Application of Se-Met to CdTe QDs significantly reduces toxicity by modulating redox balance and inhibiting apoptosis

Cadmium tellurium quantum dots (CdTe QDs) as one of the most widely used QDs have been reported the toxicity and biosafety in recent years, little work has been done to reduce their toxicity however. Based on the mechanisms of toxicity of CdTe QDs on liver target organs such as oxidative stress and apoptosis previously reported by other researchers, we investigated the mechanism of action of trace element selenium (Se) to mitigate the hepatotoxicity of CdTe QDs. The experimental results showed that Se-Met at 40-140 μg L-1 could enhance the function of intracellular antioxidant defense system and the molecular structure of related antioxidant enzymes by reduce the production of ROS by 45%, protecting the activity of antioxidants and up-regulating the expression of selenoproteins with antioxidant functions, Gpx1 increase 225% and Gpx4 upregulated 47%. In addition, Se-Met could alleviate CdTe QDs-induced apoptosis by regulating two apoptosis-inducing factors, as intracellular caspase 3/9 expression levels were reduced by 70% and 87%, decreased Ca2+ concentration, and increased mitochondrial membrane potential measurements. Overall, this study indicates that Se-Met has a significant protective effect on the hepatotoxicity of CdTe QDs. Se-Met can be applied to the preparation of CdTe QDs to inhibit its toxicity and break the application limitation.

Overcoming the structure deficiency of nanodrug coated with tannic acid shell through phenolic hydroxyl protection strategy for Alzheimer's disease combination treatment

Tannic acid (TA) shell is of great interest for nanodrug design due to its versatile application such as antioxidant, antibacterial, anti-inflammatory. However, evidence is emerging that TA air oxidation in storage stage and unfavorable interactions of TA with electrolyte or protein in drug delivery could bring great challenge for the structure stability of nanodrug. In this study, a smart TA shell of nanomicelles was constructed through phenolic hydroxyl protection strategy, and the antioxidant capacity of nanomicelles maintain stable after 24 days storage. The phenolic hydroxyl protective tannic acid micelles (PHPTA micelles) show excellent performance for combination delivery of azoramide (Azo), dantrolene (Dan), Trazodone (Tra) in accelerated senescence (SAMP8) mice. This study may pave the way for the fabrication of nanodrugs with stable and smart TA shell for oxidative stress relevant diseases.

Performance and microbial metabolic mechanism of imidacloprid removal in a microbial electrolysis cell-integrated adsorption biological coupling system

Coke used as a filler to treat imidacloprid (IMI) wastewater by both adsorption biological coupling and microbial electrolysis cells (MEC)-adsorption biological coupling technologies, the removal efficiencies on pollutions in wastewater containing IMI were investigated, and the key functional genes related to IMI degradation pathways were also revealed. Results showed that the removal rates of COD, ammonia nitrogen, TP, and IMI under the adsorption biological coupling treatment and MEC-adsorption biological coupling treatment were 94.61-95.54%, 93.37-95.79%, 73.69-83.80%, and 100%, respectively. MEC increased the relative abundance of Proteobacteria by 9.01% and transformed the dominant bacteria from Lysobacter and Reyranella to Brevundimonas and Aquincola. Moreover, MEC up-regulated the abundance of the coding genes PK (9.30%), narG (2.26%), pstS (3.63%), and phnD (1.32%), and converted the IMI degradation products to smaller molecular weight C6H8N2 and C6H6ClNO. This study provided an important reference information for efficient treatment of IMI wastewater using the MEC-adsorption biological coupling technology.

Statistical optimization, kinetic, equilibrium isotherm and thermodynamic studies of copper biosorption onto Rosa damascena leaves as a low-cost biosorbent

