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This study aims to document the phosphate ion (PO43−) adsorption capacity of a novel zirconium-based adsorbent. The physicochemical properties of the adsorbent are investigated using an array of methods and metrics such as electron microscopy, X-ray diffraction, thermal analysis, specific surface area, pore volume, pH point of zero charge (pHpzc), and surface hydroxyl groups. The batch method is used to elucidate PO43− adsorption capacity. Results suggested that the adsorption of PO43− was based on an internal diffusion and a monolayer adsorption. We also clarified that the pH of the solution significantly impacted the adsorption. Moreover, the adsorbent shows the ability to not only adsorb but also desorb PO43− for at least five cycles, based on an adsorption mechanism that we document. These findings indicate that this adsorbent could serve as a major industrial PO43− adsorbent.

AbstractIn the current study, Phosphate removal from aqueous solutions was studied using bimetallic Al/Cu modified natural zeolites (Z-Al/Cu). The Z-Al/Cu was synthesized in situ using simple chemical reduction and impregnation methods. The morphologies and structures of natural zeolites (NZ) and Z-Al/Cu were characterized by SEM, XRD, FTIR, and BET. Batch sorption experiments were carried out using various factors that can potentially influence the removal efficiency (initial pH, initial solution concentration, and adsorbent dosage). Experimental results showed higher adsorption of Z-Al/Cu as compared to NZ, indicating that the Al/Cu impregnation provides more adsorption sites to phosphate. The maximum adsorption of phosphate by the adsorbent was 99.32% at optimum pH 2, contact time of 60 min, and phosphate concentration of 25 mg/L. When the contact time between the adsorbent and adsorbate increased above the optimum time, the adsorption efficiency decreased due to the onset of the desorption process. Characterization results indicated that Al/Cu was successfully supported on the zeolites. Adsorption of phosphate by Z-Al/Cu adsorbent fitted well with Langmuir adsorption isotherm and pseudo-second-order kinetics within R2 = 0.913 and 0.999 respectively, which suggested that the adsorption process was a surface chemical reaction and mainly in a monolayer coverage manner. Reduction of removal efficiency, with regeneration cycles and in the presence of SO42-, was observed.

To improve the flame retardancy of bamboo scrimber, flame-retardant CaAl-PO4-LDHs were synthesized via the coprecipitation method using PO43− as the anion of an intercalated calcium–aluminum hydrotalcite in this work. The fine CaAl-PO4-LDHs were characterized via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), cold field scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and thermogravimetry (TG). Different concentrations (1% and 2%) of CaAl-PO4-LDHs were used as flame retardants for the bamboo scrimber, and the flame retardancy of the bamboo scrimber was characterized via cone calorimetry. The results showed that CaAl-PO4-LDHs with excellent structures were successfully synthesized via the coprecipitation method in 6 h and at 120 °C. Compared with the bamboo scrimber without the flame retardant treatment, the peak heat release rate (HRR) of the bamboo scrimber treated with 1% and 2% concentrations of flame-retardant CaAl-PO4-LDHs decreased by 16.62% and 34.46%, the time taken to reach the exothermic peak was delayed by 103 s and 204 s and the Time to Ignition (TTI) was increased by 30% and 40%, respectively. Furthermore, the residual carbon of the bamboo scrimber did not change significantly, increasing by 0.8% and 2.08%, respectively. CO production decreased by 18.87% and 26.42%, respectively, and CO2 production decreased by 11.11% and 14.46%, respectively. The combined results show that the CaAl-PO4-LDHs synthesized in this work significantly improved the flame retardancy of bamboo scrimber. This work exhibited the great potential of the CaAl-PO4-LDHs, which were successfully synthesized via the coprecipitation method and applied as a flame retardant to improve the fire safety of bamboo scrimber.

BACKGROUND AND OBJECTIVE: Rough endoplasmic reticulum is important organelle that plays a role in the regulation of a range of functions. Potassium channels in the endoplasmic reticulum membrane were recently reported that its physiological role is unknown. Hepatocyte endoplasmic reticulum is a rich source of glucose 6- phosphatase that is involved in the control of gluconeogenesis. Since phosphate ions are intra-luminal metabolites for this enzyme of endoplasmic reticulum thus, in this study, the effect of phosphate ions on potassium channel activity was studied.METHODS: Endoplasmic reticulum vesicles extraction was accomplished following liver excision in rats, homogenization and several stages of ultracentrifugation. Phosphatidylcholine was extracted from fresh egg yolk. Bilayer lipid membrane was formed in a 350 µm diameter aperture in between two chambers cis and trans contained 200/50 mMKCl solutions respectively, then vesicles were incorporated into bilayer lipid membrane. Ion channel activity was recorded by single channel recording technique both in control conditions and presence of phosphate ion in luminal face, next biophysical ion channel properties analyzed by Clampfit10 software.FINDINGS: Endoplasmic reticulum Potassium channel was 550 pS conductance and its activity changed as voltage dependent manner in voltage range of +30 to -40 mV, in this respect the open probability and the average unitary current in a voltage + 30 mV were 0.73 and 26 pA, respectively. However, at lower voltages, the channel activity was minimal. In the presence of 50 mM phosphate ion, mean unitary current and also channel open probability did not change significantly in different voltages compared to the control condition (p>0.05).CONCLUSION: Rat hepatocyte endoplasmic reticulum membranes has been a kind of potassium channel with voltage-dependent activity and it seems that its electrophysiological characteristics did not influenced by phosphate anion in luminal face.