The permeability and selectivity of nanocomposite membrane of PEBAx 1657/PEI/SiO2 for separation of CO2, N2, O2, CH4 gases: A data set

The poly ether-block-amide (PEBAx)/Poly-ether-imide (PEI)/SiO2 nanocomposite membranes were fabricated using the solution casting method and utilized for separation of N2, O2, CH4, and CO2 gases. The effect of SiO2 nanoparticles loading on permeability and selectivity of gases using the nanocomposite membranes was tested. The data showed that the permeability of the gases increased with increasing SiO2 nanoparticle content. dBy adding SiO2 nanoparticles (10 wt%), the permeability of N2, O2, CH4, and CO2 gases elevated from 0.39, 1, 1.83 and 11.1 to 2.01, 1.95, 2.98 and 19.83 Barrer unit, respectively (at a pressure of 2 Bar). In contrast, with increasing SiO2 content the selectivity of the studied gases decreased. The morphology, crystallinity and the functional groups of the fabricated membranes were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) techniques. The data presented confirm the influence of the nanoparticles on the membrane structure and thus on the permeability and selectivity of the membranes

Waste sludge from shipping docks as a catalyst to remove amoxicillin in water with hydrogen peroxide and ultrasound

The waste sludge from shipping docks contains important elements that can be used as a catalyst after proper processing. The purpose of this study was to remove of amoxicillin (AMX) from the aquatic environment using waste sludge from shipping docks as catalyst in the presence of hydrogen peroxide/ultrasound waves. The catalyst was produced by treating waste sludge at 400 °C for 2 h. N2 adsorption, SEM, XRD, XRF, and FTIR techniques characterized the structural and physical properties of the catalyst. The BET-specific surface area of the catalyst reduced after AMX removal from 4.4 m2/g to 3.6 m2/g. To determine the optimal removal conditions, the parameters of the design of experiments were pH (5–9), contaminant concentration (5–100 mg/L), catalyst dosage (0.5–6 g/L), and concentration of hydrogen peroxide (10–100 mM). The maximum removal of AMX (98%) was obtained in the catalyst/hydrogen peroxide/ultrasound system at pH 5, catalyst dose of 4.5 g/L, H2O2 concentration of 50 mM, AMX concentration of 5 mg/L, and contact time of 60 min. The kinetics of removal of AMX from urine (k = 0.026 1/min), hospital wastewater (k = 0.021 1/min), and distilled water (k = 0.067 1/min) followed a first-order kinetic model (R2>0.91). The catalyst was reused up to 8 times and the AMX removal decreased to 45% in the last use. The byproducts and reaction pathway of AMX degradation were also investigated. The results clearly show that to achieve high pollutant removal rate the H2O2/ultrasound and catalyst/ultrasound synergy plays a key role

Toxic heavy metals and nutrient concentration in the milk of goat herds in two Iranian industrial and non-industrial zones

This work aimed to explore the concentration of nickel, manganese, iron, copper, chromium, and lead in the milk of goat herds in the industrial area of Asaluyeh (southern Iran) and the non-industrial area of Kaki. The milk of 16 goat herds (each herd had at least ten goats) was collected in several villages in each area, and at the same time, the drinking water and forage of goats were sampled. The concentration of elements in the samples was determined by ICP-OES. The mean concentrations of chromium, copper, iron, manganese, lead, and nickel in milk samples of the Asaluyeh area were 16.423 ± 0.349, 0.146 ± 0.118, 6.111 ± 0.501, 0.239 ± 0.016, 0.141 ± 0.030, and 1.447 ± 0.101 mg/kg, respectively. Concentrations of heavy metals (except for copper) in the milk of goats in the industrialized area of Asaluyeh were significantly higher than that of Kaki (P < 0.05). Also, the content of heavy metals was significantly correlated with lactose levels (P < 0.05). The hazard index for drinking the goat milk was computed to be 0.444 and 0.386 for the Asaluyeh and Kaki area, respectively, which shows a minimal effect of this exposure pathway

Waste glass catalyst for biodiesel production from waste chicken fat: Optimization by RSM and ANNs and toxicity assessment

In the current study, a heterogeneous solid base catalyst was manufactured by the reaction of waste glass with NaOH and used to generate biodiesel from chicken fat. The surface technical methods were used to characterize the produced catalyst. The active phase in the catalyst was Na2SiO3. The data showed that the catalyst is efficient to produce biodiesel from chicken fat (90% efficiency up to fourth stages of reuse). The effect of important variables such as reaction time, temperature, catalyst content, and methanol to oil ratio on the biodiesel production efficiency was optimized by RSM-CCD and artificial neural network (ANN). Maximum biodiesel production was calculated as 98.77% and 97.74% using RSM-CCD and ANN, respectively. The quality of the produced biodiesel was checked by ASTM D 6751 and EN 11214 standards. Also, the produced biodiesel was not toxic to plant and microorganisms and it is a biocompatible fuel

