Addition Of Sodium Bicarbonate Research Articles

Turbulent burning velocity of methane–air–dust premixed flames

Investigation of turbulent burning velocity (ST) of methane–air–dust premixed flames with different dust types (coal, sand and sodium bicarbonate) and dust concentrations (λp = 0–75 g/m3) were conducted at three methane–air pre-mixture equivalence ratios (ϕg = 0.8, 1.0 and 1.2) and different turbulent intensities (urms′ = 0.65, 0.72 and 0.88 m/s). Experiments were conducted in a dust Bunsen burner set-up at constant pressure conditions to study stabilized premixed flames. The results indicate that based on the particle type, the variation of turbulent burning velocity with an increase in the particle concentration differs. In general, coal and sodium bicarbonate result in the heterogeneous effect of absorbing heat and releasing volatiles; whereas sand particles just absorb heat from the flame zone. The detailed time scale analysis conducted shows that the presence of particles in the concentration range considered tends to slightly enhance the cold flow turbulence whereas with the presence of flame zone, an increase in the turbulent intensity results in increasing the vaporization rate of the particles. This effects in decreasing the turbulent burning velocity of methane–air mixtures with coal and sodium bicarbonate particles at higher concentrations and turbulent intensities. Out of three dusts examined, sodium bicarbonate addition results in the lowest ST due to the release of CO2 and H2O. Between coal and sand, at fuel lean and stoichiometric conditions, ST values with coal are greater than sand due to the equivalence ratio promotion with the release of CH4. But, as the turbulent intensity increases and for ϕg = 1.0–1.2, ST values with sand becomes comparable to or greater than that of coal. Model coefficients are generated from the experimental data to estimate the turbulent burning velocity in these conditions and the results show a clear distinction in the model coefficients for gaseous and gas–dust mixtures.

A fast, sensitive, and high throughput method for the determination of esomeprazole in dog plasma by UHPLC-MS/MS: Application to formulation development of the compound preparation of esomeprazole.

To investigate deeply into the preclinical pharmacokinetics and prescription design of esomeprazole, a sensitive, high throughput and robust UHPLC-MS/MS method had been developed and fully validated for the analysis of esomeprazole in dog plasma. Esomeprazole and diazepam (IS) were fast extracted from plasma by alkalified organic solvent, and separated on MP-C18 column with methanol and 0.1% formic acid. The quantification of esomeprazole and IS had been achieved using fragmentation transitions of m/z 346.1→198.1 and m/z 285.0→193.2 in MRM detection under positive ESI mode. The concentration of esomeprazole in dog plasma was linear with the range of 3.75-500ng/mL. The precisions of intra- and inter-day were no more than 11.6%, while the accuracies were all within ±9.7% of the nominal values. The recovery was no more than 77.06%, and the matrix effect, stability, dilution integrity tests were all satisfied the currently criterion. Then the method was successfully performed to evaluating pharmacokinetics of esomeprazole and optimizing the prescription of modified esomeprazole with varied addition of sodium bicarbonate. Consequently, a pharmacokinetic study of three doses esomeprazole with the optimized addition of sodium bicarbonate in dogs has been successfully researched for the first time. It could be a promising approach to improve the stabilization of acid-labile esomeprazole and would provide a useful reference for the formulation design of esomeprazole.

Production of HIV virus-like particles by transient transfection of CAP-T cells at bioreactor scale avoiding medium replacement

Human-derived CAP-T cell line has been demonstrated to be a powerful platform for high-titer production of HIV virus-like particles (VLPs) by PEI-mediated transient transfection. Scale-up of transfection processes is key to ensure the necessary quantities for pre-clinical and clinical testing. One of the major operational challenges of large-scale transient transfection is the medium replacement step that is often required before transfection. In this work, CAP-T cells were cultured in 1L bioreactor with addition of sodium bicarbonate and surface aeration, which were observed to improve cell state for transfection. Remarkably, the medium replacement step was avoided by culturing the cells in a combination of media (FreeStyleF17+1% of PEM) compatible with cell growth and PEI-mediated transient transfection. In the conditions developed in this work, 0.5×106cells/mL were seeded in 1L bioreactor. Two days later, ∼2×106cells/mL were transfected without medium exchange, using 0.5pg of DNA/cell and 3pg of PEI/cell. Transfection efficiency and VLP production comparable to shake flasks were obtained with a production of 4×1010VLPs/mL. This novel strategy significantly simplifies large-scale transient transfection, while suitable cell growth, transfection efficiency, and high quality VLP production are achieved.

