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1.
Chirag Patel Vishwanada Sastry Datta Madamwar 《Applied biochemistry and biotechnology》1996,56(1):89-94
To obtain enriched methane content and improve the anaerobic digestion of a mixture of cattle dung, poultry waste, and cheese
whey, the effect of various doses of Tegoprens: T-3012, T-3022, T-5842, T-5843, T-5851, T-5852 has been studied, in bench-scale
digesters. Among them, Tegoprens 3022 showed more than a 45% increase in gas production with higher methane content. 相似文献
2.
In order to develop a suitable reactor for the biomethanation of high-strength salty cheese whey, the performance of anaerobic
upflow fixed-film reactors packed with different support materials, such as charcoal, gravel, brick pieces, pumicestones,
and PVC pieces, has been studied. The charcoal-bedded reactor gave the best performance, with the maximum gas production (3.3
L/L digester/d) and an enriched methane content (69% CH4). Temperature and hydraulic retention time were optimized, with the ultimate aim of improving biomethanation. Maximum gas
production (3.3 L/L digester/d) was achieved at a hydraulic retention time of 2 d at 40°C. 相似文献
3.
Emmanuel Kweinor Tetteh Gloria Amo-Duodu Sudesh Rathilal 《Molecules (Basel, Switzerland)》2021,26(21)
Digestate is characterized by high water content, and in the water and wastewater treatment settings, necessitates both large storage capacities and a high cost of disposal. By seeding digestate with four magnetic nanoparticles (MNPs), this study aimed to recover biogas and boost its methane potential anaerobically. This was carried out via biochemical methane potential (BMP) tests with five 1 L bioreactors, with a working volume of 80% and 20% head space. These were operated under anaerobic conditions at a temperature 40 °C for a 30 d incubation period. The SEM/EDX results revealed that the morphological surface area of the digestate with the MNPs increased as compared to its raw state. Comparatively, the degree of degradation of the bioreactors with MNPs resulted in over 75% decontamination (COD, color, and turbidity) as compared to the control system result of 60% without MNPs. The highest biogas production (400 mL/day) and methane yield (100% CH4) was attained with 2 g of Fe2O4-TiO2 MNPs as compared to the control biogas production (350 mL/day) and methane yield (65% CH4). Economically, the highest energy balance achieved was estimated as 320.49 ZAR/kWh, or 22.89 USD/kWh in annual energy savings for this same system. These findings demonstrate that digestate seeded with MNPs has great potential to improve decontamination efficiency, biogas production and circular economy in wastewater management. 相似文献
4.
The spectroscopy characteristics and the fluorescence lifetime for the chloroplasts isolated from the pseudo ginseng, water hyacinth and spinach plant leaves have been studied by absorption spectra, low temperature steady-state fluorescence spectroscopy and single photon counting measurement under the same conditions and by the same methods. The similarity of the absorption spectra for the chloroplasts at room temperature suggests that different plants can efficiently absorb light of the same wavelength. The fluorescence decays in PS II measured at the natural QA state for the chloroplasts have been fitted by a three-exponential kinetic model. The three fluorescence lifetimes are 30, 274 and 805 ps for the pseudo ginseng chloroplast; 138, 521 and 1494 ps for the water hyacinth chloroplast; 197, 465 and 1459 ps for the spinach chloroplast, respectively. The slow lifetime fluorescence component is assigned to a collection of associated light harvesting Chl a/b proteins, the fast lifetime component to the react 相似文献
5.
Biomethanation of leaves of the legumeL. leucocephala operated in batch reactors at different input volatile solids (12–18 g/L) proceeded in distinct metabolic phases. An initial
cellulolytic phase of 4 d was followed by an early and active methanogenic phases (5–21 d) and a terminal phase of low-rate
methanogenesis. Hydrolysis of cellulose was concentration-dependent and resulted in increased volatile acid levels. The trend
of changes showed some variations at different input volatile solids. The changes in the levels of volatile acids followed
an oscillatory pattern. The controlled rate of cellulose hydrolysis, levels of volatile acids, and steady-state levels of
soluble carbohydrates and reducing sugars observed during active methanogenesis are indicative of interactive metabolic regulations. 相似文献
6.
