, many studies have been conducted to show the benefits of biogas digester
treatment, for instance the works of (Ngan, et al., 2012; Ngan, 2011) showed that the
advantages and disadvantages of different biogas models. However, most of the previous
studies considered only on biogas production or investment cost. There is still missing data
55


Nguyen Thi Thuy Nghiem...

The efficiencies of small scale biogas digesters in...

concerning the efficiency of different biogas models and results are sometimes conflicting.
For example, the reductions of Biology oxygen demand (BOD), Chemical oxygen demand
(COD), Organic dry matter (oDM) associated to the different digester models were often
excluded in previous studies. In fact, the treatment efficiency of each model may be
different. The aim of this research is to investigate and evaluate the reduction of pollutants
from different biogas plants: polyethylene (PE), high density polyethylene (HDPE), fixed
dome and composite model.
2. MATERIALS AND METHODS
The study was conducted in Cho Gao district, Tien Giang province. This is one of the
most concentrated area of animal husbandry in Mekong Delta that they have not had the

right solution or perfunctory measures to solve this problem. According to the conducted
survey showed that most of treatment systems are traditional models such as PE, Composite
and fixed dome, which have many disadvantages during operation process. Therefore, the
investigation was conducted to compare and evaluate removal efficiencies of HDPE and
other materials like PE, composite and fixed dome. In all, 2 PE, 2 HDPE, 2 composite and
2 fixed dome models were investigated in the study.
In this study, HDPE biogas system is designed in cylindrical structure and its volume is
3
9m to handle all of manure of 25 adult pigs in 30 days. Besides that other traditional
systems like PE, Composite and fixed dome, which have the same input and output
parameters, are operated in different places.
In the study, the influents and effluents of investigated models were collected and
measured waste water quality parameters such as temperature, pH, TSS, BOD, COD,
turbidity, Dry matter (DM) and oDM. Temperature and pH measurements were conducted
at the biogas systems by pH detector, thermometer; whereas, TSS, BOD, COD, turbidity,
DM and oDM were analyzed in the laboratory of Hoa Sen university.
Samples were collected directly from the effluent of the digesters at 8 am, when pigs
are fed and cleaned completely. This work is repeated one time per week during 45 days.
Collected samples are preserved at the low temperature and transported follow by TCVN
4556-1988 Standard before analyzing in Hoa Sen’s laboratory. All of parameters are
conducted by Standard Method. BOD was analyzed by biological oxygen demand of
microorganism after 5 days. The moisture content was determined by drying the samples at
105°C until the weight was unvarying. The percentage of moisture content was calculated
in relation to the initial weight. The drying samples were then burned at 550oC for oDM
measurement. COD was determined by K2Cr2O7 and titration.
The results are analyzed by Microsoft Excel 2013 to export the average removal
efficiencies and chart.
3. RESULTS AND DISCUSSION
3.1. Temperature and pH
The average temperature and pH at different biogas digesters were shown in Tab. 1.

The mean temperature was 30oC. It is mesophilic temperature for anaerobic digestion
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process. There were no significant differences in the four types of digester. The temperature
in the composite and HDPE were slightly higher than PE and fixed dome models. The
differences could be explained by absorbing sunlight of the black material. Mean pH value
in four models was 7.5, which was an optimum condition for anaerobic decomposition
process (optimum value from 6.8 to 7.5, (Dung, et al., 2010).
Table 1. The temperature and pH in the four models
PE

Composite

Fixed dome

HDPE

Temperature (T0)

30

30.5

29

30.5

pH

8

8

7.5

6.8

3.2. The removal efficiencies of COD, BOD5 and oDM
The average removal efficiencies of COD,
BOD5 and oDM were shown by figure 1. The
results showed that the removal efficiencies of
fixed dome were the best. In average, the model
could remove 93.32, 80.15 and 74.11% of
COD, BOD5 and oDM respectively. The
second efficient model was HDPE with 78.9,
63.13 and 60.73% of COD, BOD5 and oDM
respectively. 60% and 30% of COD was
decreased after the PE and composite biogas
digesters. Composite model was inefficient in
COD reduction.
Figure 1. The removal efficiencies of COD, BOD5 and oDM

Removal efficiencies (%)

3.3. The removal efficiencies of TSS, turbidity and DM

100
TSS
Turbidity
DM

80

60

40

20

0
PE

Composite

Fixed dome

HDPE

Figure 2. The removal efficiencies of TSS, turbidity and DM

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Nguyen Thi Thuy Nghiem...

The efficiencies of small scale biogas digesters in...

