Sử dụng bùn thải từ quá trình xử lý nước thải nhà máy sản xuất bia và chế biến thủy sản trong ủ phân hữu cơ vi sinh tt tiếng anh

MINISTRY OF EDUCATION AND TRAINING
CAN THO UNIVERSITY

SUMMARY OF DOCTORAL DISSERTATION
Major in Soil Science
Identification code: 9620103

NGUYEN THI PHUONG

COMPOSTING MICROBIAL ORGANIC
FERTILIZER OF SLUDGES FROM
WASTEWATER TREATMENT PLANTS OF
BEER AND SEAFOOD PROCESSING
FACTORIES

Can Tho, 2019


This study was achieved at Can Tho University

Scientific Supervisor: Assoc. Prof. Dr. Nguyen My Hoa

This dissertation was defended at the University
Examination Council
At: ……………………………………...
At…hour.., on date…month….year…
Reviewer 1:……………………………
Reviewer 2:……………………………
Reviewer 3:……………………………

The dissertation is available at:

Learning Resource Center, Can Tho University.
National Library of Viet Nam.


PUBLICATIONS RELATED WITH THE
DISSERTATION
[1].
Nguyen Thi Phuong, Nguyen My Hoa, Do Thi Xuan,
Lam Ngoc Tuyet, Vo Thi Thu Tran, 2016. “Characteristics of sludges
from wastewater treatment plants of beer and seafood processing
factories”. Journal of Science, Can Tho University, 45A/2016, p.74-81
(In Vietnamase)
[2].
Nguyen Thi Phuong, Nguyen My Hoa, Do Thi Xuan,
Lam Ngoc Tuyet, 2017.“Composting of sludge from wastewater
treatment plants of seafood processing factories”. Science and
Technology Journal of Agriculture & Rural Development, 5, p.54-61.
(In Vietnamase)
[3].
Nguyen Thi Phuong, Nguyen My Hoa, Do Thi Xuan,
Lam Ngoc Tuyet, 2017. “Composting of sludge from wastewater
treatment plants of beer processing factories”. Journal of Vietnam soil
science, 50, p.47-52. (In Vietnamase)
[4].
Nguyen Thi Phuong, Nguyen My Hoa, Do Thi Xuan,
2018. " Effect of micro - organic composts from beer and seafood
sludge on growth and yield of Okra (Abelmoschus esculentus)" Journal
of Agricultural Science and Technology of Vietnam, 2(87), p.7-10. (In
Vietnamase)
[5].

Nguyen Thi Phuong, Nguyen My Hoa, Do Thi Xuan,
2018. “Production and assessment efficiency of microbial-organic
fertilizers from beer and seafood factories’ sludge on vegetable yield”.
Journal of Science, Can Tho University, special issue Agriculture 54
p.81-90. (In Vietnamase).
[6]. Nguyen Thi Phuong, Nguyen My Hoa, Do Thi Xuan,
2018. “Effect of microbial organic fertilizers from seafood sludge on
growth and yield of winter melon (Benincasa hispida)”. Journal of
Vietnam soil science, 54, p.19-24. (In Vietnamase)


CHAPTER 1. INTRODUCTION
Rationale of the study
In many wastewater treatment facilities, the bottleneck of the
sludge handling system is the dewatering operation. Beer (BS) and
seafood sludges (SS) were effluents dewatered in waste water
treatment plants of beer and seafood factoires. The annual sludge
production from beer breweries and seafood factories is about 6
million tons and 313,170 tons, respectively (Fillaudeau et al. (2006);
Ministry of Industry and Trade, 2009, 2016; Vo Phu Duc, 2013 ).
According to Senthilraja et al. (2013), Feng et al. (2008), and Vo Phu
Duc (2013) beer and seafood sludges are nontoxic and contained
much of the organic matter and valuable nutrients. For these reasons,
recycling of sludges for agricultural purposes seems to be an
appealing solution that enables using of valuable components and
resolve pollutants ( Ministry of Natural Resources and Environment,
2013; Oanh and Dieu,2016; Saviozzi et al., 1994; Stocks et al., 2002;
Thomas and Rahman, 2006).
Both BS and SS possessed poor compressibility and settleability
(Jin et al., 2003; Li et al., 2012). Therefore, it is necessary to mix BS

and SS with organic materials such as sugarcane sludge, bagasse and
straw that are high in cellulose and porosity to provide energy for
microorganisms during composting process, and increase compost
quality. However, the most suitable ratio mixture of sludge and organic
materials to produce high quality microbial-organic fertilized to meet
the standard of Vietnam and to increase crop yield is still
questionableAt present, there are not many research papers on beer and
seafood sludges for production of microbial-organic compost (Vo Phu
Duc, 2013; Oanh and Dieu, 2016). In addition, isolating fungal strains
from rice straw, bagasse and coconut fiber was also carried out to find
out new fungi that can decompose organic materials, resisted to
pathogenic fungi and promote organic composting process.
Because of these issues, study on production of microbial-organic
fertilizers from beer and seafood factories’ sludge is necessary as an
effective treating of sludge.
1.2.
Objectives of study
Determination of optimal composting formula for the production
of microorganic compost from beer and seafood sludges;
1.1.

1


Assessment effetiveness of microbial-organic fertilizers from beer
and seafood factories’ sludge on vegetable yield;
Isolation and selection of fungal strains capable of decomposing
organic materials for further use as a microbe in production microbial
organic fertilizer
1.3.

Research activity
Determination of physical, chemical, nutritional and biological
characteristics of BS and SS.
Efficiency of dried beer and seafood sludge on growth and yield
of vegetable grown under the greenhouse condition;
Determination of decomposability and suitable composting ratio of
beer/seafood sludge and organic materials at bag scale;
Production microbial-organic fertilizers from beer and seafood
sludge at scale of 0,5 meter cubic;
Assessing efficiency of microbial-organic fertilizers from beer and
seafood factories’ sludge on vegetable yield, consisting of mustard,
okra, cucumber, and winter melon in the field conditions;
Isolation and selection of organic material decomposable-fungal
strains
1.4.
Scope of the study
The study focused on sludges from wastewater treatment of beer
production and seafood processing plants in the Mekong delta to
produce microbial-organic fertilizer using Trichoderma spp. from
Trico-DHCT product as the beneficial microorganism. The crops
used for testing the effect of microbial-organic fertilizer were
vegetables for short growth duration. The isolation of the fungal
strain focused on organic material decomposability of the fugus for
the aim of the wide use in production of microbial-organic fertilizer.
1.5.
Scientific significance and applicability of study
The results showed that BS and SS are two sources rich in
nitrogen, phosphorus, micro nutrients and do not contain heavy metal
contaminants.
Sugarcane cake was suggested to mix with beer/seafood sludges

for the production of bio-organic fertilizer. The optimal mixing ratio of
sludge and sugarcane sludge with 20:80 is recommended for the
production of microbial-organic fertilizers with high quality.
The research has proved the efficiency of microbial organic
fertilizer produced from both sludges on vegetable yields such as

