scholarly journals The-Proof-of-Concept of Biochar Floating Cover Influence on Water pH

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1802 ◽  
Author(s):  
Zhanibek Meiirkhanuly ◽  
Jacek A. Koziel ◽  
Andrzej Białowiec ◽  
Chumki Banik ◽  
Robert C. Brown
Keyword(s):  
Buffer Capacity ◽  
Corn Starch ◽  
Tap Water ◽  
Spatial And Temporal Variation ◽  
Gaseous Emissions ◽  
Inorganic Contaminants ◽  
Ph Indicator ◽  
Ph Change ◽  
Air Interface ◽  
Water Ph

Studies have shown that biochar has the potential to remove organic and inorganic contaminants from wastewater. pH is known to have a crucial role in the transformation of pollutants. In this research, we explore the feasibility of using biochars properties to control the pH near the water–air interface, so the gaseous emissions from water (or wastewater) could be mitigated. This study aimed to test the effects of a thin layer biochar addition on the spatial and temporal variation of water pH. Two types of biochar and water were tested. Highly alkaline porous (HAP; pH 9.2) biochars made of corn stover and red oak (RO; pH 7.5) were applied surficially to tap (pH 9.5) and deionized water (DI) (pH 5.4). The spatial pH of solutions was measured every 1 mm of depth on days 0, 2, and 4 after biochar application. The results showed that HAP biochar increased the pH of both tap and DI water, while RO decreased tap water pH and increased DI water pH. On day 0, there was no effect on tap water pH, while a pH change in DI water was observed due to its lower buffer capacity. In addition, the pH (temporal) migration from topically applied biochar into an aqueous solution was visualized using a colorimetric pH indicator and corn starch to increase viscosity (to prevent biochars from sinking). The results prove that the surficial application of biochar to water was able to change both the pH near the water–air interface and the pH of the solution with time. The pH change was dependent on the biochar pH and water buffer capacity. These results warrant further research into the floatability of biochars and into designing biochars with specific pH, which could be a factor influencing gaseous emissions from liquids that are sensitive to pH.

Acids, bases and buffer solutions

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
First Principles ◽  
Buffer Capacity ◽  
Unique Feature ◽  
Dissociation Constants ◽  
Equilibrium Composition ◽  
Buffer Solutions ◽  
Acid And Base ◽  
Water Ph ◽  
Acids And Bases ◽  
Conjugate Bases

Many reactions in solution involve acids and bases, and so this chapter examines these important reactions in detail. Topics covered include the ionisation of water, pH, pOH, acids and bases, conjugate acids and conjugate bases, acid and base dissociation constants, the Henderson-Hasselbalch equation, the Henderson-Hasselbalch approximation, buffer solutions and buffer capacity. A unique feature of this chapter is a ‘first principles’ analysis of how a reaction buffered at a particular pH achieves an equilibrium composition different from that of the same reaction taking place in an unbuffered solution. This introduces some concepts which are important in understanding the biochemical standard state, as required for Chapter 23.

scholarly journals Application of the Gastrointestinal Simulator (GIS) Coupled with In Silico Modeling to Measure the Impact of Coca-Cola® on the Luminal and Systemic Behavior of Loratadine (BCS Class 2b)

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 566 ◽  
Author(s):  
Bart Hens ◽  
Marival Bermejo ◽  
Patrick Augustijns ◽  
Rodrigo Cristofoletti ◽  
Gregory Amidon ◽  
...  
Keyword(s):  
Intestinal Absorption ◽  
Buffer Capacity ◽  
Drug Product ◽  
Tap Water ◽  
Systemic Exposure ◽  
Immediate Release ◽  
Release Formulation ◽  
Gastric Emptying Rate ◽  
Physiological Variables ◽  
The Impact

