Highly Efficient Removal of 2,4,5-Trichlorophenoxyacetic Acid by Adsorption and Photocatalysis Using Nanomaterials with Surface Coating by the Cationic Surfactant.

Extensive removal of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) using titania (TiO2) nanoparticles by adsorption and photocatalysis with a surface coating by cetyltrimethylammonium bromide (CTAB) is reported. The CTAB-coated TiO2 nanoparticles (CCTN) were characterized by FT-IR, zeta-potential measurements, and UV-vis diffuse reflectance spectroscopy (UV-vis-DRS). 2,4,5-T removal increased significantly after surface modification with CTAB compared with bare TiO2 nanoparticles. Optimal parameters affecting 2,4,5-T removal were found to be pH 4, CCTN dosage 10 mg/mL, and adsorption time 180 min. The maximum adsorptive removal of 2,4,5-T using CCTN reached 96.2% while highest adsorption capacity was 13.4 mg/g. CCTN was also found to be an excellent photocatalyst that achieved degradation efficiency of 99.2% with an initial concentration of 25 mg/L. The removal mechanisms of 2,4,5-T using CCTN by both adsorption and photocatalysis are discussed in detail based on changes in functional group vibrations and surface charge. Our results indicate that CCTN is an excellent material for 2,4,5-T removal in water by both adsorption and photocatalysis.

Hyponutrition among newly diagnosed gastric cancer.

OBJECTIVES: This study aims to determine the malnutrition status among Vietnamese patients newly diagnosed with gastric cancer (GC). BACKGROUND: GC remains the top rank of common and deadly diseases. With limited clinical manifestation, most GC patients were diagnosed at late stages when tumor is not radically resected. Malnutrition was associated with poor prognosis of GC, such as prolonged hospitalization, limited treatment efficacy and low survival rate. METHODS: The cross-sectional descriptive study recruited 77 patients newly diagnosed with GC and 90 healthy individuals (HC). The data used for this study were approved by the local Ethical Committee. The data were analysed on STATA 14.0 and GraphPad Prism 8.0. RESULTS: We observed the male dominant distribution in GC cohort and over 65% of GC were firstly diagnosed at advanced stages (III and IV). Anemia was detected in about 50% of GC patients. Hyponutrition was prevalent in newly diagnosed GC. We found the decreased tendency of anemia related indexes from HC to early stages (I and II) and advanced stages (III and IV) of GC patients. CONCLUSION: Anemia and hypoproteinemia occurred frequently among Vietnamese newly diagnosed GC. The nutrition therapy would benefit GC patients (Tab. 4, Fig. 4, Ref. 20).

The diagnostic and prognostic value of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio on gastric cancer patients.

Gastric cancer (GC) is the remaining concern of cancer-associated health burden. Valuable predictive and prognostic indicators support the early diagnosis and improve outcome. Immune escape and inflammation are important cancer hallmarks. The prognostic and diagnostic value of platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) was reported in some cancers. But these cheap and convenient indexes are far from clinical use. Thus, investigation the alteration of those index on GC is needed to impose the use of those indexes in clinic. The study recruited seventy-seven hospitalized patients newly diagnosed with GC and 90 healthy individuals. The clinical and preclinical data of participants were collected from Hospital Information Management system. This study were approved by the Ethical Committee, Vietnam Military Medical University. The data were analyzed on STATA version 14.0 and GraphPad Prism 8.0. The alteration of immunological system was reported by significantly higher white blood cell count, neutrophils, platelets, PLR, and NLR as well as decreased lymphocytes on GC, compared to healthy individuals. Those indexes were elevated on advanced stage GC, compared to early stage GC. Our receiver operating characteristic curve analysis showed the significant specificity and sensitivity of PLR (cutoff 135.0) and NLR (cutoff 2.0) on GC diagnosis with respective area under receiver operating characteristic curve of 84.74% and 85.17%, P < .0001. Besides, our results reported the tendency of increased PLR and NLR and short time from clinical signs to being diagnosed. PLR and NLR have significant specificity and sensitivity in diagnosis and prognosis of GC.

Removal of Acid Orange G Azo Dye by Polycation-Modified Alpha Alumina Nanoparticles.

