Bisulfite Concentration Research Articles

Bisulfite enhances p-nitrophenol degradation by zero-valent iron under oxic conditions: Combination of indirect reduction by superoxide radical and direct reduction

Advanced oxidation processes based on the combination of zero-valent iron (ZVI) and S(IV) have been extensively investigated for oxidative degradation of organic pollutants, but little attention has been paid to their reducing capacities in the presence of oxygen. This work found bisulfite (BS) could greatly enhance the degradation of p-nitrophenol (PNP) by ZVI under oxic conditions and PNP was only reduced to p-aminophenol without further degradation. A combination of indirect reduction by superoxide radical (O2•–) and direct reduction by ZVI was verified as the mechanism of PNP degradation. Highly oxidizing species, such as hydroxyl radical (HO•) and sulfate radical (SO4•−), were also produced in the ZVI/BS system under oxic conditions but did not contribute to pollutant degradation perhaps due to the rapid consumption by reducing substances like BS ions and the released Fe2+. BS concentration, ZVI dosage, initial solution pH and coexisting anions (CO32–, PO43– and Cl–) affected the degradation of PNP. ZVI lost the reactivity after used for three times because of the production of goethite and lepidocrocite covered on its surface. This study will provide a new insight into degradation of organic pollutants in ZVI/BS system under oxic conditions.

Simultaneous determination of peroxydisulfate and bisulfite concentrations with quenching-agent-assisted iodometry

Fenton/Fenton-like reactions have gained popularity for their remarkable proficiency in decomposing organic pollutants, especially when enhanced by reductants addition for accelerating the Fe2+ regeneration. Nevertheless, these works predominantly centered on the formation and utilization of hydroxyl radicals (•OH) in the process, neglecting the evolution of oxidant and reductant due to the difficulty in the simultaneous determination of these two components. By employing the quenching-iodometric method, we could simultaneously determine the concentrations of HSO3- and peroxydisulfate (PDS). This method first employed an excess of peroxymonosulfate (PMS) to effectively quench HSO3-, and then used the iodometric spectrophotometry to simultaneously determine the concentrations of PMS and PDS in the reaction system. Finally, through precise stoichiometric relationships, we could accurately calculate the concentration of HSO3-. Based on this method, we achieved concentration measurements that, upon linear fitting, yielded a correlation coefficient (R2) surpassing 0.99, unequivocally affirming the method's accuracy and trustworthiness. In this work, an innovation approach for determining the concentrations of HSO3- (reductant) and PDS(oxidant) was explored.Additionally, the resilience of the method was verified across different pH levels and in the presence of diverse impurity ions. The results ensured precise concentration measurements in the real wastewater. This method was characterized by its simplicity, rapid analysis, and environmental friendliness, offering a new analytical strategy for the determination of PDS and HSO3- in environmental samples. The method enables more meticulous monitoring of chemical usage in water treatment, facilitating optimized dosing strategies and assessments of reductant-enhanced Fenton or Fenton-like system in water purification.

Degradation of Diclofenac by Bisulfite Coupled with Iron and Manganous Ions: Dual Mechanism, DFT-Assisted Pathway Studies, and Toxicity Assessment

Diclofenac (DCF) is often detected in diverse aquatic bodies, and ineffective management can lead to detrimental effects on human health and ecosystems. In this study, degradation of DCF by Fe(III) and Mn(II) activating bisulfite (BS) was investigated. In the Fe(III)/Mn(II)/BS system, 93.4% DCF was degraded at 200 μM BS within 120 s, and additional research on 1000 μM BS achieved 88.4% degradation efficacy. Moreover, kinetics fitting of DCF degradation with the different BS concentrations was studied to find the two highest reaction rates (200 and 1000 μM, kobs = 0.0297 and 0.0317 s−1, respectively). Whereafter, SO4•− and Mn(III) were identified as the main active species at these two concentrations, respectively. Density functional theory (DFT) calculations, molecular frontier orbital theory, and surface electrostatic potential (ESP) forecast electrophilic attack sites. DCF degradation pathways by radical and non-radical ways were proposed by attack site prediction and thirteen intermediates identified by UPLC-QTOF-MS. ECOSAR software 2.2 was used for toxicity assessment. This work studied DCF degradation by the Fe(III)/Mn(II)/BS process in the presence of different concentrations of BS, providing a new insight into water purification.

