Bioelectrochemical system for enhancing anaerobic digestion of pharmaceutical-containing domestic wastewater.

The unprecedented recent expansion in usage of paracetamol (AAP) has increased the need for suitable wastewater treatment technology. Furthermore, direct interspecies electron transfer promotion (DIET) offers simple and efficient approach for enhancing anaerobic digestion (AD). In this work, using AAP-containing domestic wastewater as feed, control AD reactor (RC) was operated, besides three DIET-promoted AD reactors (REV, RMC and REVMC, referring to electrical voltage "EV"-applied, nFe3O4-multiwall carbon nanotube (MCNT)-supplemented, and "EV applied + MCNT supplemented" reactor, respectively). Maximal treatable organic loading rates by RC, REV, RMC and REVMC were 3.9, 3.9, 7.8 and 15.6 g COD/L/d, corresponding to AAP loading rate of 26, 78, 156 and 312 µg/L/d, respectively. Methane production rate generated by RC, REV, RMC and REVMC reached 0.80 ± 0.01, 0.86 ± 0.04, 1.40 ± 0.07, and 3.01 ± 0.17 L/L/d, respectively. AAP expectedly followed hydroquinone degradation pathway, causing AD failure by acetate accumulation. However, this performance deterioration could be mitigated by DIET-promoted microbes with higher methanogenic activity and advanced electric conductivity. Economic evaluation revealed the favourability of MCNT addition over EV application, since payback periods for RC, REV, RMC and REVMC were 6.2, 7.7, 4.2 and 5.0 yr, respectively.

A perception into binary and ternary copper (II) complexes: synthesis, characterization, DFT modeling, antimicrobial activity, protein binding screen, and amino acid interaction.

Ensuring healthy lives and promoting well-being for all at all ages is the third goal of the sustainable development plan, so it was necessary to identify the most important problems that threaten health in our world. The World Health Organization declared that antibiotic resistance is one of the uppermost global public health threats facing humanity and searching for new antibiotics is slow. This problem can be approached by improving available drugs to combat various bacterial threats. To circumvent bacterial resistance, three copper(II) complexes based on the pefloxacin drug were prepared and characterized using analytical, spectroscopic, and thermal techniques. The resulting data suggested the formation of one octahedral binary and two distorted square pyramidal ternary complexes. Fluorescence spectra results revealed the formation of a turn-on fluorophore for amino acid detection. Computational calculations investigated quantum and reactivity parameters. Molecular electrostatic potential profiles and noncovalent bond interaction-reduced density gradient analysis indicated the active sites on the complex surface. The complexes were subjected to six microbial species, where the octahedral binary complex provoked its antimicrobial potency in comparison with ternary complexes. The enhanced antimicrobial activity against gram-negative bacterium E-coli compared to gentamicin was exhibited by the three complexes. Docking simulation was performed based on the crystal structure of E. coli and S. pneumoniae receptors using 5I2D and 6O15 codes. The binary complex exhibited a potent fitness score with 5I2D (TBE = - 107 kcal/mol) while ternary complexes displayed the highest docked score of fitness with 6O15.

A new antimicrobial PVC-based polymeric material incorporating bisacylthiourea complexes.

A new antimicrobial material incorporating Cu(I) and Cd(II) complexes of bisacylthiourea derivatives in a PVC film was successfully synthesized and characterized by IR, UV, NMR, SEM, and thermal analyses. The results revealed that on coordination, the electronic structure change of the ligand affects practically all their spectral vibrational pattern; however, within the complex pattern, some vibrations indicated that the thiourea derivative behaves as a neutral ligand, which coordinates the metal ion through the sulfur atom of the thiocarbonyl group. The greater affinity of the S atom for Cu+ 1 played a role in Cu(II)→Cu(I) reduction, and the intramolecular hydrogen bonds of the type of (NH···Cl) further stabilized the obtained Cu(I) complex in dioxane. The antimicrobial activity shows that all investigated compounds exhibit excellent activity compared to standard antibiotics. The antibacterial power of the PVC/Cd composite is significantly superior against the most resistant species to both disinfectants and antibiotics compared to its PVC/Cu analogue; nevertheless, the latter exhibited activity equal to an average halo diameter of 29 ± 0.33 mm against pathogenic E. coli ATCC 25,922, indicating excellent G (-) activity. Interestingly, the PVC/Cd composite exhibited excellent activity against pathogenic C. albicans RCMB 005003 (1) ATCC 10,231, while its PVC/Cu analogue was inactive. These materials may be used to reduce infection in wounds either as a composite film or coated barrier dressings, and in addition, the results should open a new direction in antimicrobial surface engineering within the biomedical field. Further challenges are the development of reusable and broad-range antimicrobial polymers..