In this study, Rosa damascena leaf powder was evaluated as a biosorbent for the removal of copper from aqueous solutions. Process variables such as the biosorbent dose, pH, and initial copper concentration were optimized using response surface methodology. A quadratic model was established to relate the factors to the response based on the Box-Behnken design. Analysis of variance (ANOVA) was used to assess the experimental data, and multiple regression analysis was used to fit it to a second-order polynomial equation. A biosorbent dose of 4.0 g/L, pH of 5.5, and initial copper concentration of 55 mg/L were determined to be the best conditions for copper removal. The removal of Cu2+ ions was 88.7% under these optimal conditions, indicating that the experimental data and model predictions were in good agreement. The biosorption data were well fitted to the pseudo-second-order and Elovich kinetic models. The combination of film and intra-particle diffusion was found to influence Cu2+ biosorption. The Langmuir and Dubinin-Radushkevich isotherm models best fit the experimental data, showing a monolayer isotherm with a qmax value of 25.13 mg/g obtained under optimal conditions. The thermodynamic parameters showed the spontaneity, feasibility and endothermic nature of adsorption. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the biosorbent before and after Cu2+ biosorption, revealing its outstanding structural characteristics and high surface functional group availability. In addition, immobilized R. damascena leaves adsorbed 90.7% of the copper from aqueous solution, which is more than the amount adsorbed by the free biosorbent (85.3%). The main mechanism of interaction between R. damascena biomass and Cu2+ ions is controlled by both ion exchange and hydrogen bond formation. It can be concluded that R. damascena can be employed as a low-cost biosorbent to remove heavy metals from aqueous solutions.

The potential application of bio-based ceramic/organic xerogel derived from the plant sources: A new green adsorbent for removal of antibiotics from pharmaceutical wastewater

A bio-based ceramic/organic xerogel (BCO-xerogel) was obtained from the combination of sugarcane bagasse ash, polyvinyl alcohol, and pine cone-derived tannin extract, which are abundant, non-toxic, and renewable sources. The as-prepared BCO-xerogel was used as a low-cost green adsorbent for the eliminate of four types of the most widely used antibiotics, including amoxicillin (AMX), tetracycline (TC), cefalexin (CLX), and penicillin G (PEN G) residuals from contaminated water. The simultaneous effects conventional variables including adsorbent dosage, antibiotic concentrations, solution pH, and contact time were studied and optimized by central composite design (CCD) under response surface methodology (RSM). Analysis of variance (ANOVA) was employed as a statistical formula to determine the significance of operating environmental conditions and their interactions with 95% confidence limits. Under optimized conditions, the experimental removal efficiencies for AMX, TC, CLX, and PEN G were 98.78 ± 3.25, 99.12 ± 2.52, 98.02 ± 1.98, and 98.42 ± 2.19, respectively. The adsorption isotherms and kinetics were better fitted with Langmuir and pseudo-second-order models, respectively. Thermodynamic studies showed that the adsorption process was endothermic, spontaneous, and occurred by combination of physical and chemical mechanisms. Also, evaluating the ability of BCO-xerogel to adsorptive removal of AMX, TC, CLX, and PEN G antibiotics in real wastewaters showed about 97.4-98.6% adsorption efficiency in river water and about 67.1-71.3% in three hospital effluents. After the adsorption process, the antibiotic-loaded adsorbent was regenerated by NaOH (0.01 mol L^-1), and the reusability tests showed that the removal efficiencies of the antibiotics in the four recovery steps were still above 90%. This work explored the development of green, efficient, and economical bio-adsorbent that can be utilized for the removal of antibiotics from contaminated wastewaters.

A comprehensive assessment of Yarrowia lipolytica and its interactions with metals: Current updates and future prospective

The non-conventional yeast Yarrowia lipolytica has been popular as a model system for understanding biological processes such as dimorphism and lipid accumulation. The organism can efficiently utilize hydrophobic substrates (hydrocarbons and triglycerides) thereby rendering it relevant in bioremediation of oil polluted environments. The current review focuses on the interactions of this fungus with metal pollutants and its potential application in bioremediation of metal contaminated locales. This fungus is intrinsically equipped with a variety of physiological and biochemical features that enable it to tide over stress conditions induced by the presence of metals. Production of enzymes such as phosphatases, reductases and superoxide dismutases are worth a special mention. In the presence of metals, levels of inherently produced metal binding proteins (metallothioneins) and the pigment melanin are seen to be elevated. Morphological alterations with respect to biofilm formation and dimorphic transition from yeast to mycelial form are also induced by certain metals. The biomass of Y. lipolytica is inherently important as a biosorbent and cell surface modification, process optimization or whole cell immobilization techniques have aided in improving this capability. In the presence of metals such as mercury, cadmium, copper and uranium, the culture forms nanoparticulate deposits. In addition, on account of its intrinsic reductive ability, Y. lipolytica is being exploited for synthesizing nanoparticles of gold, silver, cadmium and selenium with applications as antimicrobial compounds, location agents for bioimaging and as feed supplements. This versatile organism thus has great potential in interacting with various metals and addressing problems related to their pollutant status.