Visual inspection of acidic pH and bisulfite in white wine using a colorimetric and fluorescent probe

The acidic pH and total amount of SO2 are both important quality control indexes of wine, but conventional detection techniques depend heavily on specialized instrument and professional staff, thus are not available to general customers. In this paper, a hemicyanine-based colorimetric and fluorescent probe Hcy-Py was designed and synthesized. It responded to bisulfite selectively with a LOD of 0.68 μM and responded to proton with a pKa of 3.78. Upon the treatment of solutions with different pH values and concentrations of bisulfite, the probe-loaded paper strips displayed distinct color changes under both natural light and UV lamp. When a real white wine sample was subjected to the paper strip experiment, pH as well as bisulfite concentration could be determined by naked-eye quickly and conveniently, thus a visual detection of acidic pH and bisulfite in white wine without involving any sophisticated instrument or professional skill was successfully demonstrated.

Bisulfite-assisted surface Fenton-like degradation of dimethyl phthalate by ferrihydrite-H2O2 system

As a common plasticizer, phthalic acid esters (PAEs) have been widely employed to improve the flexibility and workability of polymetric materials, thus leading to their widespread distribution in soils and wastewater. Moreover, PAEs raised great public concerns due to their endocrine-disrupting effects, which could damage reproductive system and body development at low exposure dose. In the present study, a ferrihydrite-H2O2-bisulfite ternary system was developed to achieve efficient degradation of dimethyl phthalate (DMP). Our results showed that 86.6 % of total DMP could be removed within 240 min by the ferrihydrite-H2O2-bisulfite ternary system, in which the respective optimum concentration of ferrihydrite, H2O2 and bisulfite was set as 1.0 g/L, 5.0 mM and 2.0 mM. For comparison, negligible DMP removal was observed in the binary systems of ferrihydrite-H2O2, ferrihydrite-bisulfite and H2O2-bisulfite. Hydroxyl radical (•OH) was identified as the dominant reactive species for DMP degradation based on the results of electron paramagnetic resonance (EPR) analysis and free radicals quenching experiments. By complexing with iron species, bisulfite could accelerate the reduction of Fe(III) to Fe(II), thus increasing the generation of •OH by ∼4 times in the heterogeneous ferrihydrite-H2O2 system. Furthermore, ferrihydrite exhibited excellent recyclability without any modification as indicated by the negligible decrease in the catalytic degradation efficiency of DMP. Thus, in addition to efficient degradation of PAEs in wastewater, our study would shed light on the in-situ soil remediation technology on the basis of bisulfite-assisted heterogeneous Fenton-like reactions.

The Utilization of Off Grade Garlic Bulb Into Garlic Powder and Its Characteristics

During the production process of garlic seeds, about 15 - 20% are not suitable for seed use because of the small size of the cloves (<2.0 cm). Garlic powder has a potential to be developed as a seasoning in cooking, medicine, and industrial raw material. This research aimed to determine the effect of size reduction method and sodium bisulphite concentration on the characteristics of garlic powder from off-grade garlic. The raw material used was off grade garlic of Sangga Sembalun variety. The study was designed using a completely randomized design, which consisted of two factors, namely the size reduction method (x1: chopped and x2: sliced) and concentration of sodium bisulphite solution (y1: 0, y2: 0.5%, y3: 1.0%; y4: 1.5%), with three replication. The results showed that off grade garlic can be used as garlic powder with high lightness and allicin content. The garlic powder produced by the slice method and soaking in 0.5% of sodium bisulphite had a yield of 39.83%, moisture of 8.37%, ash of 3.47%, fat of 0.21%, protein of 18.30%, carbohydrate of 69.63%, allicin of 1.59%, chroma of 13.80, degree of Hue of 71.04, and degree of Lightness (L*) of 89.56.

