http://www.publicbroadcasting.net/krwg/news/news.newsmain/article/1/0/1697756/Regional/NMSU.Professor.Patents.Liquid.Organic.Fertilizer
KRWG News ( 2010-09-07 )
NMSU
Professor Patents Liquid Organic Fertilizer
LAS CRUCES (krwg) - Even in the harsh region of central Asia,
necessity is the mother of invention. It was the needs of farmers
in the rugged, impoverished area that inspired a New Mexico State
University professor to develop an easily transportable,
easy-to-apply fertilizer that could lead to long-term gains for
growers the world over.
Zohrab Samani, a professor in the NMSU College of Engineering's
civil engineering department, developed a concept for liquid
fertilizer while doing volunteer work in 2000 in the Republic of
Tajikistan.
"This was just after the civil war in that country, and I was
quite distressed with the situation of the farmers who could not
afford to buy synthetic fertilizer for their small vegetable
plots," Samani said. "It occurred to me that the waste from the
large vegetable market in the nearby town of Dushanbe could be
used to generate fertilizer."
Inspired, Samani developed a rudimentary accelerated bio-leaching
schematic, wherein vegetable waste could be placed in a sealed
batch and bacteria-laden leachate was used to hydrolyze and break
down the organics into a liquid solution. The idea was to be able
to add the solution into irrigation water.
Returning to Las Cruces, Samani went to work in a university lab,
developing a liquid fertilizer from grass clippings. He applied
the leachate to one of four tomato plants that he was growing at
home, and he noticed a sudden surge in the growth of that
particular plant.
In 2001, Samani presented his research and findings, along with a
proposal, to Abbas Ghassemi, the director of NMSU's Waste
Management, Education and Research Consortium, a consortium for
environmental education and technology development. Ghassemi
offered Samani a mini-grant and Samani used it to help fund
additional testing with a column and a recirculation pump, using
grass clippings from the NMSU golf course.
During the same time, Samani got together with Marco Huez, a
friend who was working towards his doctorate in the College of
Agriculture, Consumer and Environmental Sciences. Huez, studying
interactions of salinity and organics in chile, began using the
liquid fertilizer on green chile being grown in an NMSU
greenhouse. The results were astounding, as the liquid-fertilized
chiles were measurably larger and more abundant than those in the
control group 23 percent higher than previous yields. The organic
makeup of the liquid fertilizer had a positive effect on the
plants by countering the soil salinity.
"The experiment in the greenhouse showed that the liquid organic
fertilizer could increase the yield of green chile, especially in
saline soil," Samani said. "It clearly showed that the fertilizer
could increase the chile yield under all conditions, and the
results were especially pronounced in soil with a high salinity."
Samani and his students kept working, and they developed ways to
concentrate the mixture, via cooking it in an oven and through
solarization, accomplished by placing the fertilizer in a
container, covering it with vented, clear plastic and leaving it
in the sun for a few days. Concentrated, the fertilizer's makeup
is nutrient-rich liquid, at 6.35 percent nitrogen.
The concoction is convenient, because it can be mixed into drip
irrigation systems without plugging the drip tapes. It also is an
economical alternative for organic farmers. Fish fertilizer, for
example, can cost as much as $7,000 an acre for organic vegetable
crops. Using an alfalfa-based liquid organic fertilizer, since
alfalfa is grown organically without synthetic chemicals and is
readily available, can reduce the cost to $300 an acre. It also
can be applied multiple times to one field over one growing
season.
Samani and NMSU recently received a patent for the liquid
fertilizer and the method used to produce it. He is currently
experimenting with ways to temporarily solidify the liquid to make
transporting it easier.
US7771504
Producing liquid organic
fertilizer from organic substrates
The present invention relates to methods and apparatuses for the
production of organic liquid fertilizer from waste using a
two-phase process. The first phase comprises a successive
extraction process whereby liquid leachate is drained from one
plant or storage container and the process subsequently re-started
with new fresh water. The second phase comprises an accelerated
bio-leaching process wherein plant material is stored in a solid
bed similar to a batch process, and a leachate (e.g., water and
bacteria) is re-circulated through the solid bed until the process
of hydrolysis and acidification results in dissolution of organic
material into the re-circulating leachate. The leachate is thus
concentrated without losing the nutrient and is subsequently used
as an organic fertilizer.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
(Technical Field)
The present invention relates to methods and apparatuses for the
production of liquid fertilizer from waste using successive
extraction and accelerated bioleaching resulting in increased
nitrogen content and decreased odor during production.