In the present work, we explored if Coca-Cola® had a beneficial impact on the systemic outcome of the weakly basic drug loratadine (Wal-itin®, immediate-release formulation, 10 mg, generic drug product). To map the contribution of underlying physiological variables that may positively impact the intestinal absorption of loratadine, a multi-compartmental and dynamic dissolution device was built, namely the Gastrointestinal Simulator (GIS). The luminal behavior of one immediate-release (IR) tablet of 10 mg of loratadine was tested under four different fasted state test conditions in the GIS: (i) with 250 mL of water and applying a predetermined gastric half-life (t1/2,G) of 15 min; (ii) with 250 mL of water and applying a t1/2,G of 30 min; (iii) with 250 mL of Coca-Cola® and a t1/2,G of 15 min; (iv) with 250 mL of Coca-Cola® and a t1/2,G of 30 min. After initiating the experiments, solution concentrations and solubility were measured in the withdrawn samples, and pH was monitored. To address the impact of the present CO2 in Coca-Cola® on the disintegration time of the tablet, additional disintegration experiments were performed in a single-vessel applying tap water and sparkling water as dissolution media. These experiments demonstrated the faster disintegration of the tablet in the presence of sparkling water, as the present CO2 facilitates the release of the drug. The buffer capacity of Coca-Cola® in the presence of FaSSGF was 4-fold higher than the buffer capacity of tap water in the presence of FaSSGF. After performing the in vitro experiments, the obtained results were used as input for a two-compartmental pharmacokinetic (PK) modeling approach to predict the systemic concentrations. These simulations pointed out that (i) the present CO2 in Coca-Cola® is responsible for the enhancement in drug release and dissolution and that (ii) a delay in gastric emptying rate will sustain the supersaturated concentrations of loratadine in the intestinal regions of the GI tract, resulting in an enhanced driving force for intestinal absorption. Therefore, co-administration of loratadine with Coca-Cola® will highly likely result in an increased systemic exposure compared to co-administration of loratadine with tap water. The mechanistic insights that were obtained from this work will serve as a scientific basis to evaluate the impact of Coca-Cola® on the systemic exposure of weakly basic drugs for patients on acid-reducing agents in future work.

scholarly journals A Theoretical and Experimental Study of Electrochemical pH Control at Gold Interdigitated Microband Arrays

2021 ◽  
Author(s):  
Bernardo Patella ◽  
Robert Daly ◽  
Ian Seymour ◽  
Pierre Lovera ◽  
James Rohan ◽  
...  
Keyword(s):  
Electrode Array ◽  
Ph Control ◽  
Reduction Peak ◽  
Solution Ph ◽  
Ph Indicator ◽  
Ph Change ◽  
Initial Ph ◽  
The Impact ◽  
Strong Acids

In electroanalysis, solution pH is a critical parameter that often needs to be adjusted and controlled for the detection of particular analytes. This is most commonly performed by the addition of chemicals, such as strong acids or bases. Electrochemical in-situ pH control offers the possibility for the local adjustment of pH at the point of detection, without additional reagents. FEA simulations have been performed to guide experimental design for both electroanalysis and in-situ control of solution pH. No previous model exists that describes the generation of protons at an interdigitated electrode array in buffered solution with one comb acting as a protonator, and the other as the sensor. In this work, FEA models are developed to provide insight into the optimum conditions necessary for electrochemical pH control. The magnitude of applied galvanostatic current has a direct relation to the flux of protons generated and subsequent change in pH. Increasing the separation between the electrodes increases the time taken for protons to diffuse across the gap. The final pH achieved at both, protonators and sensor electrodes, after 1 second, was shown to be largely uninfluenced by the initial pH of the solution. The impact of buffer concentration was modelled and investigated. In practice, the pH at the electrode surface was probed by means of cyclic voltammetry, i.e., by cycling a gold electrode in solution and identifying the potential of the gold oxide reduction peak. A pH indicator, methyl red, was used to visualise the solution pH change at the electrodes, comparing well with the model’s prediction

A marine isolate of Pseudomonas nigrifaciens. I. Classification and nutrition

1968 ◽  
Vol 14 (12) ◽  
pp. 1333-1340 ◽  
Author(s):  
Cynthia F. Norton ◽  
Galen E. Jones
Keyword(s):  
Rhode Island ◽  
Culture Fluid ◽  
Chloride Ion ◽  
Water Soluble ◽  
Redox Activity ◽  
Blue Pigment ◽  
Ph Indicator ◽  
Ph Change ◽  
Deep Blue ◽  
Solid Media

