Type Of Co-substrate Research Articles

Anaerobic Treatment of N-(Phosphonometyl) Glycine Using Mixed Culture in Batch Reactor

Pesticides have been used in the fight against various pests to increase crop growth in our country and the world. In recent years, high concentrations of toxic and detection of carcinogenic pesticides indicates that these substances are transported to groundwater and pollute water resources. N- (phosphonomethyl) glycine are also used in large quantities. In this study, the optimization of anaerobic treatment of N- (phosphonomethyl) glycine was investigated by applying a statistical-based experimental design. Full factorial trials different initial pesticide concentrations and cosubstrate type were established, making up 9 different experimental setups. Trials were performed in 2 replicates. The experiments were carried out in Oxitop C bottles with stirring at a working volume of 200 mL. The pH was adjusted to 7 ± 0.2. Trials were performed at 35oC for 30 days. At the end of the process, the removal of the trials according to the input and output COD and pesticide values were examined. As a result, the most efficient COD removal was achieved 98,96 % when pesticide concentration of 5 mg L-1 and glucose as cosubstrate were used. The highest pesticide removal was found to be 74,83% when pesticide concentration of 25 mg L-1 and glucose was used as cosubstrate.

Influences of cathode potential and carbon source on parabromoaniline degradation in microbial electrolysis cell

AbstractA microbial electrolysis cell was established to explore the degradation characteristics of characteristic pollutants in wastewater for parabromoaniline (P‐BrA). Their effects on P‐BrA reduction and degradation were investigated through factors such as impressed voltage and cosubstrate type. The P‐BrA residue and degradation in wastewater were analysed quantitatively through analytical testing methods, such as ultraviolet–visible, cyclic voltammetry, high‐performance liquid chromatograph, and scanning electron microscopy. The results showed that under the cathode potential of 0.5 V, electrons and electroactive microorganisms generate coupling action to accelerate the degradation of P‐BrA, reaching 94.94%. Moreover, the addition of carbon source organisms, such as glucose and sodium acetate, can facilitate the degradation of P‐BrA in the cathode chamber on the precondition that the electroactive anaerobic microbial C/N ratio was satisfied, both reaching over 90%. In addition, the microbial community diversity and richness of bioelectrochemistry system were enhanced after bioaugmentation. The increase in the Anacrolincalcs, Betaproteobacteriales, and Micrococcales also played an important role in the granulation of bioelectrochemistry system and the removal of characteristic pollutants.

Life Cycle Assessment and Techno-Economic Assessment of Anaerobic Co-Digestion: A Short Review

Waste-to-energy conversion such as anaerobic digestion has been widely promoted under the subsidies to decouple from fossil fuel dependence system and its inherent two-fold benefits. It could diversify the renewable energy matrix and divert the waste from the landfill. Co-digestion of two and more feedstocks could enhance bioenergy production and maximise waste recovery. However, the anticipated benefits are not absolute for all circumstances, varying across the type of co-substrate, pretreatment and other settings. The present study aims to overview the life cycle assessment (LCA) and the techno-economic assessment (TEA) of the anaerobic co-digestion processes. The results could provide an insight into the several critical parameters for sustainable co-digestion. Co-digestion of two or more feedstock is favourable since higher anaerobic digestion performances and higher profitability in TEA is shown. Cultivation of energy crops, transportation, pretreatment of feedstock and storage stage each contributes some shares to eutrophication potential (EP), acidification potential (AP), global warming potential (GWP), ozone depletion and fossil depletion. Generally, high anaerobic digestion performances and biogas upgrading can offset the negative environmental impact. Positive net present value is also observed from the co-digestion of feedstock.

Investigation of Factors Affecting Biogas Production from Cassava Peels by Fractional Factorial Design Experimental Methodology

The aim of this study was to investigate parameters affecting biogas production from cassava peels by using fractional factorial design method. The parameters studied were initial pH, organic loading rate, particle size and co-substrate type. Eight biodigesters (TH1, TH2, TH3, TH4, TH5, TH6, TH7 and TH8) in duplicate were performed to produce biogas from cassava peels. The experimental results showed that organic loading rate (X2), particle size (X3) and co-substrate (X4) have significant effect on the yield of biogas. The full mathematical model developed includes two main effects (X2 and X3) and three interactions (X1X2, X2X3 and X1X2X3). Reduced model was introduced in the present study. The highest volume of biogas (2252 mL) was obtained in digester TH2 under the following conditions: initial pH 7.8, 5% TS, ≤2 mm of particle and urea as co-substrate, while digester TH8 had slightly low biogas yield (2129.5 mL). Thus, the best conditions to produce biogas from cassava peels are those of TH2.

