Abstract: Compost manufacturing plants are one of units where
wastewater is produced in significantly large amounts. Wastewater
produced in these plants contains high amounts of substrate (organic
loads) and is classified as stringent waste which creates significant
pollution when discharged into the environment without treatment. A
compost production plant in the one of the Iran-s province treating
200 tons/day of waste is one of the most important environmental
pollutant operations in this zone. The main objectives of this paper
are to investigate the compost wastewater treatability in hybrid
anaerobic reactors with an upflow-downflow arrangement, to
determine the kinetic constants, and eventually to obtain an
appropriate mathematical model. After starting the hybrid anaerobic
reactor of the compost production plant, the average COD removal
rate efficiency was 95%.
Abstract: The daily increase of organic waste materials resulting
from different activities in the country is one of the main factors for
the pollution of environment. Today, with regard to the low level of
the output of using traditional methods, the high cost of disposal
waste materials and environmental pollutions, the use of modern
methods such as anaerobic digestion for the production of biogas has
been prevailing. The collected biogas from the process of anaerobic
digestion, as a renewable energy source similar to natural gas but
with a less methane and heating value is usable. Today, with the help
of technologies of filtration and proper preparation, access to biogas
with features fully similar to natural gas has become possible. At
present biogas is one of the main sources of supplying electrical and
thermal energy and also an appropriate option to be used in four
stroke engine, diesel engine, sterling engine, gas turbine, gas micro
turbine and fuel cell to produce electricity. The use of biogas for
different reasons which returns to socio-economic and environmental
advantages has been noticed in CHP for the production of energy in
the world. The production of biogas from the technology of anaerobic
digestion and its application in CHP power plants in Iran can not only
supply part of the energy demands in the country, but it can
materialize moving in line with the sustainable development. In this
article, the necessity of the development of CHP plants with biogas
fuels in the country will be dealt based on studies performed from the
economic, environmental and social aspects. Also to prove the
importance of the establishment of these kinds of power plants from
the economic point of view, necessary calculations has been done as
a case study for a CHP power plant with a biogas fuel.
Abstract: the objective of this study is to measure the levels of
cellulas activity of ostrich GI microorganisms, and comparing it with
the levels of cellulas activity of rumen-s microorganisms, and also to
estimate the probability of increasing enzyme activity with injecting
different dosages (30%, 50% and 70%) of pure anaerobic goat rumen
fungi. The experiment was conducted in laboratory and under a
complete anaerobic condition (in vitro condition). 40 ml of
“CaldWell" medium and 1.4g wheat straw were placed in incubator
for an hour. The cellulase activity of ostrich microorganisms was
compared with other treatments, and then different dosages (30%,
50% and 70%) of pure anaerobic goat rumen fungi were injected to
ostrich microorganism-s media. Due to the results, cattle and goat
with 2.13 and 2.08 I.U (international units) respectively showed the
highest activity and ostrich with 0.91 (I.U) had the lowest cellulose
activity (p < 0.05). Injecting 30% and 50% of anaerobic fungi had no
significant incensement in enzyme activity, but with injecting 70% of
rumen fungi to ostrich microorganisms culture a significant increase
was observed 1.48 I.U. (p < 0.05).
Abstract: Anaerobic digestion process is one of the alternative
methods to convert organic waste into methane gas which is a fuel
and energy source. Activities of various kinds of microorganisms are
the main factor for anaerobic digestion which produces methane gas.
Therefore, in this study a modified Anaerobic Baffled Reactor (ABR)
with working volume of 50 liters was designed to identify the
microorganisms through biogas production. The mixture of 75%
kitchen waste and 25% sewage sludge was used as substrate.
