Effects Of Co-substrates Research Articles

Effects of co-substrate on biogas production from cattle manure: a review

This literature review surveys the previous and current researches on the co-digestion of anaerobic processes and examines the synergies effect of co-digestion with cattle manure. Furthermore, this review also pays attention to different operational conditions like operating temperature, organic loading rate (OLR), hydraulic retention time (HRT), chemical oxygen demand (COD) and volatile solid (VS) removal efficiency and biogas or methane production. This review shows that anaerobic mono-digestion of cattle manure usually causing poor performance and stability. Anaerobic studies were generally performed under mesophilic conditions maintained between 35 and 37 °C. Organic waste loading rate generally ranges from 1 to 6 g VS–COD L−1 day−1 stable condition in anaerobic digester. Generally, studies show that HRT for co-digestion of fruit–vegetables waste and industrial organic waste appears to exceed 20 days. However, the anaerobic co-digestion process is generally operated at HRT of between 10 and 20 days. VS and COD removal efficiency usually reaches up to 90 % due to co-digestion with different type organic waste. Methane–biogas production is generally obtained between 0.1 and 0.65 L CH4–biogas g−1 VS.

Enhancement of animal waste biomethanation using fruit waste as co-substrate and chicken rumen as inoculums

ABSTRACTThis work investigated the effects of co-substrates (orange, mango, and pineapple wastes) and inoculums (chicken rumen), pH, and total solid (TS) content on animal waste (cow dung, pig dung, poultry droppings) for efficient and high biomethane production. The biomethanation experiments were carried out in five different 1.5 L anaerobic digesters and incubated for 10 weeks. The results showed that co-digestion of animal wastes with fruit wastes and inoculums (additives) increased biomethane yield and reduced the startup time for biomethane generation as compared to animal wastes alone. In addition, cumulative biomethane yield increased with increase in pH while it decreased with increase in TS content.

Effects of Co-Substrates and Mixing Ratio on the Anaerobic Digestion of Navel Orange Waste

The Gannan region is the largest navel orange planting area in the world and has the largest production in China. However, about 5 million tons of navel orange waste (NOW) produced annually. NOW has a great environmental risk because of its high content of organic matter and moisture. Anaerobic digestion of NOW with high nitrogen content waste is a promising alternative to treat these wastes. The effect of swine manure (SM), waste active sludge (WAS) as co-substrates and different mixing ratio were examined in three batch-scale studies. In the first investigation, co-digestion of NOW with SM resulted low methane yield and high concentration of VFAs. In the second investigation, NOW was co-digested with WAS, the methane yield was improved by 260% when the mixing ratio of NOW to WAS (VS/VS) was shifted from 1:2 to 2:1. In the third investigation, the co-digestion of NOW with SM and WAS was conducted. Co-digestion of three substrates has higher methane yield than that of previous two studies, with the exception of equal amounts of NOW with co-substrates (mixing ratio of NOW to SM to WAS was 2:1:1). The highest methane yield of all experiments was 0.20 m3 kg-1VS added while the mixing ratio of NOW to SM to WAS was 1:2:1. It seemed to obtain stable digestion performance, the mixing ratio of co-substates to NOW should not be lower than 1:1. WAS was a better co-substrate than SM, as WAS was capable to supply more organic nitrogen to create positive synergistic effects.

Microbial Degradation of Acetamiprid by Ochrobactrum sp. D-12 Isolated from Contaminated Soil