Sustainable and energy-efficient photocatalytic degradation of textile dye assisted by ecofriendly synthesized silver nanoparticles.

In this study, we have touched on two goals of sustainable development, namely, the provision of clean water and sanitation and clean energy at acceptable prices, hoping for good health for all ages. A green economical method was used to prepare silver nanoparticles from chitosan biopolymer. AgNPs were fully characterized using UV-Vis, FTIR, XRD, HR-TEM, and EDX analysis. Different concentrations (0.02-0.18 g/L) of the nanoparticles were integrated into a mixture of heterogeneous nano photocatalysts TiO2 and ZnO (1:1 weight ratio) under UV irradiation for the photocatalytic degradation of Acid Red 37 textile dye to obtain clean water. The kinetic description of the performed photocatalytic process was presented assuming a pseudo-first-order reaction. The data revealed that increasing the concentration of AgNPs in the catalytic mixture showed a high apparent rate constant (kapp) accompanied by an increase in the apparent quantum yield (%Qapp), followed by dye destruction after a very short time (t0.5 = 3 min). Since the photocatalytic degradation process consumes electrical energy, the electrical energy per order (EE/O) was calculated, showing a low value of 20 kWh/m3/order, using 0.18 g/L AgNPs, indicating that the elicited photocatalytic degradation method is a sustainable one for the mineralization of the targeted dye.

Green synthesis of nanosized N,N'-bis(1-naphthylidene)-4,4'-diaminodiphenylmethane and its metal (II) complexes and evaluation of their biological activity.

Condensation of ecofriendly synthesized 4,4'-methanedianiline with 2-hydroxy-1-naphthaldehyde produced a (1:1) octopus-like Schiff base mixed ligand. Reaction with Co(OAc)2⋅H2O, NiCl2⋅6H2O, Cu(OAc)2⋅H2O and Zn(OAc)2⋅2H2O metals furnished their complexes in high yield and purity. All new structures were fully characterized by various spectroscopic and spectrometric measurements. The complexes exhibited high thermal stability up to 700 °C, leaving nearly 40% of their mass as residues. Antimicrobial screening results exhibited moderate activities towards all studied microbes. Antioxidant screening was concentration dependent, and their activities were in the order Ni(II) > Zn(II) > Cu(II) > Co(II) complexes. The NO inhibitory effect revealed that the nickel complex exhibited the highest activity, whereas the cobalt complex showed the lowest inhibition. All compounds showed a significant lipid peroxidation inhibitory effect against oxidative stress. The complexes significantly diminished the TBARS level, and the nickel complex exhibited the highest inhibition at p < 0.01. Antioxidants stress the oxidative damage induced by iron, indicating that the nickel complex has the highest reducing activity. The inhibitory effect against acetylcholine esterase showed that the copper complex has the highest activity. Membrane stabilization activities clearly indicated that most compounds can improve the integrity of the cells and stability of their membrane, and this result may be related to their antioxidant capacity to protect against cytotoxicity. The nickel complex exhibited a stronger total antioxidant capacity than the other complexes. The biological and antioxidant capacities of these complexes may make them promising candidates in pharmaceutical applications.

Unexpected effect of magnetic nanoparticles on the performance of aqueous removal of toxic Cr(VI) using modified biopolymer chitosan.