2. Description of Related Art
Note that where the following discussion refers to a number of
publications by author(s) and year of publication, that due to
recent publication dates certain publications are not to be
considered as prior art vis-a-vis the present invention.
Discussion of such publications herein is given for more complete
background and is not to be construed as an admission that such
publications are prior art for patentability determination
purposes.
Organic farming was one of the fastest growing segments of U.S.
agriculture during the 1990's (USDA-ERS 2002). U.S. sales of
organic food products grew 20-25% annually during the past decade
reaching $7 billion in 2000 (USDA-2002). Traditionally, organic
farming has relied on composted organic material or rotation crops
as sources of plant nutrients.
U.S. Patent Application Publication No. 2006/0172888 to Blasczyk
et al., entitled "Natural Grass Fertilizer With Weed and Grub
Control Activity," issued Aug. 3, 2006, discloses a process for
making a fertilizer by combining liquid steep-water obtained by
steeping vegetable matter in water and subsequently straining the
solid matter from the liquid. A natural fertilizer comprising
steep-water and biomass is produced.
U.S. Patent Application Publication No. 2004/0172997 to Huang et
al., entitled "Plant Nutrition Formulated By Recovery Filtrate
From Plant Fiber Biopulp And Method Thereof," issued Sep. 9, 2004,
discloses a plant nutrition formulation and method relating to the
recovery filtrate from plant biopulp that is not harmful to the
environment.
U.S. Pat. No. 7,014,768 to Li et al., entitled "Process For
Removal And Recovery Of Nutrients From digested Manure Or Other
Organic Wastes," issued Mar. 21, 2006, discloses a multi-step
process of removing nutrients and water from organic wastes and
recycling digested liquids back through the digested solids at an
elevated temperature to create a biofertilizer with an elevated
nitrogen content.
U.S. Pat. No. 6,299,774 to Ainsworth et al., entitled "Anaerobic
Digester System," issued Oct. 9, 2001, discloses a process that
involves the anaerobic digestion of feedstocks at low to high
temperatures in batch reactors to produce fertilizer.
U.S. Patent Application Publication No. 2004/0000179 to Hiraki,
entitled "Method For Composting Organic Wastes," issued Jan. 1,
2004, discloses a method for composting wastes with water and
effective microorganisms (EM) at a suitable temperature to create
a fertilizing compost.
The present invention comprises generating liquid fertilizer that
can be applied through irrigation systems. Liquid fertilizer has
several potential advantages compared to traditional composting
methods. For example, liquid fertilizer is a clean plant-based
fertilizer and does not have the typical problems of weed seeds,
pathogens, or high sodium content. Also, liquid fertilizer is
dissolved in water and is easily available for plant uptake
contrary to composted material where only a fraction of the
nutrient is available for plant uptake and often needs to be
supplemented with mineral fertilizer. Also, liquid fertilizer can
be applied to plants on a timely basis as needed. The following
are examples of devices and processes that produce fertilizer.
The present invention preferably uses a plant source,
anaerobically digests the plant source, and subsequently uses a
sequential bioleaching process which increases the amount of
nutrient extracted or leached from a fixed amount of organic plant
source. The leachate is concentrated without losing the nutrient
and is subsequently used as a fertilizer (preferably an organic
fertilizer). The present invention uses moderate heat at an
optimum temperature to enhance hydrolysis and acidification and
reduces the time required to produce the nutrient-rich leachate.
No pre-treatment is required to digest the plant source. The
present invention is lightweight, inexpensive, and uses a
successive extraction process to produce an organic fertilizer
with an enhanced nitrogen content.
BRIEF SUMMARY OF THE INVENTION
The preferred invention relates to an apparatus and method of
producing liquid fertilizer using successive extraction and
accelerated bioleaching. The preferred embodiment is described
below.