Experimental modelling studies on the removal of dyes and heavy metal ions using ZnFe2O4 nanoparticles

The presence of dyes and heavy metals in water sources as pollutants is harmful to human and animal health. Therefore, this study aimed to evaluate the efficacy of zinc ferrite (ZnFe2O4) nanoparticles (ZF-NPs) due to their outstanding properties including cost-effectiveness, availability, and applicability for removal of auramine O (AO), methylene blue (MB), and Cd (II). The effect of the main operating parameters such as AO concentration, MB concentration, Cd (II) concentration, adsorbent amount, solution pH, and sonication time was optimized by the response surface methodology (RSM). Optimal conditions were obtained at adsorbent amount of 0.25 g, pH = 6, sonication time of 15 min, and concentration of 15 mg L-1, and more than 91.56% were removed from all three analytes. The adsorption of AO, MB, and Cd (II) onto ZF-NPs followed pseudo-second-order kinetics and the equilibrium data fitted well with Langmuir isotherm. The maximum adsorption capacities of ZF-NPs for AO, MB and Cd (II) were as high as 201.29 mg g-1, 256.76 mg g-1 and 152.48 mg g-1, respectively. Also, the reuse of the adsorbent was investigated, and it was found that the adsorbent can be used for up to five cycles. Based on the results of interference studies, it was found that different ions do not have a significant effect on the removal of AO, MB, and Cd (II) in optimal conditions. The ZF-NPs was investigated successfully to remove AO, MB, and Cd (II) from environmental water samples. The results of this study showed that ZF-NPs can be used as a suitable adsorbent to remove AO, MB, and Cd (II) from aqueous solution.

New insights into denitrification and phosphorus removal with degradation of polycyclic aromatic hydrocarbons in two-sludge system

Polycyclic aromatic hydrocarbons (PAHs) have led to failure of waste water treatment plant operations. In this study, a two-sludge system was used to solve this problem of simultaneously removing phosphorus, nitrogen, and PAHs. The results showed that increasing the maximum PAHs concentration to 15 mg/L did not have any negative effect on the removal rates of total nitrogen (79.68%) and chemical oxygen demand (75.94%); however, the phosphorus removal efficiency decreased to 61.16%. The system exhibited a stronger degradation ability for phenanthrene. Thauera, Hydrogenophaga, and Hyphomicrobium were enriched, which resulted in good denitrification, and contributed to PAHs removal. PAHs mixture promoted PAHs functional genes but restrained denitrification functional genes. However, single naphthalene enhanced denitrification functional genes, which confirmed the feasibility of denitrification coupled with PAHs degradation. In conclusion, for the removal of pollutants from sewage treatment, nitrogen and phosphorus removal coupled with PAHs could be maintained by selecting a two-sludge system.

A novel artificial intelligent model for predicting water treatment efficiency of various biochar systems based on artificial neural network and queuing search algorithm

This study aims at providing a robust artificial intelligent model for predicting the efficiency of heavy metal removal from aqueous solutions of biochar systems with high accuracy and reliability. Not only is it environmentally significant, but it is also a powerful tool for improving biochar adsorption efficiency, reducing the risk of a global water shortage. Accordingly, 22 types of biomass feedstock with a total of 44 biochar systems and 353 experiments, aiming to remove six heavy metal ions (i.e., Cu²⁺, Pb²⁺, Zn²⁺, As³⁺, Cd²⁺, and Ni²⁺) from water were considered and evaluated. Subsequently, an artificial neural network (ANN) model was designed for predicting the heavy metal adsorption efficiency onto these biochar systems. To improve the accuracy of the ANN model, the queuing search algorithm (QSA), a human activities-based algorithm, was applied, aiming to optimize the parameters of the developed ANN model, called the QSA-ANN model. The results showed that the proposed optimization QSA-ANN model provided high accuracy with a root-mean-squared error (RMSE) of 0.051 and 0.074; determination coefficient (R²) of 0.978 and 0.960; variance accounted for (VAF) of 97.707 and 95.882, for the training and testing phases, respectively. Compared to the traditional ANN model, the accuracy of the proposed optimization QSA-ANN model was improved 2.7% on the training dataset and 2.9% on the testing dataset. With an accuracy of 96% in practice, the proposed optimization QSA-ANN model was recommended for practical engineering to predict and improve heavy metal adsorption efficiency onto biochar systems.