Modified biopolymer chitosan namely 2-hydroxy-1-naphthaldehyde chitosan (CTS-Nap) has been synthesized for the removal of toxic chromium from aqueous solutions. In an attempt to enhance the adsorption capacity of toxic chromium on the prepared modified biopolymer, magnetic Fe3O4 nanoparticles have been loaded on the modified adsorbent to form the magnetite adsorbent (Fe3O4@CTS-Nap). The adsorption mechanism of both adsorbents is explored by batch experiments, FT-IR, SEM, TEM, XRD, VSM, and EDS. The optimum adsorption is achieved at pH 1.5 for CTS-Nap and 1.0 for Fe3O4@CTS-Nap. Pseudo second order illustrated the best description for the adsorption process with correlation coefficient R2 = 0.999 and the film diffusion or chemisorption is the rate-limiting step. The equilibrium data is analyzed using five isotherm models, the experimental data agreed well with the Freundlich model with a maximum adsorption capacity of 78.12 mg g-1 and 57.14 mg g-1 for CTS-Nap and Fe3O4@CTS-Nap, respectively. However, this unexpected result revealed that the presence of magnetic nanoparticles does not always enhance the adsorption process and many other factors could control the adsorption process. Generally, these outcomes revealed that the unmagnetite modified adsorbent CTS-Nap have practical greater influence on wastewater treatment management rather than the magnetic modified chitosan Fe3O4@CTS-Nap.

Synthesis and biological evaluation of new nanosized aromatic polyamides containing amido- and sulfonamidopyrimidines pendant structures.

BACKGROUND: Antibiotics are biocides or products that inhibit the growth of microorganisms in the living cells and there are extensive works directed to develop efficient antimicrobial agents. The sulfonamide-containing polymers have great potential to resist gram-positive or gram-negative bacterial and fungal attacks. As a therapeutic agent, the sulfonamides have been reported as antitumor and antimicrobial agents against bacteria, being more potent against gram positive rather than gram negative strains. Design of new classes of inhibitors bearing fluorescent tails, as therapeutic and imaging agents, is currently an active area of research. Here, we describe the synthesis of a new family of polyamides based on chlorophenyl-3,5-diaminobenzamides, methyl substituted pyrimidinoamido-3,5-diamino- benzamides and methyl substituted pyrimidinosulfonamido-3,5-diaminobenzamides and evaluation of their thermal, optical and antimicrobial properties. RESULTS: We report the synthesis of a new series of nanosized polyamides containing bioactive pendent structures. The spherical nanosized polymer particles are soluble in many organic solvents and exhibited emissions ranging from blue to orange wavelength depending on the nature of the signaling unit. Pyrimidine- and p-chloroaromatic containing polymers exhibited higher bioactivity than that contain the sulfonamide group. The amidopyrimidine polymers exhibited remarkable antifungal and antibacterial activity and thus, these types of polymers are promising candidates for biomedical applications. CONCLUSIONS: The SEM analysis indicated that most of the polyamides were organized as well defined nano sized spheres, but in certain derivatives small amount of aggregated nanospheres were also observed. Thermal analyses were studied up to 700 °C and results showed comparable thermal behavior. The optical results revealed that polymeric series (A) exhibited orange emission, series (B) showed green emission while series (C) exhibited yellow and blue emissions. Benzene/pyridine structure interchange resulted in red shifted peaks attributed to the localized lone pair of electrons on a nitrogen atom which offer a greater electron affinity and better electron-transporting properties. The amido- and sulfonamide pyrimidine containing polymers exhibited the most potent antimicrobial activity. Relative to the reference Gentamicin, the polymer 54 exhibited comparable antibacterial activity against gram negative bacteria. Analogues 52 and 57 exhibited remarkable antibacterial activities compared to the references used. Thus, these polyamides are likely to be promising broad spectrum antibacterial agents and deserve further investigation at the molecular level.Graphical abstract:The synthesis and characterization of a new series of nanosized polyamides containing chloroaromatic (A), pyrimidinoamido- (B) and pyrimidosulfonamido- (C) pendent structures as promising candidates for biomedical applications is described.

Synthesis of new microbial pesticide metal complexes derived from coumarin-imine ligand.

A series of metal complexes of zinc(II), cadmium(II), copper(II), nickel(II) and palladium(II) have been synthesized from coumarin-imine ligand, 8-[(1E)-1-(2-aminophenyliminio)ethyl]-2-oxo-2H-chromen-7-olate, [HL]. The structures of the complexes were proposed in the light of their spectroscopic, molar conductance, magnetic and thermal studies. The ligand coordinated in a tridentate manner through the azomethine nitrogen, the phenolic oxygen and the amine nitrogen and all complexes were non-electrolytes with different geometrical arrangements around the central metal ion. Photoluminescence data unambiguously showed remarkable fluorescence enhancement to Zn(2+) over other cations. The antimicrobial screening tests revealed that copper(II) complex exhibited the highest potency and its minimum inhibitory concentration on the enzymatic activities of the tested microbial species was determined. No toxin productivity was detected for all tested toxigenic species upon the exposure of copper complex.