A bacterium producing a deep blue pigment was isolated from Narragansett Bay, Rhode Island, and identified as Pseudomonas nigrifaciens. It requires at least 6.4 p.p.t. salinity for growth, 9.6 p.p.t. for pigmentation, and grows from 4 to 30 C, optimally at 15–18 C. An organic nitrogen source is necessary for growth but no specific amino acids or growth factors are required. Two major seawater ions are essential, potassium (10−3 M minimum, 8 × 10−3 M optimum) and magnesium (growth occurring in 1 week on 10−5 M, 10−2 M optimum at 20 h). Growth occurs without addition of sodium or chloride ion. Optimum pigmentation occurs on solid media, but pigmentation does occur in shaken vitamin-free casamino acids medium of 35 p.p.t. salinity. Water-soluble blue pigment appears during log phase and breaks down to a brownish coloration during stationary phase, coinciding with a pH change from 7.4 to 8.3. The blue pigment in sterile filtered culture fluid exhibits redox and pH indicator properties. Redox activity is observed in culture fluid, where standing causes reduction and shaking reoxidation.

scholarly journals EXPERIMENTAL INVESTIGATION OF BIOGAS PRODUCTION USING FATTY WASTE/BIODUJŲ GAMYBOS EKSPERIMENTINIAI TYRIMAI PANAUDOJANT RIEBALINES ATLIEKAS/ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ ПРОИЗВОДСТВА БИОГАЗА C ИСПОЛЬЗОВАНИЕМ ЖИРОВЫХ ОТХОДОВ

2008 ◽  
Vol 16 (4) ◽  
pp. 178-187 ◽  
Author(s):  
Pranas Baltrėnas ◽  
Mindaugas Kvasauskas
Keyword(s):  
Experimental Investigation ◽  
Sewage Sludge ◽  
Organic Waste ◽  
Biogas Production ◽  
Ph Indicator ◽  
Ph Change ◽  
Average Value ◽  
Temperature Mode ◽  
Biogas Output ◽  
Sulphuretted Hydrogen