Biological and physicochemical properties of biosurfactants produced by Lactobacillus jensenii P6A and Lactobacillus gasseri P65

BackgroundLactobacillus species produce biosurfactants that can contribute to the bacteria’s ability to prevent microbial infections associated with urogenital and gastrointestinal tracts and the skin. Here, we described the biological and physicochemical properties of biosurfactants produced by Lactobacillus jensenii P6A and Lactobacillus gasseri P65.ResultsThe biosurfactants produced by L. jensenii P6A and L. gasseri P65 reduced the water surface tension from 72 to 43.2 mN m−1 and 42.5 mN m−1 as their concentration increased up to the critical micelle concentration (CMC) values of 7.1 and 8.58 mg mL−1, respectively. Maximum emulsifying activity was obtained at concentrations of 1 and 5 mg mL−1 for the P6A and P65 strains, respectively. The Fourier transform infrared spectroscopy data revealed that the biomolecules consist of a mixture of carbohydrates, lipids and proteins. The gas chromatography-mass spectrum analysis of L. jensenii P6A biosurfactant showed a major peak for 14-methypentadecanoic acid, which was the main fatty acid present in the biomolecule; conversely, eicosanoic acid dominated the biosurfactant produced by L. gasseri P65. Although both biosurfactants contain different percentages of the sugars galactose, glucose and ribose; rhamnose was only detected in the biomolecule produced by L. jensenii P6A. Emulsifying activities were stable after a 60-min incubation at 100 °C, at pH 2–10, and after the addition of potassium chloride and sodium bicarbonate, but not in the presence of sodium chloride. The biomolecules showed antimicrobial activity against clinical isolates of Escherichia coli and Candida albicans, with MIC values of 16 µg mL−1, and against Staphylococcus saprophyticus, Enterobacter aerogenes and Klebsiella pneumoniae at 128 µg mL−1. The biosurfactants also disrupted preformed biofilms of microorganisms at varying concentrations, being more efficient against E. aerogenes (64%) (P6A biosurfactant), and E. coli (46.4%) and S. saprophyticus (39%) (P65 biosurfactant). Both strains of lactobacilli could also co-aggregate pathogens.ConclusionsThis report presents the first characterization of biosurfactants produced by L. jensenii P6A and L. gasseri P65. The antimicrobial properties and stability of these biomolecules indicate their potential use as alternative antimicrobial agents in the medical field for applications against pathogens that are responsible for infections in the gastrointestinal and urogenital tracts and the skin.

Lipid induction of Chlamydomonas reinhardtii CC-124 using bicarbonate ion

Algal oils, which can be converted into biofuels, are one of the few possible substitutes for fossil fuels that can be used in conventional transportation systems. The algae have the distinctive advantage of having an exceptionally high productivity much higher than that of terrestrial plant-based oil production. However, the commercial viability of algal oils can only be achieved if the algal lipid content and consequently their productivity are still further enhanced. In this study, bicarbonate ions were investigated for their potential as a lipid-inducing chemical because they are one of the first key substrates in triacylglycerol (TAG) biosynthesis in microalgae. To examine this hypothesis, Chlamydomonas reinhardtii CC-124 was chosen as a model microalgae species, and the TAG content in CC-124 was semi-quantitatively detected by the Nile Red staining method. The highest TAG accumulation was observed for 12.5 g L−1 sodium bicarbonate. At this concentration, the light intensity was found to have a more important role than the cultivation temperature. This result suggests that the simple addition of sodium bicarbonate to a harvested and concentrated algae solution could serve as a facile and effective method for boosting the biofuel productivity of algae.