Observations on microorganisms in the ABR showed that there exists
a small amount of protozoa (5%) and fungi (2%) in the system, but
almost 93% of the microorganism population consists of bacteria. It
is definitely clear that bacteria are responsible for anaerobic
biodegradation of kitchen waste. Results show that in the
acidification zone of the ABR (front compartments of reactor) fast
growing bacteria capable of growth at high substrate levels and
reduced pH was dominant. A shift to slower growing scavenging
bacteria that grow better at higher pH was occurring towards the end
of the reactor. Due to the ability of activity in acetate environment the
percentages of Methanococcus, Methanosarcina and Methanotrix
were higher than other kinds of methane former in the system.
Abstract: The microbial production of ethanol from biodiesel¬derived crude glycerol by Enterobacter aerogenes TISTR1468, under micro-aerobic and anaerobic conditions, was investigated. The experimental results showed that micro-aerobic conditions were more favorable for cellular growth (4.0 g/L DCW), ethanol production (20.7 g/L) as well as the ethanol yield (0.47 g/g glycerol) than anaerobic conditions (1.2 g/L DCW, 6.3 g/L ethanol and 0.72 g/g glycerol, respectively). Crude glycerol (100 g/L) was consumed completely with the rate of 1.80 g/L/h. Two-stage fermentation (combination of micro-aerobic and anaerobic condition) exhibited higher ethanol production (24.5 g/L) than using one-stage fermentation (either micro-aerobic or anaerobic condition. The two- stage configuration, exhibited slightly higher crude glycerol consumption rate (1.81 g/L/h), as well as ethanol yield (0.56 g/g) than the one-stage configuration. Therefore, two-stage process was selected for ethanol production from E. aerogenes TISTR1468 in scale-up studies.
Abstract: Recent research on seeds of bio-diesel plants like
Jatropha curcas, constituting 40-50% bio-crude oil indicates its
potential as one of the most promising alternatives to conventional
sources of energy. Also, limited studies on utilization of de-oiled cake
have revealed that Jatropha bio-waste has good potential to be used as
organic fertilizers produced via aerobic and anaerobic treatment.
However, their commercial exploitation has not yet been possible. The
present study aims at developing appropriate bio-processes and
formulations utilizing Jatropha seed cake as organic fertilizer, for
improving the growth of Polianthes tuberose L. (Tuberose). Pot
experiments were carried out by growing tuberose plants on soil
treated with composted formulations of Jatropha de-oiled cake, Farm
Yard Manure (FYM) and inorganic fertilizers were also blended in
soil. The treatment was carried out through soil amendment as well as
foliar spray. The growth and morphological parameters were
monitored for entire crop cycle.
The growth Length and number of leaves, spike length, rachis
length, number of bulb per plant and earliness of sprouting of bulb and
yield enhancement were comparable to that achieved under inorganic
fertilizer. Furthermore, performance of inorganic fertilizer also showed
an improvement when blended with composted bio-waste. These
findings would open new avenues for Jatropha based bio-wastes to be
composted and used as organic fertilizers for commercial floriculture.
Abstract: The present investigation was undertaken to explore the biogas potentiality of Jatropha (Jatropha curcas, Euphorbiaceae) Fruit Coat (JFC) alone and in combination with cattle dung (CD) in various proportions at 15 per cent total solids by batch phase anaerobic digestion for a period of ten weeks HRT (Hydraulic Retention Time) under a temperature of 35°C+1°C. The maximum biogas production was noticed in Cattle dung and Jatropha Fruit Coat in 2:1 ratio with 403.84 L/kg dry matter followed by 3:1,1:2, 1:1 and 1:3 having 329.66, 219.77, 217.79, 203.64 L /kg dm respectively as compared to 178.49 L/kg dm in CD alone. The JFC alone found to produce 91 per cent of total biogas that obtained from Cattle dung. The per cent methane content of the biogas in all the treatments was found on par with Cattle dung.
Abstract: In this work, biohydrogen production via dark
fermentation from alcohol wastewater using upflow anaerobic sludge
blanket reactors (UASB) with a working volume of 4 L was
investigated to find the optimum conditions for a maximum hydrogen
yield. The system was operated at different COD loading rates (23,
31, 46 and 62 kg/m3d) at mesophilic temperature (37 ºC) and pH 5.5.