The paper presents the findings of experimental investigation of biogas production using hen manure and sewage sludge with fatty waste (from margarine production). The following mixtures were made using this organic waste: hen manure and sewage sludge were mixed with fatty waste at 75% : 25%, 50% : 50% and 25% : 75% in volume. The paper analyses quantitative and qualitative composition of biogas: gas emission content, the concentrations of methane, sulphuretted hydrogen and oxygen in it as well as temperature and pH change during the experiment. Mixing hen manure with fatty waste at 75% : 25% and maintaining psychrophilic temperature mode, the highest biogas output (0.09 m3) from 0.2 m3 substrate in 32 days was recorded. When using the mixture of sewage sludge and fatty waste at 75% : 25% and maintaining psychrophilic temperature mode, the highest biogas output (0.10 m) from 0.2 m substrate in 32 days was recorded. When using these mixtures, the concentration of methane was also the highest, and the average values reached 58.5% (with hen manure) and 61.7% (with sewage sludge). The evaluation of gas emissions and methane concentration in gas shows that the most efficient use of biogas could be obtained using biogas emitted from the mixture of hen manure and sewage sludge with fatty waste mixed at 75% : 25%. The concentration of sulphuretted hydrogen in biogas did not exceed 3%, the concentration of oxygen decreased from 4.9 % to 1.8%. pH indicator was decreasing when more fatty waste was added to the mixture. When using hen manure, the average value of pH changed from 6.4 to 6.3, when using sewage sludge ‐ from 6.6 to 6.3. Santrauka Pateikiami eksperimentinių biodujų gamybos tyrimų, naudojant vištų mėšlą ir nuotekų valymo dumblą su riebalinėmis (margarino gamybos) atliekomis, rezultatai. Iš šių organinių atliekų buvo paruošti mišiniai: vištų mėšlas bei nuotekų valymo dumblas buvo maišomas su riebalinėmis atliekomis 75 % : 25 %, 50 % : 50 % ir 25 % : 75 %. Darbe nagrinėjama biodujų kiekybinė ir kokybinė sudėtis: išsiskyrusių dujų kiekis, metano, sieros vandenilio ir deguonies koncentracija jose, temperatūros bei pH pokytis eksperimento metu. Eksperimentų metu bioreaktoriuose buvo palaikomas psichrofilinis temperatūrinis režimas. Nustatyta, kad didžiausias biodujų kiekis (0,09 m3 ) išsiskiria vištų mėšlą maišant su riebalinėmis atliekomis santykiu 75 % : 25 %. Naudojant nuotekų valymo dumblo ir riebalinių atliekų mišinį (75 % : 25 %), taip pat gauta didžiausia biodujų išeiga per visą eksperimento laikotarpį – 0,10 m3 . Metano koncentracija naudojant šiuos mišinius taip pat buvo didžiausia. Vidutinė reikšmė siekė 58,5 % (su vištų mėšlu) bei 61,7 % (su nuotekų dumblu). Įvertinus išsiskyrusių dujų kiekį ir metano koncentraciją jose, nustatyta, kad efektyviausiai būtų galima naudoti biodujas, išsiskyrusias iš vištų mėšlo ir nuotekų valymo dumblo su riebalinėmis atliekomis, kurių santykis 75 % : 25 %. Sieros vandenilio koncentracija biodujose neviršijo 3 %, deguonies koncentracija mažėjo nuo 4,9 % iki 1,8 %. pH rodiklis mažėjo į biomasės mišinį įdedant daugiau riebalinių atliekų. Naudojant vištų mėšlą vidutinė pH reikšmė kito nuo 6,4 iki 6,3, naudojant nuotekų valymo dumblą – nuo 6,6 iki 6,3. Резюме Представлены результаты экспериментальных исследований по производству биогаза с использованием куриного помета и ила сточных вод с жировыми отходами (от производства маргарина). Были исследованы следующие смеси из органических отходов: куриный помет и ил сточных вод были смешаны с жировыми отходами в объеме 75% : 25%, 50% : 50% и 25% : 75%. Проанализирован количественный и качественный состав биогаза: газовое содержание эмиссии, концентрации метана, сероводорода и кислорода, а также изменение температуры и фактора pH в течение эксперимента. Во время эксперимента в биореакторе поддерживался психрофильный температурный режим. Было установлено, что при смешивании куриного помета с жировыми отходами в соотношении 75% : 25% и поддерживании психрофильного температурного режима наибольший выпуск биогаза (от 0,09 м3 до 0,2 м3 субстрата) обнаружен спустя 32 дня. При использовании смеси из ила сточных вод и жировых отходов в соотношении 75% : 25% и поддерживании психрофильного температурного режима был установлен наибольший выпуск биогаза (от 0,10 м3 до 0,2 м3 субстрата) спустя 32 дня. При использовании этих смесей концентрация метана также была самая большая, ее средние значения составляли 58,5% (с куриным пометом) и 61,7% (с илом сточных вод). В результате оценки газовой эмиссии и концентрации метана в эмиссии установлено, что наиболее эффективным будет использование биогаза, получаемого от смеси куриного помета и ила сточных вод с жировыми отходами в соотношении 75% : 25%. Концентрация сероводорода в биогазе не превышала 3%, концентрация кислорода уменьшилась от 4,9% до 1,8%. Индикатор фактора pH уменьшался, когда к смеси добавлялось больше жировых отходов. При использовании только куриного помета среднее значение фактора pH менялось от 6,4 до 6,3, при использовании ила сточных вод – от 6,6 до 6,3.