2


mustard, okra, cucumber, and winter. It is recommended to use 5 tons
/ha of microbial organic fertilizer from the sludges with recommended
dose of inorganic fertilizer to increase vegetable yield.
Four strains of fungi which possessed organic material
decomposability and fungal pathogens antagonistic character were
selected. Two strains were identified as Neurospora crassa and
Neurospora intermedia, which decomposed well mixture of sludge and
sugarcane cake with ratio of 20:80.
.CHAPTER 2. METHODOLOGY
2.1. Determination physical, chemical, nutrient and biological
characteristics of beer and seafood sludges.
Sludge samples were collected at beer factories in Soc Trang, Tien
Giang, and Bac Lieu provinces and at seafood processing factories in
Dong Thap, An Giang, Hau Giang, Tien Giang, and Bac Lieu
provinces. Sugarcane cake and bagasse were collected at Hau Giang
sugarcane factory. Cow dung was collected from Long Hoa dairy
cooperative. Analytical methods of input materials are presented in
below detail (Table 2.1).
Table 2.1. Analytical methods of input materials
Analytical methods
Parameter

Unit
Moisture
%
Dry at 105oC to constant weight
Samples are taken in a 100 cm3 box
Bulk density
g/cm3
and then dried at 1050C for 24 hours
Extract with water with a soil ratio of
pHH2O
1: 5. Measure by pH meter
Extract with water with a soil ratio of
EC
mS/cm
1: 5. Measure by EC meter
The samples were dried at 1050C for
Organic cabon
%C
3 hours and at 8300C for 2 hours
Anaerobic digestion with salicylic acid +
Total nitrogen
%N
concentrated H2SO4 + H2O2 and
determined by Kjeldahl method
Anaerobic digestion with salicylic acid +
concentrated H2SO4 + H2O2 and
Total phosphorus
%P2O5
colorimetric on spectrophotometer at
880nm

Total potassium
%K2O Anaerobic digestion with salicylic acid +

3


N available

%N

P available

%P2O5

K available

mg/kg

Ca, Mg, Zn,Cu,
Mn

mg/kg

concentrated H2SO4 + H2O2 and
measured on atomic absorption
Extract with H2SO4 0.5N
(Vietnamese Standard 9295:2012)
Extract with acid citric 2%
(Vietnamese Standard 8559:2010)
Extract with HCl 0.05N

(Vietnamese Standard 8560:2010)
Anaerobic digestion with concentrated
H2SO4 + H2O2 measured on atomic
absorption
Vietnamese Standard 9291:2012
Vietnamese Standard 9290:2012
Vietnamese Standard 8467-2010
Vietnamese Standard 8882-2011

Cd
mg/kg
Pb
mg/kg
As
mg/kg
Hg
mg/kg
Ecoli, Coliforms,
CFU/g
Colony forming unit method
Salmonella
Dw
2.2. Efficiency of sun-dried beer and seafood sludges on growth
and yeild of vegetable under the greenhouse condition
2.2.1. Germination of mustard (Brassica juncea) on substrates of
sun-dried sludges
Each sludge were put in a plastic tray with a thickness of 4 cm.
Then each tray would directy exposure the Sun from 9 am up to 3 pm,
and rotate the sample every 30 minutes. The sludge wastes were
treated by directly exposing under the sunshine at 4 hours, 3 hours and

2 hours to get three levels of moistures i.e. 10%, 30% and 50%,
respectively to treat human pathogens.
The experiment was performed in trays with a completely
randomized block with eight treatments (Table 2.2) and three
replications for each. The volume of soil, sun-dried sludges, organic
fertilizer of sugarcane cake (SF) used for each tray is 0.5 kg/tray. 100
green mustard were sowing into the trays and sprinkle with 60%
humidity to ensure germination in all trays. After 14 days, germinated
percentage, height, fresh weight, dry weight of mustard were recorded.

4


Table 2.2: Substrates of sun-dried sludges on mustard germination
Treatment
Types of fertilizer
1
Control (Soil)
2
Beer sludge at 10% humidity (BS-10)
3
Beer sludge at 30% humidity (BS-30)
4
Beer sludge at 50% humidity (BS-50)
5
Seafood sludge at 10% humidity (SS-10)
6
Seafood sludge at 30% humidity (SS-30)
7
Seafood sludge at 50% humidity (SS-50)

8
Organic fertilizer of sugarcane cake (SF)
2.2.2. Evaluation efficiency of sun-dried sludges on growth and
yield of green mustard (Brassica juncea)
As a result of experiment at section 2.2.1, two samples of BS-30
and SS-50 were used as compost on growth and yield of green
mustard. The experiment was completely randomized in a pot with six
treatments and three replications (Table 2.3). Each pot contains 7kg
dry land. The BS-30 and SS-50 mixed with sugarcane cake (SC),
organic fertilizer of sugarcane cake used for each pot is 5 tons/ha and
distributed a week before sowing. Green mustard seed is sown 10

seeds into pots and watered to maintain moisture. Each pot
would choose well three plants when the plant highthened about
5 cm. Fertilizers are used according to the recommended rate of
Tran Thi Ba (1999) with 55N-32P2O5-46K2O (kg/ha).
Table 2.3: Experiment on growth and yield of green mustard
Mixture Ratio
Order
Treatment
(%Dry weight)
1
Control (soil)
2
Soil+ (BS-30: SC)
20:80
3
Soil+ (BS-30: SC)
50:50
4

Soil+ (SS-50: SC)
20:80
5
Soil+ (SS-50: SC)
50:50
6
Soil+ SF
Observed parameters after 30 days included plant height, leaves
number/plant, fresh and dry weight, pathogens i.e E. coli, Coliforms
and Salmonella. The analyzing method was described in section 2.1.