The seed sludge was pretreated before being fed to the UASB system
by boiling at 95 ºC for 15 min. When the system was operated under
the optimum COD loading rate of 46 kg/m3d, it provided the
hydrogen content of 27%, hydrogen yield of 125.1 ml H2/g COD
removed and 95.1 ml H2/g COD applied, hydrogen production rate of
18 l/d, specific hydrogen production rate of 1080 ml H2/g MLVSS d
and 1430 ml H2/ L d, and COD removal of 24%.
Abstract: In this study, we illustrated the performance and
microbial community of single- and two-phase systems anaerobically
co-digesting cassava pulp and pig manure. The results showed that
the volatile solid reduction and biogas productivity of two-phase
CSTR were 66 ± 4% and 2000 ± 210 ml l-1 d-1, while those of singlephase
CSTR were 59 ± 1% and 1670 ± 60 ml l-1 d-1, respectively. Codigestion
in two-phase CSTR gave higher 12% solid degradation and
25% methane production than single-phase CSTR. Phylogenetic
analysis of 16S rDNA clone library revealed that the Bacteroidetes
were the most abundant group, followed by the Clostridia in singlephase
CSTR. In hydrolysis/acidification reactor of two-phase system,
the bacteria within the phylum Firmicutes, especially Clostridium,
Eubacteriaceae and Lactobacillus were the dominant phylogenetic
groups. Among the Archaea, Methanosaeta sp. was the exclusive
predominant in both digesters while the relative abundance of
Methanosaeta sp. and Methanospirillum hungatei differed between
the two systems.
Abstract: In this study, the kinetic of biogas production was studied by performing a series laboratory experiment using rumen fluid of animal ruminant as inoculums. Cattle manure as substrate was inoculated by rumen fluid to the anaerobic biodigester. Laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure was fed to each biodigester and mixed with rumen fluid by manure : rumen weight ratio of 1:1 (MR11). The operating temperatures were varied at room temperature and 38.5 oC. The cumulative volume of biogas produced was used to measure the biodigester performance. The research showed that the rumen fluid inoculated to biodigester gave significant effect to biogas production (P
Abstract: This study aimed to evaluate the muscularity and tissue composition of 24 legs of Ile de France lambs. They were fed with diets containing “in nature" or hydrolyzed sugarcane with 0.6% of calcium oxide in aerobic and anaerobic environments. Animals entered the trial at 15 and were slaughtered at 32 kg of body weight. The leg tissue composition, as well as muscularity (0.47), muscle:bone (6.66) and muscle:fat (4.25) were not affected (P>0.05) by treatments. The proportions found were: 67.62% for muscle, 17.52% for bone and 10.15% for fat. In relation to lambs fed with “in nature" sugarcane, hydrolyzed sugarcane with calcium oxide in aerobic and anaerobic environments did not affect muscularity and leg tissue composition of lambs.
Abstract: A combination of photosynthetic bacteria along with
anaerobic acidogenic bacteria is an ideal option for efficient
hydrogen production. In the present study, the optimum
concentration of substrates for the growth of Rhodobacter
sphaeroides was found by response surface methodology. The
optimum combination of three individual fatty acids was determined
by Box Behnken design. Increase of volatile fatty acid concentration
decreased the growth. Combination of sodium acetate and sodium
propionate was most significant for the growth of the organism. The
results showed that a maximum biomass concentration of 0.916 g/l
was obtained when the concentrations of acetate, propionate and
butyrate were 0.73g/l,0.99g/l and 0.799g/l, respectively. The growth
was studied under an optimum concentration of volatile fatty acids
and at a light intensity of 3000 lux, initial pH of 7 and a temperature
of 35°C.The maximum biomass concentration of 0.92g/l was
obtained which verified the practicability of this optimization.