Neonicotinoid insecticides are one of the most important commercial insecticides used worldwide. The potential toxicity of the residues present in environment to humans has received considerable attention. In this study, a novel Ochrobactrum sp. strain D-12 capable of using acetamiprid as the sole carbon source as well as energy, nitrogen source for growth was isolated and identified from polluted agricultural soil. Strain D-12 was able to completely degrade acetamiprid with initial concentrations of 0–3000 mg·L−1 within 48 h. Haldane inhibition model was used to fit the special degradation rate at different initial concentrations, and the parameters q max, K s and K i were determined to be 0.6394 (6 h)−1, 50.96 mg·L−1 and 1879 mg·L−1, respectively. The strain was found highly effective in degrading acetamiprid over a wide range of temperatures (25–35°C) and pH (6–8). The effects of co-substrates on the degradation efficiency of acetamiprid were investigated. The results indicated that exogenously supplied glucose and ammonium chloride could slightly enhance the biodegradation efficiency, but even more addition of glucose or ammonium chloride delayed the biodegradation. In addition, one metabolic intermediate identified as N-methyl-(6-chloro-3-pyridyl)methylamine formed during the degradation of acetamiprid mediated by strain D-12 was captured by LC-MS, allowing a degradation pathway for acetamiprid to be proposed. This study suggests the bacterium could be a promising candidate for remediation of environments affected by acetamiprid.

Studies on xylitol production by metabolic pathway engineered Debaryomyces hansenii

Debaryomyces hansenii is one of the most promising natural xylitol producers. As the conversion of xylitol to xylulose mediated by NAD(+) cofactor dependent xylitol dehydrogenase (XDH) reduces its xylitol yield, xylitol dehydrogenase gene (DhXDH)-disrupted mutant of D. hansenii having potential for xylose assimilating pathway stopping at xylitol, was used to study the effects of co-substrates, xylose and oxygen availability on xylitol production. Compared to low cell growth and xylitol production in cultivation medium containing xylose as the only substrate, XDH disrupted mutants grown on glycerol as co-substrate accumulated 2.5-fold increased xylitol concentration over those cells grown on glucose as co-substrate. The oxygen availability, in terms of volumetric oxygen transfer coefficient, kLa (23.86-87.96 h(-1)), affected both xylitol productivity and yield, though the effect is more pronounced on the former. The addition of extra xylose at different phases of xylitol fermentation did not enhance xylitol productivity under experimental conditions.

Fermentation of biodiesel-derived glycerol by Bacillus amyloliquefaciens: effects of co-substrates on 2,3-butanediol production

Cultivation in glycerol instead of sugars inhibits 2,3-butanediol (2,3-BD) production by Bacillus amyloliquefaciens. In this study, we report that B. amyloliquefaciens readily produces 2,3-BD from biodiesel-derived glycerol in the presence of beet molasses as a co-substrate. Unexpectedly, the molasses stimulated 2,3-BD production and simultaneously reduced the duration of fermentation. Productivity of 2,3-BD was enhanced at the start of fermentation, and yields increased under continuous molasses supply. Subsequently, 2,3-BD production in molasses-supplemented fed-batch culture was observed. Prior to inoculation of fed-batch fermentation culture, 15 g/l of molasses was added to the bioreactor. After 6 h of incubation, the bioreactor was fed with a solution containing 80 % glycerol and 15 % molasses. The 2,3-BD concentration, yield, and productivity significantly improved, reaching 83.3 g/l, 0.42 g/g, and 0.87 g/l·h, respectively. To our knowledge, these results are the highest report for 2,3-BD fermentation from biodiesel-derived glycerol.

Effects of co-substrate and biomass acclimation concentration on the bioregeneration of azo dye-loaded mono-amine modified silica

Bioregeneration of mono-amine modified silica gel (MAMS) adsorbent loaded with Acid Orange 7 (AO7), Acid Yellow 9 (AY9) and Acid Red 14 (AR14), respectively, was investigated under two different operational conditions, namely absence/presence of sucrose/bacto-peptone as the co-substrate and different biomass acclimation concentrations. The results revealed that the AY9- and AR14-loaded MAMS adsorbents could almost be completely bioregenerated but only in the presence of co-substrate whereas the bioregeneration of AO7-loaded MAMS could achieve up to 71% in the absence of the co-substrate. These differences could be related to the structural properties of the investigated azo dyes. In addition, the results showed that the bioregeneration duration of AO7-loaded MAMS could be progressively shortened by using biomass acclimated to increasingly higher AO7 concentration. However, the bioregeneration efficiencies were found to be relatively unchanged under different biomass acclimation concentrations.