Protolytic Reactions in Photosystem II: a New Model for the Release of Protons Accompanying the Photooxidation of Water

1977 ◽  
Vol 32 (7-8) ◽  
pp. 617-626 ◽  
Author(s):  
Satham Saphon ◽  
Antony R. Crofts
Keyword(s):  
Electron Acceptor ◽  
Neutral Red ◽  
Glass Electrode ◽  
Ph Indicator ◽  
Ph Change ◽  
Benzyl Viologen ◽  
Ph Changes ◽  
The Third ◽  
Cresol Red ◽  
Indicator Dye

Using pH indicator dye techniques we have investigated the pH changes in dark-adapted chloro- plasts following excitation by short flashes. Two types of pH indicator, cresol red and neutral red, were used, to follow the pH changes either inside or outside the thylakoids, or the net change when the membrane was made permeable to protons by uncoupling agents. (1)With cresol red which showed the net pH changes inside and outside the thylakoids, an oscillation of the flash yield of H+ occurred with a periodicity of 4 (minima on the first and fifth flashes, the yield on the third being not significantly different from the yields on the second and fourth flashes). The pH changes did not occur in synchrony with O2-evolution. (2)The net flash yields without addition of electron acceptor were similar to those with benzyl- viologen. The results were comparable with those obtained with the glass electrode technique by Fowler and Kok (C. F. Fowler and B. Kok, Biochim. Biophys. Acta 357, 299 - 307 [1974]). (3)The net flash yields with ferricyanide as electron acceptor of photosystem I were higher than those in the absence of acceptor, or with benzylviologen. On the first and fifth flashes a net acidification was always observed. (4)In the presence of 3- (3,4-dichlorphenyl) -1,1-dimethylurea (DCMU) a rapid acidification also occured on the first flash, while the pH changes induced by subsequent flashes were inhibited. (5)The uncoupler methylamine did not inhibit the proton uptake outside the thylakoids. (6)With neutral red as indicator for the net pH change inside and outside the thylakoids, the same oscillation of the flash yield occured as with cresol red. (7)With neutral red in the precense of an external buffer, as a pH indicator for the internal aqueous phase alone, an oscillation of the flash yield with a periodicity of 4 also occured. The first and second flash yields were higher compared with the third than the equivalent yields of oxygen. (8)We discuss the results with respect to a model for the release of protons in the water- splitting enzyme reactions, in which protons are not released in synchrony with O2 , but in the transitions of all the states of the watersplitting enzyme with the exception of S1 → S2 . Our results are consistent with this model when account is taken of the release of protons inside the thylakoids with a periodicity of 2, associated with electron transfer from reduced plastoquinone.

Some factors affecting the pH change in bull semen

1947 ◽  
Vol 37 (1) ◽  
pp. 11-16 ◽  
Author(s):  
James Anderson
Keyword(s):  
Significant Positive Correlation ◽  
Buffer Capacity ◽  
Seminal Fluid ◽  
Constant Composition ◽  
Ph Change ◽  
Glucose Content ◽  
Factors Affecting ◽  
Positive Correlation ◽  
Bull Semen ◽  
Practical Object

The extent of the change in pH on incubation, when bull sperm were suspended in various fluids of different composition, was affected by the buffer capacity, the pH, and the glucose content. In one such fluid, used to replace seminal fluid, there was a highly significant positive correlation between the pH. change and the number and motility of the sperm, and between the pH change in this fluid and in undiluted semen. The various conditions which appear to affect the increase in acidity are discussed, and it is concluded that there is no practical object in determining the change in pH on incubation in an artificial fluid of uniform and constant composition, instead of in semen.

Effect of Plant Starch on the Production of Glucoamylase from Aspergillus niger

2011 ◽  
Vol 396-398 ◽  
pp. 1502-1505 ◽  
Author(s):  
Xin Hong Liang ◽  
Gong Ling Zhao ◽  
Zu Feng Guo ◽  
Yu Tang
Keyword(s):  
Sweet Potato ◽  
Corn Starch ◽  
Ph Value ◽  
Potato Starch ◽  
Wheat Starch ◽  
Ph Change ◽  
Fermentation Time ◽  
Glucoamylase Activity ◽  
Significant Difference ◽  
Sweet Potato Starch

Abstract. Glucoamylase is an inducible enzyme and generally induced in the presence of starch. Corn starch, wheat starch, sweet potato starch and potato starch were used as the carbon sources to produce the glucoamylase by A. niger FJL0801. The results showed that the maximum glucoamylase activity was 594.511.7 U/mL when 4% sweet potato starch was used as the carbon source, its enzyme activity was increased by 34.9% than potato starch, by 17.2% than wheat starch and by 4.6% than corn starch. In the four media, the adaptive phage of A. niger FJL0801 were all 0-12 h, the logarithmic growth phase all 12-60 h, and the stationary phase all 60-192 h. The maximum biomass of the strain was 1.950.09 μg/mL in the corn starch medium. The glucoamylase activity was inversely proportional to the growth rate of A. niger FJL0801. The final pH value was all within 6.960.057.110.07 in the four midia. There was no significant difference at 0.05 probability level between the pH of the four media at the same fermentation time. The pH change was not the reason for glucoamylase activity by A. niger FJL0801 used different plant starch.

