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Abstract In recent years, there has been a surge in interest in developing new polymeric materials with high performance and low cost. With increased environmental awareness, research has focused on eco-friendly materials, with terms like “renewable,” “recyclable,” “sustainable,” and “biodegradable” becoming important features of the materials, Polymer blends can provide products with a wider range of useful qualities than single polymer equivalents. In this study, Polymer blend films were prepared using dextrin at different compositions of (PVA- PMMA-PAAm) by solvent casting method. The prepared blend films were flexible and transparent and characterized using was examined by scanning electron microscopy to examine the surface morphology of the samples that show the good distribution of starch in the blend, while FT-IR was used to identify the active groups, which refer to the interaction among the materials. Also, we have studied the optical properties and recording the absorption spectrum with a visible ultraviolet spectrophotometer. Absorption spectra were recorded in the wavelength range of 200–1100 nm. The absorbance and optical conductivity were increased by dextrin additive, while the transmittance and energy gap decreased. Based on the overall results, the prepared films can be used in drug delivery and optical devices.

The agglomeration of rGO resulted from the morphological irregularities restrict its direct applications as catalyst for pollutants removal using advance oxidation processes (AOPs). In this study, we addressed this problem after incorporating the nanosheets of reduced graphene oxide (rGO) in the layers of hydroxides (LDHs) as Fe-rGO LDH hetero-composite. Based on the first order kinetic model, the fabricated composite showed excellent phenol removal with degradation rate constant of 0.16 min−1, 5–100 times higher than Fe-LDH/rGO or other control catalysts. This enhanced catalytic activity was resulted from the systematic assembly of both monolayered rGO and LDHs as superlattice materials, avoiding the aggregation of rGO during the reaction and thus promote the interfacial electron transfer among the active sites. Moreover, Fe-rGO LDH/PMS system exhibited consistent performance over a wide pH range (3.0 ─ 12.0) and broad spectrum of co-existing water constituents (anions and humic acid). The spectroscopic and analytical results suggested that the special arrangement of monolayered rGO in Fe-LDHs facilitated Fe sites to form a stable Fe intermediates after reacting PMS, offering a suitable centre to accept electron from another PMS to generate superoxides (•O2−). Finally, singlet oxygen (1O2) was accounted as dominant reactive oxygen species (ROS) for pollutants removal.

The present study aimed to investigate the renoprotective effect of therapeutic hypothermia (TH) on renal ischemia-reperfusion injury (RI/RI) induced by asphyxial cardiac arrest (CA) in rats. A total of 48 male rats were randomly divided into five groups: i) Sham (n=6); ii) Normothermia + CA (Normo.) (n=14); iii) Normo. and 2 h of TH after return of spontaneous circulation (ROSC) (n=12); iv) Normo. and 4 h of TH after ROSC (n=9); and v) Normo. and 6 h of TH after ROSC (n=7). All rats except the Sham group underwent asphyxia CA and were sacrificed 1 day after ROSC. The survival rate increased from 42.8% in the Normo. group to 50, 66.6 and 85.7% in the groups with 2, 4 and 6 h of TH after CA, respectively. TH attenuated the histopathological changes of the renal tissues following ROSC and the levels of blood urea nitrogen, serum creatinine and malondialdehyde in renal tissues. On immunohistochemistry, the relative optical density of nuclear erythroid-related factor-2 (Nrf2) and heme oxygenase (HO-1) expression in renal tissues increased in the Normo. group compared with that in the Sham group and exhibited further significant increases at 6 h of TH after ROSC. In conclusion, TH attenuated renal injury and increased the expression of Nrf2 and HO-1 in a TH treatment time-dependent manner.

In the present study, lanthanum hydroxide (La OH)-engineered sewage sludge biochar (La-SSBC) was utilized for efficient phosphate elimination from an aqueous medium. A high adsorption capacity of 312.55 mg P/g was achieved using La-SSBC at 20 °C, which was an excellent adsorbent performance in comparison to other biochar-based adsorbents. Additionally, the performance of La-SSBC was stable even at wider range of pH level, the existence of abundant active anions, and recycling experiments. Statistical physics modeling with the fitting method based on the Levenberg–Marquardt iterating algorithm, as well as various chemical characterizations, suggested the unique double-layered mechanism of phosphate capturing: one functional group of La-SSBC adsorbent describing a prone direction of the PO4 ions on the stabilize surface in a multi-ionic process, forming the first layer adsorption. Additionally, SSBC played an important role by releasing positively charged cations in solution, overcoming the electronic repulsion to form a second layer, and achieving excellent adsorption capacity. The calculation of multiple physicochemical parameters including adsorption energy further evidenced the process. This two-layered mechanism sheds light on the complex interaction between phosphate and biochar. Moreover, the management of sewage sludge associated with the requirement of cost-effectively and environmentally acceptable mode. Therefore, the present investigation demonstrated an efficient approach of the simultaneous sewage sludge utilization and phosphate removal.