Treatment of chromium-laden aqueous solution using CaCl2-modified Sargassum oligocystum biomass: Characteristics, equilibrium, kinetic, and thermodynamic studies

Biosorption properties of a CaCl2-modified Sargassum oligocystum algae biomass for removal of Cr(VI) from aqueous solutions were investigated. Experimental parameters affecting the biosorption process such as pH, contact time, biosorbent dosage, and temperature were studied. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), mapping test, energy-dispersive X-ray spectroscopy (EDX), and specific surface area were used to assess the physico-chemical properties the biosorbent. The surface area of biosorbent was found to be 35.64 m2/g. FTIR test revealed that the active groups of -OH, -NH2, -C-H, C-O, -C-N, and S=O were present on the surface of CaCl2-modified S. oligocystum biomass. The kinetic behavior of the chromium biosorption by modified S. oligocystum biomass followed well pseudo-second order kinetic (R2&gt;0.999). The biosorption equilibrium occurred at 100th min of contact time. The Langmuir, Freundlich, and Dubinin-Radushkevich models were applied to describe the biosorption isotherm of Cr(VI) onto modified S. oligocystum biomass. According to the RL and n parameters of the studied isotherms, the Cr(VI) biosorption process was physical and desirable. The chromium biosorption capacity of modified S. oligocystum biomass was found to be 34.46mg/g. The calculated thermodynamic parameters (ΔGo, ΔHo, and ΔSo) indicated that the biosorption of Cr(VI) onto modified S. oligocystum biomass algae was feasible, spontaneous, and exothermic under examined conditions. © 2018, Korean Institute of Chemical Engineers, Seoul, Korea

Biodiesel production from edible oils using algal biochar/CaO/K2CO3 as a heterogeneous and recyclable catalyst

A new heterogeneous biochar/CaO/K2CO3 catalyst was fabricated to produce biodiesel from waste edible oil. In this catalyst, the biochar was produced from brown algae of Sargassum oligocystum and CaO from eggshells. The XRD result showed that the biochar, CaO, and synthesized catalyst have a crystalline structure. Response surface methodology-central composite design (RSM-CCD) and artificial neural network (ANN) methods were used to investigate the effect of parameters and determine optimal conditions. Also, the maximum efficiency of biodiesel production (98.83%) was predicted by the RSM-CCD method at 65 °C, 4 wt% catalyst content, 200 min duration, and 18: 1 methanol to oil ratio. The process of biodiesel production was exothermic. The activation energy and frequency factor were calculated 45.53 kJ/mol and 6.03 × 10+4 min−1, respectively. Biodiesel properties were evaluated according to international standards (ASTM D6751 and EN14214). The catalyst was reused for up to 90% efficiency in up to 5 steps

Performance of algal activated carbon/Fe 3 O 4 magnetic composite for cationic dyes removal from aqueous solutions

The activated carbon of Sargassum oligocystum (ACSO) was composited with Fe 3 O 4 nanoparticle (=ACSO/Fe 3 O 4 ) by a simple method and used as a recyclable and effective adsorbent for the removal of methylene blue (MB) and methyl violet (MV) from aqueous solutions. ACSO/Fe 3 O 4 was characterized using different physicochemical methods. The value of saturation magnetization and Brunauer–Emmett–Teller (BET) surface area for ACSO/Fe 3 O 4 was obtained 26.57 emu/g and 126.77 m 2 /g, respectively. The optimal adsorption conditions, including initial pH (7), the amount of ACSO/Fe 3 O 4 (0.15 g/100 mL), and contact time (50 min) were determined. At optimized conditions and the ultrasonic wave of 45 kHz more than 98% of the cationic dyes were removed. The adsorption process data matched well with pseudo-second-order and Freundlich isotherm models. Intra-particle diffusion model showed that the adsorption of cationic dyes onto ACSO/Fe 3 O 4 magnetic composite is two-stage and the speed of the first stage is faster than the second one. Furthermore, the maximum adsorption capacity of the ACSO/Fe 3 O 4 magnetic composite toward MB and MV reached as high as 60.60 mg/g and 59.88 mg/g, respectively. Finally, seven times reusing of ACSO/Fe 3 O 4 and removing dye from a real wastewater has made it a promising and attractive option for further practical applications

