•ZnONPs were biologically synthesized using palm fruit extract as reducing and stabilizing agent.•The size and shape of bio-synthesized ZnONPs depends on the concentrations of the extract.•In vitro ...studies on ZnONPs induce a significant reduction of Bcl-2 expression on MCF-7 cells.•In vivo evaluation verified the biocompatibility of DOX-ZnONPs, no significant toxicity on blood stream as well.
The green synthesis of zinc oxide nanoparticles (ZnONPs) using Borassus flabellifer fruit extract was characterized by UV–visible spectroscopy, FT-IR, XRD, TEM, Zeta potential and EDS analysis. The UV–visible spectrum showed an absorption peak at 368nm that reflects surface Plasmon resonance (SPR) ZnONPs. TEM photograph showed that the green synthesized ZnONPs were porous in nature and rod like structure with an average size of 55nm. The Zeta potential value of −21.5mV revealed the surface charge of green synthesized ZnONPs. In this study, we examined the synthesized DOX-ZnONPs exhibited a dose-dependent cytotoxicity against MCF-7 and HT-29. The inhibitory concentration (IC50) was found to be 0.125μgmL−1 for MCF-7 and HT-29 cells. An induction of apoptosis was evidenced by nuclear stain Hoechst 33258. In vivo toxicity assessment showed that DOX-ZnONPs have low systemic toxicity in murine model system. The results prove that the DOX-ZnONPs has low toxicity and high therapy efficacy, which provides convincing evidence for the green biosynthesized ZnO as a promising candidate for a drug delivery system.
We propose an extension of the basis sets proposed by Ahlrichs and coworkers at Karlsruhe (these basis sets are designated as the second-generation default or “def2” basis sets in the
Turbomole
...program). The Karlsruhe basis sets are very appealing because they constitute balanced and economical basis sets of graded quality from partially polarized double zeta to heavily polarized quadruple zeta for all elements up to radon (
Z
= 86). The extension consists of adding a minimal set of diffuse functions to a subset of the elements. This yields basis sets labeled minimally augmented or with “ma” as a prefix. We find that diffuse functions are not quite as important for the def2 basis sets as they are for Pople basis sets, but they are still necessary for good results on barrier heights and electron affinities. We provide assessments and validations of this extension for a variety of data sets and representative cases. We recommend the new ma-TZVP basis set for general-purpose applications of density functional theory.
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•Magnetic MnFe2O4 along with H2O2 was tested for catalytic oxidation of norfloxacin.•Norfloxacin could be removed efficiently at neutral pH.•Surface OH played a key role on ...norfloxacin removal.•Degradation intermediates were identified, and three degradation pathways were proposed.
Magnetic MnFe2O4 particles were prepared by sol-gel method and used to activate H2O2 for norfloxacin removal from water. The results of hydrodynamic particle size distribution and Zeta potential analyses show that the particle size ranged from 100 nm to 500 nm, and Zeta potential from −76 mV to −25 mV at pHintial = 7.0. The MnFe2O4/H2O2 system was able to remove 90.6% of norfloxacin at neutral pH, and the spent material can be reused in multiple cycles of operations. Fluorescence detection and DMPO capture analyses indicated that OH was the main free radicals, which played a primary role in degradation of norfloxacin. The valence variations of Mn and Fe were analyzed by XPS, and the results showed that coupled transformations of Mn2+/Mn3+ and Fe2+/Fe3+ were involved in generation of OH. Moreover, the removal rate in the MnFe2O4/H2O2 system showed a positive correlation with the adsorption efficiency of NOR by MnFe2O4. Eight degradation intermediates were detected by LC-QToF-MS/MS, and consequently, three degradation pathways were proposed, including defluorination, piperazinyl ring opening, and quinolone transformation. Further analyses of F−, NH4+, NO3− and NO2− before and after the reaction showed that defluorination process was the main degradation pathway. The MnFe2O4/H2O2 system may offer an efficient alterative for degradation of emerging persistent contaminants.