Liquid fertilizer is produced in an apparatus comprising a first
phase container, a leachate distribution system, and an external
second-phase container. The first-phase container holds leachate
and packed plant matter. The leachate is distributed via a system
comprising a circulation pump, piping, a leachate distribution
system, and a leachate drain system. The external second-phase
container stores and heats the leachate.
The liquid fertilizer is produced by mixing leachate, packing
plant material, and adding a fluid in at least one first-phase
container and by accelerating bioleaching. Accelerating
bioleaching comprises recirculating the leachate periodically
through the first container, hydrolyzing the leachate, acidifying
the leachate, and dissolving the organic material into the
recirculating leachate. The leachate the first-phase container is
augmented by adding additional fluid.
The leachate is successively extracted from the first-phase
container and replaced with a fluid. The leachate is then disposed
in an external second-phase container where it is concentrated by
controlling heating by heating at above approximately 80 degrees
F., storing the leachate in the second phase container and
exposing it to sunlight, or boiling. Leachate odor is minimized by
the controlled heating, and concentrating the liquid leachate
prevents the loss of nutrient or organic content. Finally, the
leachate is removed from the external second-phase container as
liquid organic fertilizer.
Novel features and further scope of applicability of the present
invention will be set forth in part in the detailed description to
follow, taken in conjunction with the accompanying drawings, and
in part will become apparent to those skilled in the art upon
examination of the following, or may be learned by practice of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a
part of the specification, illustrate one or more embodiments of
the present invention and, together with the description, serve to
explain the principles of the invention. The drawings are only for
the purpose of illustrating one or more preferred embodiments of
the invention and are not to be construed as limiting the
invention. In the drawings:
FIG. 1 is a schematic
representation of a cross-section of an embodiment of the leaching
system of the present invention;
FIG. 2 is a graph showing
a comparison of chile yield produced with an embodiment of the
liquid fertilizer of the present invention and a commercial
mineral fertilizer;
FIG. 3 is a graph showing
salinity and fertilizer effect on plant height (cm) and shoot
diameter (cm) of chile pepper plant grown in greenhouse
conditions;
FIG. 4 is a graph showing
salinity and fertilizer effect on total yield of chile pepper
(g/plant) grown in greenhouse conditions;
FIG. 5 is a graph showing
salinity and fertilizer effect on Total Kjeldahl Nitrogen (TKN) of
some parts of chile pepper plant grown in greenhouse conditions;
FIG. 6 is a graph showing
salinity and fertilizer effect on average added water and water
use efficiency (WUE) of chile pepper grown in greenhouse
conditions;
FIG. 7 is a graph showing
salinity and fertilizer effect on soil electrical conductivity
(EC) of chile pepper grown in greenhouse conditions;
FIG. 8 is a graph showing
salinity and fertilizer effect on average added water of chile
pepper grown in greenhouse conditions;
FIG. 9 is a graph showing
salinity and fertilizer effect on plant height (cm) of chile
pepper grown in greenhouse conditions;
FIG. 10 is a schematic
representation of an embodiment of the leaching system of the
present invention; and
FIG. 11 is a graph showing
a comparison of total nitrogen produced by a continuous extraction
method and total nitrogen produced by a successive extraction
method, over time, produced with an embodiment of the liquid
fertilizer of the present invention.
DETAILED DESCRIPTION OF THE
INVENTION
An embodiment of the present invention provides a liquid
fertilizer made from waste using accelerated bioleaching and
successive extraction and a method for producing the liquid
fertilizer.
As used in the specification and claims herein, the terms "a",
"an", and "the" mean one or more. The term "leachate" means a
fluid and bacteria. The term "fluid" means continuous amorphous
substance that tends to flow and to conform to the outline of its
container, such as water, or any other liquid.
Preferably, the process of generating liquid fertilizer in
accordance with the present invention comprises a two-phase
process. In the first phase, dilute liquid fertilizer (preferably
organic liquid fertilizer) is generated through an accelerated
bioleaching process preferably utilizing a system as depicted in
FIG. 1. The process is based on an accelerated bio-leaching
process wherein material, preferably plant material including, but
not limited to, green grass and alfalfa, is stored in a solid bed
similar to a batch process, and a leachate (e.g., water and
bacteria) is re-circulated through the solid bed until the process
of hydrolysis and acidification results in dissolution of organic
material into the re-circulating leachate.
