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Heavy metal pollution in water is alarming for countries lacking advanced and frequent wastewater treatment facilities. A double-channel flow injection system was developed based on the application of a mini biosorption glass column containing an indigenous strain of immobilized Bacillus cereuson silica gel. The developed online preconcentration procedure was utilized for trace determination of Cr(VI). The manifold parameters like pH, types of eluents, sample volume, and interfering ions were investigated. After retention and elution of the analyte from the biosorption column at optimized conditions, traces of Cr(VI) were determined with chromophore 1,5-diphenyl carbazide at 545 nm spectrophotometrically. The successful immobilization, the effect of the source environment, and interaction of Cr(VI) with bacterial biomass after preconcentration were assessed by FTIR, SEM, EDX, and XRD. A maximum interference of 0.15 ± 0.084 on peak absorbance of Cr(VI) was observed with 100 mg L−1of Fe(III) at optimized parameters. The maximum preconcentration of Cr(VI) was achieved with bacterial biomass originally obtained from the contaminated environment with an enhancement factor of 20.22 and 0.01 µg L−1detection limit for Cr(VI). The proposed method had a linear calibration range from 0.01 to 100 ppb of Cr(VI), regression Y = 0.0182x + 1.632, and R2= 0.99. The analytical frequency achieved was approximately 10 samples per hour. The developed approach strongly supports its applicability in bioresource management for decontamination of Cr(VI)-related pollution in water systems.

Studies on dietary habits and niche overlap of sympatric carnivore species can be vital for their conservation. They can reveal the potential level of inter-specific competition and prey species overlap, thus highlighting species specific conservation requirements. We investigated diet composition of two such sympatric carnivore species Asiatic jackal Canis aureusand the Kashmir hill fox Vulpes vulpes grifithiiin and around Pir Lasura National Park, in northeastern Himalayan region of Pakistan by using fecal analysis after confirming the carnivore species by genetic analyses. The scats of the two carnivores were collected during four different seasons of the year and analyzed in the laboratory. Results revealed sixteen prey species in the diet of Asiatic jackal and 21 species in the diet of the Kashmir hill fox. For Asiatic jackal, wild prey contributed approximately 18%, whereas 60% of the diet comprised of domestic prey. For Kashmir hill fox, the wild prey consumption was approximately 18%, while consumption of domestic prey was 51% and plants contributed 28%. Niche breadth of the Asiatic jackal was broader (0.78) compared to Kashmir hill fox (0.31). Niche overlap between these two sympatric carnivores was found to be a rather high 0.81.

This study aims to investigate the removal efficiency of UV/H2O2/iron loaded rice husk ash (Fe-RHA) based advanced oxidation process for the removal of safranin in wastewater. The effects of several reaction parameters such as initial H2O2concentration, initial pH and catalyst dose were studied. Moreover, Fenton-like process (Fe-RHA/H2O2), adsorption (Fe-RHA alone), UV alone and synergic process (UV/H2O2/Fe-RHA) were compared. Finally, the reuse performance of catalyst and removal of chemical oxygen demand (COD) was studied. The results show that synergic process (UV/H2O2/Fe-RHA) was found to be more efficient as compared with other processes. Furthermore, the decolorization of safranin was found to be the highest near acidic pH (pH = 3). The synergic process was also found to be effective near wastewater pH, achieving decolorization efficiency up to 46% at initial pH = 6. The results further reveal that significant amount (61% in 120 min) of COD was removed using UV/H2O2/Fe-RHA process. It is, therefore, concluded that the UV/H2O2/Fe-RHA synergic process is highly effective for the removal of dyes in wastewater.

Hazards and colour of industrial wastewater due to organic compounds such as dyes are becoming a significant problem with increased urbanization owing to its direct effects on photosynthesis, ecosystem and human health. This research attempts to use for the first time Peanut Shell Ash (PSA) based Fenton-like catalyst, impregnated with iron (Fe+3), to study the decolourization and decomposition of methylene blue (MB). The materials have been characterised by using several techniques, namely, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-rays spectroscopy (EDS), N2adsorption and pH changes by mass transfer (for point of zero charge). Then, the catalytic, adsorption and hydrogen peroxide alone processes were compared. The effects of several reaction parameters such as initial hydrogen peroxide amount, initial dye concentration, initial pH, temperature, catalytic doses and adsorption on the removal efficiency of MB were studied. Furthermore, the effect of an electrolyte (hydroxyl radical scavenger) on the decolourization of dye was evaluated. The results revealed that catalytic process was the most efficient as compared to others. The results further revealed that the optimum decolourisation of MB occurred, when solution contained 0.1 g catalyst, 4 mM of hydrogen peroxide at temperature of 30°C and initial pH value of 3. The decolourisation efficiency was 84% with 0.2 g of catalyst, 16 mM of hydrogen peroxide at a temperature of 30°C, pH value of 3, and at initial MB concentration of 15 mg/L. The study, therefore, concluded that Peanut Shell Ash based Fenton-like catalyst shows good decolourisation and degradation efficiency at acidic pH values (pH = 3–5).