Enhanced degradation of amiloride over Bi2FeNbO7/bisulfite process: Key factors and mechanism

Construction of Bi2FeNbO7/bisulfite system for abatement of pharmaceutical residue was achieved. An attempt to synthesize Bi2FeNbO7 through hydrothermal technique was confirmed by X-ray diffraction. The magnetic field experiment revealed that Bi2FeNbO7 possessed a saturation magnetization of 6.99 emu/g, indicating magnetic attributes of Bi2FeNbO7. Scanning electron microscopy images showed that Bi2FeNbO7 exhibited regular octahedra in the size of 200–300 nm. In a self-made device, the activation of sodium bisulfite using Bi2FeNbO7 for the disposal of amiloride has been carefully explored. The effects of solution pH, sodium bisulfite concentration, Bi2FeNbO7 dosage, amiloride concentration, coexisting ions, and water matrix on the performance of Bi2FeNbO7/bisulfite system was investigated. The catalytic performance of Bi2FeNbO7/bisulfite to degrade amiloride was considerably higher than that of traditional iron oxides. The maximum removal efficiency of amiloride was 97.9% in Bi2FeNbO7/bisulfite process. The involvement of Fe might be crucial for activating bisulfite to create active species. The dominating radical in Bi2FeNbO7/bisulfite process was identified as SO3•‒. With the help of UHPLC/MS/MS, three new degradation products of amiloride were found. Dehalogenation and deamination of amiloride might account for the formation of these transformation products. This work provides a highly efficient Bi2FeNbO7/bisulfite process for the disposal of pharmaceutical pollutants in water treatment.

Establishing Evidence for Use of Appropriate Medicines in the Operating Room

Various issues related to clinical use of medicines remain unclear, and pharmacists are expected to establish evidence for appropriate use of medicines. The present review summarizes our findings from three areas of research regarding the use of medicines in the operating room: 1) We evaluated the extent of extravasation injury due to thiopental (2.5 mg/100 μL) and propofol (1.0 mg/100 μL) at the macroscopic and histopathologic levels in a rat model. Thiopental, which causes tissue necrosis, can be classified as a "vesicant", and propofol can be classified as an "irritant". Moreover, warming strongly exacerbated the degeneration or necrosis induced by extravasation of thiopental. 2) The cytotoxicity of povidone-iodine solution (PVP-I) for ophthalmic use and that of polyvinyl alcohol-iodine solution (PAI) was compared using a human corneal epithelial cell line. Despite exhibiting equivalent antiseptic effects, the cytotoxicity of PVP-I diluted 16-fold was greater than that of PAI diluted 6-fold. After inactivation of iodine, the cytotoxicity of PVP-I persisted; therefore, to avoid corneal damage, antisepsis should be achieved with PAI. 3) The stability of 1 μg/mL adrenaline when used as an intraocular irrigating solution to maintain pupil dilation was evaluated. After mixing for 6 h, the adrenaline concentration was 65.2% (pH 8.0) of the initial concentration. Moreover, the low concentration of sodium bisulfite in the irrigating solution could have caused adrenaline reduction. Our results strongly suggest that intraocular irrigation solution containing adrenaline should be prepared just prior to use in surgery.

Instalación y evaluación de secador solar autónomo para secado de papa en Tarma

En este trabajo se ha desarrollado un secador solar autónomo y automatizado para secar papa en la localidad de Tarma a una altitud de 3 040 m en julio de 2019, el cual cuenta con un colector solar con dos reflectores, cámara de secado con capacidad de 20 kg, panel fotovoltaico y un sistema de control. Se estudió el comportamiento térmico del secador solar sin carga, logrando incrementos de la temperatura en la cámara de secado de hasta 50.7 ±7 °C con radiaciones solares de 880 ±144 W m-2h-1. Se evaluó el efecto del pretratamiento con dos concentraciones de bisulfito de sodio(0.02% y 0.03%) y tres temperaturas de secado (50 °C, 55 °C y 60 °C) para evaluar las características físicas (L *), fisicoquímicas (acidez, pH) y químicas (humedad y cenizas). Los resultados mostraron una reducción de 70% del agua teniendo una humedad final entre 12.56% a 13.85%. Asimismo, no fue encontrado diferencia significativa (p&gt; 0.05) entre las características físicas, fisicoquímicas y química a las diferentes concentraciones de bisulfito y temperaturas de secado de la papa Yungay. Estos parámetros de calidad de papa se encuentran de acorde a la norma peruana NTP 011.119 ‘papa y sus derivados: papa, definiciones y requisitos’, lo que ofrece una alternativa eficiente al deshidratado de productos agrícolas.