Ruminal acidosis: strategies for its control

Ruminal acidosis in ruminants is a metabolic disorder of gastrointestinal origin, which occurs in animals by high feed intake of cereal grains diets, which affect the performance. According to clinical manifestations it can be classified as: a) acute lactic acidosis in which there is prolonged exposure to ruminal pH≤5.0 that triggers a systemic acidosis, with clinical manifestations and changes in biochemical patterns, starting the first twelve hours of ruminal acidosis and it takes 48 to 120 hours to reestablish, b) subacute ruminal acidosis (SARA), has no clinical manifestations, rumen pH decreases in a range of 5.5 to 5.0 and is held for 111 to 180 minutes in 24 hours, this decrease causes an imbalance in the ruminal metabolism, as well as the fluid balance. Ruminal acidosis can be prevented by the addition of sodium bicarbonate in the ration, the use of zootechnic additives as Saccharomyces cereviseae and Megasphaera elsdenii as well as essential oils (cinnamaldehyde and eugenol). It is also important to consider the forage/concentrate ratio, the forage particle size, the NDF content of the ration, as well as the cereal’s rate of degradation in the rumen. The objective of this review was to address the ruminal acidosis pathophysiology, the effects this cause on animal welfare and control strategies to minimize the detrimental impact on animal production.

Biochemical responses to bicarbonate supplementation on biomass and lipid productivity of Chlorella Sp. BTA9031 isolated from Coalmine area

The present study aims towards the investigation of lipid production capability of microalgae isolated from coal mining site. The biomass production and lipid productivity of the isolate was studied under the influence of different bicarbonate, nitrate, and phosphate concentration. The production of biomass was observed to be highest at 8.4, 0.75, and 0.06 gL−1 of bicarbonate, nitrate, and phosphate concentrations. The role of bicarbonate supplementation under different nutritional starvation conditions viz. N+ P+, N– P–, N+ P–, and N– P+ with and without sodium bicarbonate respectively was also evaluated. Addition of sodium bicarbonate increased the lipid content to 35% of dry cell weight (DCW) and carbohydrate content to 52% of DCW under the nitrate and phosphate nutritional starvation conditions. The results revealed that the microalgae grown in sodium bicarbonate can be a promising feedstock for biodiesel production. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1498–1506, 2017

Study of Pitting Resistance of Rebar Steels in Jakarta Coastal Using Simulated Concrete Pore Solution

Carbon steels are generally used to a reinforcement in the concrete constructions, such as bridges, piling, etc. These constructions are not a bit placed in the coastal areas, especially the coastal area of Jakarta. The industrial activities and urban development were a source of sediment loads and pollutants in coastal sea water Jakarta. The presence of chloride content and pollutants in sea water could affect the process of corrosion of reinforcement steel in concrete especially pitting corrosion. In this paper, the behavior of pitting corrosion of reinforcement steel in sea water of Jakarta coastal using simulated concrete pore solution has been studied. The sea waters were taken from two different locations of Jakarta coastal, Ancol beach and Muara Baru fishing port. Each of the sea water was used as a solvent in the simulated concrete pore solution with or without carbonates. The simulated concrete pore solution with chloride was also utilized for comparison test. The cyclic and potentiostatic electrochemical polarization were conducted to evaluate the behavior of pitting corrosion of reinforcing steel. The experimental results showed that the reinforcing steel was susceptible to pitting corrosion in the simulated concrete pore solutions (SPS) of sea water with or without carbonates and in the simulated concrete pore solutions containing 3.5% NaCl. The addition of sodium carbonate and sodium bicarbonate in SPS of sea water increased the breakdown potential value and the total time for the metastable pitting decreased slightly.

Effects of water-misting spray combined with forced ventilation on heat induced meat gelation in broiler after summer transport