The average removal efficiencies of TSS, turbidity and DM of four biogas system were
illustrated in the figure 2. Fixed dome had the highest of TSS reduction. Mean TSS
reduction was 74.28%. However, turbidity and DM were lower than the removal
efficiencies of PE and HDPE with 83.07% and 47.14%, respectively. The removal
efficiencies of HDPE system were high for both indicators with 72.75%, 88.72% and
63.25% of TSS, turbidity and DM respectively. PE achieved the highest turbidity reduction
with 91.43% but TSS and DM were only 45.14% and 44.05%. The removal efficiency of
the composite model was the lowest with 37.74%, 20.11% and 41.07%, respectively. These
results are in line with previous researches (Nguyen, 2011) and (Ngan, et al., 2012).
4. CONCLUSIONS
The investigated biogas digesters were operated in good conditions. All digesters
generated biogas. Produced biogas was used mainly for cooking. The four models were
shown that the digesters could reduce COD, BOD, oDM and TSS, but the reductions were
different at four models. Fixed dome model was the most efficient in pig manure treatment
compared to other models, whereas, composite model could remove only 30% of COD. For
the HDPE digester, it was recommended for small scale farmer due to low cost investment
and high efficiency in pig manure treatment.
REFERENCES
[1] Appels, L., Baeyens, J., Degrève, J. and Dewil, R. 2008. Principles and potential of the
anaerobic digestion of waste-activated sludge. Progress in Energy and Combustion Science, 34,
755-781.
[2] Møller, J., Boldrin, A. and Christensen, T. H. 2009. Anaerobic digestion and digestate use:
accounting of greenhouse gases and global warming contribution. Waste Management and
Research, 27, 813-824.
[3] Nguyen, C. N., 2011, Small-scale anaerobic digesters in Vietnam - development and
challenges, Journal of Vietnamese environment, vol. 1, pp. 12-18.
[4] Ngan, Vo Chau; Phan, Trung Hieu; Vo, Hoang Nam, 2012, Review on the most popular anaerobic
digester models in the Mekong Delta, Journal of Vietnamese environment, vol. 2, pp. 8-19.
[5] Ngo Đinh Ngoc Giao, Ngo Đuc Đat, 2014, Thực hành hóa kỹ thuật môi trường, TP. Hồ Chí Minh

[6] Nguyen Lan Dung, Nguyen Khac Tich, Nguyen Quang Khai, 2010, Hỏi đáp về công nghệ khí
sinh học, Nông Nghiệp.
[7] Thanh, N. X., 2003, Giáo trình Công nghệ vi sinh vật trong sản xuất nông nghiệp và xử lý ô
nhiễm môi trường, Nông nghiệp.

Article history:
– Received: Sep. 3.2016
– Accepted: Nov. 29.2016
– Email:
58


No 6(31) – 2016, Dec. 2016

Scientific Journal Of Thu Dau Mot University

EFFECTIVENESS OF GROUNDWATER EXPLOITATION
AND USAGE MANAGEMENT POLICIES IN O MON DISTRICT
Huynh Vuong Thu Minh1, Ho Yen Ngan1, Tran Van Ty1, Nguyen Thi Thuy
Trang2, Dang Thi Hong Ngoc3, Huynh Van Men1, Tran Thi Thanh Lan4
1
Can Tho University, 2Cau Ke general hospital, Tra Vinh City
3
Kien Giang University, 4People’s Committee of Yen Luong Commune (Go Cong Tay
District, Tien Giang Province)
ABSTRACT
This research was carried out to assess effectiveness of enforcement procedures for
groundwater management policies in O Mon district of Can Tho city. The specific research
objective were: (i) assessment of groundwater level declining from 2000 to 2013; (ii)
assessment effectiveness of groundwater policy and (iii) to propose solutions to improved