The designing of selective and efficient adsorbent for removal of heavy metals from wastewater of diverse chemistry is a challenging task for researchers. Herein, FeMgAl derived from layered double hydroxides (LDH) with different intercalated anions (CO32−, NO3−, S52− and MoS42−) as selective adsorbents were evaluated by considering capturing heavy metals from a complex aqueous environment such as: 1) adsorption of single metals ions from a mixture of Ag+, Hg2+, Pb2+, Cu2+, Cd2+, Co2+, Ni2+, Zn2+, 2) adsorption of heavy metals in the presence of huge amount of Ca2+, Mg+, Na+, Cl−, NO3− and SO42− ions, 3) adsorption under different solution pHs, 4) solutions with high salinity etc. Out of the studied materials, fast kinetics, record capacities (582 for Hg2+ and 565 mg/g for Ag+) with enormous Kd values (1.0 × 108–2.5 × 107) placed FeMgAl MoS4 (Fe MoS4 LDH) as the most selective and promising material. FeMgAl S5 (Fe S5 LDH) was also impressive due to its good capacities (279 mg/g for Hg2+ and 341 mg/g for Ag+ ions) with Kd values (8.3 × 105–1.0 × 103). In contrast, FeMgAl CO3 and FeMgAl NO3 (Fe CO3 LDH and Fe NO3 LDH) showed very poor selectivity, lower capacities and very small Kd values. Furthermore, Fe MoS4 LDH and Fe S5 demonstrated negligible efficiency loss in the presence of competitive cations/anions or with change in solution pH. As confirmed by X-ray Diffraction (XRD) and Fourier Transformed Infrared (FTIR) analysis, a mechanism for adsorbed metals in the form of various coordinated complexes inside LDH layers was proposed for Fe MoS4 or Fe S5 LDHs. In contrast, a dominant precipitation mechanism as metal-hydroxide or metal-carbonate was suggested for Fe CO3 and Fe NO3 LDHs.

This study proposed a step-by-step oxidation process based on the in-depth analysis of the catalytic mechanism of peroxymonosulfate (PMS) activated by the common MnO2-based catalyst-manganese octahedral molecular sieve (OMS-2). In the first stage, OMS-2-mediated electron transfer dominated the oxidation process. When PMS was completely consumed, the reaction entered the second stage, at which singlet oxygen (1O2) gradually turned into primary oxidation source. OMS-2-mediated electron transfer was proved based on the results of electrochemical analysis, phosphate substitution experiments, and Raman tests. Meanwhile, the oxidation process of 1O2 was unveiled by radical scavenging tests, electron paramagnetic resonance (EPR), and solvent-exchange experiment (from H2O to D2O). Moreover, superoxide radical (O2•−) generated from the reaction between PMS and metastable manganese intermediate was identified as the precursor of 1O2. O2•− generated in the first stage could significantly extend its half-life by adsorbing on the (2 1 1) plane of OMS-2, and then desorbed in the second stage and contributed to the formation of 1O2. More importantly, through the transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and DFT calculations, the essence of step-by-step oxidation driven by O2•− adsorption–desorption process was uncovered.

Purpose To investigate the role of Nrf2/HO-1 in renal histopathological ailments time-dependently in asphyxial cardiac arrest (CA) rat model. Methods Eighty-eight Sprague Dawley male rats were divided into five groups of eight rats each. Asphyxial CA was induced in all the experimental rats except for the sham group. The rats were sacrificed at 6 hours, 12 hours, one day and two days post-CA. Serum blood urea nitrogen (BUN), creatinine (Crtn) and malondialdehyde from the renal tissues were evaluated. Hematoxylin and eosin and periodic acid-Schiff staining were done to evaluate the renal histopathological changes in the renal cortex. Furthermore, Nrf2/HO-1 immunohistochemistry (ihc) and western blot analysis were performed after CA. Results The survival rate of rats decreased in a time-dependent manner: 66.6% at 6 hours, 50% at 12 hours, 38.1% in one day, and 25.8% in two days. BUN and serum Crtn markedly increased in CA-operated groups. Histopathological ailments of the renal cortical tissues increased significantly from 6 hours until two days post-CA. Furthermore, Nrf2/HO-1 expression level significantly increased at 6 hours, 12 hours, and one day. Conclusions The survival rate decreased time-dependently, and Nrf/HO-1 expression increased from 6 hours with the peak times at 12 hours, and one day post-CA.

The study was conducted in the field of poultry at the Department of Animal Production/ College of Agriculture- University of Diyala from the period from 21- 1 to 21- 4- 2019. It aimed to study the effect of adding different levels of zinc methionine to the diet in some productive qualities of laying hens. The researcher used 144 chickens (Lohmann Brown) at the age of 21 weeks for the experiment. Randomly distributed to four treatments and zinc methionine was added at a rate of 0, 30, 60, and 90 mg/ kg of diet for the four treatments (T1, T2, T3, T4), respectively. The results of the statistical analysis of the experimtal data showed a significant increase (P

Nonradical-based advanced oxidation processes for pollutant removal have attracted much attention due to their inherent advantages. Herein we report that magnesium oxides (MgO) in CuOMgO/Fe3O4 not only enhanced the catalytic properties but also switched the free radical peroxymonosulfate (PMS)-activated process into the 1O2 based nonradical process. CuOMgO/Fe3O4 catalyst exhibited consistent performance in a wide pH range from 5.0 to 10.0, and the degradation kinetics were not inhibited by the common free radical scavengers, anions, or natural organic matter. Quantitative structure-activity relationships (QSARs) revealed the relationship between the degradation rate constant of 14 substituted phenols and their conventional descriptor variables (i.e., Hammett constants σ, σ-, σ+), half-wave oxidation potential (E1/2), and pKa values. QSARs together with the kinetic isotopic effect (KIE) recognized the electron transfer as the dominant oxidation process. Characterizations and DFT calculation indicated that the incorporated MgO alters the copper sites to highly oxidized metal centers, offering a more suitable platform for PMS to generate metastable copper intermediates. These highly oxidized metals centers of copper played the key role in producing O2•- after accepting an electron from another PMS molecule, and finally 1O2 as sole reactive species was generated from the direct oxidation of O2•- through thermodynamically feasible reactions.