Degradation of piperazine by Paracoccus sp. TOH isolated from activated sludge

Piperazine is widely used as an intermediate in the manufacture of insecticides, rubber chemicals, corrosion inhibitors, and urethane. In this study, a highly effective piperazine-degrading bacteria strain, TOH, was isolated from the acclimated activated sludge of a pharmaceutical plant. This strain, identified as Paracoccus sp., utilises piperazine as the sole source of carbon, nitrogen and energy for growth. The optimal pH and temperature for the growth of TOH were 8.0 and 30°C, respectively. The effects of co-substrates and heavy metals on the degradation efficiency of piperazine were investigated. The results indicated that exogenously supplied glucose promoted the degradation of piperazine, while the addition of ammonium chloride slightly inhibited piperazine degradation. Metal ions such as Ni2+ and Cd2+ inhibited the degradation of piperazine, whereas Mg2+ increased it. In addition, metabolic intermediates were identified by mass spectrometry, allowing a degradation pathway for piperazine to be proposed for the first time.

Advanced Treatment of Vitamin C Wastewater by Coupling Electrochemical Oxidation and an Integrated Bioreactor

AbstractThis study aims to establish a new technology for the advanced treatment of vitamin C (VC) wastewater by coupling electrochemical oxidation (EO) and an integrated bioreactor. Characteristics of organic compounds in the effluent from biotreatment of VC wastewater were analyzed. EO was used to break the chromophore functional groups of these organic compounds and improve biodegradability of the effluent. The subsequent integrated bioreactor was proposed to further degrade organic compounds in the effluent from the EO. The optimum operation parameters of this combined technology and the effect of cosubstrate on the removals of color, chemical oxygen demand (COD), and nitrogen were investigated. EO could remove color with the maximum removal of 183° and improve the biochemical oxygen demand-to-COD ratio effectively from 0.07 to 0.24. Effluent COD and color of the integrated bioreactor decreased from 111.4 mg/L and 60° without glucose addition to 100.9 mg/L and 50° with glucose addition. Concomitantl...

Effects of substrate loading and co-substrates on thermophilic anaerobic conversion of microcrystalline cellulose and microbial communities revealed using high-throughput sequencing

Batch tests were conducted to investigate the effect of co-substrates, including glucose, xylose and starch, on thermophilic anaerobic conversion of microcrystalline cellulose using mixed culture enriched from anaerobic digestion sludge (ADS). Up to 30.9% of cellulose was utilized with xylose as co-substrate. When using glucose as co-substrate, cellulose conversion rate reached the maximum of 0.048 g/l/h at cellulose loading of 5.0 g/l. Illumina high-throughput sequencing of the 16S rRNA gene revealed that the thermophilic consortium exclusively consisted of Clostridium (more than 70% of all sequences). Growth of Thermoanaerobacterium over Clostridium would inhibit cellulose conversion capacity of the consortium. But the growth of Thermoanaerobacterium could be repressed by pH higher than pH 6.0. Co-substrates caused noticeable variation of bacterial community structure. Predominance of Thermoanaerobacterium over Clostridium was observed when monosugars (glucose and xylose) were used as co-substrate without pH control. Starch was ineffective as co-substrate because it competed with cellulose for Clostridium.

