Active Sulfate Research Articles

Electrochemical degradation of perfluorooctanoic acid by macro-porous titanium suboxide anode in the presence of sulfate

The present study investigated the electrochemical degradation of perfluorooctanoic acid (PFOA) by macro-porous titanium suboxide (p-TiSO) anode in the presence of sulfate at pH-neutral condition (pH 6.9 ± 0.3). Based on initial PFOA concentration of 0.1 mmol L−1, current density of 10 mA cm−2 and electrolysis of 2 h, the removal efficiencies of PFOA were 97.1% and 90.8% for Na2SO4 electrolyte (kapp = 2.1 h−1) and NaNO3 electrolyte (k = 0.84 h−1), corresponding to defluorination efficiency of 61.4% and 54.2%, respectively. The 2.3-fold enhancement of oxidation rate should be originated from the production of sulfate radicals (SO4−) by activation of sulfate via direct electron transfer with anode and indirect OH-mediated oxidation under the potential of 3.01–3.41 V versus standard hydrogen electrode (SHE). The production of OH and SO4− could be verified on a qualitative basis by using electron spin resonance (ESR) technology. Localized pH measurement achieved with a Pt/IrOx ultra-micro electrode revealed significantly lower pH inside the pores of p-TiSO anode (pH 2.6) compared to that in bulk electrolyte (pH 6.1). The formation of pH gradient should be attributed to surface interaction and diffusion restriction in the porous structure, and the resulting low pH was favorable for enhancing oxidizability of OH toward activation of bisulfate and oxidation of PFOA pollutant. This study offers a proof-in-concept demonstration of electrochemical activation of sulfate and PFOA degradation without need for chemical addition and pH adjustment, which can be realized by simply creating macro-porous structure of anode materials in electrochemical advanced oxidation process.

RATIO OF PROCESSES OF CELL PROLIFERATION AND APOPTOSIS IN THE SKIN UNDER EXPOSURE TO HEAVY METAL SALTS AND CHELATORS OF ESSENTIAL METALS

In the model experiment on C57BL /6 mice there were established features of the impact of heavy metals and chelators of essential metals on proliferation and apoptosis of epithelial skin cells (keratinocytes). For the execution of a study 40 test animals were divided into seven experimental and 1 control groups, each consisted of five animals. The proliferative and apoptotic activity of keratinocytes was determined by the immunohistochemical method and evaluated by calculating the proliferation index and the index of apoptosis in the cells of the surface epithelium and the epithelial cells of hair follicles in the late anagen stage. Comparative analysis of the proliferation index of the control group and experimental groups showed administration of zinc sulfate, sodium dichromate and zinc chelator (N, N, N`, N`-tetrakis (2-pyridylmethyl) ethylenediamine) to animals to give rise in a statistically significant increase in the proliferative activity of keratinocytes. The decline of proliferation index was detected in animals treated with lead acetate and copper chelator (ammonium tetrathiomolybdate). Introduction of an iron chelator (deferoxamine) had no effect on the proliferative activity of keratinocytes in experimental animals. Induction of apoptosis of epithelial cell was noted under the administration of nickel sulfate, sodium dichromate, lead acetate and zinc chelator (N, N, N`, N`-tetrakis (2-pyridylmethyl) ethylenediamine) to animals. In mice received deferoxamine zinc sulfate and apoptotic activity of keratinocytes has not changed. The use of cluster analysis allowed to classify substances administered to experimental animals, taking into account their simultaneous effect on the studied cellular processes. Lead acetate, iron chelator (deferoxamine) and copper chelator (ammonium tetrathiomolybdate) were shown to reduce the proliferative activity of keratinocytes and have little effect on apoptosis of the epithelial cells of the skin. Zinc sulfate, nickel sulfate, sodium dichromate and zinc chelator (N, N, N`, N`-tetrakis (2-pyridylmethyl) ethylenediamine) activate cell proliferation and induce apoptosis of keratinocytes.