5


2.3.

Determination of decomposition ability, suitable
composting ratio of sludges in the bag
2.3.1. Evaluation decomposable capacity of organic materials
Beer sludge (BS) was collected from Tien Giang beer factory and
seafood sludge (SS) was collected from Hau Giang seafood company.
Both sugarcan cake (SC) and bagasse were sampled from Vi Thanh
sugarcane factory. Experimental equipment and chemicals used
department of soil science, Can Tho University, including of
Trichoderma-DHCT fungus.The experiment was arranged in a
completely randomized block of 13 treatments with 3 replications for
each treatment (Table 2.4).
For incubation, 2 g a mixture of sludge and organic materials at
moisture of 65%, and placed in 150-mL plastic jars. One vial
containing NaOH solution (3N) were placed into 150-mL plastic jars.

After this, the vial containing the NaOH solution was renewed weekly.
Moisture was checked by weighing at each sampling date. The amount
of Trichoderma fungus was injected into each treatment with 100g /m3
(Dw) at initial compost. After this, all of the jars were placed in the
dark at a constant temperature of 300C for 45 days. Carbon
mineralisation was measured at 7, 14, 21, 30 and 45 day after
incubation. The CO2 was titrated with H2SO4 (0.01 N). Mass loss was
determined by weighing the sample after 45 days of incubation.
Table 2.4: Treatments, mixture ratio and C/N ratio
Order
1
2
3
4
5
6
7
8
9
10
11
12
13

Treatments
Rice straw
Bagasse
Sugarcane cake
Beer sludge
Seafood sludge

BS: SC
SS: SC
BS: SC:straw
SS: SC:straw
BS: SC:bagasse
SS: SC:bagasse
BS: SC:bagasse
SS: SC:bagasse

Ratio (%Dry weight) C/N
71
271
19
12
8
20:80
20
20:80
20
20:60:20
24
20:60:20
23
10:60:30
30
10:60:30
30
20:60:20
30
20:60:20

30

6


2.3.2. Composting beer and seafood sludges in bag condition
The samples of BS, SS, rice straw, sugarcane cake, bagassem and
cow dung were collected and disposed as similarly as sections 2.1.1
and 2.3.1. Incubation equipments consisted of plastic bags of 50kg,
weighing scale of 30kg, canvas cover plastic bag, thermometer, and
Trichoderma-DHCT fungus. The experiment was arranged in a
completely randomized block of 14 treatments with 3 replications for
each treatment (Table 2.5). The treatments were mixed by dry weight.
The amount of Trichoderma fungus was injected into each treatment
with 100g /m3 (Dw) at initial and after 15-day incubation with 50 for
each injection. The basis on the results of section 2.3.1 and initial C/N
ratio, combination sludge with sugarcane cake and straw or bagasse
with ratio of 10:60:30; 10:70:20, 20:60:20, and 20:80 was studied.
Table 2.5. treatment and mixture ratio
Order
Treatments
Ratio (%Dw) C/N
1
BS: SC:bagasse
10:60:30
30
2
BS: SC:bagasse
10:70:20
23

3
SS: SC:bagasse
10:60:30
30
4
SS: SC:bagasse
10:70:20
23
5
Cow dung: SC:bagasse
10:60:30
21
6
Cow dung: SC:bagasse
10:70:20
20
7
BS: SC: rice straw
20:60:20
24
8
BS: SC: rice straw
10:70:20
21
9
SS: SC: rice straw
20:60:20
23
10
SS: SC: rice straw

10:70:20
20
11
Cow dung: SC: rice straw
20:60:20
23
12
Cow dung: SC: rice straw
10:70:20
21
13
BS: SC
20:80
20
14
SS: SC
20:80
20
Note: BS: Beer sludge, SS: seafood sludge, SC: sugarcane cake. Dw: dry
weight.

Parameters included temperature, humidity and weight loss were
monitored weekly until 75 days after incubation. At days 0, 49, 63, and
75 from initiation, one composite sample (~1 kg dry matter) of three
subsamples was collected from each pile. These samples were used for
analyses of total C, N, pH, and EC. These samples were also used for
analyses of total N, phosphorus (P), potassium (K), amount of

7

Trichoderma and pathogens such as E. coli, Coliforms, Salmonella
after 49-days incubation. The analyzing method was described in
section 2.1. Weight loss also observed at final composting.
2.4. Production microbial-organic fertilizers from beer and
seafood factories’ sludge in 0.5 meter cubic
Based on the results of section 2.3, the optimal mixtue ratio of
sludge and sugarcane cake at 20:80 was chosen to product microbialorganic fertilizers in 0.5 meter cubic.
The samples of BS, SS, straw, sugarcane cake (SC), bagasse and
cow dung were collected and disposed as similarly as sections 2.1.1
and 2.3.1. Composts were a mixture of BS or SS and SC by dry weight
and 3 replication for each. The composting experiments were
conducted at the experimental Farm of the Agriculture and Applied
Biology, Can Tho university. Six square piles were prepared on an
experimental scale (1m high and 1m basal diameter) in a shed, to
prevent excessive drainage and nutrient leaching. The piles were
manually turned at 7, 14, and 30 days after establishment to promote
aeration and ensure that all material was exposed to high temperatures.
The amount of Trichoderma fungus was injected into each
treatment with 200 g/0.5m3 (Dw) at initial (with 100 g), 28 and after
15-day incubation with 50g for each injection.
At days 0, 21, 28, 49, and 63 from initiation, one composite sample
(~1 kg dry matter) of three subsamples was collected from each pile.
These samples were used for analyses of temperature, humidity, pH,
and EC. Total C, N, phosphorus (P), potassium (K), available N, P, K,
calcium (Ca), magnesium (Mg), micro nutrients (Zn,Cu, Mn), heavy
metal contaminants (total Cd, Pb, As, Hg) and amount of Trichoderma
and pathogens were analysied after composting days of 0, 49 and 63.
The analyzing method was described in section 2.1. Weight loss also
observed at final composting.