Biodegradation of Basic Violet 3 by Candida krusei isolated from textile wastewater

Basic Violet 3 (BV) belongs to the most important group of synthetic colorants and is used extensively in textile industries. It is considered as xenobiotic compound which is recalcitrant to biodegradation. As Candida krusei could not use BV as sole carbon source, experiments were conducted to study the effect of cosubstrates on decolorization of BV in semi synthetic medium using glucose, sucrose, lactose, maltose, yeast extract, peptone, urea and ammonium sulphate. Maximum decolorization (74%) was observed in media supplemented with sucrose. Use of sugarcane bagasse extract as sole nutrient source showed 100% decolorization of BV within 24h under optimized condition. UV-visible, FTIR spectral analysis and HPLC analysis confirmed the biodegradation of BV. Six degradation products were isolated and identified. We propose the biodegradation pathway for BV which occurs via stepwise reduction and demethylation process to yield mono-, di-, tri-, tetra-, penta- and hexa-demethylated BV species which was degraded completely. The study of the enzymes responsible for decolorization showed the activities of lignin peroxidase, lacasse, tyrosinase, NADH-DCIP reductase, MG reductase and azoreductase in cells before and after decolorization. A significant increase in activities of NADH-DCIP reductase and laccase was observed in the cells after decolorization. The yeast C. krusei could show the ability to decolorize the textile dye BV using inexpensive source like sugarcane bagasse extract for decolorization.

Effects of Co-Substrates and Inorganic Ions on Biodegradation of Oil-Degrading Strains

Six strains named SY1 to SY6 were isolated from oil-polluted soil. The degradation tests of oil by our isolates were carried out under still-reaction-bottle-aeration and shaking-aeration conditions. The co-metabolic characteristics of two co-substrates (ethanol and glucose) and inorganic ions on the biodegradation of oil by our isolates were also studied. The results show that oil can be degraded by the six isolates effectively. The degradation ability of strains is enhanced due to co-substrates added. The enhanced roles of glucose are stronger than ethanol to SY1 and SY5; while the enhanced roles of ethanol are stronger than glucose to SY3.And the enhanced roles of glucose and ethanol are similar to SY2, SY4 and SY6. Inorganic ions, such as Ca2 + Fe2 +, Mg2+, etc, could promote the degradation ability of strains and improve the growth of strains. The degradation effects of mixed strains were inferior to that of single strain. After five days, the degradation rate of SY3 was worst, which was 65.7%. In the mixed strains, there were only 11 groups’ degradation rates greater than that of SY3, and other 46 groups’ degradation rates were less than that of SY3.

Enhancement of Aromatic Hydrocarbon Biodegradation by Toluene and Naphthalene Degrading Bacteria Obtained from Lake Sediment: The Effects of Cosubstrates and Cocultures

Toluene and naphthalene degrading (ND) bacteria, obtained from contaminated lake sediment, were used to degrade both monoaromatics and polycyclic aromatic hydrocarbons (PAHs) and the effects of cos...

Effects of co-substrates and inhibitors on the anaerobic O-demethylation of methyl tert-butyl ether (MTBE)

Methyl tert-butyl ether (MTBE) contamination is widespread in aquifers near urban areas around the world. Since this synthetic fuel oxygenate is resistant to most physical methods of treating fuel-contaminated water, biodegradation may be a useful means of remediation. Currently, information on anaerobic MTBE degradation is scarce. Depletion has been observed in soil and sediment microcosms from a variety of locations and under several redox conditions, but the responsible organisms are unknown. We are studying anaerobic consortia, enriched from contaminated sediments for MTBE-utilizing microorganisms for over a decade. MTBE degradation occurred in the presence of other fuel components and was not affected by toluene, benzene, ethanol, methanol, or gasoline. Many aryl O-methyl ethers, such as syringic acid, that are O-demethylated by acetogenic bacteria, were also O-demethylated by the MTBE-utilizing enrichment cultures. The addition of these compounds as co-substrates increased the rate of MTBE degradation, offering a potentially useful method of stimulating the MTBE degradation rate in situ. Propyl iodide caused light-reversible inhibition of MTBE degradation, suggesting that the MTBE degradation process is corrinoid dependent. The anaerobic MTBE degradation process was not directly coupled to methanogenesis or sulfidogenesis and was inhibited by the bactericidal antibiotic, rifampicin. These results suggest that MTBE degradation is mediated by acetogenic bacteria.