Some Oil Characteristics of Fruit of Le002 And Mt087 Olive Cultivar Candidates

Abstract PDF Full-Text e-Pub Heparin is a natural anticoagulant from animal organs with excellent anticoagulant activity, and it is of high price as the raw material for the preparation of heparin originates from the special organs of animals. There is also the problem of biological rejection. As Pentosan sulfate has a similar chemical structure to heparin and is prepared from renewable plant-derived pentosan, so the preparation and biological activity evaluation of pentosan sulfate has become a new research hotspot in the field. This paper mainly reviews the structure, physical and chemical properties, preparation methods and the analysis and evaluation of various biological activities of pentosan sulfate. The future development of pentosan sulfate is to find plant-based pentosans with similar structure to hep.....

Directed aryl sulfotransferase evolution toward improved sulfation stoichiometry on the example of catechols.

Sulfation is an important way for detoxifying xenobiotics and endobiotics including catechols. Enzymatic sulfation occurs usually with high chemo- and/or regioselectivity under mild reaction conditions. In this study, a two-step p-NPS-4-AAP screening system for laboratory evolution of aryl sulfotransferase B (ASTB) was developed in 96-well microtiter plates to improve the sulfate transfer efficiency toward catechols. Increased transfer efficiency and improved sulfation stoichiometry are achieved through the two-step screening procedure in a one-pot reaction. In the first step, the p-NPS assay is used (detection of the colorimetric by-product, p-nitrophenol) to determine the apparent ASTB activity. The sulfated product, 3-chlorocatechol-1-monosulfate, is quantified by the 4-aminoantipyrine (4-AAP) assay in the second step. Comparison of product formation to p-NPS consumption ensures successful directed evolution campaigns of ASTB. Optimization yielded a coefficient of variation below 15% for the two-step screening system (p-NPS-4-AAP). In total, 1760 clones from an ASTB-SeSaM library were screened toward the improved sulfation activity of 3-chlorocatechol. The turnover number (kcat = 41 ± 2 s-1) and catalytic efficiency (kcat/KM = 0.41 μM-1 s-1) of the final variant ASTB-M5 were improved 2.4- and 2.3-fold compared with ASTB-WT. HPLC analysis confirmed the improved sulfate stoichiometry of ASTB-M5 with a conversion of 58% (ASTB-WT 29%; two-fold improvement). Mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) confirmed the chemo- and regioselectivity, which yielded exclusively 3-chlorocatechol-1-monosulfate. For all five additionally investigated catechols, the variant ASTB-M5 achieved an improved kcat value of up to 4.5-fold and sulfate transfer efficiency was also increased (up to 2.3-fold).

Antibacterial effect of copper sulfate against multi-drug resistant nosocomial pathogens isolated from clinical samples.

Background and Objective:With the emergence of antibiotic resistance and the hospital acquired infection, the interest for antimicrobial agents has recently increased again in public health. Copper is recommended as a supplementary method of increasing biological safety in the hospital environment. The objective of this study was to determine the antibacterial activity of copper sulfate salts on strains of bacterial pathogens isolated from different clinical pictures in different health establishment in Algeria.Methods:A total of 25 different bacterial isolates (16 Enterobacteriaceae, 5 Staphylococci, and 4 Pseudomonas) were tested for susceptibility to copper sulfate using minimum inhibitory concentration (MIC-Cu) and minimum bactericidal concentrations (MBC-Cu) determinations. All isolates were also tested for susceptibility to six antibiotics.Results:Antibiotic susceptibility studies revealed that 100% of isolates were resistant to one or more antibiotics. Fifty two percent of isolates were very susceptible to copper sulfate, with MICs ranging from 100 to 200 µg/ml. MBC-Cu = 1600 μg/ml showed the best bactericidal effect against the great majority of studied bacteria (52%). A good bactericidal activities of copper sulfate were recorded against Proteus vulgaris and Staphylococcus aureus (MBC/MIC=1). The Gram-negative bacteria isolates which were copper resistant also showed a high resistance to chloramphenicol (r=0.78) and Trimethoprime (r=0.61). Furthermore, the strains that were no-susceptible to three different antimicrobial classes (Escherichia coli, Staphylococcus saprophyticus) were not resistant to copper sulfate.Conclusion:Copper sulfate salts has significant antibacterial activity against multi-drug resistant nosocomial pathogens.