A non-limiting embodiment of the present invention is shown in
FIG. 1. System 50 comprises, in part, column 100 (which can be of
any appropriate material such as PVC and of suitable dimensions
such as of approximately 3 feet high and one foot in diameter).
Drip irrigation leachate distribution system 110 is provided at
the top of column 100. Sub-drain system 120 with a filter is
installed at the bottom of column 100 to collect leachate 200.
Fresh grass waste 300 is packed in column 100 between leachate
distribution system 110 and sub-drain system 120. Sufficient water
is applied to satisfy the field capacity of the organic media and
provide an additional 20% leachate at the bottom. Leachate 200 is
re-circulated (via, for example, pump 130) periodically through
system 50. Preferably, samples are taken periodically to analyze
for nutrient and organic content of leachate.
In the second phase, the dilute liquid fertilizer is concentrated
using either or both of two different methods. In a first method,
leachate 200 is concentrated through controlled heating at 80-85
degrees F. In the second method, leachate 200 is concentrated
using a solarization approach where liquid is stored in an outdoor
container covered with clear plastic with vents and leaving in the
sun for a few days. The purpose of the concentration is to
facilitate the handling, transportation and application of the
organic liquid fertilizer.
The present invention also addresses the problem of salinity that
is detrimental to many crops. Salt accumulation limits the uptake
and transport to nutrients that have an effect on plant growth.
Uptake of nitrogen in saline conditions is reduced in addition to
dry mass production. Increased inorganic nitrogen nutrition has
been shown to decrease ion toxicity under this condition.
Additionally, it is well known to apply manure to provide organic
nitrogen. However, the use of organic nitrogen from an organic
liquid fertilizer in saline conditions is beneficial to plant
growth.
Thus, the present invention comprises producing liquid fertilizer
from waste (e.g., green waste) using an accelerated bio-leaching
process. The liquid fertilizer can be concentrated using
controlled heating without a significant loss of nutrient or
organic content. The concentrated liquid can be classified as
fertilizer in accordance with both international and U.S.
fertilizer standards. The fertilizer can be applied through
irrigation systems on a timely basis and can produce higher crop
yield in comparison to mineral fertilizer. The fertilizer can be
applied through drip tapes in a field scale or other drip
irrigation system.
Example 1
A non-limiting example of a system for the production of liquid
fertilizer was constructed and used as described herein for
approximately three weeks of leaching. Table 1 shows the nutrient
composition for the resulting dilute leachate composition at the
end of the first phase.
TABLE 1
Nutrient composition of dilute leachate at the end of first phase.
Measured parameters Amount, mg/L
Total organic content 27,800
Total N 7,100
Total P 950
Potasium, K 3,300
Ca 1,100
Mg 290
Fe 49
Mn 8
Zn 0.51
The dilute liquid had a pH of 5.7. The liquid was then heated at a
controlled temperature of 80-85 degrees F. in order to concentrate
the nutrient. The volume of the concentrated liquid was 10% of the
original volume, and had a pH of 5.4. Table 2 shows the nutrient
content of the concentrated fertilizer.
TABLE 2
Nutrient composition of concentrated samples at the end of second
phase.
Measured parameters Amount, mg/L
Total organic content 230,00
Total N 63,500
Total P 7,505
Potasium, K 27,500
Ca 10,300
Mg 2,500
Fe 420
Mn 78
Zn 5.2
The concentrated liquid described in Table 2 is properly
classified as commercial fertilizer as it has more than 6%
nutrient by weight. The International Fertilizer Industry
Association ("IFA") defines fertilizer as "a natural or
manufactured material with at least 5% of one or more of the three
primary nutrients (N, PsO5, K2O). In the United States, fertilizer
preferably has a combined NPK of at least 6% in order to be
classified as fertilizer. Fertilizers with only one primary
nutrient are called "straight fertilizer", and with two or three
primary nutrients are called "multi-nutrient fertilizers."
One noticeable effect of the concentration was that, a few days
after the treatment was begun, the liquid had virtually no odor,
contrary to the dilute sample following the first phase which has
a strong odor like that of sewage. It appears that compounds
causing the odor are the first to break away from the liquid as
the concentration process begins.