This study aims to explore the use of non-chemical addition in improving the functions of meat proteins in broilers transported during summer. The effects of a water-misting spray with forced ventilation on heat induced ground meat gelation in broilers were investigated through rheology, texture, and nuclear magnetic resonance analyses. The facilities of water-misting sprays with forced ventilation characterized with an extremely thin droplet (diameter: approximately 0.05 mm) and supplying updraughting air ventilation in an enclosed space were examined. For comparison, typical processing treatments using sodium bicarbonate or sodium tripolyphosphate were performed to grind the broiler meat which had not undergone water-misting and forced ventilation. Results showed that transport for 45-min followed by application of water-misting spray with forced ventilation for 15-min and resting for 45-min (TWFR) increased water holding capacity (WHC) by 2.51%; this finding was not significantly different from the effect of transport for 45 min followed by 1 h rest and sodium tripolyphosphate treatment (TRT) on meat batter (P > 0.05). TWFR treatment exhibited the highest storage modulus increase among four samples well as significant higher hardness and chewiness values on than those of sample treated with 45-min transport and 1-h rest (TR) (P < 0.05). TWFR, 45 min of transport, 1 h rest, and addition of sodium bicarbonate (TRB) and TRT induced T22 (relaxation time of water trapped within myofibrils) shift to shorter relaxation time and narrower relaxation distribution compared with TR. Overall, TWFR treatment can be a potential non-chemical addition method for improving the heat induced gelation protein function after broiler undergoing summer transport.

CO2 capture using limestone for cultivation of the freshwater microalga Chlorella sorokiniana PAZ and the cyanobacterium Arthrospira sp. VSJ

The present study reports a process wherein CO2 is captured in the form of bicarbonates using calcium oxide and photosynthetically fixed into biomass. Microalgal cultures viz. Chlorella sorokiniana PAZ and Arthrospira sp. VSJ were grown in the medium containing bicarbonates. The rate of bicarbonate utilization by C. sorokiniana PAZ was higher when CO2 trapped in the presence of 2.67mM calcium oxide than in the presence of 10mM sodium hydroxide and with direct addition of 10mM sodium bicarbonate. For Arthrospira sp. VSJ the bicarbonate utilization was 92.37%, 88.34% and 59.23% for the medium containing CaO, NaOH and NaHCO3, respectively. Illumination of photosynthetically active radiation (PAR)+ultraviolet A radiation (UVA) enhanced the yield of C. sorokiniana PAZ and Arthrospira sp. VSJ by 1.3 and 1.8 folds, respectively. FTIR analysis revealed elevation in the biosynthesis of specific metabolites in response to the UVA exposure.

Sodium Bicarbonate as Inorganic Carbon Source for Higher Biomass and Lipid Production Integrated Carbon Capture in Chlorella vulgaris

Chlorella vulgaris was isolated from sewerage treatment plant and grown in the presence of sodium bicarbonate as carbon source at 0.25, 0.5 and 1.0gL−1. Highest specific growth rate (0.653μd−1) was obtained with 1gL−1 bicarbonate followed by 0.5gL−1 (0.641d−1) on 15th day culturing. Total chlorophyll content of microalgae has increased in a dose dependent fashion with bicarbonate addition and maximum level recorded in 1gL−1 (0.769±0.09gL−1). The biomass productivity was in the range of 0.237–0.996gd−1L−1. Rate of CO2 fixation and carbon content, in terms of quantity was estimated. Results showed that at 1gL−1 sodium bicarbonate concentration, maximum CO2 fixation (0.497g/dry weight) and carbon content (0.69gmL−1day−1) was found. Biomass concentration was significantly higher (p<0.05) in cultures (1.54gL−1) supplemented with 1gL−1 bicarbonate whereas there was no much difference in cellular lipid concentration (16mgmL−1). GC–MS analysis of fatty acids showed highest amounts of palmitic acid, myristic and stearic acid. In summary, the addition of sodium bicarbonate increases cellular abundance, chlorophyll content and to some extent in the case of lipid content in C. vulgaris integrated with CO2 sequestration.