To meet the current challenges of waste water, an efficient, environment friendly and economical treatment process is always desirable for the degradation of toxic organic compounds. Herein, we reported a stable and active bimetallic CuOx@Co-LDH catalyst for the degradation of phenol using persulfate (PS) under mild conditions. The system of PS/CuOx@Co-LDH completely degraded 0.1 mM of phenol in less than 40 min while at the same time, all the other tested catalysts including catalyst precursors remained sluggish. In view of the practical application, CuOx@Co-LDH/PS system demonstrated consistent performance over a broad pH range (pH 5.0–12.0), during which minimum leaching could be detected. Moreover, good resistance to various inorganic anions was demonstrated in CuOx@Co-LDH/PS system. The consistent performance of CuOx@Co-LDH/PS system may originate from the constant buffer pH of catalyst (9.5 ± 0.8), minimum leaching and the generation of diverse free radicals ( SO4−, OH or − O2) under different pH conditions. Additionally, LDH structure offered strong synergetic interactions among active components which might also help in minimum leaching and good reactivity of CuOx@Co-LDH catalyst. The results of radical scavengers, EPR and XPS studies collectively proved the mechanism of diverse free radicals, which was accounted to the redox cyclic reactions of active sites (Cu(III)–Cu(II)–Cu(III) and Co(III)–Co(II)–Co(III)) during degradation of phenol.

Yolk shell Mn2O3@Mn5O8 was prepared through a facile synthetic procedure and was demonstrated to be a highly efficient and stable catalyst in peroxymonosulfate (PMS) activation for the catalytic degradation of organic contaminants. Mn2O3@Mn5O8 exhibits much improved activity compared with other classic manganese catalysts such as e-MnO2, Mn2O3 and Mn3O4, and this performance was due to its yolk shell structure, mesoporous shell, well-defined interior voids, particular particle size and mixed valence states. The long-term stability and efficiency of Mn2O3@Mn5O8 was observed in activating PMS to generate sulfate radicals for the removal of various organic pollutants such as phenol, 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DP) and 2,4,6-trichlorophenol (2,4,6-TCP) in aqueous medium. The effects of the initial solution pH, influence of anions, catalyst stability and the temperature effect on 4-CP degradation were also investigated. Furthermore, electron paramagnetic resonance (EPR) spectroscopy and radical quenching tests were employed to investigate sulfate, hydroxyl, superoxide radicals and even 1O2 for organic degradation processes. Finally, a possible activation pathway of Mn2O3@Mn5O8/PMS was proposed that involved the inner-sphere interactions between the HSO5− and the catalyst surface, electron transfer from Mn species to PMS, and the generation of sulfate radicals. These findings provide new insights into PMS activation by using nano-particle catalysts of non-toxic metal oxides.

Wide-ranging researches have been executed to treat groundwater from different mining areas, although complex behaviors of diverse metal ion species in the groundwater have not been illustrated clearly. This research study explored the mechanisms through which Pb(II) and V(V) are eliminated in single and binary-metal removal processes by oxygen, nitrogen, and sulfur-doped biochars also considering the kinetic and characterization techniques. The adsorption efficiency of V (V) was enhanced by oxygen-doped biochar at pH 4 with an adsorption capacity of ~70 mg/g. However, Pb (II) was rapidly removed at pH 6 with a higher adsorption capacity of ~180 mg/g by the nitrogen and sulfur-doped biochar forming PbCO3 and V(CO)6 crystals along the single-metal removal process. These results could be explained by the Hard Soft Acid Base theory. The hard Lewis acid vanadium was attracted by the hard Lewis base oxygen, and the intermediate Lewis acid lead was attracted by the intermediate and soft Lewis base nitrogen and sulfur. Besides, the removal ability of Pb(II) and V(V) in the binary-metal removal process showed a similar phenomenon for all types of biochars at pH 4 with the adsorption capacity of ~400 mg/g for Pb(II) and 175 mg/g for V(V), but the composition of vanadium species remains unclear on the surface of the biochars. Initially, H3V2O7−, H2VO4−, and HVO42− species were electrostatically attracted by the oxygen-based functionalities, then V(V) species was partially reduced to VO2+ by the oxygen, nitrogen, and sulfur functionalities in different ratios. Finally, H3V2O7−, H2VO4−, and HVO42− species produced Pb5(VO4)3Cl and Pb2V2O7 which co-precipitate with Pb(II), but VO2+ does not generate any form of precipitates. The above-explained technique supports the treatment of vanadium mining groundwater with valuable vanadinite (Pb5(VO4)3Cl) mineral.

Highly efficient elimination of anionic chromate remains a critical task from the biological and ecological perspective owing to their carcinogenic effects on the biosphere and ecosphere. In literature, varieties of functional materials have been applied to remove Cr(VI) from the environmental sources. In which the chemical reduction of Cr(VI) to Cr(III) by a reductant and simultaneous adsorption of Cr species is an effective technique for the removal of Cr(VI). Many effective reductants were applied in the past years, which could be categorized according to their active functional atom/group. Although very few studies illustrated the complete coordination mechanisms between Cr ions and functional groups during the reduction coupled adsorption. This review focuses on recently investigated Cr(VI) reduction coupled adsorption systems based on the electron donor (reductant) functionalities with the interactions of Cr2O72−, CrO42− and Cr3+ ions by the metal and nonmetal functional groups. Also, the removal capacity and equilibrium time were analyzed based on the findings from isotherm and kinetic studies. To conclude, we offered our insights based on the coordination of chromium species with various functionalities into future research prospects and issues in the hope of motivating more researchers to involve in this new area of functional materials for environmental pollution control.