Abstract: The estimation of overall on-site and off-site greenhouse gas (GHG) emissions by wastewater treatment plants revealed that in anaerobic and hybrid treatment systems greater emissions result from off-site processes compared to on-site processes. However, in aerobic treatment systems, onsite processes make a higher contribution to the overall GHG emissions. The total GHG emissions were estimated to be 1.6, 3.3 and 3.8 kg CO2-e/kg BOD in the aerobic, anaerobic and hybrid treatment systems, respectively. In the aerobic treatment system without the recovery and use of the generated biogas, the off-site GHG emissions were 0.65 kg CO2-e/kg BOD, accounting for 40.2% of the overall GHG emissions. This value changed to 2.3 and 2.6 kg CO2-e/kg BOD, and accounted for 69.9% and 68.1% of the overall GHG emissions in the anaerobic and hybrid treatment systems, respectively. The increased off-site GHG emissions in the anaerobic and hybrid treatment systems are mainly due to material usage and energy demand in these systems. The anaerobic digester can contribute up to 100%, 55% and 60% of the overall energy needs of plants in the aerobic, anaerobic and hybrid treatment systems, respectively.
Abstract: This paper describes technological possibilities to
enhance methane productionin the anaerobic stabilization of wastewater treatment plant excess sludge. This objective can be achieved by the addition of waste residues: crude glycerol from biodiesel production and residues from fishery. The addition
ofglycerol in an amount by weight of 2 – 5% causes enhancement of methane production of about 250 – 400%. At the same time the
percentage increase of total solids concentration in the outgoing sludge is ten or more times less. The containment of methane in
biogas is higher in case of admixed substrate.
Abstract: In this research, an anaerobic co-digestion using decanter cake from palm oil mill industry to improve the biogas production from frozen seafood wastewater is studied using Continuously Stirred Tank Reactor (CSTR) process. The experiments were conducted in laboratory-scale. The suitable Hydraulic Retention Time (HRT) was observed in CSTR experiments with 24 hours of mixing time using the mechanical mixer. The HRT of CSTR process impacts on the efficiency of biogas production. The best performance for biogas production using CSTR process was the anaerobic codigestion for 20 days of HRT with the maximum methane production rate of 1.86 l/d and the average maximum methane production of 64.6%. The result can be concluded that the decanter cake can improve biogas productivity of frozen seafood wastewater.
Abstract: A horizontal anaerobic digester was developed and
tested in pilot scale for Korean food waste with high water contents
(>80%). The hydrogen sulfide in the biogas was removed by a
biological desulfurization equipment integrated in the horizontal
digester. A mixer of the horizontal digester was designed to easily
remove the sediment in the bottom and scum layers on surface in the
digester. Experimental result for 120 days of operation of the pilot
plant showed a high removal efficiency of 81.2% for organic
substance and high stability during the whole operation period were
acquired. Also food waste was treated at high organic loading rates
over 4 kg•VS/m3∙day and a methane gas production rate of 0.62
m3/kg•VSremoved was accomplished.
The biological desulfurization equipment inside the horizontal
digester was proven to be an economic and effective method to reduce
the biogas desulfurization cost by removing hydrogen sulfide more
than 90% without external desulfurization equipments.
Abstract: Anaerobic treatment has many advantages over other
biological method particularly when used to treat complex
wastewater such as petroleum refinery wastewater. In this study two
Up-flow Anaerobic Sludge Blanket (UASB) reactors were operated
in parallel to treat six volumetric organic loads (0.58, 1.21, 0.89,
2.34, 1.47 and 4.14 kg COD/m3·d) to evaluate the chemical oxygen
demand (COD) removal efficiency. The reactors were continuously
adapting to the changing of operation condition with increase in the
removal efficiency or slight decrease until the last load which was
more than two times the load, at which the reactor stressed and the
removal efficiency decreased to 75% with effluent concentration of
1746 mg COD/L. Other parameters were also monitored such as pH,
alkalinity, volatile fatty acid and gas production rate. The UASB
reactor was suitable to treat petroleum refinery wastewater and the
highest COD removal rate was 83% at 1215 kg/m3·d with COD
concentration about 356 mg/L in the effluent.