MODELING OF BATCH AND CONTINUOUS ANAEROBIC DIGESTION OF PALM OIL MILL EFFLUENT: THE EFFECT OF WASTEWATER-SLUDGE RATIO

In this work, both models for batch and continuous anaerobic digestion of palm oil mill effluent were developed based on Monod’s kinetics. Then the authors attempt to understand the effect of wastewater-sludge (WW:S) ratio on the biogas production efficiency in batch digesters. The experiments were carried out at a controlled temperature of 35±0.5 °C. Two series of the experiment were conducted. In the first series, the wastewater-sludge ratios covered 1:1 (add sodium bi-carbonate), 1:1, 1:2 and 2:1. It was found that the ratio of 1:2 gave the highest biogas producing efficiency followed by the ratio 1:1 (add sodium bi-carbonate). At 1:1 ratio, sodium bi-carbonate addition was required to start anaerobic digestion at a workable pH range whereas at 1:2 ratio the initial pH is in the workable range without the need of its addition. However, at the ratio of 2:1 the starting pH was too low to adjust pH economically by adding sodium bi-carbonate. The second series was to confine experiments to a narrower ratio range, namely: 1:1 (add sodium bi-carbonate), 1:1.5, 1:2, 1:2.5. In both sets of experiment, the ratio 1:2 gave the best biogas production potential of 76.62 and 78.52 ml of biogas/g COD removed respectively. In all treatments, the process was able to remove more than 80% of wastewater initial COD. The modified Gompertz equation was used to estimate the maximum specific biogas production rate (MBPR or Rm/S0). It was also found that the ratio of 1:2 gave the best MBPR in both experimental series (26.87 ml biogas/g COD-day). A modified Monod-type Model was also developed to describe the microbial growth, substrate consumption and biogas production in continuous operation. In general, sludge recycle provided active biomass which can use the substrate in the wastewater instantly without significant lag phase or delay. Furthermore, continuous-flow model developed, with parameters estimated from batch experiments, predicted the experimental kinetics of the actual continuous experiments satisfactory.

Effects of the Addition of Glucose, Sodium Bicarbonate, and Vitamin E to the Drinking Water of Pre-Slaughter Broiler Chickens on Carcass Yield, Gastric Emptying and Meat Quality

An experiment was conducted of the poultry facilities of La Salle Agricultural College in Xanxere, SC, Brazil, to evaluate the effect of the administration of sodium bicarbonate, glucose and vitamin E to the drinking water during pre-slaughter feed withdrawal on carcass yield, organ relative weights (heart, liver, proventriculus, and gizzard), gizzard emptying, and meat quality of broiler chickens. The applied treatments were: water as control; 50g/L of glucose; 50g/L de glucose + 200mg/L of vitamin E; 75g/L of glucose; 75g/L + 200mg/L of vitamin E; 0.45% of sodium bicarbonate; 0.45% of sodium bicarbonate + 200mg/L of vitamin E; 0.55% of sodium bicarbonate; 0.55% of sodium bicarbonate + 200mg/L of vitamin E; 200mg/L de vitamin E. On the last day before slaughter, during the water diet period,500 birds were distributed in a completely randomized experimental design with ten treatments and ten replicates of five birds each. No difference in broiler carcass yield and organ relative weights was found. There were no significant changes in gizzard contents, in ultimate meat, cooking loss, shear force value, or in the meat color parameters L* (lightness), a* (redness) and b* (yellowness). It was concluded is that the addition of glucose, sodium bicarbonate, and vitamin E to the drinking water during pre-slaughter feed withdrawal period has no influence on carcass yield or on relative organ weight, neither on the emptying of the gizzard contents and the meat quality of broiler chickens.

Encapsulation of SALEN- and SALHD-Mn(III) complexes in an Al-pillared clay for bicarbonate-assisted catalytic epoxidation of cyclohexene

[Mn(3,5-dtSALEN)Cl] (I) and [Mn(3,5-dtSALHD)Cl] (II) complexes (3,5-dtSALEN=N,N′-bis(3,5-di-tert-butylsalicylaldehyde)ethylenediamine; 3,5-dtSALHD=N′N-bis-(3,5-di-tert-butylsalicylaldehyde)-1,2-cyclohexanediamine) were successfully encapsulated within a natural bentonite by using three preparative approaches: (A) direct adsorption of every metal complex on the previously Al-pillared bentonite, Al-PILC; (B) two-step liquid phase methodology: (i) cationic adsorption of Mn2+ in Al-PILC by substituting its residual cationic exchange capacity (CEC), followed by (ii) diffusion of either 3,5-dtSALEN or 3,5-dtSALHD ligands, for in-situ generation of the corresponding interlayered metal complexes; and (C) simultaneous pillaring/encapsulation of the complexes on the raw starting clay. The materials were characterized by cationic exchange capacity, X-ray diffraction, atomic absorption, FT-Infrared and UV–vis spectroscopies, and N2 adsorption at 77K. The physical encapsulation of the complexes into final materials was proven by spectroscopic analyses. Method C yielded both highest metal incorporation and enhanced basal space on the modified clay. All materials showed to be active catalysts in cyclohexene epoxidation with hydrogen peroxide using acetonitrile as solvent (0.79atm, 293K). Addition of sodium bicarbonate as co-catalyst led to enhanced conversion (100%) and selectivity (70%) towards the epoxide in the presence of such a kind of heterogeneized metal-complex catalysts. The catalysts were stable and reusable along at least two catalytic cycles.