In this paper, we surprisingly found that the incorporation of unreducible metal oxides MxOy (M = Mg, Zn, Ca, Ba, Al) onto CuO hybrid magnetic nano ferric oxide (Cu@Fe3O4) may alter the reaction pathway in persulfate activation, and increase the reaction rate constant. The activation of peroxymonosulfate (PMS) by Cu@Fe3O4 led to a classic sulfate radical based oxidation process (SR-AOP) with an acetaminophen (ACE) degradation rate constant of 0.004 min−1, while 1O2-dominated nonradical oxidation process was disclosed in CuM@Fe3O4 with wildly fluctuated reaction rate constants from 0.003 to 0.242 min−1. Mechanism studies indicated that singlet oxygen (1O2) derived from the direct oxidation of superoxide anions radicals (O2 −) or the recombination of O2 − was the main reactive oxygen species (ROS) in CuM@Fe3O4/PMS system. A series of characterization experiments (pHpzc tests, XPS, H2-TPR, et al.) and DFT calculation disclosed that the addition of an unreducible metal M yielded many positive effects: (1) the formation of surface oxygen vacancies (OV) raised the zero point charge (pHpzc) of CuM@Fe3O4, thus enhanced the adsorption and activation of PMS; (2) promoting the generation of a new Cu species (Cu3+) on the surface of CuM@Fe3O4, which then participated in the generation of 1O2. The different reducibility of Cu3+ led to differences in the catalytic properties of CuM@Fe3O4. In addition, the effects of various water matrix species and the results of reusability experiment, mineralization experiment, and ecotoxicity test exhibited that CuM@Fe3O4/PMS system possessed excellent practical application value.

It has always been a serious challenge to design efficient, selective, and stable absorbents for heavy-metal removal. Herein, we design layered double hydroxide (LDH)-based Fe-MoS4, a highly efficient adsorbent, for selective removal of heavy metals. We initially synthesized FeMgAl-LDH and then enriched its protective layers with MoS42– anions as efficient binding sites for heavy metals. Various characterization tools, such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray, X-ray photoelectron spectroscopy (XPS), CHN analysis, and inductively coupled plasma analysis, were applied to confirm structural and compositional changes during the synthesis of Fe-MoS4 as final product. The prepared Fe-MoS4 offered excellent attraction for heavy metals, such as Hg2+, Ag+, Pb2+, and Cu2+, and displayed selectivity in the order Hg2+ ∼ Ag+ > Pb2+ > Cu2+ > Cr6+ > As3+ > Ni2+ ∼ Zn2+ ∼ Co2+. The immense capacities of Hg2+, ...

Highly efficient magnetic sewage sludge biochar (MSSBC) discloses feasible fabrication process with lower production cost, superior adsorption capacity, usage of waste sewage sludge as resource, selected by external magnetic field and exceptional regeneration property. 2 g L−1 MSSBC exhibited a high adsorption capacity of 249.00 mg g−1 in 200 ppm Pb(II) and the lead-MSSBC equilibrium was achieved within one hour, owing to the existence of the copious active sites. The adsorption kinetics was well described by the pseudo-second-order model while the adsorption isotherm could be fitted by Langmuir model. Mechanism study demonstrated the adsorption involved electrostatic attraction, ion exchange, inner-sphere complexation and formation of co-precipitates at the surface of MSSBC. Additionally, adsorption performance maintained remarkable in a broad pH window. These outcomes demonstrated the promising waste resource utilization by a feasible approach that turns the solid waste of sewage sludge into biochar adsorbent with auspicious applications in elimination of Pb(II) from wastewater.

The development of transition metal based heterogeneous catalysts with efficient reactivity and intensive stability is of great demand in peroxymonosulfate based AOPs in water treatment. Herein, we present a novel approach of creating stable and effective nano-rod catalyst of CuCo@MnO 2 with tetragonal structure. A remarkable synergetic effect was found between bi-metallic oxides of Cu and Co: 0.5%Cu-2%Co-MnO 2 can efficiently degrade 100% of 30 ppm phenol, while 0.5%Cu@MnO 2 or 2%Co@MnO 2 alone is apparently sluggish for the degradation of organic contaminants. The nanocatalyst retained good stability in recycling tests, during which little leaching of Co and Cu ions can be detected and crystallinity of support α˗MnO 2 remained unchanged. Mechanism study indicated that SO 4 − and OH are accounted to participate the degradation, and the generation of radicals is originated from the interaction of CuCo@MnO 2 and PMS through metal site with peroxo species bond. The redox cycle among the active metals (M 2+ ↔ M 3+ ↔ M 2+ ) and Cu enhanced generation of Co(II)–OH complex are critical for the remarkable performance in CuCo@MnO 2 /PMS system. Both the synergetic acceleration of catalyst activity and instinct mechanism are highly suggestive to the design of heterogeneous catalysts for the degradation of organic contaminants in PMS based advanced oxidation processes.

Redox metal ions play the crucial role in versatile advanced oxidation technologies, in which controlling the active species formation through catalyst design is one of the key challenges in oxidant utilization. This work describes an example of different active species formations in CuO-mediated degradation just because of supporting material differences. Although three CuO catalysts were prepared by similar procedures, it was found that CuO-MgO catalyst demonstrated high efficiency in phenol degradation with bicarbonate activated H2O2, in which the superoxide radical is crucial, while hydroxyl radical and singlet oxygen are ignorable. For the CuO-MgO-Al2O3 and CuO-Al2O3 catalysts, the degradation proceeds by popular hydroxyl radical based process, however, the efficiency was poor. The EPR experiments also confirmed the absence of hydroxyl radical in CuO-MgO system but its presence in CuO-MgO-Al2O3 and CuO-Al2O3 system. The high catalytic efficiency with ignorable hydroxyl radical in the CuO-MgO system leads us to propose that an alternative Cu(III) species dominates the degradation. The basic MgO support may facilitate the formation of the Cu(III) species, whereas the neutral MgO-Al2O3 and acidic Al2O3 supports are unable to stabilize the high valent Cu(III) species, leading to the common hydroxyl radical mechanism with low efficiency of H2O2 in alkaline conditions.