Effect of cellulose as co-substrate on old landfill leachate treatment using white-rot fungi

Conventional wastewater treatment technologies are ineffective for remediation of old LandFill Leachate (LFL), and innovative approaches to achieve satisfactory removal of this recalcitrant fraction are needed. This study focused on old LFL treatment with a selected fungal strain, Bjerkandera adusta MUT 2295, through batch and continuous tests, using packed-bed bioreactors under non-sterile conditions. To optimize the process performance, diverse types of co-substrates were used, including milled cellulose from beverage cups waste material. Extracellular enzyme production was assayed, in batch tests, as a function of a) cellulose concentration, b) leachate initial Chemical Oxygen Demand (COD) and Soluble COD (sCOD), and c) co-substrate type. Bioreactors were dosed with an initial start-up of glucose (Rg) or cellulose (Rc). An additional glucose dosage was provided in both reactors, leading to significant performance increases. The highest COD and sCOD removals were i) 63% and 53% in Rg and ii) 54% and 51% in Rc.

Pengaruh Konsentrasi Xilosa dan Kosubstrat Terhadap Produksi Xilitol oleh Candida shehatae Way 08

The objectives of the research were to determine the optimum cultivation condition of initial xylose concentration, type of cosubstrate and ratio of cosubstrate to substrate (xylose) for xylitol production by Candida shehatae WAY 08. The initial xylose concentrations were varied within the range of 2-14 %. The cosubstrates were arabinose, galactose, glucose, and mannose. Ratios of cosubstrate to xylose were the range of 1:6 - 3:6 %. The fermentation was performed at 30`C in a 500 ml Erlenmeyer flask placed in a shaker incubator at 200 rpm for 72 h. Biomass concentration was determined by drying method. Xylose, cosubstrate and xylitol concentrations were determined using HPLC. The result indicated that with the medium containing 6 % xylose produced the highest product yield ( 0,75 g/g) and xylitol volumetric productivity was 0,73 g/Lh. The addition of cosubstrate of arabinose increased xylitol production, while the addition of glucose, galactose, and mannose decreased its productions.

Bioelectro-Claus processes using MFC technology: Influence of co-substrate

This work is focused on the removal of sulphide from wastewater using a two chamber microbial fuel cell, seeded with activated sludge and operated in semi-continuous mode. Two co-substrates were used in order to provide the system for carbon and nutrient source: actual urban wastewater and synthetic wastewater. Results show that sulphide is efficiency depleted (removals over 94%) and that electricity is efficiently produced (maximum power density is 150mWm−2) meanwhile COD is also oxidised (removals higher than 60%). Sulphur and sulphate are obtained as the final products of the oxidation and final speciation depends on the type of co-substrate used. The start-up of the system is very rapid and production of electricity and polarisation curves do not depend on the co-substrate.

Optimization of biogas production from Sargassum sp. using a design of experiments to assess the co-digestion with glycerol and waste frying oil

A design of experiments was adopted to assess the optimal conditions for methane production from the macroalgae Sargassum sp. co-digested with glycerol (Gly) and waste frying oil (WFO). Three variables were tested: % total solids of algae (%TSSargassumsp.), co-substrate concentration (gGly/WFOL−1), and co-substrate type (Gly or WFO). The biochemical methane potential (BMP) of Sargassum sp. was 181±1L CH4kg−1 COD. The co-digestion with Gly and WFO increased the BMP by 56% and 46%, respectively. The methane production rate (k), showed similar behaviour as the BMP, increasing 38% and 19% with Gly and WFO, respectively. The higher BMP (283±18L CH4kg−1 COD) and k (65.9±2.1L CH4kg−1 CODd−1) was obtained in the assay with 0.5% TS and 3.0gGlyL−1. Co-digestion with glycerol or WFO is a promising process to enhance the BMP from the macroalgae Sargassum sp.