2.5. Assessment efficiency of microbial-organic fertilizers from
beer and seafood sludges on vegetable yield in the field conditions
Assessment efficiency of microbial-organic fertilizers from beer
and seafood sludges on vegetable yield of mustard, cucumber, okra,
and winter melon in the field conditions was carried out. All
experimental designs were arranged randomly block with 6 treatments
and three replications for each, listed as follows: T1: Farmer rate

8


fertilizer (FR) (control); T 2: Recommended rate chemical fertilizer
(RR): T3: RR+ 5 tons/ha micro-organic fertilizer from BS (bioF-BS);
T4: 70% RR + 5 tons/ha bioF-BS; T5: RR+ 5 tons/ha micro-organic
fertilizer from SS (bioF-SS); T 6: 70% RR + 5 tons/ha bioF-SS.
The research on mustard, cucumber and winter mellon was carried
out at Long Tuyen commune, Binh Thuy district, Can Tho city. Okra
research was carried out at My Hoa commune, Binh Minh district,
Vinh Long province. Mustard plants spacing were 40 cm between the
plants within each row and 30 cm between the rows. The area of one
treatment plot was 15.75 m2 (10.5 long × 1.5 m wide). For cucumber,
plants spacing were 40 cm between the plants within each row and 1.5
m between the rows. The area of one treatment plot was 10.5 m × 2. 5
m. Winter melon plants spacing were 40 cm between the plants within
each row and 60 cm between the rows. The area of one treatment plot
was 9,6 x 2,6 m. For okra, each block was 30 m long and equally
divided into two treatment plots, with each treatment 15 m long and a
width of 1.5 m.
Yield (tons/ha) of vegetables was determined at harvest.
2.6. Isolation and selection of fungal strains capable of

decomposing organic materials
2.6.1. Isolation fungal strains decomposed cellulose and chitin
The samples rice straw (R) was collected in Dong Thap and Vinh
Long provinces. Coconut fiber (D) was sampled in Vinh Long
province. Bagasse (M) sample was collected in Vinh Long province
and Can Tho city. The stubble was cut further into small pieces and
aseptically incubated on sterile Hagen agar amended with sodium
carboxy methyl cellulose (10g/l) and Streptomycin 30 ppm for
isolation of cellulolytic fungi. In addition, crude chitin was washed and
neutralized with acid for pH = 7.
To examine if all colonies appearing on cellulose amended media
were cellulolytic, fresh pure cultures were treated with 0.1% congo red
stain followed by procedure described by Alström (2000). Presence of
chitinolytic activity of fungi was evaluated according to Arora et al
(2005). The degree of enzymatic activity was assessed by measuring
the radius of the clear zone appearing around each colony.

9


2.6.2. Assessment effect of isolated fungi on rice straw and
bagasse decomposition
Rice straw was cut into approximately 5 cm pieces and bagasse
was verificated 5mm. The microcosms used for the experiment
consisted of aucto clavable polyethylene bags (50 cm x 31 cm)
containing straw and bagasse (20 gram dry weight) and distilled water
enough to give 60% moisture. The bag was closed with a cotton plug
and autoclaved twice for one hour each.
A total of 8 isolated fungi, including D91B7, M-LT3, M-LT4, RĐT1, R-NVT1, M-2HA1, M-NK1, M-TA3, Trichoderma-ĐHCT
(positive control), and non fungus (negative control). The suspensions

were diluted before aseptically inoculated to microcosms (106 CFU/1g
gram dry weight) using as syringe and sealing the needle hole with
tape.
After eight weeks, the rice straw and bagasse were harvested and
dried over night in an oven at 60oC. The biomass from each microcosm
was calculated and transformed to % weight loss compared with the
weight at the beginning of the experiment.
2.6.3. Resistance of isolated fungi to the R. solani fungus
Rice straw and basgass decomposed by four advanced strains were
used as substrates to assess the antagonistic capacity of R. solani
pathogen over a 4 week period as well as the resistance of these fungal
strains against R. solani on PDA agar. The experiment was arranged in
a randomized form with 6 treatments and 3 replications for each
treatment. After 4 weeks of incubation, the diameter of R. solani was
measured and compared with the control diameter of R. solani.
2.6.4. Identify fungal strains isolated by molecular biological
methods
The PCR reaction was performed according to the method
described by Kennedy et al., (2005) and Do Thi Xuan (2007).
2.6.5. Evaluation of the decomposition of mixed sludge and
sugarcane cake with isolates of fungal strains
Four fungal cellulosic and chitin decomposed strains in section
2.6.2 were selected to verify their degree of decomposition on mixture
of sludge and sugarcane cake. All equipment and researched method
were similar to Section 2.3.1.

10


2.7.

Measurements and Statistical Analysis
Data was analyzed using the SPSS package version 16.0. Data
were analyzed by analysis of variance (ANOVA) and Duncan’s
multiple range tests. National standards is used to evaluate the quality
of sludge and microbial organic compost.
CHAPTER 3. RESULTS AND DISCUSSION
3.1. Determination physical, chemical, nutrient and biological
characteristics of beer and seafood sludges and other materials
3.1.1. Physical characteristics of materials
As sludges do not contain cellulose compounds but they contain
many protein compounds, sugars, starches and organic acids (Feng et
al., 2008; Mook et al., 2012; Olajire, 2012). Whether BS and SS were
not only good porosity but also high moisture, so it is necessary to
mixure these sludges with other high cellulose materials such as
sugarcane sludge, bagasse, or straw (Table 3.1).
Table 3.1. Bulk density and moisture of materials before compost
Bulk densidy
Moisture
EC
pHH2O
(g/cm3)
(%)
(mS/cm)
Rice straw
18,66
Bagasse
0,07±0,00
29,00
6,20±0,01 0,56±0,00

Sugarcane cake
0,25±0,02
55,76
6,15±0,08 6,05±0,09
Cow dung
0,18±0,01
18,84
7,07±0,00 4,44±0,00
BS-Soc Trang
0,16±0,01
81,43
6,15±0,03 2,71±0,00
BS-Tien Giang
0,24±0,01
74,95
5,80±0,43 2,10±0,06
BS-Bac Lieu
0,18±0,01
81,51
6,29±0,03 4,56±0,05
SS-Tien Giang
0,18±0,01
80,11
7,60±0,16 2,30±0,06
SS-Dong Thap
0,12±0,00
76,92
7,09±0,02 4,18±0,07
SS-An Giang
0,13±0,01

83,26
7,43±0,02 2,12±0,06
SS-Hau Giang
82,01
5,71±0,3
2,40±0,13
SS-Bac Lieu
0,11±0,01
86,19
6,91±0,06 3,19±0,55
Note: Mean ±SD, BS: beer sludge, SS: seafood sludge, “-“: not data
Materials