We have proposed a novel strategy for the reduction plus adsorption process for hexavalent chromium elimination by thiol functional hybrid materials through a self-gating process. Namely, we exploit that coating dithiocarbamate chitosan at the surface of SBA-15 affords a core-shell composite that undergoes reversible shape transformations while thiol functional groups acted as proton-coupled electron donor for [Cr2O7]2−. The reduction of [Cr2O7]2− to Cr3+ was highly efficient and exceptionally rapid, occurred within 5 min with the reduction amount of 899.66 mg of [Cr2O7]2− / 1 g of nanocomposite as a record high value. During the reduction of [Cr2O7]2−, thiol functional groups (-SH) were oxidized into disulfide linkages ( S S ), and simultaneously chitosan matrix turned into shrunken structure because of the consuming of protons, preventing any release of Cr3+. Disulfides can also be reversely reduced to thiols by thiosulphates (S2O32−), which was attractive for regeneration and recyclability of the nanocomposite. Moreover, the [Cr2O7]2− elimination through self-gating process was highly selective against a huge concentration of background electrolytes. This alternative strategy ensures the outstanding and stable performance in applied fields, and could be conducted in various pollution control techniques like permeable reactive barriers.

A rod-like SDBC-Mg(II) composite was synthesized and optimized in the conditions of 25% Mg(II) loading and 500 °C calcination temperature. As-prepared SDBC-25%Mg(II)-500 adsorbent attained equilibrium in 30 min, with an extraordinary capacity of 2931.76 mg g−1 (Pb(II)) and 861.11 mg g−1 (Cd(II)), revealing a promising adsorbent for the removal of such metals so far. The adsorption kinetics was well described by the pseudo-second-order model while the adsorption isotherm could be fitted by Redlich-Peterson model. Furthermore, SDBC-25%Mg(II)-500 has a high anti-interference and selectivity in the presence of competing ions/other environmental factors and, also effectively eliminates >99% of Pb2+, Cd2+, Ag+ and Cu2+ ions from pond water, lake water and tap water. The adsorption process demonstrated a synergetic adsorption mechanism comprised of ion exchange with Mg(II), coordination with surface and inner carboxylic or carbonyl functional groups and co-precipitations as metal silicates, which is responsible for its superb adsorption performance. Besides, surface carvings of Mg(II) and tunnels on the rods resulting from the sludge carbonization provided a high surface area (91.57 m2 g−1), extra sorption sites and room for easy pollutant diffusion which contributed to surface physical adsorption. Furthermore, this technique demonstrate an alternative pathway that will relieve the burdens of sewage sludge treatment process and turn this solid waste into highly efficient adsorbent for eliminating heavy metal ions from wastewater. This can be considered as a feasible waste resource utilization to meet with the requirement from both ecology and economy for auspicious applications in industries.

In this study, we report on an active and stable CoMgAl layered double hydrotalcite (LDH) catalyst for phenol degradation by heterogeneous activation of peroxymonosulfate (PMS). The CoMgAl-LDH catalyst was synthesized by hydrothermal method. The PMS/CoMgAl-LDH system overcomes the drawbacks of traditional Fenton processes. Various effects, e.g., scavengers, chloride ion, catalyst dosage, PMS concentration, temperature, and pH, were also inspected to evaluate the system. The results indicated that the PMS/CoMgAl-LDH system had extremely high efficiency for phenol degradation, 0.1 mM phenol could be completely degraded by 0.3 g/L catalyst and 3 mM PMS within 60 min at 30 &deg, C. The CoMgAl-LDH catalyst appeared to possess outstanding reusability and stability. After four rounds of recycling, nearly 100% of the phenol was removed within 80 min by the PMS/CoMgAl-LDH system, with only 0.05 mg/L Co2+ leaching. A sulfate radical was the main oxidation species in the PMS/Co-LDH system. The degradation rate of phenol was influenced by temperature, and the activation energy was 65.19 kJ/mol. These advantages proved the PMS/CoMgAl-LDH system is an effective strategy for the treatment of organic contaminants.

This study focused on the photocatalytic decolourization of cobaltous phthalocyaninate dye (PcCo) from ZnO suspension solution under artificial UV-A light. The results showed that the photo-decolourization process of this dye process was obeyed to pseudo-first order kinetics. Moreover, the optimization results explained that the maximum value of decolourization efficiency of this dye was achieved at the conditions: initial dye concentration 25 mg/L and the initial pH of dye aqueous solution is equal to 11.01. Arrhenius plot obtained at temperatures ranged (287.15-303.15) K, which is equal to 28.995 kJ mol-1. The thermodynamic parameters were calculated also and determined that the photoreaction is endothermic and non-spontaneous.

Over the past, extensive works executed to treat anionic and cationic heavy metal ions from wastewater. Although very few adsorbents were developed to adsorb anionic and cationic heavy metal ions from the same system. In this study, we explored the pH tunable complete reduction plus adsorption mechanism of Pb2+ and Cr2O72− by dithiocarbamate-based composite. The pH study recommended that; adsorption of Pb2+ occurred at pH 5.5, besides Cr2O72− reduction coupled adsorption executed at pH 3. Furthermore, quick adsorption occurred within 60 min with adsorption capacities of 228.69 and 219.75 mg g−1 for Pb2+ and Cr2O72−, respectively. Adsorption isotherm well described by the Redlich-Peterson model, also adsorption processes were fitted by pseudo-second-order kinetics model. Interestingly, characteristic techniques, a physical monolayer model and thermodynamic models were applied to the experimental results to further understand the adsorption mechanisms. The results indicated that the physical model with two types of interaction energies was more appropriate to interpret the adsorption mechanism. Based on the physical model, three thermodynamic functions were calculated and interpreted to attribute new macroscopic interpretations at the molecular level of the adsorption systems. Inspiringly, the metal-composite system highly effective for 5 regeneration cycles and fixed-bed column could decontaminate 17.2 L of ~10 mg L−1 Pb2+ and 7.3 L of ~10 mg L−1 Cr2O72− to the EPA’s wastewater discharge limit by 5 g of CSC@SDBC with the yielding of 400 and 346 mL of eluent, respectively. Theoretically, a liter of CSC@SDBC column may efficiently adsorb 145,646 mg of Pb2+ and 57,518 mg of Cr2O72− from industrial effluent, these were calculated from the Bohart-Adams model. These collective batch and fixed-bed systems were cost-effective and environmentally tolerable techniques to remove anionic and cationic heavy metal ions from industrial wastewater.