Degradation of an Organic Dye by Bisulfite Catalytically Activated with Iron Manganese Oxides: The Role of Superoxide Radicals.

Metal-activated bisulfite systems have been widely used to treat recalcitrant wastewater. However, due to the disadvantages of their narrow effective pH range and difficulty in recovering metal ions, homogeneous systems are severely limited in practical applications. To overcome these problems, Fe/Mn bimetallic catalysts with different molar ratios were prepared using a simple sol–gel method to activate bisulfite. Influential factors, such as catalyst and system types, catalyst dosage, bisulfite concentration, pH value, and bisulfite addition modes, were investigated. The new system exhibited a wide effective pH range and high degradation efficiency, and it was found that the dissolved oxygen content played an important role in the activation system. The radical quenching test showed that a superoxide radical (O2•–), instead of a hydroxyl radical (HO•) or a sulfate radical (SO4•–), was the main oxide species for the degradation of rhodamine B (RhB).

A double-indole structure fluorescent probe for monitoring sulfur dioxide derivatives with distinct ratiometric fluorescence signals in mammalian cells.

Based on the addition reaction of the sulfur dioxide derivative to the CC double bond, the probe HDI was designed and synthesized. The two-channel fluorescent probe HDI changed from orange to colorless and the fluorescence changed from red to blue when the bisulfite was detected. And the probe responds rapidly to bisulfite within 2 min, with high sensitivity and specificity. In addition, the probe can be used to detect the concentration of bisulfite with a low detection limit (80 nM). Cytological experiments have also demonstrated that probe HDI has low cytotoxicity and could be used for ratiometric detection of sulfur dioxide derivatives in living cells.

Degradation of diclofenac by Fe(II)-activated bisulfite: Kinetics, mechanism and transformation products

As an emerging pollutant, Diclofenac (DCF) has potential threats to ecosystem and human health, and it can hardly be removed by conventional wastewater treatment processes. In this study, Fe(II)-activated bisulfite (BS), an advanced oxidation process, was used for rapid removal of DCF. The effect of initial pH, Fe(II) dosage, BS concentration, dissolved oxygen and reaction temperature on DCF removal and its degradation mechanism were investigated. Compared to Fe(II)/persulfate system, the removal efficiency of DCF was higher by Fe(II)/BS, and its degradation followed pseudo-first order kinetic model. Due to the morphology of Fe(II) and BS, the optimal pH for DCF degradation was 4.0. The increased initial Fe(II) or BS concentration promoted DCF degradation while excess Fe(II) or BS caused an inhibition effect as a SO4− scavenger. Dissolved oxygen was an essential factor inducing the conversion of SO3− to SO4−, while it had no effect on DCF removal in the range of 4.6–8.3 mg L−1. The activation energy of this reaction was calculated to be 120.75 ± 3.43 kJ mol−1 based on the improved DCF degradation with increasing temperature. According to the radical scavenging experiments, the contribution of SO4−, HO and the other reactive species to DCF degradation in Fe(II)/BS system were 71.1%, 24.6% and 4.3%, respectively. Nine transformation products were detected using UPLC-Q-TOF-MS. The potential degradation mechanism of DCF was thus proposed showing five reaction pathways including hydroxylation, decarboxylation, dehydration, dechlorination and formylation.

A fluorescent probe for colorimetric detection of bisulfite and application in sugar and red wine

A new fluorescent probe made from (E)-2-(benzo[d]thiazol-2-yl)-3-(6-hydroxynaphthalen-2-yl) acrylonitrile (Probe 1) was synthesized for the determination of bisulfite concentrations in real food samples (red wine and sugar). Adding bisulfite to a Probe 1 solution caused a markeddecrease in fluorescence intensity and a visual color change from yellow to lightyellow. This distinct color response indicates that Probe 1 could be used as a visual sensor for bisulfite. Probe 1 can detect bisulfite quantitatively in the range 0-400μM with a detection limit of 0.10μM. This makes Probe 1 a convenient signaling instrument for determining bisulfite levels in sugar and red wine samples.