The pH value of BS and SS varied from 5.71 to 7.6, which was
suitable for reuse in composting organic fertilizers. The EC value was
also high in all materials, including both sludges (table 3.1) because
several chemicals and salts were mixed milled malt, gelatinized
adjunct and water to obtain a high yield of extract product (Olajire,
2012; Park et al 2010). For seafood sludge, high levels of EC could be
attributed to the origin of aquatic species as saltwater aquaculture
(Mirzoyan et al., 2008). However, despite of the high EC value, many

11


authors such as Jones et al. (2011), Bui Thi Nga et al. (2014), Lakhdar
et al. (2010), and Duong Minh Vien et al. (2011) evidenced EC value
did not affect plant and soil.
In addition, contains of total nitrogen and phosphorus in the both
beer and seafood sludges were high, higher than other sludge sources

such as sugarane sludge, pond sludge,sewage sludge but the level of
potassium from the two these sludges reached the level of poverty.
The total nitrogen content (NT) in the sludge was high because malt,
adjuncts, and nitric acid used for cleaning may contribute to the total
nitrogen content (Olajire, 2012). Phosphorus can also come from
cleaning agents. The actual phosphorus concentration will depend on
the water ratio and the cleaning agent used (Olajire, 2012) (Table 3.2).
Table 3.2. Nutrients characteristics of material before conpost
TN
TP
TK
Na
Pa
Ka
(%)
(%P2O5)
(%)
(%)
(%)
(%)
Rice straw
0.6
0.31±0.00
1.37
Bagasse
0.21 0.13±0.01
0.20
0.02
0.002
0.16

Sugarcane cake
2.31 6.37±0.01
0.78
0.45
3.37
0.48
Cow dung
1.31 3.76±0.00
1.18
0.22
2.87
1.08
BS-Soc Trang
3.95 4.99±0.02
0.2
0.29
1.93
0.16
BS-Tien Giang
2.61 10.7±0.03
0.97
0.18
2.38
0.10
BS-Bac Lieu
2.59 5.56±0.10
0.23
0.33
1.04
0.16

SS-Tien Giang
2.11 7.27±0.02
0.16
0.25
5.54
0.09
SS-Dong Thap
3.87 7.29±0.04
0.50
0.74
4.72
0.36
SS-An Giang
2.94 6.32±0.07
0.16
0.22
3.85
0.05
SS-Hau Giang
5.62 7.17±0.16
0.74
0.32
4.97
0.18
SS-Bac Lieu
4.65 4.66±0.02
0.45
0.27
3.53
0.3

Note: Mean ±SD, BS: beer sludge, SS: seafood sludge, TN: total nitrogen, TP:
total phosphorus, TK: total potassium, Na: available nitrogen, Pa: available
phosphorus, Ka: available potassium. “-“: not data
Materials

The organic carbon content (% C) from both sludges was low,
leading to low C/N ratio. therefore, beer and seafood sludges should be
mixed with organic materials with high fiber content such as sugarcane
cake, bagasse and rice straw to increase porosity and supply carbon
source for microorganisms growth during composting (Table 3.3).
Table 3.3. Organic carbon and C/N ratio of materials
Materials
C (%)
C/N
Rice straw
42.67
71
Bagasse
57.94
276

12


Sugarcane cake
Cow dung
BS-Soc Trang
BS-Tien Giang
BS-Bac Lieu
SS-Tien Giang

SS-Dong Thap
SS-An Giang
SS-Hau Giang
SS-Bac Lieu

31.78
46.66
21.53
31.75
31.38
42.09
41.71
34.24
42.81
37.43

14
36
6
12
12
20
11
12
8
8

Note: BS: beer sludge, SS: seafood sludge

3.1.2. Contains calcium, magnesium, micronutrients, heavy

metals, and pathogenic microbes
The results showed that contains of Ca, Mg, Mn, Zn, and Cu in
both BS and SS were high and equal or higher than sugarcane sludge.
Furthermore, the nutrient content of micro elements got under standard
limit of Vietnam 50/2013 / MoRE. Therefore, these sludges provided
additional useful sources for microbial organic composting (Table 3.4).
Table 3.4. Calcium, magnesium, manganese, copper, zinc in materials
Ca
Mg
Mn
Zn
Cu
Materials
(% CaO)
(% MgO) (mg/kg) (mg/kg)
(mg/kg)
Bagasse
0.05
0.09
70
11
3
Sugarcane cake
4.44
0.61
327
256
106
Cow dung
2.35

1.31
664
567
159
BS-Soc Trang
0.84
0.72
359
132
454
BS-Tien Giang
1.23
0.42
436
1327
201
BS-Bac Lieu
1.13
0.84
293
144
514
SS-Tien Giang
4.78
0.01
114
104
13
SS-Dong Thap
3.72

0.13
174
272
53
SS-An Giang
5.41
0.15
154
771
74
SS-Hau Giang
3.02
0.39
293
349
340
SS-Bac Lieu
5.79
1.57
187
526
539
Note: BS: beer sludge, SS: seafood sludge

The samples of BS and SS did not contain heavy metal toxic but
the microbial population is E. coli and Coliforms exceed the limit
allowed under Decree 108/2017/goverment Decree for E. coli and

13

Vietnam standard No. 40/2011/MoRE for Coliforms. Hence, microbial
organic composting was essential to kill pathogens (Table 3.5 and 3.6).
Table 3.5. Contains heavy metals in materials
Cd
Pb
As
Hg
Materials
(mg/kg)
(mg/kg) (mg/kg) (mg/kg)
Bagasse
0.01
1.58
Sugarcane cake
0.48
1.10
0.04
ND
Cow dung
1.06
0.66
BS-Soc Trang
0.11
BS-Tien Giang
0.55
0.55
0.67
ND
BS-Bac Lieu

0.15
SS-Tien Giang
0.08
0.37
SS-Dong Thap
0.12
0.45
SS-An Giang
0.38
1.10
SS-Hau Giang
1.18
0.09
0.09
ND
SS-Bac Lieu
5.03
8.66
Threshold limit
<10
<300
<40
<4
Table 3.6. Human pathogenic microbial population in sludges
Coliforms
E.Coli
Salmonella
Materials
(CFU/gDw)
(CFU/g Dw)

(CFU/g Dw)
Sugarcane cake
2700
541
ND
BS-Soc Trang
4.5 x 104
1.6 x 103
ND
BS-Tien Giang
2.7 x 105
2.7 x 105
ND
BS-Bac Lieu
ND
SS-Tien Giang
ND
4
3
SS-Dong Thap
3.2 x 10
1.7 x 10
ND
SS-An Giang
ND
SS-Hau Giang
5.5 x 104
5.4 x 106
ND
Threshold limit

< 3000
<1100
ND
Note: BS: beer sludge, SS: seafood sludge, “-“: not data. ND: not
detected.Dw: dry weight

3.2.