The serious limitations of available technologies for decontamination of wastewater have compelled researchers to search for alternative solutions. Catalytic treatment with hydrogen peroxide, which appears to be one of the most efficient treatment systems, is able to degrade various organics with the help of powerful ·OH radicals. This review focuses on recent progress in the use of bicarbonate activated hydrogen peroxide for wastewater treatment. The introduction of bicarbonate to pollutant treatment has led to appreciable improvements, not only in process efficiency, but also in process stability. This review describes in detail the applications of this process in homogeneous and heterogeneous systems. The enhanced degradation, limited or lack of leaching during heterogeneous degradation, and prolonged catalysts stability during degradation are salient features of this system. This review provides readers with new knowledge regarding bicarbonate, including the fact that it does not always harm pollutant degradation, and can significantly benefit degradation under some conditions.

Catalytic wastewater treatment is confronted by varied challenges like catalyst stability and efficiency in aqueous media due to the complex chemistry during organic compound degradation. Herein, we attempt to address this challenge by creating a synergistically stable and active bimetallic CuCoOx–LDH catalyst via facile copper ion hydrothermal impregnation in a CoOx–LDH catalyst. Different instrumental techniques like BET, XRD, FTIR, SEM, XPS and electrochemical studies etc. were conducted to investigate the properties of the catalyst before and after impregnation of copper ions. It was found that the changes in the electrochemistry and redox properties of the CuCoOx–LDH catalyst based on cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS) appeared in the form of enhanced activity and excellent stability. In the bicarbonate activation of hydrogen peroxide (BAP) system, the synthesized CuCoOx–LDH catalyst can efficiently degrade 200 ppm 4-chlorophenol (4-CP) with 84% COD and 78% TOC removal in less than 40 minutes, and even 1000 ppm of 4-CP in hours, while the CoOx–LDH and CuOx–LDH catalysts or their physical mixtures are apparently sluggish. This catalyst can also effectively degrade various substituted phenols including 2,4-dichlorophenol (DCP), 2,4,4-trichlorophenol (TCP), 2-chlorophenol (2-CP), phenol, and chlorobenzene with significant COD removal. The findings from fluorescence, scavengers, electron paramagnetic resonance (EPR), XPS, and electrochemical studies suggest collectively the generation of ˙OH, 1O2, and ˙O2− species and that the regeneration of active sites may be part of the degradation process. This approach based on CV, EIS and XPS studies has provided novel knowledge about the intrinsic origins of synergetic acceleration of catalyst activity.

Black liquor (BL) is an agro-industrial residue with high number of lignocellulosic components which could be recognized as a biomass feedstock. In this work, BL coupled with red mud (RM), were applied to prepare cost-effective zero-valent iron (ZVI) embedded in biochar. The oligomers in BL acted as reductants for RM to generate ZVI, while the organic components could be converted into biochar during pyrolysis. The RM/BL demonstrated excellent performance in the removal of Cr(VI) (349.5 mg/g), as the mechanisms were reduction and adsorption. The fixed-bed column study was conducted and 1.7 L simulated wastewater could be treated by 1.0 g RM/BL. After reaction, 95.5% ± 0.8% and 82.5%±3.2% Cr-loaded adsorbents could be recovered by an external magnet for batch and fixed-bed experiments, respectively. All these results shed light on valorizing these two widespread agro-industrial byproducts, and bridged the knowledge gap between magnetic bio-adsorbent preparation and its industrial practicality on wastewater purification.

The aims of this study were to characterize carrot residues and to determine the removal of Cr(VI) in water depending on the temperature and the dosage of carrot residues. To identify the functional group present in carrot residue, Fourier-Transform Infrared (FTIR) was used to characterize it. The functional group that responsible for the metal binding is hydroxyl (-OH) group. The adsorption of Cr(VI) was conducted by using batch experiment. The effect of temperature and dosage were studied in batch experiment, in which temperatures were varied from 25ºC to 55ºC and the dosages were varied from 0.5 mg/L to 2 mg/L. Preliminary study was done to determine the time equilibrium for adsorption. The equilibrium contact time was 30 min with 12.66% removal efficiency. Meanwhile, the highest dosage for removal efficiency of metal that used was 2 mg/L with 13.09%. The optimum temperature was 25ºC with 12.66% removal efficiency. This study has indicated that the carrot residues is less likely a good adsorbent for removal of Cr(VI).

Protease was extracted from the viscera of torpedo scad fish (Megalspis cordyla) to obtain the crude extract which was then partially purified in 70% ammonium sulphate. The collected precipitate was dialysed and subsequently immobilized in sodium alginate and calcium chloride solution. The optimum concentrations of sodium alginate and calcium chloride to produce the highest yield of immobilized protease was determined by using Response Surface Methodology (RSM). From the results, the optimum conditions obtained were 2.5% of sodium alginate and 0.25 M of calcium chloride achieving a yield of 55.52%. Thus, the utilization of 2.5% sodium alginate and 0.25 M calcium chloride as the immobilization media were able to produce yield of immobilized protease from torpedo scad viscera with the highest proteolytic activity.