An improved method for determining HNMs in drinking water

2013 ◽  
Vol 13 (5) ◽  
pp. 1257-1264 ◽  
Author(s):  
F. Q. Huang ◽  
M. Y. Ruan ◽  
J. D. Yan ◽  
H. C. Hong ◽  
H. J. Lin ◽  
...  
Keyword(s):  
Drinking Water ◽  
Extraction Efficiency ◽  
Tap Water ◽  
Correlation Coefficients ◽  
Method Detection Limit ◽  
Good Reliability ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Water Ph

Halonitromethanes (HNMs) in drinking water are increasingly becoming a public concern due to their high health risks, so development of a sensitive method for their analysis has become a priority. Liquid–liquid extraction (LLE) method is dominantly used in current studies regarding HNMs. However the sensitivity is far from ideal. The present study aims to investigate the factors that may influence the extraction efficiency during HNM analysis by LLE method, and as a result develop a more sensitive extraction method for HNM determination. Results showed that the dose of sodium sulfate exerted the most significant influence, followed by copper sulfate, while the pH and manual shaking times have little effect. Under the suitable conditions (for extracting HNMs in 45 mL water: pH = 3.5–5, CuSO4 = 1.0 g, Na2SO4 = 6 g, shaking times = 120–180), the correlation coefficients (r) of the calibration curves for nine HNMs were all more than 0.9925. The method detection limit (MDL) ranged from 0.017 to 0.217 μg L−1 with an average of 0.076 μg L−1, which was dominantly lower than the method reported. The recovery (spiked blank samples: 98–108%; spiked tap water: 81–120%) and precision (relative standard deviation: 0.46–6.72) also showed good reliability and reproducibility of the method. Finally, the developed method was applied to the determination of HNMs in real water samples.

scholarly journals Influence of electrical conductivity on water uptake and vase life of cut gladiolus stems

2015 ◽  
Vol 21 (2) ◽  
pp. 221
Author(s):  
Lucas Cavalcante Da Costa ◽  
Fernanda Ferreira De Araújo ◽  
Teresa Drummond Correia Mendes ◽  
Fernando Luiz Finger
Keyword(s):  
Electrical Conductivity ◽  
Water Uptake ◽  
Room Temperature ◽  
Tap Water ◽  
Vase Life ◽  
Distilled Water ◽  
Cut Flowers ◽  
Water Ph ◽  
Maximum Water ◽  
Standard Composition

<p>Several experiments reveal that distilled water varies among different laboratories and also does not have a standard composition. Water electrical conductivity (EC) of vase solution is one of the parameters that influence the water uptake by cut flowers. Therefore, the objective of this work was to evaluate the influence of electrical conductivity on water uptake and vase life in cut stems of gladiolus. The stems harvested and kept in distilled water (pH 6.6, EC &lt;0.01dS m-1) and tap water (pH 7.0, EC 0.75 dS m-1) at room temperature. Flowers kept in tap water showed lower fresh weight loss after the second day and higher water uptake during vase life. In a second set of experiments, we verified the limit EC saturation supported by the flower. For this, flowers were placed in individual test tubes containing four different solutions with varying ion concentrations. Solution 2 (EC 0.60 dS m-1) promoted increased vase life and allowed maximum water uptake by the flowers. The results show that the electrical conductivity of vase solution is a major parameter in experiments with vase life of cut gladiolus. The presence of ions in the vase solution increases the overall vase life and improves water uptake of flowers with favorable optimal EC between 0.60 to 0.87 dS m-1.</p>

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