Abstract: One of the main challenges for one phase anaerobic digestion processes is the high concentration of NH4+ and PO4 3- ions
in the digested sludge supernatant. This project focuses on enhancing the removal of nutrients during the anaerobic digestion process through fixing both NH4+ and PO4 3- ions in the form of struvite (magnesium ammonium phosphate, MAP, MgNH4PO4.6H2O) within the anaerobic sludge. Batch anaerobic digestion tests showed that Mg2+ concentration in the range 279 – 812 mg/L had insignificant effect on CGP but incurred a slight increase in COD removal. The reactor that had soluble Mg2+:NH4+:PO43- at a molar ratio of 1.28:1:00:1:00 achieved the best performance enhancement of 8% increase in COD removal and 32% reduction in NH4+ in the reactor supernatant. Overall, the results show that there is a potential to optimise conventional anaerobic digestion such that supernatant lean in P and N, and sludge rich in nutrients are obtained.
Abstract: BioEnergy is an archetypal appropriate technology
and alternate source of energy in rural areas of China, and can meet
the basic need for cooking fuel in rural areas. The paper introduces
with an alternate mean of research that can accelerate the biogas
energy production. Tithonia diversifolia or the Tree marigold can be
hailed as mesophillic anaerobic digestion to increase the production
of more Bioenergy. Tithonia diversifolia is very native to Mexico and
Central America, which can be served as ornamental plants- green
manure and can prevent soil erosion. Tithonia diversifolia is widely
grown and known to Asia, Africa, America and Australia as well.
Nowadays, Considering China’s geographical condition it is found
that Tithonia diversifolia is widely growing plant in the many tropical
and subtropical regions of southern Yunnan- which can have great
usage in accelerating and increasing the Bioenergy production
technology. The paper discussed aiming at proving possibility that
Tithonia diversifolia can be applied in biogas fermentation and its
biogas production potential, the research carried experiment on
Tithonia diversifolia biogas fermentation under the mesophilic
condition (35 Celsius Degree). The result revealed that Tithonia
diversifolia can be used as biogas fermentative material, and 6%
concentration can get the best biogas production, with the TS biogas
production rate 656mL/g and VS biogas production rate 801mL/g. It
is well addressed that Tithonia diversifolia grows wildly in 53
Counties and 9 cities of Yunnan Province, which mainly grows in
form of the road side plants, the edge of the field, countryside, forest
edge, open space; of which demersum-natures can form dense
monospecific beds -causing serious harm to agricultural production
landforms threatening the ecological system as a potentially harmful
exotic plant. There are also found the three types of invasive daisy
alien plants -Eupatorium adenophorum, Eupatorium Odorata and
Tithonia diversifolia in Yunnan Province of China-among them the
Tithonia diversifolia is responsible for causing serious harm to
agricultural production. In this paper we have designed the
experimental explanation of Biogas energy production that requires
anaerobic environment and some microbes; Tithonia diversifolia
plant has been taken into consideration while carrying experiments
and with successful resulting of generating more BioEnergy
emphasizing on the practical applications of Tithonia diversifolia.
This paper aims at- to find a new mechanism to provide a more
scientific basis for the development of this plant herbicides in Biogas
energy and to improve the utilization throughout the world as well.
Abstract: The aim of this study was to investigate the
effectiveness of anaerobic digestion for the treatment of wool
scouring wastes. The experiments design comprised three ratios of
waste (W) to seed(S) (W:S) of 25:75, 50:50 and 75:25, corresponding
to 1.9. 1.7 and 1.5g tCOD/g TS, respectively, with or without
chemicals addition. NH4Cl was added to the reactors as a source for
nitrogen to achieve C:N:P of 420:14:3. A cationic flocculent was
added at 0.5 and 0.75% to enhance flocculation of sludge. The results
showed that the reactors that received W:S at a ratio of 25:75
produced the largest volume of biogas. The final soluble COD
(sCOD) was below the limits for discharge to the sewer system.