Assessing anaerobic co-digestion of pig manure with agroindustrial wastes: The link between environmental impacts and operational parameters

Anaerobic co-digestion (AcoD) is established as a techno-economic profitable process by incrementing biogas yield (increased cost-efficiency) and improving the nutrient balance (better quality digestate) in comparison to mono-digestion of livestock wastes. However, few data are available on the environmental consequences of AcoD and most of them are mainly related to the use of energy crops as co-substrates. This work analysed the environmental impact of the AcoD of pig manure (PM) with several agroindustrial wastes (molasses, fish, biodiesel and vinasses residues) using life cycle assessment (LCA) methodology. For comparative purposes, mono digestion of PM has also been evaluated.Four out of six selected categories (acidification, eutrophication, global warming and photochemical oxidation potentials) showed environmental impacts in all the scenarios assessed, whereas the other two (abiotic depletion and ozone layer depletion potentials) showed environmental credits, remarking the benefit of replacing fossil fuels by biogas. This was also confirmed by the sensitivity analysis applied to the PM quality (i.e. organic matter content) and the avoided energy source demonstrating the importance of the energy recovery step. The influence of the type of co-substrate could not be discerned; however, a link between the environmental performance and the hydraulic retention time, the organic loading rate and the nutrient content in the digestate could be established. Therefore, LCA results were successfully correlated to process variables involved in AcoD, going a step further in the combination of techno-economic and environmental feasibilities.

A review of dark fermentative hydrogen production from biodegradable municipal waste fractions

Hydrogen is believed to play a potentially key role in the implementation of sustainable energy production, particularly when it is produced from renewable sources and low energy-demanding processes. In the present paper an attempt was made at critically reviewing more than 80 recent publications, in order to harmonize and compare the available results from different studies on hydrogen production from FW and OFMSW through dark fermentation, and derive reliable information about process yield and stability in view of building related predictive models. The review was focused on the effect of factors, recognized as potentially affecting process evolution (including type of substrate and co-substrate and relative ratio, type of inoculum, food/microorganisms [F/M] ratio, applied pre-treatment, reactor configuration, temperature and pH), on the fermentation yield and kinetics. Statistical analysis of literature data from batch experiments was also conducted, showing that the variables affecting the H2 production yield were ranked in the order: type of co-substrate, type of pre-treatment, operating pH, control of initial pH and fermentation temperature. However, due to the dispersion of data observed in some instances, the ambiguity about the presence of additional hidden variables cannot be resolved. The results from the analysis thus suggest that, for reliable predictive models of fermentative hydrogen production to be derived, a high level of consistency between data is strictly required, claiming for more systematic and comprehensive studies on the subject.

Initiating Biodegradation of Polyvinylpyrrolidone in an Aqueous Aerobic Environment: Technical Note / Zainicjowanie Biodegradacji Poliwinylopirolidonu W Środowisku Wodno-Tlenowym: Notatki Techniczne

Abstract A synthetic polymer, polyvinylpyrrolidone (PVP - E 1201) primarily finds applications in the pharmaceutical and food industries due to its resistance and zero toxicity to organisms. After ingestion, the substance passes through the organism unchanged. Consequently, it enters the systems of municipal wastewater treatment plants (WWTP) without decomposing biologically during the waste treatment process, nor does it attach (through sorption) to particles of activated sludge to any significant extent, therefore, it passes through the system of a WWTP, which may cause the substance to accumulate in the natural environment. For this reason the paper investigates the potential to initiate aerobic biodegradation of PVP in the presence of activated sludge from a municipal wastewater treatment plant. The following agents were selected as the initiators of the biodegradation process - co-substrates: acrylamide, N-acethylphenylalanine and 1-methyl-2-pyrrolidone, a substance with a similar structure to PVP monomer. The biodegradability of PVP in the presence of co-substrates was evaluated on the basis of biological oxygen demand (BOD) as determined via a MicroOxymax O2/CO2/CH4 respirometer. The total substrate concentration in the suspension equaled 400 mg·dm-3, with the ratio between PVP and the cosubstrate being 1:1, while the concentration of the dry activated sludge was 500 mg·dm-3. Even though there was no occurrence of a significant increase in the biodegradation of PVP alone in the presence of a co-substrate, acrylamide appeared to be the most effective type of co-substrate. Nevertheless, a recorded decrease in the slope of biodegradation curves over time may indicate that a process of primary decomposition was underway, which involves the production of metabolites that inhibit activated sludge microorganisms. The resulting products are not identified at this stage of experimentation.

Biodegradation performance of anaerobic sequencing batch biofilm reactor for oil with polychlorinated biphenyls