Characteristics and inhibition of mercury re-emission from desulfurization slurry by Fenton reagent

In this paper, the mercury re-emission from desulfurization slurry and mercury distribution in gas-liquid-solid three-phase at different desulfurization slurry parameters were studied. Besides, the inhibition performance of Fenton reagent for mercury re-emission and distribution was also investigated. The results show that the Hg0 would re-emit from desulfurization slurry, and the proportions of mercury in gas-liquid-solid three-phase were about 12.17%, 77.72% and 12.08% at typical desulfurization slurry parameter. The S(IV) concentration (sulfite and/or bisulfite concentration), temperature and pH value of desulfurization slurry had great impacts on mercury re-emission and distribution. The increase of S(IV) concentration weakened the mercury re-emission, increased the proportions of mercury in solid phase and liquid phase. The increase of slurry temperature could intensify the mercury re-emission, increase the proportion of mercury in solid phase, but decrease the proportion of mercury in liquid phase. Higher pH value was favorable for the weakening of mercury re-emission, but would increase the proportion of mercury in solid phase and liquid phase. Moreover, the introduction of Fenton reagent into desulfurization slurry could inhibit the mercury re-emission and some mercury that should be re-emitted before would be restrained in solid phase, leading a slight increase of proportion of mercury in solid phase. The existing of oxygenated free radicals, which were generated from Fenton reagent, was the main reason for the inhibition of mercury re-emission. The increase of Fe2+ and H2O2 concentration was conducive to the promotion of inhibition performance, but the effect gradually to weaken. The appropriate value of Fe2+ concentration was 0.04 mM with the H2O2 concentration of 0.30 mM in experiments. In addition, the better inhibition performance (about 80%) of Fenton reagent for mercury re-emission would be realized at lower S(IV) concentration (1–5 mM), lower temperature (30–40 °C) and lower pH value (4.0–5.0) of slurry.

Origin of Life's Building Blocks in Carbon- and Nitrogen-Rich Surface Hydrothermal Vents.

There are two dominant and contrasting classes of origin of life scenarios: those predicting that life emerged in submarine hydrothermal systems, where chemical disequilibrium can provide an energy source for nascent life; and those predicting that life emerged within subaerial environments, where UV catalysis of reactions may occur to form the building blocks of life. Here, we describe a prebiotically plausible environment that draws on the strengths of both scenarios: surface hydrothermal vents. We show how key feedstock molecules for prebiotic chemistry can be produced in abundance in shallow and surficial hydrothermal systems. We calculate the chemistry of volcanic gases feeding these vents over a range of pressures and basalt C/N/O contents. If ultra-reducing carbon-rich nitrogen-rich gases interact with subsurface water at a volcanic vent they result in – concentrations of diacetylene (C4H2), acetylene (C2H2), cyanoacetylene (HC3N), hydrogen cyanide (HCN), bisulfite (likely in the form of salts containing HSO3−), hydrogen sulfide (HS−) and soluble iron in vent water. One key feedstock molecule, cyanamide (CH2N2), is not formed in significant quantities within this scenario, suggesting that it may need to be delivered exogenously, or formed from hydrogen cyanide either via organometallic compounds, or by some as yet-unknown chemical synthesis. Given the likely ubiquity of surface hydrothermal vents on young, hot, terrestrial planets, these results identify a prebiotically plausible local geochemical environment, which is also amenable to future lab-based simulation.

A novel colorimetric and ratiometric fluorescent probe for selective detection of bisulfite in real samples and living cells

An abnormal level of bisulfite can induce toxicological effects associated with lung cancer, cardiovascular and neurological disorders. Therefore, it is of significance to develop an effective fluorescent probe to detect bisulfite in living cells. Herein, a novel fluorescent probe QPCT, based on a 1,4-addition mechanism, was constructed for the colorimetric and ratiometric detection of bisulfite. QPCT displayed high selectivity and anti-interference ability to bisulfite over other anions and biothiols. The probe renders a sensitive ratiometric response to bisulfite with a remarkable fluorescence blue shift from 590 to 537 nm and the fluorescence ratio was linear with bisulfite concentration over the range of 0–120 μM. More importantly, QPCT has been successfully applied to detect bisulfite in sugars and living A549 cells, which indicated that QPCT had a great capability for monitoring bisulfite in complex systems.