Effect of cosubstrates on primary biodegradation of triphenylmethane dyes by <i> Pseudomonas</i> sp.

The effect of substrates (glucose, starch, lactose and sucrose) on primary biodegradation (decolourisation) of recalcitrant triphenylmethane dyes Brilliant green and Crystal violet) by Pseudomonas sp was investigated. Biodegradation was enhanced in cultures with substrate supplementation. Glucose and starch were the best among the substrates tested. The percentage decolourisation increased with increasing concentration up to maximum of 0.2mgL-1 for glucose and 0.3mgL-1 for starch. The percentage with glucose was 93.30 ± 1.40% for Brilliant green and 90.20± 0.75% for Crystal violet. With 0.30 mgL-1 of starch the percentage decolourisation was 85.30± 0.180% for Brilliant green and 88.50± 0.90% for Crystal violet. Enhanced biodegradation was attributed to generation of redox equivalent (electron donors) as a result of metabolism of glucose and starch as cosubstrates. Decrease in percentage decolorisation at concentration above the maximum for glucose and starch was attributed to saturation of the binding; sites for redox equivalents to the chromophoric group (of quinone) of the dyes and/or metabolite repression of the peroxidase enzyme that catalyses the reductive cleavage of the chromophoric group. Cassava peeling (an agricultural waste) gave values of percentage decolourisation of 63± 0.8% for Brilliant green and 67.70± 0.60% for Crystal violet. The potential of agricultural wastes to enhance primary biodegradation of recalcitrant synthetic dyes is also revealed in this work. Keywords: Pseudomonas sp., Triphenylmethane dyes, primary biodegradation, cosubstrates AJAZEB Vol. 7 2005: pp. 38-44

Effect of co-substrate on anaerobic slurry phase bioremediation of TNT-contaminated soil

Molasses and starch were used to estimate the effect of co-substrate on anaerobic slurry phase bioremedia- tion of TNT (2,4,6-trinitrotoluene)-contaminated soil. Degradation efficiency of TNT in molasses and starch addition was approximately 97% and 87%, which is 50-60% higher than 38% without co-substrate addition. Molasses and starch addition enhanced TNT degradation. It was proved that the TNT degradation was a mainly biological process from the result of an abiotic control experiment. In case of molasses addition, overall first order degradation rate was 0.0161/ day indicating the most active TNT degradation. The first order degradation rates (k1=0.0056 for molasses, k1=0.0033/ day for starch) before 60 days were slower than those thereafter (k2=0.0237 for molasses, k2=0.0136/day for starch). Lower degradation rate in early stage might be due to adaptation of native soil microorganisms.

牛ふん尿のメタン発酵における食品廃棄物投入の効果

食品廃棄物が牛ふん尿のメタン発酵に及ぼす影響を三大栄養成分別に調べるために，たんぱく質，炭水化物，脂質をそれぞれ主成分としたプロテイン，パン粉，バターを牛ふん尿とともに有効容積6Lの発酵槽に投入し，水理学的平均滞留日数30日の中温連続メタン発酵実験を行った。発酵性能の低下が発生しない食品廃棄物の限界VS負荷は，パン粉2.2gVS/L・day，バター2.4gVS/L・day，プロテイン0.8gVS/L・dayであった。食品廃棄物の投入VSあたり平均メタンガス発生量はバターが最も大きく0.82L/gVS，次いでパン粉0.42L/gVS，プロテイン0.31L/gVSの順であった。プロテインのメタンガス発生量は理論値の54%と低かった。たんぱく質の共発酵では発酵阻害物質であるアンモニアが発生するためと考えられる。食品廃棄物のメタンガス濃度はバターが最も高く68%，次いでプロテイン64%，パン粉57%であった。

Simultaneous treatment of sewage sludge and food waste by the unified high-rate anaerobic digestion system