In this study, two biomass-based adsorbents were used as new precursors for optimizing synthesis conditions of a cost-effective powdered activated carbon (PAC). The PAC removed dyes from an aqueous ...solution using carbonization and activation by KOH, NaOH, and H
SO
. The optimum synthesis, activation temperature, time and impregnation ratio, removal rate, and uptake capacity were determined. The optimum PAC was analyzed and characterized using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), a field emission scanning electron microscope (FESEM), Zeta potential, and Raman spectroscopy. Morphological studies showed single-layered planes with highly porous surfaces, especially PAC activated by NaOH and H
SO
. The results showed that the experimental data were well-fitted with a pseudo-second-order model. Based on Langmuir isotherm, the maximum adsorption capacity for removing methylene blue (MB) was 769.23 mg g
and 458.43 mg g
for congo red (CR). Based on the isotherm models, more than one mechanism was involved in the adsorption process, monolayer for the anionic dye and multilayer for the cationic dye. Elovich and intraparticle diffusion kinetic models showed that rubber seed shells (RSS) has higher α values with a greater tendency to adsorb dyes compared to rubber seed (RS). A thermodynamic study showed that both dyes' adsorption process was spontaneous and exothermic due to the negative values of the enthalpy (ΔH) and Gibbs free energy (ΔG). The change in removal efficiency of adsorbent for regeneration study was observed in the seventh cycles, with a 3% decline in the CR and 2% decline in MB removal performance. This study showed that the presence of functional groups and active sites on the produced adsorbent (hydroxyl, alkoxy, carboxyl, and π - π) contributed to its considerable affinity for adsorption in dye removal. Therefore, the optimum PAC can serve as efficient and cost-effective adsorbents to remove dyes from industrial wastewater.
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•A relationship exists between biosorption and bioflocculation in MBFs application.•Heavy metal removal depends on the adsorption but also on the separation of MBFs.•Zeta potential ...presents a similar profile in the heavy metal hydroxide precipitation.•Three-phase division of zeta potential guides the addition of MBFGA1.•Insufficient precipitation favors the simultaneous biosorption and bioflocculation.
The microbial flocculants (MBFs) hold the potential of biosorption to removal the heavy metals. However, it remains unclear what the relationship between biosorption and bioflocculation. Here, during the hydroxide precipitation of Cu, Zn, Pb and Cd, besides the commonly used pH, a three-phase division of zeta potential curves provided an orientation for the addition of MBFs. The plateau phase of zeta potential, indicating an insufficient hydroxide precipitation, was appropriate for introducing MBFGA1, a polysaccharide-based MBF. Its removal capacities on Cu, Zn, Pb and Cd reached the highest of 250 mg/g, 96.7 mg/g, 551.1 mg/g and 233.3 mg/g, respectively. A sufficiently suspended hydroxide precipitates of Pb could receive a higher dosage of MBFGA1, ensure their thorough separation, and finally improve the removal efficiency. In order to further control the residual risk of MBFGA1, the response surface methodology (RSM) was employed to optimize this process. The compromised results improved the Pb removal rate to 98% in a weak acidic solution at pH 6.2. The precipitates composition and crystallinity, the functional groups and the molecular morphology were characterized by the X-ray diffraction (XRD), fourier transform-infrared spectra (FTIRs) and atomic force microscopy (AFM), respectively. The results indicated that the negatively-charged hydroxyl, carbonyl, amino and phosphoryl played the significant roles on fixing the molecular of MBFGA1 on the precipitates, providing the points for the aggregation of flocs, and capturing the residual Pb ions. The insufficient hydroxide precipitation laid the foundation for these multiple functions of MBFGA1, and promoted the synergistic effects between biosorption and bioflocculation.
In this paper, we first investigate several further interesting properties of the multiple Hurwitz–Lerch Zeta function
Φ
n
(
z,
s,
a) which was introduced recently by Choi et al. J. Choi, D.S. Jang, ...H.M. Srivastava, A generalization of the Hurwitz–Lerch Zeta function, Integral Transform. Spec. Funct., 19 (2008). We then introduce and investigate some
q-extensions of the multiple Hurwitz–Lerch Zeta function
Φ
n
(
z,
s,
a), the Apostol–Bernoulli polynomials
B
k
(
n
)
(
x
;
λ
)
of order
n, and the Apostol–Euler polynomials
E
k
(
n
)
(
x
;
λ
)
of order
n. Relevant connections of the results presented here with those obtained in earlier works are also indicated precisely.
As part of efforts to reduce pressure on the Amazon and other biomes, one approach considered by Brazilian authorities and scientists is more intensive use of the soils of the interior of the ...northeast of the country, which are generally sandy, with low contents of organic matter and low water holding capacity and are frequently affected by severe droughts. In this work, biochars produced from waste biomasses were tested for the improvement of these soils. The highest BET (Brunauer-Emmett-Teller) specific surface areas were observed for all biochars. In the pH range studied, the water hyacinth plants (WH) sample showed the most negative zeta potentials, as well as the highest water holding capacity (WHC) values, while the zeta potentials of two quartzarenic neosol soils were consistent with their WHC values. The results suggested that despite the effect of porosity on water retention, the zeta potential could be associated with the presence of negative charges by which hydrated cationic counterions were absorbed and retained. The surface energy and its polar and dispersive components were associated with water retention, with sugar cane bagasse, orange peel, and water hyacinth biochars presenting higher SE values and larger polar components.