Example 2
In another non-limiting example, green house experiments were
conducted to evaluate the feasibility of utilizing organic
fertilizer in the production of organic green chile. A randomized
block design experiment with nine treatments and four replications
was used. The treatments consisted of three levels of soil
salinity (ECe=1, 5, 4.5, 6.5) and three levels of fertilizer. The
levels of fertilizers were: 120 Kg of N/ha of commercial mineral
fertilizer, 120 Kg N/ha of organic liquid fertilizer and 200 Kg
N/ha of organic liquid fertilizer.
FIG. 2 shows the results of the experiment with the first three
harvests. In the green house experiment, liquid fertilizer was
diluted in the irrigation water and applied on a periodic basis
according to experiment station recommendations. The green house
experiment showed that the yield of green chile was increased
significantly by using organic liquid fertilizer, especially in
soils with high salinity. The organic liquid fertilizer not only
increases the yield, but also produces an organic crop that has
considerably higher market value. Traditionally, one of the
challenges of the organic farming industry has been to match the
quality and quantity of crops grown by commercial fertilizer. A
high level of organic in the solution reduces the negative impact
of salinity in the soil.
Example 3
In another non-limiting example, the liquid organic fertilizer was
compared to a chemical fertilizer for chile pepper growth.
Chile pepper (Capsicum annuum L. cv. Sandia) was grown in green
house conditions. The type of soil is a Brazito sandy loam with an
electrical conductivity (EC) of 0.59 dS m<-1 >and a pH of
7.7. A mixture of CaCl2 and NaCl in a ratio of 1:1 was used to
prepare saline solutions, which were sprayed evenly over each
plastic pot of 15 kg soil according to three levels of salinity:
S1 (1.7 dS/m), S2 (5.0 dS/m), and S3 (6.5 dS/m). Ammonium nitrate
and an organic liquid fertilizer were the two nitrogen sources.
The first was applied at a rate of 120 kg ha<-1 >(F1), and
the second in two rates: 120 kg ha<-1 >(F2) and 200 kg
ha<-1 >(F3). The organic liquid fertilizer's chemical
properties are shown in Table 3.
TABLE 3
Chemical properties of organic liquid fertilizer.
Property Value
Organic matter 2.78%
pH 5.7
Electrical conductivity 22.7 dS/m
Nitrogen 0.70%
Phosphate 0.55%
Potash 0.33%
Ca 1100 ppm
Na 267 ppm
Mg 290 ppm
Fe 49 ppm
Mn 8 ppm
Zn 0.51 ppm
The three salinity levels were combined with the three rates of
fertilizer to give nine treatments. Fertilizers were manually
applied and split in four applications. Pepper seedlings were
transplanted in pots arranged in a randomized complete block
design with four replications.
Water use efficiency (WUE) was calculated as the ratio of yield
(g/plant) and the amount of water used to reach this yield.
Soil pH and EC was measured in the saturation extract using a
glass pH electrode and a temperature-compensating conductivity
meter, respectively. Soil NH4<+> and NO3<-> were
analyzed using a Multiscan Ascent plate reader spectrophotometer.
Dry weights of roots, shoots, leaves, and fruits were determined
after drying for 76 hours at 70 degrees C. Total plant nitrogen
was determined using the Kjeldahl digestion procedure (TKN).
Ground plant parts were digested in concentrated H2SO4 in a block
digester and quantified as NH4<+> on an AutoAnalyzer II
ammonia system.
Data was analyzed with the SAS statistical package. Differences
between treatments were tested using Tukey's students test.
The final soil solution reaction salt and nitrogen concentrations
are shown in Table 4.