The space BVσ{\mathrm{BV}_{\sigma}}was introduced and studied by Mursaleen [21]. In the present article we study the double sequence spaces (0BV(M,p)σI)2{{}_{2}(_{0}\mathrm{BV}{{}^{I}_{\sigma}}(M,p))}, BV2(M,p)σI{{}_{2}\mathrm{BV}{{}^{I}_{\sigma}}(M,p)}and (∞BV(M,p)σI)2{{}_{2}(_{\infty}\mathrm{BV}{{}^{I}_{\sigma}}(M,p))}with the help of the space BVσ{\mathrm{BV}_{\sigma}}and an Orlicz function M, where p=(pi⁢j){p=(p_{ij})}is the double sequence of strictly positive real numbers. We study some of its properties and prove some inclusion relations related to these new spaces.

AbstractThis study shows the potential of modified Rhizopus arrhizus(MRA) for the removal of Zn(II) in water and to investigate the effect of various parameters such as temperature, initial pH, initial concentration, and co-ions. Additionally, kinetic studies and adsorption isotherms have been studied in order to investigate the mechanism of the biosorption process. The results revealed that biosorption on MRA could substantially remove the Zn(II) in water. The biosorption have been found to be pH dependent. The uptake of Zn(II) on MRA increased with the increase in pH. The effect of initial concentration was studied by varying it from concentration 2 to 100 mg/l. The results indicated that the uptake of Zn(II) increases with the increase in initial concentration. The temperature variation (5–40°C) showed Zn(II) uptake on MRA follows an increasing trend. The process was found to be independent of the presence of co-ions. The kinetics studies showed that the uptake of Zn(II) on MRA follows pseudo-second-order kinetics. Results further revealed that the adsorption of Zn(II) on MRA fitted best on the Freundlich isotherm model (R2 = 0.998). Therefore, it is concluded that MRA is an affective biosorbent for the removal of Zn(II) in water.

This study shows the potential of modified Rhizopus arrhizus(MRA) for the removal of Zn(II) in water and to investigate the effect of various parameters such as temperature, initial pH, initial concentration, and co-ions. Additionally, kinetic studies and adsorption isotherms have been studied in order to investigate the mechanism of the biosorption process. The results revealed that biosorption on MRA could substantially remove the Zn(II) in water. The biosorption have been found to be pH dependent. The uptake of Zn(II) on MRA increased with the increase in pH. The effect of initial concentration was studied by varying it from concentration 2 to 100 mg/l. The results indicated that the uptake of Zn(II) increases with the increase in initial concentration. The temperature variation (5–40°C) showed Zn(II) uptake on MRA follows an increasing trend. The process was found to be independent of the presence of co-ions. The kinetics studies showed that the uptake of Zn(II) on MRA follows pseudo-second-order kinetics. Results further revealed that the adsorption of Zn(II) on MRA fitted best on the Freundlich isotherm model (R2 = 0.998). Therefore, it is concluded that MRA is an affective biosorbent for the removal of Zn(II) in water.

AbstractThe current exploration presents a primary study on the uptake of Mn(II) by ripped Citrus paradisipulp waste (RCPW). The effects of various engineering parameters such as biosorbent dose, agitation, contact time, initial concentration, temperature, and different eluents were evaluated. Pseudo-second-order kinetic model fits well with the process, and uptake of Mn(II) by RCPW showed monolayer formation as enumerated by Langmuir’s model. Increased temperature enhanced the biosorption capacity indicating endothermic nature of the phenomenon. Among HNO3, H2SO4, HCl, and EDTA, 0.1 N NaOH was found to be the best desorbing agent.

The current exploration presents a primary study on the uptake of Mn(II) by ripped Citrus paradisipulp waste (RCPW). The effects of various engineering parameters such as biosorbent dose, agitation, contact time, initial concentration, temperature, and different eluents were evaluated. Pseudo-second-order kinetic model fits well with the process, and uptake of Mn(II) by RCPW showed monolayer formation as enumerated by Langmuir’s model. Increased temperature enhanced the biosorption capacity indicating endothermic nature of the phenomenon. Among HNO3, H2SO4, HCl, and EDTA, 0.1 N NaOH was found to be the best desorbing agent.

Zinc oxide (ZnO)-based photocatalysis has great potential in wastewater treatment, but its photocatalytic performance suffers from the limitation of low-wavelength photon absorption. Herein, a near-infrared-responsive photocatalyst is developed to tackle this challenge, which is composed of Prussian blue (PB) dye conjugated iron oxide-zinc oxide hybrid nanoparticles (Fe3O4@PB@ZnO) with spherical morphology (∼14 nm). Fe3O4@PB@ZnO shows a higher-wavelength absorbance region centered at 781 nm as compared with PB-free Fe3O4-ZnO composite (Fe3O4@ZnO, 494 nm) and pristine ZnO (361 nm). The inclusion of a charge transfer band (FeII-CN-FeIII) after the conjugation of PB is responsible for such a profound absorbance shift. A comparative study of three samples as potential photocatalysts is performed in terms of the methylene blue degradation, which is found to be in an order of Fe3O4@PB@ZnO ˃ Fe3O4@ZnO ˃ ZnO. The enhanced photocatalysis rate of Fe3O4@PB@ZnO is credited to the lower bandgap of 1.2 eV from the presence of PB with low bandgap, retarded the recombination rate of electron-hole pair to produce enough reactive oxygen species from the rich surface vacancies and hole scavenging properties of PB. A plausible degradation mechanism of photocatalysis is proposed, revealing the singlet oxygen as the central point of enhanced performance.