It is usually difficult to design selective, stable and efficient adsorbent for the reduction and adsorption of Cr(VI) oxoanions from wastewater. Herein, we report an effective, selective and easily recyclable adsorbent for the elimination of Cr(VI) oxoanions using sulfide assembled hydrotalcite of Fe/Mg/Al hydroxides. Various characterization tools such as XRD, FTIR, SEM, XPS, CHN and ICP were applied to confirm the layered structure and chemical compositions. The prepared adsorbent displayed fast kinetics, high adsorption capacity and outstanding selectivity to Cr(VI) removal. The factors affecting Cr(VI) removal including pH, adsorbent dosage, contact time and initial Cr(VI) concentration was studied. Under the optimum conditions, >99.99% Cr(VI) was removed in 180 min with remarkable distribution coefficients of (Kd > 107). The maximum removal capacity (135.59 mg/g) placed the prepared adsorbent on the top of materials list known for Cr(VI) removal. Pseudo-second-order kinetic model expresses well the adsorption behavior towards Cr(VI), indicating a chemisorption process, while the sorption isotherm agreed with the Langmuir model, suggesting monolayer adsorption. The ( S )2− in MoS42− was involved in reducing Cr(VI) to Cr(III) while itself simultaneously being oxidized to SO42− and the redox reaction was evidenced by XPS analysis. Moreover, due to the unique memory effect of layered double hydroxides, significant stability and excellent reusability were also achieved. Based on the results obtained, hybrid adsorbent by embedding sulfide into hydrotalcite of Fe/Mg/Al hydroxides can be considered as one of a compelling candidate for the remediation of hexavalent chromium.

In this paper, sewage sludge, a solid waste from wastewater treatment plant, which eagerly requires proper treatment was reused as solid support in the form of sewage sludge biochar, then modified with carboxymethyl chitosan to form a bio-adsorbent. Further, carboxymethyl chitosan coating on sewage sludge biochar improved carboxymethyl chitosan's stability in water. The prepared bio-adsorbent revealed a shorter equilibrium time (60 min) for Pb(II) adsorption and a superior capacity of 594.17 mg g

Phenylurea herbicide residuals in soil may continuously contaminate surface water and groundwater due to unregulated and improper use. Herein, we reported a stable and active oxidation system including heterogeneous Fe-based layered double hydroxide materials as persulfate (PS) activators. Under mild conditions, 1% LDH in weight and 70 mM PS can completely degrade 500 mg/kg isoproturon in soil within 10 h, during which less than 0.1 ppm heavy metal leaching was detected. This remarkable performance was consistent in a broad pH range (3~11) and was resistant to various inorganic anions (Cl−, Br−, NO3−, HCO3−) and humic acid. Mechanism studies from scavenging tests, EPR, and fluorescence spectra collectively proved that besides •OH and •SO4−, singlet oxygen (1O2) and superoxide (•O2−) were also generated and were accounted for the oxidative degradation. This unique mechanism of generating diverse radicals was clearly distinguished from classic Fe(II)/PS system, significantly reduced the influence of varying parameters in water and soil matrix, and was suggestive to chemical oxidation system in soil remediation to avoid scavenging effects by background electrolytes or other components in water/soil matrix.

A new pyridine alkaloid derivative named as 2-(6-benzyl-4-oxo-5-phenyl-1,4-dihydro pyridine-3-yl)-benzoic acid ethylester (3) has been prepared by the reaction of ninhydrin with 1,3-diphenylacetonep-tosylhydrazone and the structure has been established with the help of spectral analysis and X-ray analysis. The title compound demonstrated potent inhibitory activity against butyrylcholinesterase (BChE; IC50 = 4.91 µM) comparable to physostigmine (IC50 = 4.72 x 10-1 µM). However it showed moderate inhibitory activity against acetylcholinesterase (AChE; IC50 = 82.00 µM)). It was BChE selective over AChE, in contrast to physostigmine, which was more AChE selective. Being a potent and selective BChE inhibitor, it may serve as a new class of drug for prevention of the progression of neurodegeneration as well for symptomatic treatment of Alzheimer patient.

Background: Heterocyclic molecules have been synthesized by a green and facile strategy. These mole-cules contain a 8-membered azocine ring. The structures have been determined by spectral analysis and single crystal X-ray analysis. These compounds have anticancer activity. Method: A mixture of ninhydrin and acetone/ethylmethylketone in acetic acid in molar ratio 1: 1 were heated on water bath for 15 minutes. The reaction mixtures were dried on rotary evaporator and crystallized with chloro-form- n-hexane (1: 1 v/v) to give the colorless crystals of 1 And 2 respectively. Compounds 3 and 4 were synthe-sized by adding o-phenylenediamine to the completed reaction mixtures of 1 and 2 and each was further heated on water bath for 5 minutes. The dried reaction mixtures were chromatographed over a silica gel column and crystalized as 3 and 4. Results: This strategy resulted novel class of anticancer benzazocines (3 and 4). Conclusion: This method features mild reaction conditions and simple operation. The synthesis completes in two steps; from ninhydrin to 1 and 2 and from 1 and 2 to 3 and 4. The same basic skeleton of 3 and 4 and the same synthesis procedure clearly shows the general applicability of this reaction that is also proved enough by single crystal X-ray analysis and the strategy can be applicable for a wide range of other substrates. The obtained compounds are potential anticancer agents.