Efficiency of dried beer and seafood sludge wastes on
growth and yeild of vegetable grown under the greenhouse
condition
3.2.1. Survey on the germination of mustard (Brassica juncea) on
substrates of sun-dried sludges

14


After treatment by sun drying method, the nutrient content of the
two sludge sources did not change significantly, but the microbial
population was lower than before treatment and reached below the
Vietnam standard. Therefore, the treatment of both BB and BTS
sources by sun drying had eliminated the pathogen so it could be used
as a fertilizer for green mustard.
The germination index of green mustard on four substrates
consisted of BS-30, BSB-50, SS-30, and SS-50 was not significantly
different from the control treatments for 14 days. However, the
application of sludge after sun-drying treatment for growth and
biomass of shoot mustard was significantly higher than control (Table
3.7). In particular, BS-30 and SS-50 showed the best growth of green
mustard compared to the treatment of sludge at the remaining moisture

content.
Table 3.7: Germination index of green mustard on substrates
Treatment
GI (%)
Shoots height
Fresh biomass
Dry biomass
(cm)
(g/tray)
(g/tray)
Soil (Control)
91
5.63 b
5.73 b
0.08 c
BS-30
96.33
9.72 a
9.24 a
0.76 b
BS-50
95.33
6.53 ab
7.31 ab
0.64 b
SS-30
92.33
6.62 ab
7.67 ab
0.74 b

SS-50
97.33
7.88 a
9.68 a
1.25 a
CV(%)
4.11
5.3
10.2
18.2
Note: Values followed by similar letters under the same column are not
significantly different at p = 0.05. GI: germination index.

2.6.4.
Evaluation efficiency of sun-dried sludges on
growth and yield of green mustard (Brassica juncea)
In general, when using BS-30 and SS-50 mixed with sugarcane
cake as organic fertilizer, the growth and yield of green mustard were
higher than that of control (soil) and organic fertilizer from sugarcane
cake. The formula for mixture ratio of BS or SS with sugarcane cake at
20:80 was recommended because in this formula, green mustard was
good quality and nontoxin from pathogenic microorganisms in humans
(Tables 3.8 and 3.9).

15


Table 3.8: Effect of sun-dried sludges mixed with sugarcane cake on
yield of green mustard
Treatment

Soil (Control)
BS:SC (50:50)
SS:SC (50:50)
BS:SC (20:80)
SS:SC (20:80)
SF
CV (%)

Number of
Leaves/plant
7,62 b
9,17 a
10,2 a
8,67 ab
9,73 a
8,63 ab
6,4

Plant height
(cm)
24,3 b
30,9 a
28,03 ab
27,7 ab
27,73 ab
26,67 ab
6,6

Fresh biomass
(g/tray)

40,02 b
95,91 a
113,18 a
88,92 a
86,81 a
45,24 b
14,4

Dry biomass
(g/tray)
6,24 e
7,93 b
8,33 a
7,54 cd
7,79 bc
7,16 d
13,3

Table 3.9: Human pathogenic microbial population on green mustard
Treatment
Soil (Control)
BS:SC (50:50)
SS:SC (50:50)
BS:SC (20:80)
SS:SC (20:80)
SF
Threshold limit (*)

Microbial populations ( CFU/g dry weight)
Coliforms

E.Coli
Salmonella
7400
1710
ND
6 000
1100
ND
53000
1700
ND
3800
754
ND
5400
387
ND
1782
712
ND
< 10 (a)
<1000 (b)
ND

Note: Values followed by similar letters under the same column are not
significantly different at p = 0.05. (a) Decision No 04:2007/Decision of
MoFE; (b) Vietnam Stantard 8-3/2012/Ministry of Health; ND:not detected.

3.3.

Determination of decomposition ability, suitable
composting ratio of sludge and sludge in the bag
3.3.1. Evaluation decomposable capacity of organic materials
Research results showed that both the primary organic materials
and mixing of materials in corresponding proportion had a strong
decomposition. Unmixing, both BS and SS decomposed the slowest
compared to straw, sugarcane cake and bagasse as evidenced by CO2
release (Fig 3.1) and reduced weight percentage (Fig 3.2). Among
mixed formulations, the mixing ratio of beer or seafood sludge with
rice straw or sugarcanr cake with ratio of 20:80 for the most
decomposed ability. However, based on sampling conditions and
economic benefits, sugarcane cake is the optimal option for further
research.

16


cd

abc
abcd

abcd
bcd

abc

abcd abcd

ab

abcd

SS:SC:B (20:60:20)

a

80

BB:SC:B (20:60:20)

100

abcd
d

600

30

45

BS:SC(20:80)

SS:SC (20:80)

SS:SC:B (10:60:30)

21

Incubation time (days)

SS:SC:R (20:60:20)

14

BS:SC:B (10:60:30)

7

BS:SC:R (20:60:20)

0

Beer sludge (BS)

100

0

Seafood sludge (SS)

200

20

Bagasse (B)

300

40

Sugarcane cake (SC)

400

Rice straw (R)

CO2 evolution (g/kg)

Rice straw (R)
Bagasse (B)
Sugarcane cake (SC)
Beer sludge (BS)
Seafood sludge (SS)
BS:SC (20:80)
SS:SC(20:80)
BS:SC:R (20:60:20)
SS:SC:R (20:60:20)
BS:SC:B (10:60:30)
SS:SC:B (10:60:30)
BS:SC:B(20:60:20)
SS:SC:B (20:60:20)

% Mass loss

60
500

Treatment

Figure 3.1. The CO2 evolution rate

Figure 3.2. Mass loss (%)

Note: BS: beer sludge, SS: seafood sludge, SC: sugarcane cake, The error bar
on the graph represents the standard deviation, n=3. Similar letters under the
same column are not significantly different at p = 0.05