Динаміка лабораторних показників щурів після імплантації матеріалу біоскла і склокераміки

Aim. To explore the recovery of the structure and density of the spongy and cortical bone after filling the defect with the bioglass developed by the authors. Material and Methods. The experiment was performed on white rats where the dynamics of blood biochemical markers were studied after implantation of glass-based and glass-ceramic materials. The study rats were divided into 2 groups. In the first group a material on the basis of glass ceramics AC-5 was implanted; in the second group - a material on the basis of glass FAR-5. Implant toxicity was determined based on the study of the dynamics of serum protein content, urea and alanine aminotransferase (ALT) enzyme activity. The state of restoration of the structure and density of the spongy and cortical bone was examined using alkaline phosphatase level. Results and Discussion. The study found no impact of implants based on glass ceramics AC-5 on the functional state of the liver and kidneys of experimental animals, but revealed the presence of inflammatory-regenerative changes in bone tissue at the implant site manifested only on day 7 of observation, which is normal regeneration after implantation. The dynamics of alkaline phosphatase activity in the serum of rats corresponded to the stages of bone regeneration and implant survival. In the rats of the second group, the content of total protein, unlike the animals of the first group, was significantly higher compared to the intact rats at all observation periods, indicating the presence of intoxication in animals. The glycoprotein content was increased, indicating the presence of inflammation in the animals at the end of the study. In contrast to the rats of the first group, the activity of alkaline phosphatase was significantly increased compared with that of the intact rats. The indicator increased with the observation period and returned to the reference values by the 90th day. Conclusion. Based on the study of the markers of bone metabolism (alkaline phosphatase activity and serum level of chondroitin sulfate ), a longer process of bone remodeling in case of implantation of the FAR-5 implant material was revealed, which increased compared to the test parameters of the intact animals.

Low-Abundance Members of the Firmicutes Facilitate Bioremediation of Soil Impacted by Highly Acidic Mine Drainage From the Malanjkhand Copper Project, India.

Sulfate- and iron-reducing heterotrophic bacteria represented minor proportion of the indigenous microbial community of highly acidic, oligotrophic acid mine drainage (AMD), but they can be successfully stimulated for in situ bioremediation of an AMD impacted soil (AIS). These anaerobic microorganisms although played central role in sulfate- and metal-removal, they remained inactive in the AIS due to the paucity of organic carbon and extreme acidity of the local environment. The present study investigated the scope for increasing the abundance and activity of inhabitant sulfate- and iron-reducing bacterial populations of an AIS from Malanjkhand Copper Project. An AIS of pH 3.5, high soluble SO42− (7838 mg/l) and Fe (179 mg/l) content was amended with nutrients (cysteine and lactate). Thorough geochemical analysis, 16S rRNA gene amplicon sequencing and qPCR highlighted the intrinsic metabolic abilities of native bacteria in AMD bioremediation. Following 180 days incubation, the nutrient amended AIS showed marked increase in pH (to 6.6) and reduction in soluble -SO42− (95%), -Fe (50%) and other heavy metals. Concomitant to physicochemical changes a vivid shift in microbial community composition was observed. Members of the Firmicutes present as a minor group (1.5% of total community) in AIS emerged as the single most abundant taxon (∼56%) following nutrient amendments. Organisms affiliated to Clostridiaceae, Peptococcaceae, Veillonellaceae, Christensenellaceae, Lachnospiraceae, Bacillaceae, etc. known for their fermentative, iron and sulfate reducing abilities were prevailed in the amended samples. qPCR data corroborated with this change and further revealed an increase in abundance of dissimilatory sulfite reductase gene (dsrB) and specific bacterial taxa. Involvement of these enhanced populations in reductive processes was validated by further enrichments and growth in sulfate- and iron-reducing media. Amplicon sequencing of these enrichments confirmed growth of Firmicutes members and proved their sulfate- and iron-reduction abilities. This study provided a better insight on ecological perspective of Firmicutes members within the AMD impacted sites, particularly their involvement in sulfate- and iron-reduction processes, in situ pH management and bioremediation.