Highly positively charged poly(vinyl benzyl trimethylammonium chloride) (PVBMA) was successfully synthesized with approximately 82% of yield. The PVBMA was characterized by the molecular weight (Mw ) of 343.45 g mol-1 and the molecular weight distribution, (D) of 2.4 by 1 H NMR and SEC measurements. The PVBMA was applied as an effective agent for α-Al2 O3 surface modification in the adsorptive removal of the azo dye acid orange G (AOG). The AOG removal performance was significantly enhanced at all pH compared to without surface modification. The experimental parameters were optimal at pH 8, free ionic strength, 15 min of adsorption time, and 5 mg mL-1 α-Al2 O3 adsorbents. The AOG adsorption which was mainly controlled by the PVBMA-AOG electrostatic attractions was better applicable to the Langmuir isotherm and the pseudo-second kinetic model. The PVBMA-modified α-Al2 O3 demonstrates a high-performance and highly reusable adsorbent with great AOG performances of approximately 90.1% after 6 reused cycles.

Adsorptive removal of dichlorophenoxyacetic acid (2,4-D) using novel nanoparticles based on cationic surfactant-coated titania nanoparticles.

A novel nanomaterial based on cationic surfactant-coated TiO2 nanoparticle (CCTN) was systematically fabricated in this work. Synthesized titania nanoparticles were thoroughly characterized by XRD, FT-IR, HR-TEM, TEM-EDX, SEM with EDX mapping, BET, and ζ potential measurements. The adsorption of cationic surfactant, cetyltrimethylammonium bromide (CTAB), on TiO2 was studied under various pH and ionic strength conditions. Adsorption of CTAB on TiO2 increased with ionic strength increment in the presence of hemimicelle monolayer structure, indicating that nonelectrostatic and electrostatic forces control CTAB uptake. CTAB adsorption isotherms on TiO2 were according to a two-step model. Potential application in pesticide removal of 2,4-dichorophenoxy acetic acid (2,4-D) using CCTN was also studied. Optimum parameters for 2,4-D treatment through adsorption technique were pH 5, adsorption time of 120 min, and CCTN dosage of 10 mg·mL-1. Very low 2,4-D removal efficiency using TiO2 without CTAB coating was found to be approximately 28.5% whereas the removal efficiency was up to about 90% by using CCTN under optimum conditions, and the maximum adsorption capacity of 12.79 mg·g-1 was found. Adsorption isotherms of 2,4-D on CCTN were more suitable with the Langmuir model than Freundlich. Adsorption mechanisms of 2,4-D on CCTN were mainly governed by Columbic attraction based on isotherms and surface charge changes.

Two-stage anaerobic membrane bioreactor for co-treatment of food waste and kitchen wastewater for biogas production and nutrients recovery.

Co-digestion of organic waste and wastewater is receiving increased attention as a plausible waste management approach toward energy recovery. However, traditional anaerobic processes for co-digestion are particularly susceptible to severe organic loading rates (OLRs) under long-term treatment. To enhance technological feasibility, this work presented a two-stage Anaerobic Membrane Bioreactor (2 S-AnMBR) composed of a hydrolysis reactor (HR) followed by an anaerobic membrane bioreactor (AnMBR) for long-term co-digestion of food waste and kitchen wastewater. The OLRs were expanded from 4.5, 5.6, and 6.9 kg COD m-3 d-1 to optimize biogas yield, nitrogen recovery, and membrane fouling at ambient temperatures of 25-32 °C. Results showed that specific methane production of UASB was 249 ± 7 L CH4 kg-1 CODremoved at the OLR of 6.9 kg TCOD m-3 d-1. Total Chemical Oxygen Demand (TCOD) loss by hydrolysis was 21.6% of the input TCOD load at the hydraulic retention time (HRT) of 2 days. However, low total volatile fatty acid concentrations were found in the AnMBR, indicating that a sufficiently high hydrolysis efficiency could be accomplished with a short HRT. Furthermore, using AnMBR structure consisting of an Upflow Anaerobic Sludge Blanket Reactor (UASB) followed by a side-stream ultrafiltration membrane alleviated cake membrane fouling. The wasted digestate from the AnMBR comprised 42-47% Total Kjeldahl Nitrogen (TKN) and 57-68% total phosphorous loading, making it suitable for use in soil amendments or fertilizers. Finally, the predominance of fine particles (D10 = 0.8 µm) in the ultrafiltration membrane housing (UFMH) could lead to a faster increase in trans-membrane pressure during the filtration process.