Aims: The biodegradability of oil containing polychlorinated biphenyls (PCBs) from electrical transformer by the anaerobic sequencing biofilm batch reactor (ASBBR) with was assessed.Materials and Methods: Two anaerobic sequencing batch biofilm reactor (ASBBR) containing polyurethane foam cubes as inert support was used. The reactors were operated for 310 days at 35 ± 2°C. The reactors with a total volume of 7 L, 5 L effective volume and 3.5 L for gas production, were operated in a cycle per day. The effect of operational parameters including organic loading rate, PCBs loading rate, co-substrate type, initial PCBs and COD concentration was evaluated.Results: The results point to admirable reactors stability and over 95% efficiency in PCBs removal, with effluent PCBs concentration of lower than 10 mg/L. However, degradation rates increased as the initial concentration of PCBs as increased. The average of COD removal efficiency by two ASBBR reactors was more than 92% that corresponding to > 9 μg/L of effluent COD. In over all operation, average of biogas production in R1 was 5.7 ± 2.2 L/d and maximum produced biogas was 8.02 L/d at 310 day. The kinetic studies revealed that second - order kinetic model described the COD removal by ASBBR reactors from synthetic wastewater better than two other kinetic model.Conclusion: Therefore, this investigation demonstrated that the ASBBR have good potential for biodegradation of oil containing PCBs, despite variation of influent PCBs and organic loading rate (OLR).

Microbial production of biovanillin

This review aims at providing an overview on the microbial production of vanillin, a new alternative method for the production of this important flavor of the food industry, which has the potential to become economically competitive in the next future. After a brief description of the applications of vanillin in different industrial sectors and of its physicochemical properties, we described the traditional ways of providing vanillin, specifically extraction and chemical synthesis (mainly oxidation) and compared them with the new biotechnological options, i.e., biotransformations of caffeic acid, veratraldehyde and mainly ferulic acid. In the second part of the review, emphasis has been addressed to the factors most influencing the bioproduction of vanillin, specifically the age of inoculum, pH, temperature, type of co-substrate, as well as the inhibitory effects exerted either by excess substrate or product. The final part of the work summarized the downstream processes and the related unit operations involved in the recovery of vanillin from the bioconversion medium.

Biosynthesis of multicomponent polyhydroxyalkanoates by Wautersia eutropha

The effect of carbon supply on polyhydroxyalkanoate (PHA) synthesis by bacteria Wautersia eutropha was studied. Synthesis of multicomponent PHA composed of short- and long-chain monomers (C4-C8) by two natural strains (H16 and B5786) under mixotrophic conditions (CO2 + alkane acids as cosubstrates) was demonstrated for the first time. The PHA composition was shown to be dependent on the cosubstrate type. In the presence of odd fatty acids, four- and five-component polymers were synthesized; hydroxybutyrate, hydroxyvalerate, and hydroxyheptanoate were the major monomers, while hydroxyhexanoate and hydroxyoctanoate were minor and irregular. In the presence of even fatty acids, PHA contained not only the corresponding molecules (hydroxyhexanoate and hydroxyoctanoate), but also hydroxyvalerate; synthesis of four-component PHA which contain mainly hydroxybutyrate and hydroxyhexanoate (up to 18 mol %) is therefore possible. A series of four- and five-component PHA was synthesized and their physicochemical characteristics were determined.

Asymmetric Reduction of o‐Chloroacetophenone with Candida pseudotropicalis104

The asymmetric reduction of o-chloroacetophenone 1 with Candida pseudotropicalis 104 produced the corresponding (S)-1-(2-chloro-phenyl)-ethanol 2 with the enantiomeric excess (ee >99%) without addition of any cosolvent. The cell could tolerate high ketone 1 concentration of 233.8 mmol/L (i.e., 36 g/L) with considerable reduction activity in this method. The product 2 concentration achieved 38.9 and 58.4 mmol/L with cells of 40 and 60 g(DCW) (dry cell weight)/L, respectively, in 24 h. The optimum reaction time, the effect of substrate concentration, cosubstrate type and concentration, and cell concentration in the reaction were investigated in this paper.

Effects of culture conditions on enhancement of 2,4-dinitrotoluene degradation by Burkholderia engineered with the Vitreoscilla hemoglobin gene.

Growth and degradation of 2,4-dinitrotoluene (2,4-DNT) were compared in liquid cultures in shake flasks for Burkholderia sp. strain DNT and strain DNT engineered to produce Vitreoscilla (bacterial) hemoglobin (strain YV1). Parameters varied included aeration rate, initial 2,4-DNT concentration (50 and 200 ppm), and concentration and type of cosubstrate (yeast extract, succinate, casamino acids, and tryptic soy broth). 2,4-DNT degradation increased with increasing cosubstrate concentration and was greater for strain YV1 than strain DNT under most conditions tested; the greatest advantages of YV1 (up to 3.5-fold) occurred under limited aeration. A third strain (YV1m), derived from YV1 by repeated growth on 2,4-DNT-containing medium, demonstrated increased 2,4-DNT degradation (up to 1.3-fold compared to YV1) at 200 ppm 2,4-DNT. The growth profiles of the three strains with respect to each other were in general similar to those of the degradation patterns of 2,4-DNT.