Effects of the human SULT1A1 polymorphisms on the sulfation of acetaminophen,O-desmethylnaproxen, and tapentadol.

Non-opioid and opioid analgesics, as over-the-counter or prescribed medications, are widely used for the management of a diverse array of pathophysiological conditions. Previous studies have demonstrated the involvement of human cytosolic sulfotransferase (SULT) SULT1A1 in the sulfation of acetaminophen, O-desmethylnaproxen (O-DMN), and tapentadol. The current study was designed to investigate the impact of single nucleotide polymorphisms (SNPs) of the human SULT1A1 gene on the sulfation of these analgesic compounds by SULT1A1 allozymes. Human SULT1A1 genotypes were identified by database search. cDNAs corresponding to nine SULT1A1 nonsynonymous missense coding SNPs (cSNPs) were generated by site-directed mutagenesis. Recombinant wild-type and SULT1A1 allozymes were bacterially expressed and affinity-purified. Purified SULT1A1 allozymes were analyzed for sulfation activity using an established assay procedure. Compared with the wild-type enzyme, SULT1A1 allozymes were shown to display differential sulfating activities toward three analgesic compounds, acetaminophen, O-desmethylnaproxen (O-DMN), and tapentadol, as well as the prototype substrate 4NP. Results obtained indicated clearly the impact of genetic polymorphisms on the drug-sulfation activity of SULT1A1 allozymes. Such information may contribute to a better understanding about the differential metabolism of acetaminophen, O-DMN, and tapentadol in individuals with different SULT1A1 genotypes.

Sulfation of hesperetin, naringenin and apigenin by the human cytosolic sulfotransferases: a comprehensive analysis

Previous studies have revealed sulfation as a major pathway for the metabolism of hesperetin, naringenin and apigenin. The current study was designed to identify the human cytosolic sulfotransferase (SULT) enzyme(s) capable of sulfating these flavonoid compounds. Of the thirteen human SULTs, six (1A1, 1A2, 1A3, 1B2, 1C4, 1E1) displayed significant sulfating activity toward hesperetin, five (1A1, 1A2, 1A3, 1B2, 1C4) displayed sulfating activity towards naringenin, and four (1A1, 1A2, 1A3, 1C4) showed sulfating activity towards apigenin. Of the four human organ specimens tested, liver and intestine cytosols displayed much higher hesperetin-, naringenin- and apigenin-sulfating activity than lung and kidney cytosols. Moreover, sulfation of hesperetin, naringenin and apigenin was shown to take place in HepG2 human hepatoma cells and Caco-2 human colon adenocarcinoma cells under cultured conditions. Taken together, these results provided a biochemical basis underlying the metabolism of hesperetin, naringenin and apigenin through sulfation in humans.

Modifiers in magnesia stone structure

The additives, most often used for modifying the structure of different binders, are considered in this article. However, their influence on the properties of magnesium composites based on sulfate activators has not been studied enough. It was found that the iron content of the additives makes it possible to improve the structure of the sulfomagnesium stone and reduce its hygroscopicity. Due to the cation exchange between iron and magnesium, iron cations can be included into the structure of the magnesium stone, forming new non-hygroscopic hydrate phases. This process takes place after 3 days of the magnesium stone hardening. In addition, the use of iron-containing additives makes it possible to increase the water resistance of such stone due to the ability of metal cations to be adsorbed on the surface of sparingly soluble magnesium hydrogensulfates. This way the surface area, capable of adsorbing water molecules, is reduced.