Synthesis and characterization of thermally stable aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles containing pendant substituted bezamides.

BACKGROUND: The introduction of pendent bulky groups along the polymer backbone results in a less ordered polymer matrix and increases the solubility characteristics without affecting thermal properties. The inclusion of chromogenic chemical moieties in the chains can give rise to the luminescent converter material which permits the preparation of materials with potential applications. Aromatic polymers containing heterocyclic rings in the main chain are known for their high thermal resistance, good hydrolytic stability, low dielectric and tough mechanical properties. There is currently much research directed towards the discovery of new blue light-emitting polymers, with characteristics of high efficiency and high reliability. Herein, we describe the preparation of aromatic polyamides and poly (1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups, where the acetoxybenzamide groups act as signaling units due to their fluorescent and chromogenic characteristics. RESULTS: Aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups were successfully prepared and characterized using different analytical methods. Most polyamides were obtained as well-separated spherical nanoparticles while aramide containing pyridine produced aggregated particles attributed to the molecular self assembly via H-bond directed organization of molecular precursors. The thermal behavior of all polymers exhibited two major thermal decompositions due to the subsequent breakage of the acetoxy group in the lateral chain and cleavage of the main amide bonds. Photoluminescence studies revealed that the blue emissions for the polyamide derived from benzidine were blue-shifted (shifted to a lower wavelength) compared to that of polyamides containing flexible linkages. CONCLUSIONS: We report the synthesis of aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups. The thermal behavior of all polymers exhibited two major decompositions due to breakage of the acetoxy group in the lateral chain and cleavage of the main amide bonds. Structure- photoluminescence correlation demonstrated an interesting connection between structural modification and optical properties. The blue emissions for the polyamide derived from benzidine, attributed to the highly conjugation system, was blue shifted with the introduction of flexible linkages. The prepared polymers dissolved in warm polar aprotic solvents. Further investigations to obtain films with reasonably good mechanical properties for different applications are in progress.

Antimicrobial and antitumor activity of platinum and palladium complexes of novel spherical aramides nanoparticles containing flexibilizing linkages: structure-property relationship.

Square planar Pd (II) and octahedral Pt (IV) complexes with novel spherical aramides nanoparticles containing flexible linkages ligands have been synthesized and characterized using analytical and spectral techniques. The synthesized complexes have been tested for their antimicrobial activity using Kirby-Bauer disc diffusion method. The antitumor activity has been performed using liver carcinoma (HEPG2), breast carcinoma (MCF7) and colon carcinoma (HCT 116) cell lines. Palladium complexes of polyamides containing sulfones showed the highest potency as antibacterial and antifungal agents. Platinum complexes containing sulfone and ether flexible linkages and chloro groups exhibited high potency as antitumor and antimicrobial agents. The uniform sizes of these nanomaterials could find biological uses such as immune assay and other medical purposes.

Antioxidant activity of new aramide nanoparticles containing redox-active N-phthaloyl valine moieties in the hepatic cytochrome P450 system in male rats.

We report the synthesis of aramide nanoparticles containing a chiral N-phthaloyl valine moiety and their antioxidant activities on hepatic contents of cytochrome P450, amidopyrene N-demethylase, aniline-4-hyroxylase and induced the hepatic content of cytochrome b5 and nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome C-reductase. Polymers were obtained as well-separated spherical nanoparticles while highly aggregated particles via H-bonding organization of the aramide-containing pyridine led to a thin layer formation. The effects of the nanoparticles and CCl4 on enzyme activities and thiobarbituric acid reactive substances (TBARS) levels of male rat liver were studied. Pretreatments of rats with the polyamides prior to the administration of CCl4 decreased the hepatic content of the tested enzymes. Doses reduced the toxic effects exerted by (•CCl3) upon the liver through inhibition of the cytochrome P450 system. Inhibition of such metabolizing enzymes could reduce the carcinogenic effects of chemical carcinogens.