This study aimed to evaluate the performance of the unified high-rate anaerobic digestion (UHAD) system treating co-substrate of sewage sludge and food waste. A 24-hr operating sequence consisted of four steps including fill, react, settle, and draw. The effects of co-substrate and organic loading rate (OLR) on the performance were investigated to verify the system applicability. In each OLR, the UHAD system showed higher CH4 recovery (> 70%), CH4 yield (0.3 L CH4/g VSadded) and CH4 production rate (0.6 L CH4/L/d) than the control system. In the specific methanogenic activity (SMA) tests on thermophilic biomass of the UHAD system, the average SMA of acetate (102 mL CH4/gVSS/d) was much higher than those of butyrate (85 mL CH4/g SS/d) and propionate (42 mL CH4/gVSS/d). It was demonstrated that the UHAD system for co-digestion resulted in higher methane yield and methane production rate due to sequencing batch operation, thermophilic digestion, and co-digestion. The enhanced performance could be attributed to longer retention time of active biomass, faster hydrolysis, higher CH4 conversion rate, and balanced nutrient conditions of co-substrate in the UHAD system. Consequently, this optimized unification could be a viable option for the simultaneous treatment of two types of OFMSW with high stability.

Anaerobic thermophilic digestion of cutting oil wastewater: Effect of co-substrate

This paper describes the thermophilic (55 °C) anaerobic biodegradation of a mixed feed composed of vinasses and cutting oil wastewater (COW) in a laboratory upflow anaerobic fixed-film reactor (UAFF) with a porous support medium. The experimental protocol was defined to examine the effect of increasing the percentage of cutting oil wastewater in the feed. The UAFF reactor was initially started-up with vinasses as the only carbon source at an organic loading rate of 22.3 kg COD/m 3 day and HRT of 0.8 days using porous particles as the support (SIRAN). The percentage of organic matter composed of vinasses was subsequently reduced while increasing the amount of cutting oil until 100% of cutting oil wastewater was added in the feed. Four stages were considered in the study (0, 42.4, 66.6 and 100% COW). HRT was adjusted in order to maintain an approximately constant organic loading rate applied to the system. Under theses conditions, the UAFF reactor was subjected to a programme of steady-state operation with hydraulic retention times (HRT) in the range 0.8–0.15 days and organic loading rates (OLR) between 22.3 and 14.9 kg COD/m 3 day in order to evaluate the treatment capacity of the system. The COD removal efficiency was found to be 87% COD and 94.6% TOC in the reactor when treating vinasses at 22.3 kg COD/m 3 day. The volumetric methane level produced in the digester reached 0.45 m 3/m 3 day. After an operating period of 120 days, the reactor was fed with cutting oil wastewater (COW) as the only source of carbon. An OLR of 16.7 kg COD/m 3 day was achieved with 85.8% COD removal efficiency (58.1%TOC) in the experimental UAFF reactor. Under these conditions the volumetric methane produced in the digester was negligible. Hence, COW can be removed, if not degraded, by anaerobic treatment in the presence of a biodegradable co-substrate. Wine vinasses degradation creates conditions for non-biological removal of COW constituents. More studies are necessary in order to test the mechanisms of organic removal when biodegradation apparently had ceased. Also, toxicity assays of COW are necessary to evaluate the toxicity to the methanogenic community.

Effect of co-substrate, biomass and sulfate concentration on the performance of a control strategy used to determine the anaerobic stage length of an anaerobic/aerobic SBR degrading p-nitrophenol

The effect of the p-nitrophenol to propionic acid ratio, the biomass concentration, and the presence of sulfates on the performance of a control strategy of an anaerobic/aerobic SBR degrading p-nitrophenol was studied. The duration of the anaerobic stage was controlled by an algorithm based on the on-line measurement of the oxidation-reduction potential, which indicates the end of the reduction of p-nitrophenol to p-aminophenol. It was observed that no significant influence on the performance of the algorithm was found when the co-substrate, the biomass concentration and the presence of sulfates were varied, indicating the robustness of the control strategy. Only for the case when a low concentration of cosubstrate was used, was there no transformation of p-nitrophenol.