3.3.2. Composting beer and seafood sludges in bag condition
3.3.2.1.
Characteristic of compost
In compost process from BS and SS, the temperature of the
treatments remained low (reaching a maximum of 520C after 14-day
incubation) and then decreased in the range of 40-430C and stabilized
at 32-340C. reason for low temperature was the small size of the block
that dispersed temperature during compost. Moisture content after final
incubation was 53%. According to Shammas and Wang (2009) and
Shilev et al. (2007) compost did not attain the required moisture
content (<40% moisture content) and also did not attain the
requirement of microorganism compost according to Vietnam standard
526: 2002 (no more than 35%) and according to Decree
108/2017/Goverment Decree ( ≤ 30%). Values of pH and EC in final
composts were in accordance with
Vietnam standard 5262002/MoARD . Simillarly with the comments of Duong Minh Vien et
al., (2011) and Shilev et al. (2007), they suggested that the value of pH
ranged of 6-9 and EC < 4 dS/m (Table 3.10).
Table 3.10. Values of pH and EC in compost
Treatment
BS: SC:bagasse (10:60:30)

BS: SC:bagasse (10:70:20)
SS: SC:bagasse (10:60:30)
SS: SC:bagasse (10:70:20)

pH
6.08
6.42
6.49
6.49

17

EC
1.98a
1.30abc
0.92c
1.28abc


Cow dung: SC:bagasse (10:60:30)
Cow dung: SC:bagasse (10:70:20)
BS: SC:straw (20:60:20)
BS: SC:straw (10:70:20)
SS: SC:straw (20:60:20)
SS: SC:straw (10:70:20)
Cow dung: SC:straw (20:60:20)
Cow dung: SC:straw (10:70:20)
BS: SC (20:80)
SS: SC (20:80)
CV(%)

6.73
6.72
6.90
6.83
6.53
6.79
6.67
6.84
7.06
6.68

0.83c
1.25bc
1.21bc
1.22bc
1.21bc
1.05c
1.31abc
1.82ab
0.87c
1.07c
30,9

The quality of organic compost after incubation at the bag size for
N, P, K was very high. The organic carbon and C/N ratio was required
organic fertilizer quality. The Trichoderma fungus population attained
a useful microbial population (≥1,0x106 CFU/g dry weight).
Salmonella and E.Coli microorganisms were not detected at the end of
compost process (Table 3.11 and 3.12). Thus, organic fertilizer from

BS and SS got up Vietnam standard and mixture ratio of BS or SS with
sugarcane cake with ratio of 20:80 was optimal recommendation.
Table 3.11. Contents of total N, P, K, %C, C/N ratio and % mass loss
Treatment

TN

TP

TK

%C

C/N

% Mass
loss

BS: SC:bagasse (10:60:30)
BS: SC:bagasse (10:70:20)
SS: SC:bagasse (10:60:30)
SS: SC:bagasse (10:70:20)
CD: SC:bagasse (10:60:30)
CD: SC:bagasse (10:70:20)
BS: SC:straw (20:60:20)
BS: SC:straw (10:70:20)
SS: SC:straw (20:60:20)
SS: SC:straw (10:70:20)
CD: SC:straw (20:60:20)
CD: SC:straw (10:70:20)

BS: SC (20:80)
SS: SC (20:80)
CV(%)

2,01e
2,3c
2,06e
2,25cd
2,06e
2,13de
2,96ab
2,3c
3,07ab
3,13a
2,99ab
2,28cd
3ab
3,02ab
3,51

6,7ef
7,14de
6,32f
6,37f
4,75g
4,82g
7,47cd
7,38cd
8,92b
7,79c

6,55f
5,06g
8,95b
9,47a
3,86

3,15a
2,62ef
2,78bcdef
2,69cdef
2,71cdef
2,68def
2,84bcde
2,98abc
2,57ef
3,02ab
2,82bcdef
2,95abcd
2,55f
2,85bcde
5,28

31.27f
41,61a
42,60a
33,54e
36,06cd
34,55de
31,85f
36,62bc

36,70bc
37,88b
33,81e
31,57f
36,45bc
33,76e
2,74

17,53b
19,1a
19,15a
16,65c
19,4a
18,06b
12,15g
13,69e
13,41ef
13,57e
12,61fg
15,5d
17,71b
12,54fg
3,31

21,75de
25,70d
15,89e
22,32de
39,87bc
42,89b

38,54bc
24,90d
22,92de
20,18de
34,95c
50,53a
39,98bc
27,39d
12,57

Note: Values followed by similar letters under the same column are not significantly
different at p = 0.05 according to Duncan’s multiple range test. BS: beer sludge, SS:
seafood sludge, SC: sugarcane cake, CD: cow dung.

18


Table 3.12. Microbial population in composts
Treatment

Microbial population (CFU/g dry weight)
Trichoderma
Salmonella
E.Coli
BS: SC:bagasse (10:60:30)
1,23 x 107
ND
ND
BS: SC:bagasse (10:70:20)
7,99 x 106

ND
ND
SS: SC:bagasse (10:60:30)
1,48 x 107
ND
ND
SS: SC:bagasse (10:70:20)
1,18 x 107
ND
ND
CD: SC:bagasse (10:60:30)
2,32 x 107
ND
ND
CD: SC:bagasse (10:70:20)
1,01 x 107
ND
ND
BS: SC:straw (20:60:20)
1,18 x 107
ND
ND
BS: SC:straw (10:70:20)
8,95 x 106
ND
ND
SS: SC:straw (20:60:20)
1,1 x 107
ND
ND

SS: SC:straw (10:70:20)
1,11 x 107
ND
ND
CD: SC:straw (20:60:20)
1,22 x 107
ND
ND
CD: SC:straw (10:70:20)
1,48 x 107
ND
ND
BS: SC (20:80)
1,59 x 107
ND
ND
SS: SC (20:80)
1,68 x 107
ND
ND
Threshold limit
≥1x106
ND
< 1,1 x 103
Note: BS: beer sludge, SS: seafood sludge, SC: sugarcane cake, CD: cow
dung. ND: not detected. Threshold prescribed under Decree 108/2017 /
Government decree and Vietam standard 526/2002/Ministry of Agriculture
and Rural Development.

3.4.

