Functionalization of Shorea faguetiana biochar using Fe2O3 nanoparticles and MXene for rapid removal of methyl blue and lead from both single and binary systems.

The synthesis of polymeric magnetic composites is a promising strategy for the rapid and efficient treatment of wastewater. Lead and methyl blue are extremely hazardous to living organisms. The sorption of Pb2+ and the dye methyl blue (MB) by biochar is an ecologically sustainable method to remediate this type of water pollution. We functionalized Shorea faguetiana biochar with Fe2O3 and MXene, resulting in Fe2O3/BC/MXene composites with an efficient, rapid, and selective adsorption performance. Based on X-ray photoelectron and Fourier transform infrared spectrometry, we found that the Fe2O3/BC/MXene composites had an increased number of surface functional groups (F-, C[double bond, length as m-dash]O, CN, NH, and OH-) compared with the original biochar. The batch sorption findings showed that the maximum sorption capacities for Pb2+ and MB at 293 K were 882.76 and 758.03 mg g-1, respectively. The sorption phenomena obeyed a pseudo-second-order (R2 = 1) model and the Langmuir isotherm. There was no competition between MB and Pb2+ in binary solutions, indicating that MB and Pb2+ did not influence each other as a result of their different adsorption mechanisms (electrostatic interaction for Pb2+ and hydrogen bonding for MB). This illustrates monolayer sorption on the Fe2O3/BC/MXene composite governed by chemical adsorption. Thermodynamic investigations indicated that the sorption process was spontaneous and exothermic at 293-313 K, suggesting that it is feasible for practical applications. Fe2O3/BC/MXene can selectively adsorb Pb2+ ions and MB from wastewater containing multiple interfering metal ions. The sorption capacities were still high after five reusability experiments. This work provides a novel Fe2O3/BC/MXene composite for the rapid and efficient removal of Pb2+ and MB.

Synthesis of Fe-THC MOFs and functionalizing MOFs by MXenes for the selective removal of lead(ii) ions from wastewater.

The elimination of heavy metals, especially lead, from wastewater is vital for the environment and human health and using a proper adsorbent to achieve this goal is highly desirable. Initially, Fe-THC MOF was prepared using a simple method and functionalized using MXene for efficient, rapid, and selective elimination of lead. Different characterization tools demonstrated that Fe-THC MOF and its composite Fe-THC/MXene were successfully prepared. The adsorption outcomes showed that the maximum sorption capability was 674 mg g-1 at 305 K and pH 4.5. The sorption kinetics obeys the pseudo-second-order kinetic model, and the sorption isotherms fit the Langmuir isotherm model. This finding suggests monolayer sorption on Fe-THC/MXene, and the rate-controlling step is chemisorption. Thermodynamic findings exhibit that sorption was a spontaneous and exothermic process. The sorption process can selectively adsorb Pb ions from aqueous media. After five adsorption-desorption tests, the adsorption efficiency of Fe-THC/MXene was still high. The sorption mechanism of lead on Fe-THC was mainly due to the interaction of lead ions with -F and -O ions and porosity of the Fe-THC/MXene composite. The -O and -F ions were derived from MXene, while the porosity was derived from the MOFs of composites. These findings confirmed that Fe-THC/MXene enables rapid, efficient, and selective elimination of lead from wastewater, which is of practical importance.

Compositing of MOFs with ceramic and nanoparticles for efficient and rapid adsorptive desalination of artificial seawater or NaCl solution.

Poor water availability with the fast-growing population creates crucial issues for universal water security, and efficient approaches ought to be accomplished to balance the demand and supply. One of the most energy- and cost-effective methods for removing NaCl is adsorption desalination. Metal-organic frameworks with ceramic and nanoparticles are a comparatively new research route that increases the desalination capacity. The synthesized composites were examined for efficient and rapid removal of NaCl from NaCl solution or artificial seawater. The adsorption desalination properties were analyzed based on adsorption isotherm, adsorption kinetics, contact time, NaCl, and adsorbent dosage. The adsorptive desalination rate of ZnO@MIL88A(Fe)@α-cordierite composite was only decreased by 4% as the maximum loss after 5 consecutive cycles.

Studies on the expression and processing of human proinsulin derivatives encoded by different DNA constructs.

A synthetic gene encoding human proinsulin, containing Escherichia coli preferred codons, with an additional N-terminal methionine, was used for the expression, of M-proinsulin and construction of nine derivatives. No improvement in expression was noted, relative to that of M-proinsulin, when the 5'- of the gene was appended to codons for seven amino acids of a well expressed E. coli protein (threonine dehydrogenase), or the constructs contained multiple copies of the proinsulin gene. That in the latter constructs only the gene adjacent to the prometer sequence is expressed, was shown by a construct containing a proinsulin gene followed by that for interferon α-2b. With the latter construct, the proinsulin was, predominantly, expressed. The availability of data on the constructs prompted, subjecting these to analysis by two models designed to predict the expression of proteins from the sequences, of putative mRNA, around the start of translation but no significant relationship was noted. In all cases the proteins were expressed as inclusion bodies, which were refolded to give products of desired masses and successfully converted into insulin derivatives. Of all the constructs containing a trypsin sensitive site before phenylalanine (F), the N-terminal sequence, MKR↓F, was most efficiently processed, by a cocktail of trypsin and buffalo carboxypeptidase B, to give insulin with the removal of the N-terminus linker as well as the C-peptide in a single step, without cleaving the trypsin sensitive K(29)T(30) peptide bond.