Dielectric relaxation and electrical properties of Al doped polycrystalline bismuth ferrite (BAFO) nano-structured ceramics (13–20 nm having composition Bi 1− x Al 2 x Fe 1− x O 3 (0.0 ≤ x ≤ 0.3) were investigated over a wide range of frequency and temperature. Relaxation peaks were obtained in low as well as high frequency regions for all samples which are explained on the basis of Debye-type relaxation model. The replacement of Fe 3+ and Bi 3+ by Al 3+ ions in the BFO system creates oxygen vacancies and hence Schottky barriers, which are responsible for the anomalous behaviour in the dielectric properties. Debye relaxation model and Maxwell–Wagner charge carriers hopping were utilized in overall estimation of the dielectric behaviour of the system. The values of dielectric constant and loss tangent were found to decrease with the increase in frequency, while these parameters increase with the increase in temperature as well as dopant concentration. The a.c. conductivity has a general decreasing trend as a function of composition while it increases with the increase in frequency. The temperature dependence of a.c. conductivity and relaxation time follow well-defined Arrhenius behaviour. The calculated values of activation energies are in the order of 0.54 eV–0.73 eV ( 2− vacancies.

Aluminum doped Bismuth ferrite (BFO) nanopowders (grain size 13–20 nm) having composition Bi 1− x Al 2 x Fe 1− x O 3 ( x = 0.00, 0.025, 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) were successfully synthesized by solution combustion method using citric acid as fuel at a temperature as low as 200 °C. As-prepared samples were examined by powder XRD for phase identification and crystallite size determination. The d.c. resistivity as a function of temperature was measured by standard two probe setup which exhibits clear metal to insulator transition for all samples. FTIR analysis was carried out to identify the chemical bonds present in the system. The optical band gap was calculated from the UV–vis absorbance spectra using classical Tauc relation which was found to vary from 2.78 eV to 2.93 eV for different Al 3+ concentrations. The activation energies calculated from the slopes of ln( ρ ) versus 10 3 / T plots are in the range 0.54–0.73 eV.

Cyclohexyl N-phenylcarbamate, C13H17NO2 (I), which is a useful target for biotransformations by fungi, has been synthesized and the structure has been solved by X-ray diffraction. The crystals are triclinic, space group P $$ \bar{1} $$ , with a = 5.2581 (2) A, b = 9.5080 (3) A, c = 12.6165 (4) A, α = 70.544 (2)°, β = 89.075 (2)°, γ = 80.447 (2)°, M r = 219.28, V = 585.96 (3) A3, Z = 2 and R = 0.065. In the title compound the phenyl ring makes a dihedral angle of 30.68(7)° with the carbamate group The molecules are linked into infinite chains via N–H···O hydrogen bonds along the a axis. These hydrogen-bonded chains are further linked by weaker C–H···π interactions. Quantum-mechanical ab initio calculations for the free molecule reproduce well the observed bond lengths and valency angles but show that the crystal packing might be responsible for the rotation of the phenyl ring out of the carbamate plane in the solid state conformation. In cyclohexyl N-phenylcarbamate the molecules are linked into infinite chains via N–H...O hydrogen bonds along the a axis. Ab initio calculations for the free molecule show that the crystal packing might be responsible for the rotation of the phenyl ring out of the carbamate plane in the solid state conformation.

Toxic and bioresistant compounds have attracted researchers to develop more efficient and cost-effective technologies for degradation of organic compounds in wastewater. This work demonstrates the degradation of 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and phenol as model compounds using bicarbonate-activated H2O2 oxidation system in the presence of supported catalysts. The catalytic activity of the catalyst was investigated in term of degradation of target compounds, chemical oxygen demand (COD), and total organic carbon (TOC) removals both for batch mode and in fixed bed reactor using CoMgAl-HTs and CoMgAl-SHTs, respectively. The leaching of cobalt ion was efficiently prohibited because of the presence of a weakly basic medium provided by bicarbonate, and the CoMgAl-SHTs catalyst was found to retain its stability and good catalytic activity in fixed bed reactor for over 300 h. Extensive chemical probing, fluorescence, and electron paired resonance (EPR) studies were conducted to identify the actual reactive species in the degradation pathway, which revealed that the reaction proceeds through generation of superoxide, hydroxyl radical along with carbonate radical.

Alzheimer disease (AD), a chronic and progressive neurodegenerative disease is the leading cause of dementia among older people. Several hypotheses exist on the pathogenesis of AD. According to the cholinergic hypothesis, there is an irreversible deficiency in cholinergic functions of brain resulting in substantial reduction of the neurotransmitter, acetylcholine. In contrast, amyloid hypothesis suggests that amyloid beta (Aβ) deposits are fundamental cause of the neurodegeneration. There is also an involvement of another protein, tau protein, which twists into abnormal tangles and lead to the death of brain cells. This chapter aims to provide a comprehensive review on the various enzymes involved in the pathogenic cascade of AD and their potential inhibitors. The chapter starts with a general overview on the enzymes, outlining their morphological and functional features and how they are involved in the pathogenesis of AD. The following section addresses the enzymes inhibitors at various stages of drug development, highlighting their mechanisms of action, advantages, limitations and potential clinical applications.

Conditions are described by which a group of up to ten sulfonamide drugs, namely, (1) sulfanilamide, (2) sulfaguanidine, (3) sulfacetamide, (4) sulfathiazole, (5) sulfamethoxydiazene, (6) sulfamethoxypyridazine, (7) sulfamethazine, (8) sulfadimethoxine, (9) sulfapyridine, and (10) sulfadiazene, in admixture, may be separated by thin-layer chromatography. Each drug can be identified qualitatively and determined quantitatively by pyrolysis-gas chromatography. Each separated zone is cut from the plate and pyrolysed at 780°C in a stream of nitrogen gas in a continuous mode pyrolyser designed in this laboratory. The pyrolysis products are separated on Tenax TA in a glass column held at 210°C and the amount of drug related to the aniline peak height as determined by the flame ionization detector. Linear calibration curves for up to 6 μg of drug were obtained for drugs 1 to 8 and up to 4 μg for 9 and 10.