Treatment of tannery wastewater using aluminium formate: influence of the formate over sulphate based coagulant

<p>Tannery industries provoke the conspicuous quantity of deleterious effluent which has to be treated prior to discharge into the environment. Pre-treatment of tannery wastewater with aluminium sulphate is well known over decades, but due to the corrosive nature of sulphate this pre-treated water causes several issues in the biological treatment system. To overcome this issue a study was performed to understand the coagulant activity of aluminium formate and aluminium sulphate. The effect of coagulant activity as a function of pH and coagulant dose of Aluminium formate was studied and found that it surpassed aluminium sulphate in terms of Cr(VI), sulphate and COD removal by 10%, 6% and 10% respectively, while turbidity removal for both coagulants was found approximately equal. Possible mechanistic approach to the coagulation property of aluminium formate and aluminium sulphate could be inter particle bridging and sweep coagulation respectively. Formate [HCOO-] can be utilized as a counter anion in the place of commonly used sulphate anions as it is biodegradable, non-toxic and corrosive free compound. Therefore, Aluminium formate can be a promising coagulant for the pre-treatment of tannery wastewater.</p>

Steroid sulfatase promotes invasion through epithelial-mesenchymal transition and predicts the progression of bladder cancer.

Androgen signal has been recently suggested to be associated with the progression of bladder cancer. Steroid sulfatase (STS) is a steroid sulfate activation enzyme, considered to be one of the key enzymes in the androgen signaling pathway. However, the role of STS in bladder cancer has not been elucidated. The purpose of the present study was to determine the clinical and functional significance of STS in bladder cancer. Immunohistochemical analysis of surgical specimens obtained by radical cystectomy (n=114) demonstrated that overexpression of STS was associated with the invasion of bladder cancer, as evidenced by the incidence of STS-positive cancers (11.5 and 37.1% in non-muscle invasive and muscle invasive bladder cancers, respectively; P=0.003). STS-positive cancer demonstrated shorter recurrence-free survival and cancer-specific survival (P=0.0027 and 0.0030, respectively). Furthermore, knockdown of STS significantly reduced cell migration and invasion capacities of bladder cancer cells (P<0.001 and P=0.005, respectively), accompanied by the upregulation of E-cadherin and downregulation of vimentin. In summary, the present study demonstrated that STS promotes the invasion capability of bladder cancer via regulation of the epithelial-mesenchymal transition, and may be a useful marker for predicting the progression of bladder cancers.

Effects of dextran sulfate, 4-t-butylcyclohexanol, pongamia oil and hesperidin methyl chalcone on inflammatory and vascular responses implicated in rosacea.

BackgroundRosacea is a chronic facial skin disorder characterized by inflammation and vascular abnormalities. The pathophysiology of rosacea involves increased activation of the capsaicin receptor, TRPV1, the vascular endothelial growth factor (VEGF) pathway, and cathelicidin LL-37, MMP-9, and KLKs. We evaluated the activity of four compounds (dextran sulfate, 4-t-butylcyclohexanol [BCH; TRP-regulin®], pongamia oil, and hesperidin methyl chalcone [HMC]) on inflammatory and vascular responses implicated in rosacea.Materials and methodsThe anti-inflammatory activity of dextran sulfate was evaluated on PGE2 production after PMA stimulation of NCTC-2544 keratinocytes, and on normal human epidermal keratinocytes (NHEKs) after proinflammatory stimulation to mimic a rosacea environment. The anti-angiogenic activity of dextran sulfate was measured by analyzing pseudotube formation in co-cultured human microvascular endothelial cells/normal human dermal fibroblasts. HMC modulation of vascular responses and IL-8 cytokine production after SP stimulation was evaluated in human skin explants. We also assessed the effect of BCH on TRPV1 activation, and the effect of combined BCH and pongamia oil on the inflammatory response of NHEKs.ResultsDextran sulfate strongly and significantly inhibited PMA-induced PGE2 production, inhibited KLK5 and MMP-9 mRNA expression, and IL-8, IL-1α and VEGF production, and displayed a highly significant inhibitory effect on VEGF-induced pseudotube formation. In SP-stimulated human skin explants, HMC significantly decreased the proportion of dilated vessels, total vessel area, and IL-8 production. BCH significantly and dose-dependently inhibited TRPV1 activation, and BCH and pongamia oil inhibited CXCL1 and CXCL6 mRNA expression and IL-8 production in NHEKs. Combined BCH/pongamia oil inhibited IL-8 production synergistically.ConclusionThese in vitro results showed that dextran sulfate, BCH, pongamia oil and HMC, possess complementary soothing and anti-redness properties, supporting their combination in Avène redness-relief cosmetic products for sensitive skin prone to redness, and for topical adjunctive rosacea treatment.