Highly adsorptive protein inorganic nanohybrid of Moringa seeds protein and rice husk nanosilica for effective adsorption of pharmaceutical contaminants.

The present study aims to investigate adsorption characteristics and mechanisms of Moringa (MO) seeds protein on nanosilica rice husk and their applications in removal of pharmaceutical residues including the fluoroquinolone antibiotic levofloxacin (LFX) and the nonsteroidal anti-inflammatory drug diclofenac (DCF) in aquatic environment. Molecular weight of MO protein was determined by gel-permeation chromatography (GPC) method while its amino acids were quantified by high performance liquid chromatography (HPLC). The number-(Mn) and weight-average molecular weights (Mw) of MO protein were 1.53 × 104 and 1.61 × 104 g/mol, respectively. Different effective conditions on adsorption protein on nanosilica including contact time, pH, adsorbent dosage, and ionic strength were systematically optimized and found to be 180 min, 10, 10 mg/mL and 1 mM KCl, respectively. The surface charge change by zeta potential, surface modification by Fourier-transform infrared spectroscopy (FT-IR) and adsorption isotherms demonstrated that protein adsorption on nanosilica was governed by both electrostatic and non-electrostatic interactions. Application of protein functionalized nanosilica (ProFNS) in LFX and DCF removal were also thoroughly studied. The selected conditions for LFX and DCF removal using ProFNS were 1 mM KCl for both LFX and DCF; pH 8 and pH 6; contact time 90 and 120 min, and adsorption dosage 10 and 5 mg/ml for LFX and DCF, respectively. Adsorption isotherms of protein on nanosilica as well as LFX and DCF onto ProFNS at different ionic strengths were reasonably fitted by the two-step model while a pseudo-second-order model could fit adsorption kinetic well. The removal of LFX and DCF using ProFNS significantly increased from 51.51% to 87.35%, and 7.97%-50.02%, respectively. High adsorption capacities of 75.75 mg/g for LFX and 59.52 mg/g for DCF, indicate that ProFNS is a great performance for pharmaceutical residues removal in water environment.

Adsorptive Removal of Azo Dye New Coccine Using High-Performance Adsorbent-Based Polycation-Modified Nano-Alpha Alumina Particles.

The azo dyes new coccine (NCC) were successfully removed through the adsorption onto PVBTAC-modified α-Al2O3 particles. The optimal conditions of both the surface modification by PVBTAC adsorption and the NCC adsorption were thoroughly investigated. Formerly, polycations PVBTAC were adsorbed onto the nanosized α-Al2O3 particles at pH 8, NaCl 100 mM, with a contact time of 2 h, and initial concentration of 1000 ppm to modify the α-Al2O3 surface. Latterly, the NCC adsorptive removal was conducted at pH 8, NaCl 10 mM, α-Al2O3 adsorbent dosage of 3 mg mL-1, and a contact time of 45 min. Interestingly, the optimal pH of 8 potentially applies to treat real wastewater as the environmental pH range is often about 7-8. High removal efficiency and adsorption capacity of the NCC azo dyes were, respectively, found to be approximately 95% and 3.17 mg g-1 with an initial NCC concentration of 10 ppm. The NCC adsorption on the modified α-Al2O3 particles was well fitted with a Freundlich model isotherm. A pseudo-second kinetic was more suitable for the NCC adsorption on the PVBTAC-modified α-Al2O3 surface than a pseudo-first kinetic. The NCC adsorptive removal kinetic was also affirmed by the FT-IR spectra, based especially on the changes of functional group stretch vibrations of -SO3 - group in the NCC molecules and -N+(CH3)3 group in the PVBTAC molecules. The high reusability of the α-Al2O3 particles was proved to be higher than 50% after four generation times.

Degradation of glyphosate herbicide by an electro-Fenton process using carbon felt cathode.