Application of neural network in metal adsorption using biomaterials (BMs): a review

ANN models for predicting wastewater treatment efficacy of biomaterial adsorbents.

Synthesis of highly porous three-dimensional PVA/GO/ZIF-67 cryogel for the simultaneous treatment of waters contaminated with cadmium (II) and lead (II) heavy metal ions

In this research, PVA/GO/ZIF-67 cryogel as a highly porous three-dimensional polymeric adsorbent was synthesized by freeze-drying method and applied for the simultaneous removal of Cd2+ and Pb2+ ions from contaminated...

Process optimization and enhancement of pesticide adsorption by porous adsorbents by regression analysis and parametric modelling

In the present study, the adsorptive removal of organophosphate diazinon pesticide using porous pumice adsorbent was experimentally investigated in a batch system, modelled and optimized upon response surface methodology (RSM) and artificial neural network-genetic algorithm (ANN-GA), fitted to isotherm, kinetic and thermodynamic models. The quantification of adsorbent elements was determined using EDX. XRD analysis was utilized to study the crystalline properties of adsorbent. The FT-IR spectra were taken from adsorbent before and after adsorption to study the presence and changes in functional groups. The constituted composition of the adsorbent was determined by XRF. Also, the ionic strength and adsorbent reusability were explored. The influences of operational parameters like pH, initial pesticide concentration, adsorbent dosage and contact time were investigated systematically. ANN-GA and RSM techniques were used to identify the optimal process variables that result in the highest removal. Based on the RSM approach, the optimization conditions for maximum removal efficiency is obtained at pH = 3, adsorbent dosage = 4 g/L, contact time = 30 min, and initial pesticide concentration = 6.2 mg/L. To accurately identify the parameters of nonlinear isotherm and kinetic models, a hybrid evolutionary differential evolution optimization (DEO) is applied. Results indicated that the equilibrium adsorption data were best fitted with Langmuir and Temkin isotherms and kinetic data were well described by pseudo-first and second-order kinetic models. The thermodynamic parameters such as entropy, enthalpy and Gibbs energy were evaluated to study the effect of temperature on pesticide adsorption.

Potentiality of living Bacillus pumilus SWU7-1 in biosorption of strontium radionuclide

Bacillus pumilus SWU7-1 was isolated from strontium ion (Sr(II))-uncontaminated soil, its biosorption potential was evaluated, and the effect of γ-ray radiation treatment on its biosorption was discussed. Domesticated under Sr(II) stress promoted the biosorption ability of B. pumilus to Sr(II), and the biosorption efficiency increased from 46.09% to 94.69%. At a lower initial concentration, the living bacteria had the ability to resist the biosorption of Sr(II). The optimal initial concentration range was 54-130 mg/L. The biosorption profile was better matched by Langmuir than Freundlich model, showing that the biosorption process of Sr(II) by the experimental strain was closer to the surface adsorption. According to Langmuir model, the maximum biosorption capacity of B. pumilus on Sr (II) was 299.4 mg/g. During the bacterial growth in the biosorption process, the changes in biosorption capacity and efficiency can be divided into two phases, and a pseudo-second-order model is followed in each phase. There was no significant difference in the biosorption efficiency of bacteria with different culture time after γ-ray radiation, and all of them were above 90%, which showed that B. pumilus had significant radiation resistance under experimental conditions. This study emphasized the potential application of B. pumilus in the treatment of radioactive Sr(II) pollution by biosorption.