Serum bactericidal activity of colistin and azidothymidine combinations against mcr-1-positive colistin-resistant Escherichia coli

To examine the serum bactericidal activity of colistin sulphate (CS) and azidothymidine (AZT) combinations, time-kill curves were performed in native and heat-inactivated human serum with five colistin-resistant and four colistin-susceptible Gram-negative strains. Serum samples were spiked according to median and minimum plasma peak concentrations measured in a phase 1 clinical study in which seven healthy subjects received three (q12h) 1-h intravenous infusions of 4, 2 and 2 MIU colistin methanesulfonate (CMS) co-administered with 200, 100 and 100 mg AZT, respectively. This trial was performed to assess pharmacokinetics and safety of CMS/AZT combination therapy. Minimum bactericidal concentrations of CS in native, but not heat-inactivated, serum were strongly reduced compared with Mueller-Hinton broth for all tested Enterobacteriaceae, except one colistin-resistant (serum-resistant) strain. For colistin-susceptible strains, the minimum CS concentration after 2 MIU CMS was already bactericidal in native and heat-inactivated serum. Median, but not minimum, CS concentrations after 2 MIU CMS were sufficient to kill the serum-resistant, colistin-resistant Escherichia coli strain in native serum. In heat-inactivated serum, even the median CS concentration after 2 MIU CMS was not bactericidal for all colistin-resistant strains. In general, combinations with AZT accelerated killing of colistin-resistant E. coli or showed bactericidal activity even if the substances alone were not bactericidal. Thus, combination with AZT potentiates the bactericidal effect of colistin against colistin-resistant E. coli. Although the dosage of 2 MIU CMS plus AZT may be sufficient to treat infections with colistin-susceptible strains, for infections caused by colistin-resistant E. coli, dosing should be further optimised.

The Clock Protein Bmal1 Regulates Circadian Expression and Activity of Sulfotransferase 1a1 in Mice.

Sulfotransferase 1a1 (Sult1a1) is a phase II enzyme that contributes extensively to metabolism and detoxification of various drugs and chemicals. Here we aimed to investigate a potential role of the clock protein Bmal1 (brain and muscle Arnt-like protein-1) in circadian regulation of Sult1a1 in mice. The regulatory effects of Bmal1 on Sult1a1 were assessed both in vivo (using Bmal1- deficient mice) and in vitro (using both normal and serum-shocked Hepa-1c1c7 cells). The relative mRNA and protein levels of Sult1a1 in the cells or mouse livers were measured by RT-qPCR and Western blotting, respectively. Sulfation activities of two Sult1a1 substrates (i.e., p-nitrophenol and galangin) were determined using mouse liver S9 fractions. Transcriptional regulation of Sult1a1 by Bmal1 was investigated using luciferase reporter, electrophoretic mobility shift (EMSA), and chromatin immunoprecipitation (ChIP) assays. We first showed that hepatic Sult1a1 was rhythmically expressed at both mRNA and protein levels (higher expressions during the night than the daytime). Consistently, the liver sulfation activities toward two Sult1a1 substrates were circadian time dependent with a higher activity at ZT14 than at ZT2. Furthermore, deletion of Bmal1 in mice blunted the circadian rhythmicity of hepatic Sult1a1 (with reduced expression levels). Likewise, Bmal1 positively regulated Sult1a1 expression in conventionally cultured Hepa-1c1c7 cells, and Bmal1 knockdown blunted expression rhythmicity of Sult1a1 in serum-shocked Hepa-1c1c7 cells. A combination of promoter analysis, EMSA and ChIP assays revealed that Bmal1 stimulated Sult1a1 transcription through its specific binding to the-571- to -554-bp region (an E-box element) in the promoter. In conclusion, Bmal1 activated the transcription of Sult1a1 and controlled circadian expression and activity of the enzyme.