•The effect of seven hydroxamate collectors on malachite flotation was investigated.•Separation of malachite from quartz in a synthetic ore was obtained.•All seven collectors investigated selectively ...adsorb onto the surface of malachite.•Benzo- and two C8 alkyl hydroxamates resulted in the best flotation response.
Copper oxide minerals, such as malachite, do not often respond well to traditional copper sulphide collectors, and require alternative flotation schemes. Hydroxamic acid collectors have been suggested as a means to directly float malachite; however, there is limited information on the effect of reagent structure on the performance of these collectors. This paper investigated the effect of five alkyl hydroxamates and two aromatic hydroxamates on the flotation of a synthetic ore composed of pure, fully liberated, malachite and quartz. Zeta potential measurements were used to aid in understanding reagent adsorption onto the surface of the two minerals. The collectors were then evaluated using bench scale flotation results. While zeta potential measurements suggested that all the collectors investigated selectively adsorb onto the surface of malachite, only benzohydroxamic acid and C8 alkyl hydroxamates were effective collectors in the flotation of malachite. Benzohydroxamic acid was the most selective; however, significantly lower dosages of C8 alkyl hydroxamates were required to obtain similar malachite recoveries, with minimal increases in quartz recovery. Benzo- and octylhydroxamic acid were further examined for the flotation of fine (−38μm) particles. For fine particle flotation experiments the effect of temperature was also investigated as a means to improve the flotation performance.
The pristine points of zero charge (PZC) and isoelectric points (IEP) of metal oxides and IEP of other materials from the recent literature, and a few older results (overlooked in previous searches) ...are summarized. This study is an update of the previous compilations by the same author Surface Charging and Points of Zero Charge, CRC, Boca Raton, 2009; J. Colloid Interface Sci. 337 (2009) 439; 353 (2011) 1; 426 (2014) 209. The field has been very active, but most PZC and IEP are reported for materials, which are very well-documented already (silica, alumina, titania, iron oxides). IEP of (nominally) Gd2O3, NaTaO3, and SrTiO3 have been reported in the recent literature. Their IEP were not reported in older studies.
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•Up to date (recent 3years) list of PZC and IEP•Critical review (erroneous results filtered out)•Detailed description of apparatus and experimental conditions•277 carefully selected references•Also new and atypical methods
Eighteen biochar samples were produced from the pyrolysis of Douglas fir wood (DFW), Douglas fir bark (DFB), and hybrid poplar wood (HP) at six temperatures (623, 673, 723, 773, 823 and 873 K) in a ...lab scale spoon reactor. Changes in the bulk composition of the biochar produced were examined by elemental and proximate analyses. The mass fraction of volatiles, oxygen and the ratios of oxygen to carbon (O/C) and hydrogen to carbon (H/C) decreased linearly with pyrolysis temperature. Surface properties of all the biochars produced (SEM morphology, CO2 and N2 adsorption, XPS analysis, Boehm titration, cation exchange capacity (CEC) and ζ-potential) were also studied. The removal of volatiles resulted in the gradual creation of microporosity detectable by CO2 adsorption but which was difficult to detect with N2 adsorption, suggesting that the chars contain micropores mostly less than 1 nm in entrance dimension. The XPS and Boehm titration confirmed that most oxygenated surface functional groups (presence of carbonyl, carboxyl and hydroxyl groups) are gradually removed as pyrolysis temperature increases. The changes in surface charge were studied by ζ-potential measurements and were found to vary directly with the content of oxygenated functional groups. Properties that depend on both surface area and the surface oxygenated functional groups, such as the cation exchange capacity, showed a more complex behavior. The composition of the ash and associated properties such as pH and electric conductivity (EC) were also measured. The total alkaline content increases with pyrolysis temperature leading to higher pHs and ECs.
•Biochar surface increases gradually with pyrolysis temperature.•Small pore size in biochars produced below 500 °C cannot be studied by N2 adsorption.•Biochars produced below 500 °C should be analyzed by CO2 adsorption.•Oxygen bulk and surface content decreases linearly with pyrolysis temperature.•Biochars with high surface oxygen content are more negatively charged.
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