Efforts were made to assess the efficiency of an anaerobic filter packed with porous floating ceramic media and to identify
the optimum operational condition of anaerobic filter as a pretreatment of swine wastewater for the subsequent biological
removal of nitrogen and phosphorus. A stepwise decrease in hydraulic retention time (HRT) and an increase in organic loading
rate (OLR) were utilized in an anaerobic filter reactor at mesophilic temperature (35°C). The optimum operating condition
of the anaerobic filter was found to be at an HRT of 1 d. A soluble chemical oxygen demand (COD) removal efficiency of 62%
and a total suspended solids removal efficiency of 39% at an HRT of 1 d were achieved with an OLR of 16.0 kg total COD/(m3·d), respectively. The maximum methane production rate approached 1.70 vol of biogas produced per volume of reactor per day
at an HRT of 1 d. It was likely that the effluent COD/total Kjeldahl nitrogen ratio, of 22, the COD/total phosphorous ratio
of 47, and the high effluent alkalinity >2500 mg/L as CaCO3 of the anaerobic filter operated at an HRT of 1 d was adequate for the subsequent biological removal of nitrogen and phosphorus. 相似文献
7.
This study investigated acid splitting wastewater (ASW) and interphase (IF) from soapstock splitting, as well as matter organic non glycerol (MONG) from glycerol processing, as potential substrates for biogas production. Batch and semicontinuous thermophilic anaerobic digestion experiments were conducted, and the substrates were preliminary treated using commercial enzymes kindly delivered by Novozymes A/C. The greatest enhancement in the batch digestion efficiency was achieved when three preparations; EversaTransform, NovoShape, and Lecitase were applied in the hydrolysis stage, which resulted in the maximum methane yields of 937 NL/kg VS and 915 NL/kg VS obtained from IF and MONG, respectively. The co-digestion of 68% ASW, 16% IF, and 16% MONG (wet weight basis) performed at an organic loading rate (OLR) of 1.5 kg VS/m3/day provided an average methane yield of 515 NLCH4/kg VSadded and a volatile solid reduction of nearly 95%. A relatively high concentration of sulfates in the feed did not significantly affect the digestion performance but resulted in an increased hydrogen sulfide concentration in the biogas with the peak of 4000 ppm. 相似文献
8.
S. Tejeda G. Zarazúa P. Ávila-Pérez L. Carapia-Morales T. Martínez 《Spectrochimica Acta Part B: Atomic Spectroscopy》2010
The Lerma River is one of the most polluted body water in Mexico. For this reason, only the highly resistant organisms such as water hyacinth are able to reproduce in this river. The aim of this work was to evaluate the concentration of K, S, Fe, Ca, Mn, Ti, Zn, Sr, Rb, Cu, Cr, Ni, Pb and Br in roots of water hyacinth (Eichhornia crassipes) from the Lerma River. The samples were collected from five sites in the river and analyzed in triplicate using a TXRF Spectrometer ‘TX-2000 Ital Structures’ with a Si(Li) detector and a resolution of 140 eV (FWHM) at Mn Kα. A Mo tube (40 kV, 30 mA) with 17.4 KeV excitation energy was used for a counting time of 500 s. Results show that the average metal concentration in the water hyacinth roots decrease in the following order: K (9698.2 µg/g) > S (7593.3 µg/g) > Fe (4406.6 µg/g) > Ca (2601.8 µg/g) > Mn (604.2 µg/g) > Ti (230.7 µg/g) > Zn (51.65 µg/g) > Sr (43.55 µg/g) > Rb (18.61 µg/g) > Cu (12.78 µg/g) > Cr (6.45 µg/g) > Ni (4.68 µg/g) > Pb (4.32 µg/g) > Br (4.31 µg/g) and the bioconcentration factors in the water hyacinth decrease in the sequence: Ti > Fe > Mn > Cu > Ni > Zn > S > Pb > Rb > K > Cr > Sr > Br > Ca. The concentrations in roots of water hyacinth reflect the high pollution level of the river. 相似文献
9.