Effect of increase in ph of local anaesthetics on quality of epidural anesthesia

Background: The most persistent criticisms for epidural analgesia for surgery are the latency of onset and marginal intensity of sensory and motor block, so clinical trials were carried out to find out a method to decrease the latency of onset of epidural block. The present study was carried out to determine the effect of increasing pH of 2% lignocaine hydrochloride with adrenaline (1:200000) and 0.5% bupivacaine hydrochloride by addition of sodium bicarbonate administered for epidural anesthesia in inguinal herniorrhaphy. Methods: Eighty male patients aged 18–60 years physical status American Society of Anesthesiology I and II posted for inguinal herniorrhaphy, were enrolled in this study. After placing epidural catheter in epidural space at L3–L4, test dose of 2% lignocaine with adrenaline 3ml was given. After making patient supine, epidural dose is given with local anesthetic according to the group. Group I - 15 ml of 2% lignocaine hydrochloride with adrenaline (1:200000) +0.5 ml normal saline (pH 3.58), Group II - 15 ml of 2% lignocaine hydrochloride with adrenaline (1:200000) +0.5 ml of 7.5% (w/v) sodium bicarbonate (pH 6.78), Group III - 15 ml of 0.5% bupivacaine hydrochloride (pH 5.5) and Group IV - 15 ml of 0.5% bupivacaine hydrochloride + 0.1 ml of 7.5% (w/v) sodium bicarbonate (pH 7.5). In Groups II and IV, pH of solution was increased by addition of sodium bicarbonate. All patients were monitored for the onset of sensory and motor block, intensity of sensory and motor block, highest level of analgesia, duration of sensory and motor blockade, and effects on cardiovascular and respiratory parameters. Results: Onset of sensory and motor block was significantly faster in study Groups (II and IV) as compared to control Groups (I and III). Intensity of block even duration of block was significantly better in pH adjusted group. Conclusion: Increase in pH of local anesthetic solutions used in epidural blockade improves the quality of epidural block.

The Effect of Different Intervention Strategies to Alleviate Heat Stress on Behavior, Performance and Some Blood Parameters of Growing Muscovy Ducks

An experiment was conducted to investigate the effect of heat stress on growing Muscovy ducks during summer season and some strategies to alleviate adverse effect of heat stress as nutrition strategies addition of ascorbic acid (AA) and sodium bicarbonate (NaHCO3) to feed and swimming access. Forty eight (seven week old) Muscovy ducks randomly allotted to 4 groups (heat stressed group (HS) without any supplementation, ascorbic acid (AA), sodium bicarbonate (NaHCO3) group and swimming access (SWIM)). The results indicated that the swimming access significantly improved Muscovy duck welfare by improving body care behavior (preening, head shake, body shake and ruffling) and significantly increased the standing behavior and reduced crouching percent with significant reduction in blood corticosterone level and( heterophils / lymphocyte) H/L ratio. However, swimming access had significant reduction in relative weight gain than control group.