An electro-Fenton system, which consists of a Pt gauze anode and a commercial carbon felt cathode, is commonly employed to generate in situ hydrogen peroxide, hydroxyl radical and regenerate ferrous catalyst for glyphosate degradation (a widely used herbicide in Vietnam) in aqueous solution. The absorbance measurements used to determine the glyphosate concentration during the electrolysis proved that glyphosate was degraded by pseudo-first-order kinetic. The influence of pH, current density, catalyst concentration and initial content of the glyphosate on mineralisation efficiency were studied by monitoring the total organic carbon (TOC) and hydrogen peroxide concentration during electrolysis. The results show that the maximal removal percentage of glyphosate was 91.91% with applied current density of 10 mA cm-2, pH 3, 0.1 mM Fe2+, 0.05 M Na2SO4, and 0.1 mM glyphosate in 40 min. The degrading rate constant of glyphosate degradation was calculated to be kapp = 0.063 min-1. In this 91.91% removal, 81.65% of glyphosate was mineralised and the remainder consists of intermediates produced during the electro-Fenton process.

Influence of Brønsted and Lewis acidity of the modified Al-MCM-41 solid acid on cellulose conversion and 5-hydroxylmethylfurfuran selectivity.

The modified Al-MCM-41 solid acids with turning Si/Al molar ratio were successfully fabricated through a hydrothermal route and utilized as a suitable catalyst in the cellulose conversion into 5-hydroxylmethylfurfural (5-HMF). The crystal structure, composition, morphologies and porosity of as-synthesized acids were characterized by XRD, FT-IR, N2 adsorption-desorption, TEM and EDS. The 27Al MAS NMR and 29Si-MAS NMR results revealed the existence of both Al framework and Al extra framework. Besides, the existence of medium-weak and strong acid sites, according to Brønsted and Lewis acidity, in Al-MCM-41 acids was confirmed by NH3-TPD and FTIR-pyridine adsorption. The 30Al-MCM-41 solid acid (Si/Al molar ratio = 30) exhibited excellent activity with the highest 5-HMF yield of 40.56% compared to other samples. We also discovered that 5-HMF production, as well as cellulose conversion, strongly depended on the total acid, strong/medium-weak acid ratio, as well as Brønsted/Lewis acid ratio. Therefore, these parameters have been considered as essential factors for the design of solid acid for 5-HMF production.

Removal of Lindane from Aqueous Solution Using Aluminum Hydroxide Nanoparticles with Surface Modification by Anionic Surfactant.

In the present study, we investigated the removal of an emerging pesticide lindane from aqueous solution using synthesized aluminum hydroxide Al(OH)3 (bayerite) nanomaterials with surface modification by an anionic surfactant sodium dodecyl sulfate (SDS). The Al(OH)3 nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and zeta potential. The lindane removal using SDS-modified nano-aluminum hydroxide nanoparticles (SMNAH) achieved removal of up to 93.68%, which was 3.3 times higher than that of nano-aluminum hydroxide nanoparticles. The adsorptive removal conditions were studied and found to have an adsorption time of 60 min, a pH of 6, an adsorbent dosage of 25 mg/mL and an ionic strength of 10 mM NaCl. After reusing four times, the removal efficiency of lindane using SMNAH still reached 75%. Two-step adsorption can fit adsorption isotherms of lindane onto SMNAH at two salt concentrations. On the basis of the change in zeta potential, surface functional groups and adsorption isotherms, we suggest that the formation of a bilayer micelle induced the removal of lindane.

Synthesis, Characterization, and Modification of Alumina Nanoparticles for Cationic Dye Removal.

In the present study, alumina nanoparticles (nano-alumina) which were successfully fabricated by solvothermal method, were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), and Brunauer⁻Emmett⁻Teller (BET) methods. The removal of cationic dye, Rhodamine B (RhB), through adsorption method using synthesized nano-alumina with surface modification by anionic surfactant was also investigated. An anionic surfactant, sodium dodecyl sulfate (SDS) was used to modify nano-alumina surface at low pH and high ionic strength increased the removal efficiency of RhB significantly. The optimum adsorption conditions of contact time, pH, and adsorbent dosage for RhB removal using SDS modified nano-alumina (SMNA) were found to be 120 min, pH 4, and 5 mg/mL respectively. The RhB removal using SMNA reached a very high removal efficiency of 100%. After four times regeneration of adsorbent, the removal efficiency of RhB using SMNA was still higher than 86%. Adsorption isotherms of RhB onto SMNA at different salt concentrations were fitted well by a two-step model. A very high adsorption capacity of RhB onto SMNA of 165 mg/g was achieved. Adsorption mechanisms of RhB onto SMNA were discussed on the basis of the changes in surface modifications, the change in surface charges and adsorption isotherms.