Efficiency of enhanced oil recovery by injection of low-salinity water in barium-containing carbonate reservoirs

When low-salinity water containing sulfate ions is injected into carbonate reservoirs, rock dissolution and in situ precipitation occur, altering rock permeability and wettability. Particularly, when barium ions are present in formation water, they react chemically with {text{SO}}_{4}^{2 - }, and BaSO4 is precipitated. These reactions can cause a serious impact on the efficiency of enhanced oil recovery (EOR). Therefore, the main purpose of this study was to identify EOR efficiency induced by low-salinity waterflooding (LSWF) when Ba2+ is present in carbonate reservoirs. From the experimental results, it was confirmed that the permeability calculated by the measured pressure difference was improved because of rock dissolution predominating over in situ precipitation for the case of low Ba2+ concentrations. In the analysis of wettability alteration through the measurements of relative permeabilities before and after LSWF, the higher Ba2+ concentration case consumed more {text{SO}}_{4}^{2 - } in precipitating the BaSO4, resulting in weaker wettability alteration due to the reduction of sulfate activity. These phenomena ultimately influenced EOR efficiency, i.e., the oil recovery was greater for the lower Ba2+ concentration.

Electrochemical activation of sulfate by BDD anode in basic medium for efficient removal of organic pollutants

Electrochemical advanced oxidation processes (EAOPs) based on hydroxyl radicals (OH) have some limitations when they are applied to real wastewater treatment, such like strict requirements on pH (acidic electrolyte) and high energy consumption. Compared to OH, Sulfate radicals (SO4–) have high redox potential in wider range of pH (2–9). In this study, SO4– were efficiently produced by electrochemical activation of SO42− at boron doped diamond (BDD) anode. The degradation rate of 2,4-DCP (k = 0.828 ± 0.05 h−1) in the presence of Na2SO4 was approximately 4 times than that without Na2SO4 (k = 0.219 ± 0.01 h−1), indicating that SO4– exhibited higher reactivity than OH at initial pH = 9. Moreover, the amount of O2 decreased by 65% after 100 min during electro-oxidation of 2,4-DCP and the specific energy consumption per unit TOC (ECTOC) was reduced by 70% when the concentration of Na2SO4 increased from 0.01 to 0.1 M. The impact of sulfate ions in the electrochemical advanced oxidation were investigated. Electron spin resonance (ESR) measurements were conducted to identify the formation of SO4–. Electrolysis of 2,4-DCP with specific radical scavengers (ethanol and tert-Butanol) were conducted and the results revealed that SO4– were mainly produced by one-electron loss of sulfate at basic condition. Electro-generation persulfate was measured and participation of non-radical activation of persulfate was investigated. O2 production was quantified and we found electrochemical activation of sulfate could inhibit water dissociation. Taken all findings, a mechanism of electrochemical activation of sulfate at BDD anode was summarized. This technology eliminates the requirement for pH adjustment for wastewater treatment and makes EAOPs more effective and economic as well.