Application of geopolymers synthesized from incinerated municipal solid waste ashes for the removal of cationic dye from water

In this study, municipal solid waste bottom ash (MSW-BA) and fly ash (MSW-FA) were used as a source of aluminosilicate to prepare geopolymer (GEO) adsorbents (GEO-MSWBA and GEO-MSWFA) for the removal of methylene blue (MB) from water. The effects of temperature, pH, and initial concentration on the MB adsorption onto GEO-MSWBA and GEO-MSWFA were evaluated. The adsorption isotherms parameters and thermodynamics were also determined. Detailed physical and chemical characterizations of the prepared adsorbents were carried out to further understand their impact on MB adsorption. The results from the scanning electron microscopy revealed a uniform granule-sphere like structure on both prepared geopolymers, which would facilitate the MB adsorption onto the adsorbents. The X-ray diffraction allowed observation of the microstructural transformations that occur after the alkaline activation. The surface areas of the GEO-MSWBA and the GEO-MSWFA were recorded as 32.78 m²/g and 4.5 m²/g, respectively. From the Fourier transform infrared, a stretching vibration of the aluminosilicate tetrahedral was observed, which indicated the success of geopolymerization. The prepared geopolymers showed a high capability of MB adsorption from an aqueous solution. The adsorption process was best suited and explained using the Langmuir isotherm model with a maximum adsorption capacity of 666.7 mg/g for the GEO-MSWBA (at 25°C) and 769.2 mg/g for the GEO-MSWFA (at 35°C). The positive value of the enthalpy (ΔH^o) for the GEO-MSWBA suggested the reaction favored endothermic reaction while the negative value of entropy (ΔS^o) indicated a solid/liquid random interaction. On the other hand, the negative ΔH^o value for the GEO-MSWFA indicated the reaction followed an exothermic reaction causing energy to be released, the positive ΔS^o value indicated a good affinity at the solid-liquid surface. The overall negative value for Gibbs free energy (ΔG^o) for both adsorbents suggested the adsorption was spontaneous and feasible. It was also inferred that n- π interaction, direct and indirect hydrogen bond, and electrostatic interaction between the MB and the prepared geopolymers facilitated the adsorption process. The current study shows that the GEO-MSWBA and the GEO-MSWFA have a great potential of removing MB as a cationic dye from water without performing any sort of laborious pretreatments.

Synthesis and application of hydrazono-imidazoline modified cellulose for selective separation of precious metals from geological samples

A new hydrazono-imidazoline modified cellulose (HIMC) was synthesized for selective recovery of Pt(IV), Pd(II) and Au(III) from geological samples. Cellulose was oxidized by periodate and was further functionalized with hydrazono-imidazoline moieties to afford N-donor chelating fibers. Scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), N₂ physisorption, elemental analysis, and energy-dispersive X-ray spectroscopy (EDX) were used for characterization. Introducing the hydrazono-imidazoline groups at the surface of cellulose fibers did not alert their ordered structure and crystallinity, as indicated by XRD and SEM results. Factors affecting the adsorption were systematically investigated. Under the optimized conditions, the HIMC sorbent exhibited high adsorption capacities of 105, 88 and 75 mg g^-1 for Pt(IV), Pd(II) and Au(III), respectively. Besides, the metal ion adsorption process fitted by pseudo-second-order kinetic model and Langmuir adsorption isotherm. These results highlight the applicability of this carbohydrate-based sorbent for the selective recovery of precious metals from various matrices.

Biodegradation and metabolic fate of thiamphenicol via Chlorella sp. UTEX1602 and L38

Thiamphenicol (TAP) is a typical medicament in animal husbandry and aquaculture for treating diverse infections. In this work, thiamphenicol biodegradation performance via microalgae was tested. The cultivation results showed that TAP could be biodegraded via the target algae. Chlorella sp. L38 presented strong adaptive ability to high concentration TAP. Biodegradation, biosorption and bioaccumulation were the dominant metabolic fates. Biodegradation contributed around 97% of the total removal efficiency at the TAP concentration of 46.2 mg·L^-1. The removal of TAP by Chlorella L38 and UTEX1602 agreed with the kinetic range of zero-order reaction, and the shortest half-lives were 3.2 d and 5.0 d. Based on the identification of metabolites, the metabolic pathway of TAP by microalgae was proposed, including chlorination, chlorine substitution, dehydration and hydroxylation. Therefore, biological treatment via microalgae has the potential for TAP purification.

Synthesis and application of Ce-doped TiO2 nanoparticles loaded on activated carbon for ultrasound-assisted adsorption of Basic Red 46 dye

Ce was doped on TiO₂ nanoparticles (NPs), and this association was loaded on activated carbon (Ce-TiO₂-NPs-AC). The characterization was completed by FE-SEM, TEM, and XRD, and finally these NPs were used for the ultrasonic-assisted adsorption of Basic Red 46 (BR 46) from aqueous solution. An experimental model suggested by the central composite design (CCD)-as a branch of response surface methodology (RSM)-provides insight into the influence of variables, such as BR 46 concentration, pH, adsorbent mass, and sonication time, on BR 46 removal. Experimental results revealed that setting conditions at 25 mg L^-1 of BR 46, pH 5.0, 0.02 g of Ce-TiO₂-NPs-AC and 4 min sonication resulted in a high coefficient of determination (R² > 0.99) and low probability values. The difference in the values is likely due to the accumulation of more than 99% of BR 46, while equilibrium data described by Langmuir isotherm model with a high adsorption capacity of 58.61 mg g^-1 and adsorption process were successfully correlated with pseudo-second-order kinetics model.

Bacterial community shift in response to a deep municipal tail wastewater treatment system

In previous studies, ozone oyster shell fixed-bed bioreactor and membrane bioreactor (OFBR-MBR) were developed for municipal tail wastewater treatment, and qualified good effects. This study mainly discussed the bacterial community shift in response to the treatment process of OFBR-MBR. Proteobacteria, Chloroflexi, Planctomycetes, Actinobacteria and Firmicutes were dominant bacteria after ozone treatment in phylum level in OFBR-MBR; Aciditerrimonas, Blastopirellula, Pasteuria, Planctomyces, Paracoccus, Caldilinea and Defluviicoccus were adapted and enriched after ozone treatment in genus level in OFBR-MBR. Ozone played key role in the species selection of bacteria in OFBR-MBR. The chemical oxygen demand (COD), ammonium and total phosphorus (TP) removal efficiency possessed by OFBR-MBR were 79.05%, 98.74% and 38.10%, which due to the function of ozone and these enriched bacteria. OFBR-MBR has exhibited huge potential for municipal tail wastewater, and it would also provide an alternative and promising technology for other kinds of tail wastewater recycling in future.

Ultrasound wave assisted adsorption of congo red using gold-magnetic nanocomposite loaded on activated carbon: Optimization of process parameters

In this study, gold-magnetic nanocomposite in the presence of ultrasound wave assisted was synthesized and loaded on activated carbon (Au-Fe₃O₄-NCs-AC) by simple, fast and low-cost process. This novel material was applied for ultrasound assisted adsorption of congo red (CR) as model of toxic and even carcinogenic substance from aqueous solution. The detail of morphology and identity of Au-Fe₃O₄-AC was characterized by SEM and TEM techniques and correlation among response to variables such as pH (2-10), adsorbent mass (0.005-0.025 g), initial CR concentration (10-30 mg L^-1) and ultrasound time (2-6 min) was investigated by response surface methodology (RSM) under central composite design (CCD). Analysis of variance (ANOVA) exhibit a high R² value of 0.999 and confirm suitability of constructed second-order regression model for excellent evaluation and prediction of the experimental data. The interaction and main factor and optimum conditions of the under study process were determined from response surface plots based on desirability function. The maximum CR adsorption were achieved at pH of 4, 15 mg L^-1 of CR, 0.017 g of Au-Fe₃O₄-AC and 5 min sonication which owing to 99.49% removal efficiency is highly recommended for future CR removal from different matrixes. Adsorption kinetic follow second-order rate expression in combination to inter particle diffusion and equilibrium adsorption data best represented by the Langmuir isotherm with maximum mono-layer adsorption capacity of 43.88 mg g^-1.

Isotherms and kinetic study of ultrasound-assisted adsorption of malachite green and Pb2+ ions from aqueous samples by copper sulfide nanorods loaded on activated carbon: Experimental design optimization

Copper sulfide nanorods loaded on activated carbon (CuS-NRs-AC) was synthesized and used for simultaneous ultrasound-assisted adsorption of malachite green (MG) and Pb²⁺ ions from aqueous solution. Following characterization of CuS-NRs-AC were investigated by SEM, EDX, TEM and XRD, the effects of pH (2.0-10), amount of adsorbent (0.003-0.011g), MG concentration (5-25mgL^-1), Pb²⁺ concentration (3-15mgL^-1) and sonication time (1.5-7.5min) and their interactions on responses were investigated by central composite design (CCD) and response surface methodology. According to desirability function on the Design Expert optimum removal (99.4%±1.0 for MG and 68.3±1.8 for Pb²⁺ions) was obtained at pH 6.0, 0.009g CuS-NRs-AC, 6.0min mixing by sonication and 15 and 6mgL^-1 for MG and Pb²⁺ ions, respectively. High determination coefficient (R²>0.995), Pred-R²-value (>0.920) and Adju-R²-value (>0.985) all are good indication of best agreement between the experimental and design modelling. The adsorption kinetics follows the pseudo-second order model and adsorption isotherm follows the Langmuir model with maximum adsorption capacity of 145.98 and 47.892mgg^-1 for MG and Pb²⁺ ions, respectively. This adsorbent over short contact time is good choice for simultaneous removal of large content of both MG and Pb²⁺ ions from wastewater sample.

Investigate the ultrasound energy assisted adsorption mechanism of nickel(II) ions onto modified magnetic cobalt ferrite nanoparticles: Multivariate optimization

In present study, magnetic cobalt ferrite nanoparticles modified with (E)-N-(2-nitrobenzylidene)-2-(2-(2-nitrophenyl)imidazolidine-1-yl) ethaneamine (CoFe₂O₄-NPs-NBNPIEA) was synthesized and applied as novel adsorbent for ultrasound energy assisted adsorption of nickel(II) ions (Ni²⁺) from aqueous solution. The prepared adsorbent characterized by Fourier transforms infrared spectroscopy (FT-IR), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). The dependency of adsorption percentage to variables such as pH, initial Ni²⁺ ions concentration, adsorbent mass and ultrasound time were studied with response surface methodology (RSM) by considering the desirable functions. The quadratic model between the dependent and independent variables was built. The proposed method showed good agreement between the experimental data and predictive value, and it has been successfully employed to adsorption of Ni²⁺ ions from aqueous solution. Subsequently, the experimental equilibrium data at different concentration of Ni²⁺ ions and 10mg amount of adsorbent mass was fitted to conventional isotherm models like Langmuir, Freundlich, Tempkin, Dubinin-Radushkevich and it was revealed that the Langmuir is best model for explanation of behavior of experimental data. In addition, conventional kinetic models such as pseudo-first and second-order, Elovich and intraparticle diffusion were applied and it was seen that pseudo-second-order equation is suitable to fit the experimental data.

Multi-responses optimization of simultaneous biosorption of cationic dyes by live yeast Yarrowia lipolytica 70562 from binary solution: Application of first order derivative spectrophotometry

Present study is based on application of live yeast Yarrowia lipolytica 70562 as new biosorbent was investigated for the simultaneous biosorption of Crystal Violet (CV) and Brilliant Green (BG) from wastewater. The effect of operating parameters such as initial dye concentrations (6-14mgL^-1), solution pH (4.0-8.0) and contact time (4-20h) was investigated by response surface methodology (RSM) for modeling and optimization of biosorption process and accordingly the best operational conditions was set as: initial CV and BG concentration of 8.0, and 10mgL^-1, pH of 7.0 and contact time of 16h. Above specified conditions lead to achievement of maximum biosorption of 98.823% and 99.927% for CV and BG dyes, respectively. The experimental equilibrium data well explained according to Langmuir isotherm model with maximum biosorption capacity of 65.359 and 56.497mgg^-1 for BG and CV, respectively. The second order and intraparticle diffusion models as cooperative mechanism has high efficiency and performance for interpretation of real data.

Mechanism of palladium(ii) biosorption by Providencia vermicola

Palladium uptake process, multi-scale visualization and functional groups of Providencia vermicola biomass in palladium biosorption were analyzed for the first time.