Rutile TiO2 nanocrystals with exposed {331} facets for enhanced photocatalytic CO2 reduction activity.

Rutile TiO2 nanocrystals with exposed high-index facets have been investigated in detail by high-resolution transmission electron microscopy (HR-TEM) and selected-area electron diffraction (SAED). It was found that the each branched nanocrystal is bound by 4 facets of high-index {331}. Additionally, rutile {101} twinned structures are formed in the boundary of branches during the growth of multi branches in a hierarchical flower-like nanostructures. Notably, the synthesized nanostructures showed significantly higher photocatalytic activities than that of rod particles with exposed {110} facets in photocatalytic CO2 reduction. Correlating the presence of high-energy surface on rutile nanocrystals with the photocatalytic activity clearly shows the significant role of surface steps in enhancing intrinsic activity for CO2 reduction to methanol.

Electrochemical degradation and mineralization of glyphosate herbicide.

The presence of herbicide is a concern for both human and ecological health. Glyphosate is occasionally detected as water contaminants in agriculture areas where the herbicide is used extensively. The removal of glyphosate in synthetic solution using advanced oxidation process is a possible approach for remediation of contaminated waters. The ability of electrochemical oxidation for the degradation and mineralization of glyphosate herbicide was investigated using Ti/PbO2 anode. The current intensity, treatment time, initial concentration and pH of solution are the influent parameters on the degradation efficiency. An experimental design methodology was applied to determine the optimal condition (in terms of cost/effectiveness) based on response surface methodology. Glyphosate concentration (C0 = 16.9 mg L-1) decreased up to 0.6 mg L-1 when the optimal conditions were imposed (current intensity of 4.77 A and treatment time of 173 min). The removal efficiencies of glyphosate and total organic carbon were 95 ± 16% and 90.31%, respectively. This work demonstrates that electrochemical oxidation is a promising process for degradation and mineralization of glyphosate.

Microbiologic characterization and antimicrobial susceptibility of Clostridium tetani isolated from wounds of patients with clinically diagnosed tetanus.

Clostridium tetani is the etiologic agent of the muscle-spasming disease tetanus. Despite an effective vaccine, tetanus is an ongoing problem in some developing countries. Diagnosis by bacterial culture is not done because it is generally unnecessary and the entry of route of the bacteria can be inapparent. We attempted to isolate and evaluate C. tetani from the wounds of 84 patients with tetanus. We effectively isolated C. tetani from 45 patients. All strains tested positive by polymerase chain reaction for the gene encoding tetanus neurotoxin. Antimicrobial susceptibilities were determined by disc diffusion and E-test. All C. tetani isolates were susceptible to penicillin and metronidazole but resistant to co-trimoxazole. Despite treatment with high doses of penicillin, C. tetani was isolated after 16 days of intravenous penicillin in two cases. These data show that the intravenous route for penicillin may be inadequate for clearing the infection and emphasizes wound debridement in the treatment of tetanus.

Study on microbiology agent characteristics causing reproductive tract infections in married women at some communities of Ha Tay province

Object: 2875 married woman in child bearing age (15 to 49) at 15 commune/ward in 7 suburban distric of Ha Tay province. The result show that: Reproductive tract infections rate is 64,24%. Incidence of countryside woman is higher than city woman. At the age group of 25-39 has the highest incidence. Types of pathogenic organism is multiform, leading is vagina bacterium with exiting of bacillus G (1), cocus G (+) particular is Gardnerella vaginalis. Infected Candida rate is quite high, infected Trichomomas is in low level. Antibiotic is resisted in various level.

The quality of reproductive health care services and family planning for women at reproductive age - Some assessments from a survey in Ha Tay province

The quality of reproductive health care services at studied communes were rather good, above 50% clients answered well all 5 contents. At present, the most difficulty and obstacles to ensure the quality of reproductive health care services at health stations were lack of medical equipments, and insufficience of specialized stuff and limited abilities. In order to enhance the quality of reproductive health care services at health stations, it should be done an intergrated set of solutions: Adding specialized equipments and personnel; re-educating; Improving the attitude of services.