Application of sulfate radicals from ultrasonic activation: Disintegration of extracellular polymeric substances for enhanced anaerobic fermentation of sulfate-containing waste-activated sludge

Sulfate radicals produced by ultrasonic activation of persulfate (PS) or sulfate were applied to disintegrate sludge flocs and extracellular polymeric substances (EPSs). The pretreatment facilitated the production of volatile fatty acids (VFAs) and hydrogen from subsequent anaerobic fermentation, yielding a potential method for improving the utilization of sulfate-containing waste-activated sludge (WAS). Sulfate radicals produced using ultrasound (US) in the presence of PS/sulfate showed a synergetic effect of advanced oxidation on WAS pretreatment. Among the three types of pretreatment (US, US + Sulfate, and US + PS), US + PS pretreatment was the most favoured for chemical oxygen demand (COD) solubilization, protein release, and sludge disintegration under a US density of 1.5 W/mL. Tightly bound EPS (TB-EPS) could be effectively disintegrated, and organic compounds were transformed into loosely bound EPS and soluble EPS. Unexpected COD consumption by excessive free radicals was also observed, when increasing the ultrasonic energy input (e.g. to 12 W/mL), towards a positive role for sludge disintegration and subsequent anaerobic fermentation. It was found that small particles (0.1–0.5 μm) from released organics could be preferentially overoxidized. An appropriate low ultrasonic strength initiated attack on the polymeric substances in WAS by the produced radicals, which TB-EPS could be primary target.

Affinity adsorption of bovine hyaluronidase with ligands targeting to active site

Four affinity ligands were designed from 6-chloromethyluracil and 2-aminobenzimidazole and simulated for the interaction with bovine hyaluronidase-1. Regarding sequence alignment, bovine hyaluronidase-1 precursor showed circa 83.6% similarity with human hyaluronidase-1. Regarding structural modeling and molecular docking, bovine hyaluronidase-1 interacted with ligands in the active site. Using epichlorohydrin, 1,3-propanediamine and cyanuric chloride as spacers, 6-chloromethyluracil and 2-aminobenzimidazole were composed to Sepharose beads. The modified Sepharose beads were then subjected to adsorption analysis with bovine hyaluronidase. After one step of affinity adsorption, the samples extracted from bovine testes were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis and activity assay. As calculated, the densities of four ligands on sorbents (entitled as L-1, L-2, L-3 and L-4) were 37.7 ± 2.3, 36.4 ± 3.2, 42.4 ± 4.2 and 33.7 ± 2.3 μmol/g wet gel; the theoretical maximum adsorption (Qmax) of bovine hyaluronidase on the four sorbents were 63.6 ± 1.6, 72.0 ± 0.7, 111.0 ± 4.1 and 121.7 ± 2.3 mg/g wet gel, respectively; the dissociation constants (Kd) of the four sorbents were 18.5 ± 0.8, 48.1 ± 4.3, 35.0 ± 3.0, 40.6 ± 2.7 μg/g wet gel, respectively. After optimization, the proteins captured by sorbents attaching 2-aminobenzimidazole based ligands (L-3 and L-4) revealed the main single band at approximately 50 kDa, and the purities were about 85.2 and 96.4%; the bioactivity recoveries were 83.5 and 89.4%. In addition, the bands on SDS-PAGE gel were also extracted and confirmed with linear trap quadropole mass spectrometry (LTQ-MS) analysis.

Alkali-Sulfate Activated Blended Portland Cements

Early strength of the blended Portland cements containing granulated blast furnace slag and natural pozzolanas (zeolite tuff, etc.) can be enhanced by the alkali-sulfate activation. High early strength of the blended Portland cements as a result of alkali-sulfate activation can be attributed to acceleration of pozzolanic reaction at the early stages and formation of more quantities of ettringite at the early stages of structure formation. The results of the study showed that with high amounts of sodium sulfate in the alkali-sulfate activator, contents of gypsum dihydrate as a setting regulator of the blended Portland cements could be reduced. The effect of sodium sulfate activator on properties of the blended Portland cements was studied and the results are discussed.