Sonication alkaline–assisted preparation of Rhizopus oryzae biomass for facile bio-elimination of tetracycline antibiotic from an aqueous matrix

The present study aimed to remove tetracycline (TET) antibiotic molecule from an aqueous medium using adsorbents prepared from Rhizopus oryzae biomass. The TET adsorption process was discontinuous and the adsorbent biomass was crude and NaOH-sonication–modified Rhizopus oryzae fungi. Specific active surface area for crude and modified Rhizopus oryzae was 10.38 m2/g and 20.32 m2/g, respectively. The results showed that the maximum TET adsorption efficiency was determined at pH 4, temperature 25 °C, initial TET concentration 10 mg/L, contact time 80 min, and biomass quantity 2 g/L. The equilibrium behavior showed that the Langmuir model suitably described the process. The maximum TET adsorption capacity was determined to be 38.02 mg/g and 67.93 mg/g, respectively, indicating that the method of biomass modification promoted the bio-adsorption capacity. A higher correlation coefficient (R2) and lower RMSE for the pseudo-first-order kinetic than other models showed its ability to describe the behavior of TET bio-adsorption. The enthalpy thermodynamic parameter (ΔH°) for the TET adsorption process was determined − 63.847 kJ/mol and − 85.226 kJ/mol for the raw and modified Rhizopus oryzae, respectively. Therefore, it can be suggested that the biomass of Rhizopus oryzae especially the modified version can be effectively used for the TET removal from aqueous environments

Performance of ultrasonic-assisted synthesis of date stones activated carbon for copper ions removal from aqueous media and electroplating wastewater

Copper (Cu2+) is found in various industrial wastewaters and has been associated to environmental and health adverse effects. The aim of this paper was to evaluate the adsorption property of ultrasonic-assisted- synthesized adsorbent prepared from date stones for copper ions elimination from aqueous solution. Physicochemical characteristics of the adsorbent including surface morphology, specific surface area, pore volume, functional groups, and pHzpc were determined. The adsorbent showed a high specific surface area of 512.38 m2 g-1, pore volume of 0.314 cm3 g-1, and the mean pore diameter of 26.6 nm. The effect of pH (3, 5, 6), adsorbent dose (0.25-4 g L-1), and contact time (3-60 min) on the copper adsorption was investigated. The copper adsorption by studied adsorbent was dependent on pH and the maximum removal was achieved at the solution pH of 6. The copper concentration of 40 mg L-1 was completely removed at the adsorbent dosage of 3 g L-1 and the contact time of 30 min. The equilibrium study was observed to conform with the Langmuir model (R2 = 0.997 and qmax = 188.67 mg g-1). Adsorption data were suitably described by the pseudo-second-order kinetic model (R2 > 0.99). Besides, used mesoporous activated carbon could be effectively reused for at least five times after treatment with HCl solutio

Modification of bio-hydroxyapatite generated from waste poultry bone with MgO for purifying methyl violet-laden liquids

In the present work, biological hydroxyapatite (Bio-HAp) was generated from waste poultry bone and modified with magnesium oxide (MgO) nanoparticles (Bio-HAp/MgO) and used in the adsorption process of methyl violet (MV). The Bio-HAp and Bio-HAp/MgO mesoporous composites were characterized using physicochemical techniques. Bio-HAp and Bio-HAp/MgO composites had crystalline and mesoporous structures. The specific surface area of Bio-HAp/MgO mesoporous composites (14.7 m2/g) was higher and lower than that of Bio-HAp (4.6 m2/g) and MgO (154.9 m2/g), respectively. The effect of pH (2–10), temperature (25–45 °C), contact time (10–50 min), initial MV concentration (5–25 mg/L), and Bio-HAp/MgO quantity (0.5–2.5 g/L) on the adsorption efficiency was optimized through response surface methodology-central composite design (RSM-CCD). Among four isotherm models, the Freundlich isotherm (R2 > 0.98) was better matched with the equilibrium data. Based on the isotherm parameters (E, n, and RL), the MV adsorption process using Bio-HAp particles and Bio-HAp/MgO mesoporous composites is physical and desirable. The pseudo-second-order (R2 > 0.97) was more potent than the other models for modeling kinetic data. According to the thermodynamic investigation, the MV adsorption was an exothermic and spontaneous process. The mesoporous composite had good reusability to remove MV dye from liquid media up to 5 steps. Bio-HAp particles and Bio-HAp/MgO mesoporous composites were tested for treatment, which significantly reduced the dye content of the real sample. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature