Efficiency evaluation of Falcaria vulgaris biomass in Co(II) uptake from aquatic environments: characteristics, kinetics and optimization of operational variables.

In the present research, the seeds of Falcaria vulgaris were extracted from the investigated environment and used for crop cultivation. This study has focused on the efficiency evaluation of Falcaria vulgaris biomass (FVB) in cobalt ions removal from aqueous solutions. The biosorbent was characterized using FTIR, BET, EDAX-EDS, and SEM. The optimal conditions were determined by the response surface methodology (RSM) based on a Box-Behnken design (BBD) model. The BBD model had  R2,  Radj2 and  Rpred2 values of 0.9919, 0.9774, and 0.8929, respectively. The cobalt removal under different conditions of the BBD model varied from 36.14% to 82.11%. Based on the numerical optimization of the quadratic model, the maximum cobalt removal at a biosorbent-to-metal ratio of 10:1, pH = 4.88 and contact time of 70 min was calculated at 80.941%. The high accuracy of the model in predicting the optimal conditions for cobalt adsorption by FVB was confirmed using statistical analysis and validation tests. The adsorption process of FVB also follows a pseudo-second-order kinetic model, which suggests that the rate-controlling step in cobalt removal is the chemical interaction between functional groups in FVB and Co+2 ions. This study shows that FVB, a low-cost biosorbent, can be a suitable candidate for removing heavy metals such as cobalt from aqueous solutions.

In this research, the FVB biosorbent was prepared after seed extraction and planting of Falcaria vulgaris and then characterized and applied to cobalt adsorption. In addition, the operating parameters that affect metal adsorption were optimized using the RSM based on a BBD model. The FVB, in optimized conditions, as an efficient biosorbent, considerably has the potential for the adsorptive removal of metal ions from aquatic environments.

The Lantana camara L. stem biomass as an inexpensive and efficient biosorbent for the adsorptive removal of malachite green from aquatic environments: kinetics, equilibrium and thermodynamic studies.

Plant biomass is one of the available and economic biomaterials used to remove environmental pollutants. The presence of colored compounds in aqueous solutions is one of the problems that can be solved by biological methods. Herein, the efficiency of available and inexpensive biomass obtained from Lantana camara L. stem for cationic dye uptake has been evaluated. The effect of operational factors, including dosage of L. camara L. stem biomass (LSB), pH of the solution, initial concentration of malachite green (MG), and residence time on the optimal conditions of analyte uptake was studied. The experimental data of adsorption studies fit with P-S-O kinetic (R2=0.999) and L.I.M (R2=0.998), indicating MG dye adsorption onto LSB occurred in monolayers due to its chemical affinity. The maximum uptake capacity of LSB for the removal of MG dye was 100 mg g-1. Thermodynamic parameters, including ΔG° (from -2.13 to -2.469 kJ  mol-1), ΔH° (+2.916 kJ  mol-1), and ΔS° (+16.934 J  mol-1 K-1) suggested that the adsorption process was endothermic and spontaneous. The results revealed that LSB considerably has potential for adsorptive removal of cationic dyes such as, MG from aquatic environments.

To the best of our knowledge, there is no report on the investigation of biomass efficiency obtained from L. camara L. stem for cationic dye biosorption. In the present research, the L. camara L. stem biomass was introduced as an inexpensive and suitable biosorbent for the adsorptive removal of cationic dyes.

Rate enhancement of plant growth using Ormus solution: optimization of operating factors by response surface methodology.

Phytoremediation is an economical technique for the biological treatment of soil and water contamination. Improving the growth of plants used in this technique leads to greater efficiency of the process. Herein, Lemna minor plant used in phytoremediation was collected from Sarab-e Nilufar region of Kermanshah province, Iran, and maintained in a culture medium. This study focused on the preparation of Ormus solution based on crystalline salt extracted from the salt mountains of Karmowstaj region in Fars province, Iran, to increase the proliferation of Lemna minor. The optimal growth conditions, including the pH of the medium, the residence time in the Ormus preparation process, and the concentration of Ormus solution were analyzed using the response surface methodology (RSM) based on a Box-Behnken design (BBD) model. Numerical optimization based on the quadratic model was carried out to achieve the maximum growth percentage. The percentage of the proliferation of Lemna minor varied from 34.6% to 117.3%, while growth was highest at a medium pH value of 10.75, a residence time of 72 h in the Ormus preparation process, and an Ormus concentration of 17 g.L-1. The results revealed that Ormus, as a supplemental fertilizer, under optimal conditions can significantly increase the rate of plant reproduction.

Herein, the Ormus solution was applied for the first time to increase plant growth. In addition, the operating factors, including the pH of the medium, the residence time in the Ormus preparation process, and the concentration of Ormus solution, were optimized using the RSM based on a BBD model. In this study, Ormus was introduced under optimal conditions as a suitable additive to increase the proliferation rate of plants.

A Brief Review of Recent Results in Arsenic Adsorption Process from Aquatic Environments by Metal-Organic Frameworks: Classification Based on Kinetics, Isotherms and Thermodynamics Behaviors.

In nature, arsenic, a metalloid found in soil, is one of the most dangerous elements that can be combined with heavy metals. Industrial wastewater containing heavy metals is considered one of the most dangerous environmental pollutants, especially for microorganisms and human health. An overabundance of heavy metals primarily leads to disturbances in the fundamental reactions and synthesis of essential macromolecules in living organisms. Among these contaminants, the presence of arsenic in the aquatic environment has always been a global concern. As (V) and As (III) are the two most common oxidation states of inorganic arsenic ions. This research concentrates on the kinetics, isotherms, and thermodynamics of metal-organic frameworks (MOFs), which have been applied for arsenic ions uptake from aqueous solutions. This review provides an overview of the current capabilities and properties of MOFs used for arsenic removal, focusing on its kinetics and isotherms of adsorption, as well as its thermodynamic behavior in water and wastewater.

Signal amplification of novel sandwich-type genosensor via catalytic redox-recycling on platform MWCNTs/Fe3O4@TMU-21 for BRCA1 gene detection.

The MWCNTs/Fe3O4@TMU-21 as a novel electrochemical sandwich-type genosensor was fabricated to detect the BRCA1 gene using the redox-cycling ferrocene functionalized reporter label probe (r-Fc-DNA). In the designed genosensor, the capture probe (cDNA) and r-Fc-DNA were used to detect the BRCA1 gene in sandwich-type genosensor, in which DNA sequences are well -hybridized with the BRCA1 gene (t-DNA). The cDNA was immobilized on the multiwall carbon nanotube and metal-organic framework with Fe3O4 nanoparticle core, which is the sensor platform. Target DNA was assayed by redox-recycling reporter probe (r-Fc-DNA) using the electro-catalytic activity of ferri/ferrocyanide, which results in significantly enhanced the oxidation peak current of r-Fc-DNA. The electrochemical redox cycling led to a high signal-to-noise ratio for gene assay. MWCNTs and Fe3O4@TMU-21 were applied to increase the platform conductivity and suitable binding of the recognition elements. This constructed genosensor plays an influential role in increasing the sensitivity of BRCA1 gene sequence recognition. So that under optimal conditions, this genosensor illustrated a wide linear range from 1.0×10-15 to 1.0×10-10 M with a detection limit of 0.57 × 10-15 M. Moreover, the genosensor exhibited high selectivity, stability, and reproducibility. The obtained recoveries (between 91 and 105%) of the BRCA1 gene assay in human blood samples satisfactory, which can be used for BRCA1 gene measurement in the laboratory.