Impact of fluid velocity on hot water only pretreatment of corn stover in a flowthrough reactor 总被引:1,自引:0,他引:1
Flowthrough pretreatment with hot water only offers many promising features for advanced pretreatment of biomass, and a better
understanding of the mechanisms responsible for flowthrough behavior could allow researchers to capitalize on key attributes
while overcoming limitations. In this study, the effect of fluid velocity on the fate of total mass, hemicellulose, and lignin
was evaluated for hot water only pretreatment of corn stover in tubular flow through reactors. Increasing fluid velocity significantly
accelerated solubilization of total mass, hemicellulose, and lignin at early times. For example, when fluid velocity was increased
from 2.8 to 10.7 cm/min, xylan removal increased from 60 to 82% for hot water only pretreatment of corn stover at 200°C after
8 min. At the same time, lignin removal increased from 30 to 46%. Dissolved hemicellulose was almost all in oligomeric form,
and solubilization of hemicellulose was always accompanied by lignin release. The increase in removal of xylan and lignin
with velocity, especially in the early reaction stage, suggests that chemical reaction is not the only factor controlling
hemicellulose hydrolysis and that mass transfer and other physical effects may also play an important trole in hemicellulose
and lignin degradation and removal. 相似文献
10.
Effect of mixture of surfactants and adsorbents on anaerobic digestion of water hyacinth-cattle dung
Datta Madamwar Anami Patel Vikram Patel N. V. Shastri 《Applied biochemistry and biotechnology》1992,36(3):163-169
In an effort to improve the anaerobic digestion of water hyacinth-cattle dung with enriched methane content, the effects of mixtures of surfactant-surfactant, adsorbent-adsorbent and surfactant-adsorbent have been studied in various combinations. Among the combinations tested, bentonite and gelatin, gelatin and Tegoprens 43, sodium lauryl sulfate and Tegoprens 42, and Tegoprens 47 and Tegoprens 63 showed more than a 100% increase in gas production with higher methane yield. 相似文献
11.
A series of novel self-dispreading phenoxy carboxylic acid derivatives were designed and synthesized by I2 catalyzed one-step reaction. Their structures were confirmed by IR, NMR, and HRMS. The derivatives can self-spread and float on the water surface. Preliminary bioassays showed that some compounds, 3i–3p, had excellent herbicidal activities against water hyacinth. This strategy provided a novel approach for the water hyacinth control. 相似文献
12.
Kinetics of biomethanation of solid tannery waste and the concept of interactive metabolic control 总被引:1,自引:0,他引:1
Anaerobic digestion of calf skin collagenous waste was optimized for a batch process based on accelerated maximal methane
yield per gram of input volatile solid. A kinetic analysis with respect to changes in the levels of volatile solid, collagen,
amino sugars, amino acids, hydroxyproline, ammonium ions, and volatile fatty acid were followed for a period of 80 d. Distinct
metabolic phases included an initial high rate collagenolysis for 4 d, with 50% degradation and was followed by an acidogenic
phase between 4–12 d with voltatile fatty acids levels increasing to 215 mmol/L. Subsequently methanogenesis ensued and was
maximal between 12–24 d when volatile fatty acids attained steady state levels. During the period of 80 d, the overall decrease
in volatile solid level was 65%, whereas the collagen level declined by 85% with 0.45 L of methane yield/g of volatile solid
degraded. Based on the levels of various metabolites detected, the concept of interactive metabolic control earlier proposed
has been validated. 相似文献
13.