TABLE 4
Effects of salinity and fertilizer levels on some soil
characteristics of chile pepper grown in greenhouse conditions
EC NH2<+> NO3 Total-N
Treatments pH dS m<1> Mg
kg<-1> Mg kg<-1> Mg kg<-1>
S1F1 7.93 ab 1.375 c 0.287 b 1.323
ab 1.610 ab
S1F2 8.00 a 1.580 c 0.000 b 2.650
ab 2.650 ab
S1F3 7.84 bcd 1.877 c 0.395 b 0.000
b 0.395 b
S2F1 7.63 c 3.997 b 0.820 b 2.538
ab 3.358 ab
S2F2 7.76 cdc 4.382 b 1.352 ab 0.000
b 1.353 b
S2F3 7.70 cde 4.315 b 1.950 ab 0.000
b 1.950 ab
S3F1 7.69 de 6.405 a 0.960 b 22.135
a 23.095 a
S3F2 7.75 de 5.902 a 2.535 ab 1.395
ab 3.930 ab
S3F3 7.91 abc 6.475 a 4.140 a 9.805
ab 13.945 ab
Each value in the columns is the mean value of four plants. Means
with different letters indicate significant differents (P <=
05) by Tukey's test.
Soil reaction (pH) showed some variation. The final electrical
conductivities (EC) show a light decrement compared to original
values: from 1.7 to 1.61 dS m<-1 >for 51, from 5.0 to 4.23
dS m<-1 >for S2, and from 6.5 to 6.26 dS m<-1 >for S3.
However, there were differences between treatments. Soil NH4-N was
slightly affected by the kind of fertilization and salinity. The
same response had soil NO3-N and Total-N. However, a high
concentration was observed for NO3-N form in the S3F1 treatment.
According to ANOVA, plant height showed a similar response to
saline (65.83 cm for S2, and 66.00 cm for S3) and non-saline
(78.45 cm for 51) conditions while the treatments had small
effects on shoot diameter (1.13 cm for S1, 1.01 cm for S2, and
0.97 cm for S3). Results are shown in FIG. 3.
Influence of salinity and nitrogen source on leaves, shoots, and
root dry weights are shown in Table 5. The dry weights of shoots
and roots components decreased significantly in response to
increments in salinity (from 35.685 g to 25.886 g for 51 and S3 in
roots, and 112.226 g to 83.386 g for the same salinity levels for
shoots). However, in leaves there was a decrement in dry weight
for S2 (57.165 g), and an increment in S3 (68.509 g) with respect
to S1 (66.329 g).
TABLE 5
Effects of salinity and fertilizer levels on dry weights (g) of
some chile pepper plant parts.
Treatments Leaves Shoot Root
S1F1 71.313 ab 119.955 a 35.965 ab
S1F2 44.440 c 101.130 abc 31.508 abc
S1F3 83.205 a 115.595 ab 40.065 a
S2F1 69.358 abc 89.575 abcd 28.475
abc
S2F2 44.743 c 62.845 d 22.205 c
S2F3 57.395 bc 99.648 abc 31.028
abc
S3F1 84.843 a 83.088 cd 25.478 bc
S3F2 46.203 c 84.158 bcd 25.863 bc
S3F3 74.485 ab 84.115 bcd 26.320 bc
Each value in the columns is the mean value of four plants. Means
with different letters indicate significant differences (P <=
0.05) by Turkey's test.
Generally, yields for chile pepper plants were affected by saline
and fertilizer treatments. The total yield is shown in FIG. 4
while the fresh weights in different harvests are provided in
Table 6.
TABLE 6
Effects of salinity and fertilizer levels on yield of chile pepper
in different harvests (g/plant).
Treatments Harvest 1 Harvest 2 Harvest 3
Harvest 4 Harvest 5
S1F1 146.37 a 105.22 abc 140.11 abc 112.65
ab 73.47 a
S1F2 144.01 a 154.52 a 149.07 ab
85.00 ab 21.29 a
S1F3 131.28 ab 168.48 a 187.01 a 149.84
a 2.82 a
S2F1 62.42 ab 91.64 abc 56.95
bc 74.06 ab 78.85 a
S2F2 113.90 ab 125.93 ab 98.09
abc 57.93 ab 8.24 a
S2F3 123.22 ab 95.60 abc 114.77 abc
106.16 ab 39.83 a
S3F1 50.42 b 21.06 c 13.91
c 65.89 ab 85.19 a
S3F2 126.14 ab 34.65 bc 27.61
bc 30.42 b 29.41 a
S3F3 58.17 ab 41.81 bc 81.02
abc 132.82 ab 51.17 a
Each value in the columns is the mean value of four plants. Means
with different letters indicate significant differences (P <=
0.05) by Tukey's test.