A fluorescence probe for bisulfite sensing based on the bisulfite-induced binding site transfer between Zn2+ and an aminoquinoline derivate

A fluorescent probe is constructed to quickly and accurately detect bisulfite. The detection mechanism was considered to operate via the bisulfite, causing deprotonation of amido bond of 8-aminoquinoline derivative leading to fluorescence enhancement. The probe has a good selectivity for bisulfite over the other competitive substances such as F−, Cl−, Br−, I−, C2O42−, NO2−, ClO4−, OAc−, PO43−, CO32−, HCO3−, HS−, HSO4−, SCN−, SO42−, S2O32−, Cys, Hcy and GSH. There is a good linear relationship between fluorescence intensity and the concentration of bisulfite in the range of 0–200 μM. The limit of detection was calculated to be 0.61 μM. Furthermore, the probe has also been successfully used for imaging bisulfite in living cells.

A colorimetric and fluorogenic probe for bisulfite using benzopyrylium as the recognition unit.

A coumarin-benzopyrylium (CB) platform has been developed for the colorimetric and fluorogenic detection of bisulfite. The proposed probe utilizes coumarin as the fluorophore and positively charged benzopyrylium as the reaction site. The method employs the nucleophilic addition of bisulfite to the benzopyrylium moiety of CB to inactivate the electron-deficient oxonium ion. The driving force for photo-induced electron transfer is considerably diminished, thereby promoting the emission intensity of the coumarin fluorophore. The fluorescence intensity at 510nm is linear with bisulfite concentration over a range of 0.2-7.5μM with a detection limit of 42nM (3δ). CB shows a rapid response (within 30s) and high selectivity and sensitivity for bisulfite. Preliminary studies show that CB has great potential for bisulfite detection in real samples and in living cells.

Mitochondria-targeted ratiometric fluorescent probe based on FRET for bisulfite

A new FRET-based ratiometric fluorescent probe (DSPT) for the detection of bisulfite was developed by the dansyl-piperazine-benzothiazolium conjugate platform, in which CC conjugated with benzothiazolium was recognition unit and benzothiazolium moiety was mitochondria-targeted unit. The CC double bond group would undergo Michael addition reaction with bisulfite, triggering significant fluorescence ratio increasing which was linear to the concentrations of bisulfite. The probe can be used in real sample including dry white wine and tap water. Besides, the test strips for bisulfite were prepared. Moreover, cell imaging results indicate that this probe is cell-membrane permeable and mitochondria-targetable, and can be applied to monitor both exogenous and endogenous bisulfite in ratiometric fluorescence imaging.

Evaluation and Optimization of Chemical Treatments for Reducing Yellow Discoloration of Channel Catfish (Ictalurus punctatus) Fillets During Cold Storage

ABSTRACTThe effects of chemical treatments on color change of yellow discolored catfish fillets during both refrigerated and frozen storage were investigated in this work. For the refrigerated storage (4°C), the effects of concentration of sodium bisulfite on reducing the yellow discoloration were studied. Compared to the untreated fillets, sodium bisulfite treatments with concentrations ranging from 0.75 to 1.50% could evidently reduce the yellowness and increase the brightness of the fillets after 7 days refrigerated storage. Since no notable improvement was observed when increasing the concentration of sodium bisulfite beyond 1.0%, the concentration range of 0.75–1.0% is recommended in this work. For the frozen storage (−20°C), the effects of sodium bisulfite and sodium bicarbonate treatments were investigated. Both 1.0% sodium bisulfite and 0.5% sodium bicarbonate treatments made the fillets slightly less yellow and less red. The 1.0% sodium bisulfite treatment also made the fillets slightly brighter. These effects were similar to those under refrigerated storage, but the changes in color were much less. The color changes were related to the degradation of carotenoids in the discolored fillets. The low temperature of frozen storage significantly limited the reaction rates and suppressed the color change processes.