分别以甲基萘磺酸盐(MF)及改性碱木质素磺酸钠(B1)为分散剂,考查了水葫芦与神府煤的成浆性能。结果表明,当100 g煤中加入19.16 g的水葫芦时,以MF为分散剂,60%浓度水葫芦煤浆的表观黏度为1 154 mPa.s,Fe2(SO4)3改性水葫芦煤浆的表观黏度为999 mPa.s。以B1为分散剂,水葫芦煤浆的表观黏度略有提高。Fe2(SO4)3的加入减少了与水缔合的含氧官能团数量,增加了水葫芦中起降黏作用的自由水含量。水葫芦能有效的提高水煤浆的稳定性,使出现硬沉淀的时间从2 h延长到60 h,Fe2(SO4)3作用后的水葫芦可进一步提高水煤浆的稳定性,使其出现硬沉淀的时间延长到88 h以上。水葫芦中大量的亲水性含氧官能团以及纤维素等大分子是水煤浆稳定性提高的主要原因。 相似文献
14.
Counter‐current chromatography (CCC) was investigated as a new sample pretreatment method for the determination of trace polycyclic aromatic hydrocarbons (PAHs) in water environmental samples. The experiment was performed with a non‐aqueous binary two‐phase solvent system composed of n‐heptane and acetonitrile. The CCC column was first filled with the upper stationary phase, and then a large volume of water sample was pumped into the column while the CCC column was rotated at 1600 rpm. Finally, the trace amounts of PAHs extracted and enriched in the stationary phase were eluted out by the lower mobile phase and determined by gas chromatography–flame ionization detector (GC‐FID) or gas chromatography–mass spectrometry (GC‐MS). The enrichment and cleanup of PAHs can be fulfilled online by this method with high recoveries (84.1–103.2%) and good reproducibility (RSDs: 4.9–12.2%) for 16 EPA PAHs under the optimized CCC pretreatment conditions. This method has been successfully applied to determine PAHs in lake water where 8 PAHs were detected in the concentration of 40.9–89.9 ng/L. The present method is extremely suitable for the preparation of large volume of environmental water sample for the determination of trace amounts of organic pollutants including PAHs as studied in this paper. 相似文献
15.
Marek Gryta 《Chemical Papers》2008,62(1):100-105
Membrane distillation was used to produce demineralized water from ground water. The influence of feed water pretreatment
carried out in a contact clarifier (softening with Ca(OH)2 and coagulation with FeSO4 · 7H2O) followed by filtration, on the process effectiveness was evaluated. It was found that the chemical pretreatment decreased
the membrane fouling; however, the degree of water purification was insufficient because precipitation of small amounts of
deposit on the membrane surface during the process operation was still observed. The permeate flux was gradually decreasing
as a result of scaling. The morphology and composition of the fouling layer were studied using scanning electron microscopy
coupled with energy dispersion spectrometry. The presence of significant amounts of silica, apart from calcium and magnesium,
was determined in the formed deposit. The removal of foulants by heterogeneous crystallization performed inside the filter
(70 mesh), assembled directly at the module inlet, was found to be a solution preventing the membrane scaling.
Presented at the 34th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 21–25 May
2007. 相似文献
16.
The pretreatment of waste-activated sludge (WAS) by electron beam irradiation was studied in order to improve anaerobic sludge
digestion. The irradiation dose of the electron beam was varied from 0.5 to 10 kGy. Batch and continuous-flow stirred tank
reactors (CFSTRs) were operated to evaluate the effect of the electron beam pretreatment on anaerobic sludge digestion. Approximately
30–52% of the total chemical oxygen demand (COD) content of the WAS was solubilized within 24 h after electron beam irradiation.
A large quantity of soluble COD, protein, and carbohydrates leached out from cell ruptures caused by the electron beam irradiation.