The greater yields were obtained when 200 kg ha<-1 >(F3) of
organic fertilizer was applied to chile pepper plants. Total
yields of chile pepper increased 18.19% (1155.7 g), 15.17% (1126.1
g), and 14.59% (1462.7 g) for S1 (1.8 dS m<-1>), S2 (4.3 dS
m<-1>), and S3 (6.4 dS m<-1>) respectively compared
with yield of chile pepper (977.82 g) grown with NH4NO3 (F1, 120
kg ha<-1>) in non-saline soil conditions S1 (1.3 dS
m<-1>).
In relation to yields in different harvests (Table 6), the higher
yields were obtained using organic fertilizer as the nitrogen
source. Only in non-saline conditions were yields using NH4NO3
greater than yields using organic fertilizer in the first and last
harvests. However, in the last harvest there were no differences
between treatments.
Table 7 and FIG. 5 show the total Kjeldahl Nitrogen for the
different plant components. While fruit TKN was not affected by
salinity and fertilization treatments, in shoots and roots TKN,
salinity and nitrogen source had a small effect. However, leaves
TKN concentrations decreased at higher salinities for F1 and F2
treatments.
TABLE 7
Effects of salinity and fertilizer levels on Total Kjeldahl
Nitrogen (TKN, %) of some chile pepper plants)
Treatments Fruit Leaves Shoot Root
S1F1 3.087 a 3.582 ab 1.305 ab 2.712 ab
S1F2 2.642 a 3.275 abc 0.620 b 2.680 ab
S1F3 3.085 a 2.737 d 0.637 b 2.632 ab
S2F1 3.260 a 3.477 ab 1.110 ab 2.930 a
S2F2 2.542 a 2.782 cd 0.780 b 2.390 ab
S2F3 2.585 a 3.602 a 0.765 b 2.390 ab
S3F1 3.132 a 3.155 abcd 1.192 ab 2.830 a
S3F2 2.757 a 3.027 bcd 0.947 ab 2.027 b
S3F3 2.832 a 3.372 ab 1.540 a 2.840 a
Each value in the columns is the mean value of four plants. Means
with different letters indicate significant differences (P = 0.05)
by Turkey's test.
The difference in value of applied water as salinity increased is
shown in FIG. 6. Significantly, the quantity of water was
diminished by increasing salinity: from an average of 46,310.17 ml
for S1, 37,325.15 ml for S2 to 32,762.17 ml for S3.
The higher plant water use efficiencies (FIG. 6) were achieved
using organic fertilizer for the three salinity levels: 13.26,
12.17, and 11.45 g fruit per kg added water in treatments
fertilized with 200 kg ha<-1 >of organic fertilizer 12.21,
11.52, and 7.40 g fruit per kg added water in the treatments
fertilized with 120 kg ha<-1 >of organic fertilizer compared
to 12.78, 9.70, and 7.19 g fruit per added water in the treatments
fertilized with 120 kg ha<-1 >of NH4NO3 for S1, S2, and S3,
respectively.
Example 4
Another embodiment of the present invention was demonstrated by a
non-limiting example of a system for the production of liquid
fertilizer, constructed and used as described herein, for
approximately three weeks of leaching. Grass and/or alfalfa were
placed in the system container. Bacteria were added at 120[deg.]
F. Water was added to the container and then the container was
sealed. The dilute liquid was stored in the external storage
container. The system preferably comprises two digesters because
these digesters are smaller, less expensive, and improve leaching.
The liquid was removed after fifteen days and replaced with fresh
water. Fresh water was added two or three more times during the
bioleaching process. This resulted in a twice higher yield.
Previous yields were, after one week, a 30% yield of 0.3 mg/liter.
After two weeks, a 72% yield of 0.76 mg/l resulted.
The liquid was then boiled in order to concentrate the nutrient.
Heated water was subsequently added and the concentration was
doubled. An acid or base, depending on the type of bacteria, was
added.
One noticeable effect of the concentration was that, a few days
after the treatment was begun, the liquid had virtually no odor,
contrary to the dilute sample following the first phase which had
a strong odor like that of sewage. Compounds that caused the odor
were the first to break away from the liquid as the concentration
process began.