effective groundwater management in the research area. Methods were used: (i) collection and
classification of legal groundwater resources documents (valid); (ii) basic statistical data
analysis to assess groundwater level declining; (iii) field trip observation and interview both
households and businesses were used groundwater about current groundwater management
policy; and (iv) Consultation both experts and local authorities were proposed solutions to
improved efficiency of groundwater management. The research results showed that, from 2001
to 2010, groundwater level has been declining rapidly in upper-Pleistocen and lowerPleistocen, in which, lower-Pleistocen was the highest declining with average speed (-0,39
m/year). From 2010 to 2013, groundwater level trends stabilize. The groundwater management
policy for groundwater exploited license and adjourn groundwater exploited license were
shown integrity and unity. However, effective enforcement is not high appreciation due to lack
of human resource management without water resources management major. Local staffs
manage not only groundwater resources but also mineral resources, hydrometeorology,
climate change. Due to expert’opinion, department of environment and Natural resources need
high quality staffs with major in Water Resources Engineering, Hydrogeology. Besides,
exploited violations have been popularized, especially, lack of exploited groundwater license.
Penance violations were showed both integrity and concretize due to Viet Nam water resources
law. According to expert’opinion, Punishment is enough for dissuasive groundwater overexploitation. However, we should enhance education and popular Viet Nam water resources
law in communities combined with regular inspection of enforced law so that ensuring
groundwater resources management is more effective.
Keywords: groundwater, management policy, effectiveness, O Mon District.
1. INTRODUCTION
Together with rapid urbanization, industrialization process, Can Tho city has been
facing with a a lot of environmental issues. Especially, groundwater level drawdown. In the
59


Huynh Vuong Thu Minh...

Effectiveness of groundwater exploitation and...

context of climate change, domestic surface water pollution and saline intrusion have been
occurred increasingly complex led to groundwater exploitation both domestic activities and
industrial production purpose in Vietnamese Mekong Delta.

Figure 1: Study area

Using groundwater is more favorable than using surface water. Further more, it is
cheaper than using pure water from water supply factory. So, local residents and businesses
has been chosen to use groundwater than others. Groundwater in Can Tho city has mainly
exploited in shallow and average depth located in Pliocene and Pleistocene aquifers, not in
Holocene and Miocene aquifers. In particular, Pleistocene aquifer accounting for 61.54% of
total licensed wells. Groundwater exploitation has been mainly exploited to serve domestic
water supply that total exploitation volume is 62,708 m3/day (accounting for 79.3%). For
groundwater exploitation license and renewal, there are 312 groundwater exploitation
licenses with total exploitation volume 79,068 m3/day. In particular, O Mon district has
exploited 16,866 m3/day (accounting for 21.5% total groundwater exploitation volume in
Can Tho city). Most of groundwater exploitation areas are concentrated in the city's
industrial zones (According to general statistics from Can Tho Department of Natural
resources and Environment). So, this leds to decline groundwater level in Can Tho city,
especially, industrial zone. Currently, the application of Vietnam water resources law as
well as the policies of local authorities in management have been still facing many
difficulties and shortcomings. Before this situation, the study "Effective management of
groundwater exploitation and use in O Mon District - Can Tho City" is going to kick off
with following specific objectives: (i) evaluating groundwater level trend (ii) determine
effective groundwater management in O Mon District – Can Tho city.
2. MATERIALS AND METHODS
2.1. Data collection
Secondary data: collecting data on groundwater level in 2001 - 2013 period from Can
Tho Monitoring Centre of Natural Resources and Environment, Can Tho Department of
Water Resources - Minerals - Hydrometeorology. Since 2000, Can Tho Department of

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Natural Resources and has designed and run groundwater level monitoring network system
in whole city. Currently, Can Tho city has 16 groundwater level monitoring stations, of
which there is one of the important national monitoring well (QT16) located in Tra Noc 2
Industrial zone. At each cluster station, it divided into three groundwater level monitoring
wells: (i) in upper Pleistocene aquifer; (ii) in lower Pleistocene aquifer; (iii) in Holocene
aquifer. Collect law, decision that have been applied in the study area.
Primary data: interviews from experts from Can Tho water resource management, Can
Tho Department of Natural Resources and Environment, businesses companies from Tra
Noc industrial zone, local households.
2.2. Data analysis
Using mathematical functions (Average, Max, Min) to calculated the groundwater level
changes in 2001-2013 period; represent calculated data as graphs and tables.
To assess the integrity and consistency of groundwater exploitation licensed,
sanctioned delinquent behavior due to Vietnam water resources law, research was
conducted: (i) comparision general policies with the general law guidelines; (ii)
comparision policies with reality requests; (iii) comparision separated policies with policies
management system.
To evaluate performance of licensed activities, license renewal and sanctions
delinquent behavior about groundwater resources field, research conducted: (i) assess the
impact of effective influence working licensed use and exploitation and sanctioned
activities; (ii) assess the effects (positive and negative) of these impacts.
3. RESULTS AND DISCUSSION
3.1. Assessment of groundwater level trend in O Mon district, Can Tho city

The results showed that groundwater level in upper-Pleistocene and lower-Pleistocene
have been declining over time (Fig 2).

(A)

(B)

Figure 2. Groundwater level trend at QT16 (A) and QT8 (B) monitoring station in 2001-2013
period

61