Volatile fatty acids production from the irradiated sludge was approx 90% higher than that of the unirradiated sludge. The
degradation of irradiated sewage sludge was described by two distinct first-order decay rates (k
1 and k
2). Most initial decay reaction accelerated within 10 d, with an average k
1 of 0.06/d for sewage sludge irradiated at all dosages. The mean values for the long-term batch first-order decay coefficient
(k
2) were 0.025/d for irradiated sewage sludge and 0.007/d for unirradiated sludge. Volatile solids removal efficiency of the
control reactor fed with unirradiated sewage sludge at a hydraulic retention time (HRT) of 20 d was almost the same as that
of the CFSTRs fed with irradiated sludge at an HRT of 10 d. Therefore, disintegration of sewage sludge cells using electron
beam pretreatment could reduce the reactor solid retention time by half. 相似文献
17.
Kim Sung Bae Um Byung Hwan Park Soon Chul 《Applied biochemistry and biotechnology》2001,91(1-9):81-94
The effect of pretreatment reagent and hydrogen peroxide on enzymatic digestibility of oak was investigated to compare pretreatment
performance. Pretreatment reagents used were ammonia, sulfuric acid, and water. These solutions were used without or in combination
with hydrogen peroxide in the percolation reactor. The reaction was carried out at 170°C for the predetermined reaction time.
Ammonia treatment showed the highest delignification but the lowest digestibility and hemicellulose removal among the three
treatments. Acid treatment proved to be a very effective method in terms of hemicellulose recovery and cellulose digestibility.
Hemicellulose recovery was 65–90% and digestibilities were >90% in the range of 0.01–0.2% acid concentration. In both treatments,
hydrogen peroxide had some effect on digestibility but decomposed soluble sugars produced during pretreatment. Unlike ammonia
and acid treatments, hydrogen peroxide in water treatment has a certain effect on hemicellulose recovery as well as delignification.
At 1.6% hydrogen peroxide concentration, both hemicellulose recovery and digestibility were about 90%, which were almost the
same as those of 0.2% sulfuric acid treatment. Also, digestibility was investigated as a function of hemicellulose removal
or delignification. It was found that digestibility was more directly related to hemicellulose removal rather than delignification. 相似文献
18.
Weiland P 《Applied biochemistry and biotechnology》2003,109(1-3):263-274
The production of biogas for reducing fossil CO2 emissions is one of the key strategic issues of the German government and has resulted in the development of new process
techniques and new technologies for the energetic use of biogas. Progress has been made in cultivating energy crops for biogas
production, in using new reactor systems for anaerobic digestion, and in applying more efficient technologies for combined
heat and power production. Recently, integration of fuel cells within the anaerobic digestion process was started, and new
technologies for biogas upgrading and conversion to hydrogen were tested. This article describes the trends in Germany for
achieving more efficient energy production. 相似文献
19.
R. Torget M. Himmel J. D. Wright K. Grohmann 《Applied biochemistry and biotechnology》1988,17(1-3):89-104
A preliminary process design for dilute sulfuric acid pretreatment of aspen wood chips in order to obtain fermentable sugars
has been prepared and subjected to an economic evaluation. The process design was prepared according to experimental data
on the kinetics of dilute sulfuric acid prehydrolysis and particle size effects obtained in this study and our previous work.
The initial economic evaluation shows woodchips are 56% of the cost of production, whereas the reactor is only 4%, and the
comminution operation is just under 10%, indicating that the process economics are extremely vulnerable to feedstock costs
and are thus yield-sensitive. Although chances for major cost improvements by modification of the reactor design and finding
alternatives to dry milling of aspen chips to small (20–80 mesh) particles needed for acid penetration and enzymatic saccharification
are not great, design improvements of the process will necessitate development of a cheaper acid resistant pretreatment reactor
and a less energy intensive comminution system. Experimental results on effects of particle size on the dilute acid pretreatment
design are presented. 相似文献