In addition to high nutrient concentration and ease of handling,
not having an odor is a noteworthy advantage for an organic
fertilizer. Odor was also reduced when the liquid fertilizer was
put in a container and left in the sun for a few days so that the
volatile aromatic compounds were vaporized.
Preferably, the process of generating liquid fertilizer in
accordance with the present invention comprises a two-phase
process. The first phase comprises a successive extraction process
whereby liquid leachate is drained from one plant or storage
container after four weeks and the process subsequently started
with new fresh water. The successive extraction process is based
on an accelerated bio-leaching process wherein material,
preferably plant material including, but not limited to, green
grass and alfalfa, is stored in a solid bed similar to a batch
process, and a leachate (e.g., water and bacteria) is
re-circulated through the solid bed until the process of
hydrolysis and acidification results in dissolution of organic
material into the re-circulating leachate.
A non-limiting embodiment of the present invention is shown in
FIG. 10. System 10 comprises, in part, mixing container 20 into
which bacteria, organic material such as grass or alfalfa, and
water is added. External storage container 30 is provided to
collect leachate 51. Fresh grass waste 70 is packed in container
20 between leachate distribution system 60 and external storage
container 30 that facilitates using multiple fermenters with a
single storage unit. Liquid leachate 80 is successively extracted.
Sufficient water is applied to satisfy the field capacity of the
organic media and provide an additional 20% leachate at the
bottom. Leachate 51 is re-circulated (via, for example, pump 40)
periodically through system 10. Preferably, samples are taken
periodically to analyze for nutrient and organic content of
leachate.
Example 5
In the second phase, the dilute liquid fertilizer is concentrated
using either or both of two different methods. In a first method,
the leachate (e.g. from grass) was concentrated through controlled
heating at 50[deg.] C. for two days. After two days, only a small
amount of odor was detectable compared to a very strong odor in
the beginning. The sample volume was reduced to 0.18 liters and
the total nitrogen content was measured at 75,400 mg/liter
compared to 7,000 mg/liter prior to the treatment. The sample was
therefore concentrated by a factor of eleven with only a small
amount of nitrogen loss. In a second method, leachate was heated
in a closed environment at 90[deg.] C. The heat treatment was
required to kill potential pathogens and to increase nitrogen
concentration. Nitrogen concentration increased from 7,000 parts
per million (ppm) to 12,600 ppm. The volume was reduced by 53%.
The organic liquid fertilizer was heat treated without losing
nitrogen. The purpose of the concentration is to facilitate the
handling, transportation and application of the organic liquid
fertilizer.
The preceding examples can be repeated with similar success by
substituting the generically or specifically described reactants
and/or operating conditions of this invention for those used in
the preceding examples.
FIG. 7 shows salinity and fertilizer effect on soil electrical
conductivity (EC) of chile pepper grown in greenhouse conditions.
FIG. 8 shows salinity and fertilizer effect on average added water
of chile pepper grown in greenhouse conditions. FIG. 9 shows
salinity and fertilizer effect on plant height (cm) of chile
pepper grown in greenhouse conditions.
FIG. 11 shows the increased efficiency using successive extraction
methods where the liquid is removed from the storage container at
discrete intervals. Fresh water is subsequently added to the
external storage containers. A resulting increased efficiency is
noted after four weeks.
The present invention also uses warm water (e.g. 120 to 130[deg.]
F.) with grass or other plant materials to accelerate the
fermentation process. The pH dropped much faster with warm water
than with ambient temperature water.
Although the invention has been described in detail with
particular reference to these preferred embodiments, other
embodiments can achieve the same results. Variations and
modifications of the present invention will be obvious to those
skilled in the art and it is intended to cover all such
modifications and equivalents. The entire disclosures of all
references, applications, patents, and publications cited above
and/or in the attachments, and of the corresponding
application(s), are hereby incorporated herein by reference.
US7682813
Methane generation from
waste materials
Inventor: SAMANI ZOHRAB A [US] ; HANSON ADRIAN T [US]
Abstract -- An organic
solid waste digester for producing methane from solid waste, the
digester comprising a reactor vessel for holding solid waste, a
sprinkler system for distributing water, bacteria, and nutrients
over and through the solid waste, and a drainage system for
capturing leachate that is then recirculated through the sprinkler
system.