Closure to “Effect of Fertigation on Soil Salinization and Aggregate Stability” by J. M. Moreira Barradas, A. Abdelfattah, S. Matula, and F. Dolezal

The authors would like to thank the discussers for their interest and appreciation of this research. • The discussers extracted information from the graphs of ethanol extract (EC) evolution at all depths into Table 1, which seems correctly done. The information discussed was correctly interpreted as being related only to the first 10-cm layer (where salinization and consequent recovering seem to have been more significant). • The authors have chosen the nutritive solution commonly used for tomato, which is the Hoagland solution by default for a reason, which is that the Hoagland solution is commonly used in a number of different crops with good results in all of them. Nevertheless, the point of this study is not to analyze these minor differences on the crop performance using different nutritive balances according to the fertigation efficiency index (FEI) (Moreira Barradas et al. 2012) but rather the effect of the solution on the soil. • The discussers are incorrect when stating that “more fertilizer resulted in higher dry matter production” because the differential of EC between solutions A and B was obtained by addition of sodium bicarbonate (in order to simulate the use of groundwater with high contents of bicarbonate and sodium ions in irrigation and its further consequences on the soil structure) and not by addition of more fertilizer or nutritive ions. • The salinity evolution based on the soil EC measurements by the ECH2O system generally decreased, however with peaks of increment due to soil moisturizing during rainfall periods and respective conversion between bulk ECmS=cm and ECw mS=cm. The authors agree more analysis and further research on this topic is convenient.

Effects of alkalinity on membrane bioreactors for reject water treatment: Performance improvement, fouling mitigation and microbial structures

Two submerged membrane bioreactors (MBRs) for reject water treatment were operated to investigate effects of sodium bicarbonate (SB) addition on enhancing process performance and mitigating membrane fouling. Results showed that SB addition enhanced average removal efficiencies of COD and NH4-N by 14.6% and 38.3%, respectively. With SB addition, the extracellular polymeric substances (EPS) content in activated sludge increased, but those in membrane foulants greatly decreased. Gel permeation chromatography analysis demonstrated that EPS in MBRs for reject water treatment had much larger molecular weight (MW) and broader MW distribution than those in MBRs for municipal wastewater treatment. The fouling mitigation by SB was attributed to a deprotonation mechanism reduced EPS adsorption on negatively charged membrane surfaces, and improvement of degradation efficiency of macromolecular organic matters. SB addition into MBRs for reject water treatment increased microbial abundance, enriched nitrifying bacteria, and converted predominant AOB genus from Nitrosomonas to Nitrosospira.

Bicarbonate supplementation enhanced biofuel production potential as well as nutritional stress mitigation in the microalgae Scenedesmus sp. CCNM 1077

The aim of the present study was to find out the optimum sodium bicarbonate concentration to produce higher biomass with higher lipid and carbohydrate contents in microalgae Scenedesmus sp. CCNM 1077. The role of bicarbonate supplementation under different nutritional starvation conditions was also evaluated. The results clearly indicate that 0.6g/L sodium bicarbonate was optimum concentration resulting in 20.91% total lipid and 25.56% carbohydrate along with 23% increase in biomass production compared to normal growth condition. Addition of sodium bicarbonate increased the activity of nutrient assimilatory enzymes, biomass, lipid and carbohydrate contents under different nutritional starvation conditions. Nitrogen starvation with bicarbonate supplementation resulted in 54.03% carbohydrate and 34.44% total lipid content in microalgae Scenedesmus sp. CCNM 1077. These findings show application of bicarbonate grown microalgae Scenedesmus sp. CCNM 1077 as a promising feedstock for biodiesel and bioethanol production.

Effects of formulation and extrusion cooking conditions on furfural and hydroxymethylfurfural content

The objective of this research was to investigate the effects of different ingredients (reducing sugars, leavening agents, citric acid), processing conditions (feed moisture content, exit die temperature), and extrusion cooking methods (with/without CO2 injection) on furfural and 5-hydroxymethylfurfural (HMF) formation in corn-based extrudates. The decrease in furfural levels was 16% upon addition of sodium-bicarbonate, while the increase was 12% upon addition of ammonium-bicarbonate for extrudates produced at 150 °C and feed moisture content of 22%. The furfural concentration of extrudates produced at 150 °C and feed moisture content of 22% without leavening agents was 810 μg/100 g and increased to 11,901 μg/100 g upon citric acid addition (about a 15-fold increase). Furthermore, both low feed moisture and high exit die temperature had promoting effects on furfural and HMF contents. The CO2 injection method did not have considerable effect on furfural and HMF levels of the extrudates; however, it positively affected the physical properties of extrudates.