Production microbial-organic fertilizers from beer and
seafood factories’ sludge in 0.5 meter cubic
3.4.1. Temperature, humidity during compost process
In period of 0-21 days after composting, temperature increased was
at 470C for SS-SC and 550C for BS-SC. In period of 21-49 days
incubation, the temperature was slightly reduced and reached 47-530C
for 28 days and remained a stable equivalent to an external ambient
temperature of about 30-310C (Fig 3.3). The humidity of microbial
organic compost in the final composting was higher standard of Decree
108/2017/Goverment Decree (Fig 3.3).

19


60

SS:SC (%M)
SS:SC (T0)

100

50

80

40

60

30
40

20

20

10
0

Moisture (%)

Temperature (0C)

BS:SC (%M)
BS:SC (T0)

0
7

14

21

28

35 42
Days

49

56

63

Figure 3.3. Change in temperature and moisture during composting
Note: BS: beer sludge, SS: seafood sludge, SC: sugarcane cake, The error bar
on the graph represents the standard deviation n=3. T0: temperature, M:
moisture.

3.4.2.

Nutrient content of micribial organic fertilizer
Nutritional quality of microbial organic fertilizers had high levels
of nitrogen, phosphorus and potassium. Most of P content was
available for the crop. Total N and available P levels were higher than
those of Vietnam standard on microbial organic fertilizer, but available
K was lower than Vietnam standard 7185/2002 /MoARD (Table 3.13).
Table 3.13: Chemical characterisation of microbial organic fertilizer
TN
TP
TK
Aa
Pa
Ka
(%)
(%P2O5) (%K2O)
(%)
(%P2O5)
(%K2O)

BS:SC
2.85
6.63
2.11
0.073
5.46
0.64
SS:SC
2.83
5.60
2.10
0.067
4.62
0.58
Note: BS: beer sludge, SS: seafood sludge, TN: total nitrogen, TP: total
phosphorus, TK: total potassium, Na: available nitrogen, Pa: available
phosphorus, Ka: available potassium.
Treatment

Organic carbon content (% C) after incubation of treatments
ranged from 35.21% to 40.98% (Table 3.15), met Vietnam standardof
Decree 108/2017 on microbial organic fertilizer. The C/N ratio ranged
from 12.41 to 14.41 (Table 3.14). similarly with Shilev et al. (2007)
and Duong Minh Vien et al. (2011), they suggested that the C/N ratio
after incubation should be about 10/1 to 20/1 because of decomposed
organic matter and stability.

20

Table 3.14: Change in C and C/N ratio during the composting process
Treatment
%C
C/N
BS:SC
40,98
14,41b
SS:SC
35,21
12,44b
Note: BS: beer sludge, SS: seafood sludge

3.4.3. Contents of Ca, Mg, micronutrients, heavy metals,
Trichoderma and pathogen in microbial organic fertilizer
Microbial organic fertilizers after incubation had the content of Ca,
Mg,micronutrients, and heavy metals in accordance with Vietnam
standard, so the using of these fertilizers would provide more nutrients
soil for the soil and plants (Table 3.15 and 3.16).
Table 3.15: Change in Ca and Mg during the composting process
Ca (% CaO)
Mg (% MgO)
Treatment
BS:SC
2.49
1.11
SS:SC
2.77
0.94
Table 3.16 Micronutrient characterisation of microbial organic fertilizer
Treatment

BS:SC
SS:SC
Threshold limit

Cu
(mg/kg)
214
119

Zn
Mn
Cd
Pb
As
(mg/kg) (mg/kg) (mg/kg) (mg/kg)
(mg/kg)
305
1103
1.11
11.74
0.56
646
1030
1.09
25.23
0.15
<750
<5
<200
<10

Note: BS: beer sludge, SS: seafood sludge, SC: sugarcane cake

Trichoderma population in microbial organic fertilizer residues at
the end of the experiment were 7.82 x 107 CFU/g dry matter (SS-SC)
and 7.14 x 107 CFU/g dry matter (BS-SC). After 1 month and 2
months, Trichoderma sp had still the order of 1.99 x 106 and 1.99 x 106
for SS-SC and 2.02 x 106 and 2 x 106 for BS-SC, repestively for each.
Those population gained the number of beneficial microorganisms
according to Decree 108/2017/Government Decree (> 106 CFU/g dry
weight). E.coli and Salmonella were not detected, in accordance with
microbiological quality of Vietnam standards (Table 3.17).

21

Hg
(mg/kg)
KPH
KPH
<2


Bảng 3.17: Trichoderma population and
microorganism in microbial organic fertilizer
Treatment

BS:SC
SS:SC
Threshold
limit

Trichoderma
(CFU/g dry weight)
The final
survival
survival
experiment ability after ability after
1 month
2 month
7.82 x 107 1.99 x 106
1.99 x 106

human

pathogenic

Pathogen
(CFU/g dry weight)
E.coli

Salmonella

ND

ND

ND
ND
2.02 x 106
2 x 106
6

3
1 x 10
< 1.1 x 10
ND
Note: BS: beer sludge, SS: seafood sludge, ND: not detected. Threshold
prescribed under Decree 108/2017/Government decree and Vietam standard
526/2002/Ministry of Agriculture and Rural Development.
7.14 x 107

Thus, the mixing of BS or SS with sugarcane cake was a suitable
environment for the development of fungi populations, so production
of microbial fertilizer promised application and reuse beer and seafood
sludges to resolve environmental pollutant.
3.5. Efficiency of microbial organic fertilizer on vegetable
yields
For mustard, applying 5 t / ha of microbial organic fertilizer from
sludge combined with 100% recommended rate (RR) improved yield
higher than 45% compared to farmer rate (FR) and 42% higher than
RR. For cucumber, yield increased 1.1 times compared to FR and 1.6
times higher than RR. However, the sharp decrease in N, P, K
compared to the RR and FR had not raised yields of both mustard and
cucumber in the first crop. This had proven that combination of
organic and inorganic fertilizers are necessarily required to maintain a
stable growth of the vegetable. According to the opinions of Do Dinh
Thuan and Nguyen Van Bo (2001), in order to develop vegetables with
high yields, it is necessary to combine organic and chemical fertilizers
(Figures 3.4 and 3.5).
When applying 5 tons / ha micribial organic fertilizer from two
sources of sludge + RR for okra yield reached 13.65-14.92 tons/ha
increased 50.73% compared to RR and more than 40.91% compared

with FR. The yield of winter melon ranged 44.71-40.78 tons/ha,
increasing 24.83% compared with RR and 18.29% in comparision to
FR. The application of microbial organic fertilizer combined low

22