Nicolaisenfrancis8494

The experimental data of adsorption fitted well with the Langmuir and Freundlich isotherms with a high correlation coefficient (R2 > 0.9), showing that monolayer adsorption took place on the surface of GLU-MCSB absorbents. The negative values of entropy change, -175.64 and -163.30 J/(mol·K), and enthalpy change, -54.75 and -49.58 kJ/mol, for MCSB and GLU-MCSB suggest that the process is spontaneous and exothermic in nature.In this work, the natural and modified carnauba powder from the addition of bentonite was evaluated for the adsorption of Cu(II) ions in synthetic solution. The results showed that the carnauba powder treated with bentonite (CPTB) showed a better percentage of removal of Cu(II) ions when compared to natural carnauba powder (NCP). The best results for both adsorbents were obtained with pH 5. The adsorption kinetics was governed by the pseudo-second-order model for both bioadsorbents studied. While the isothermal behavior was governed by the Langmuir model and showed that the adsorption capacity of the CPTB for Cu(II) was 21.98 mg·g-1. The interaction of the metal and CPTB was also investigated by means of thermodynamic parameters showing that the adsorption process is not spontaneous, although the values of ΔG° decrease with the increase in temperature from 20 to 40 °C and endothermic causing an increase in the degree of disorder at the solid/liquid interface. The results showed that the CPTB is a material with potential adsorbent for the removal of copper ions.With the increasing application of hydraulic fracturing technology in exploration of tight oil and shale gas, the treatment of accompanying fracturing flowback fluids has become more urgent. Fe/Ni catalyst was successfully applied in the treatment of the flowback fluid for the first time in this paper. The effects of different oxidants and catalysts on the treatment of fracturing flowback were investigated. selleck chemicals llc Electrolytic brine was an optimal oxidation gel breaker and molecular sieve loaded with Fe/Ni as catalyst for the treatment of fracturing flowback. Fe/Ni catalyst was characterized by SEM, EDS analysis, TEM and XRD, and the catalytic effect of the Fe/Ni proportion was explored. Fracturing flowback that dealt with catalytic oxidation was mixed with polyaluminum chloride (PAC) and polyacrylamide (PAM) for flocculation and sedimentation, through a filter, and was continuously treated for 20 days to simulate on-site operation. Finally, the suspended solids (SS) content of the fracturing flowback was steadily less than 15 mg/L, which meets the reinjection standard of fracturing flowback (SY/T 5329-2012 (China)). Hence, electrolytic brine-catalyzed oxidation treatment of high viscosity fracturing flowback possess broad application prospects.Double functional groups modified bagasse (DFMBs), a series of new zwitterionic groups of carboxyl and amine modified adsorbents, were prepared through grafting tetraethylenepentamine (TEPA) onto the pyromellitic dianhydride (PMDA) modified bagasse using the DCC/DMAP method. DFMBs' ability to simultaneously remove basic magenta (BM, cationic dye) and Congo red (CR, anionic dye) from aqueous solution in single and binary dye systems was investigated. FTIR spectra and Zeta potential analysis results showed that PMDA and TEPA were successfully grafted onto the surface of bagasse, and the ratio of the amount of carboxyl groups and amine groups was controlled by the addition of a dosage of TEPA. Adsorption results showed that adsorption capacities of DFMBs for BM decreased while that for CR increased with the increase of the amount of TEPA in both single and binary dye systems, and BM or CR was absorbed on the modified biosorbents was mainly through electrostatic attraction and hydrogen bond. The adsorption for BM and CR could reach equilibrium within 300 min, both processes were fitted well by the pseudo-second-order kinetic model. The cationic and anionic dyes removal experiment in the binary system showed that DMFBs could be chosen as adsorbents to treat wastewater containing different ratios of cationic and anionic dyes.The study demonstrates the efficiency of the soil aquifer treatment (SAT) towards removal of heavy metals within electroplating wastewater thereby rendering it suitable for ground water discharge. The unique proposition of this research is to use a combination of soil and adsorbent properties to enhance the remediation of heavy metals such as nickel, copper and zinc. A comparative study through statistical analysis is employed to illustrate the effectiveness of the various SAT systems build using various combinations of SM and SC soil types along with bioadsorbents such as eucalyptus leaves, sawdust and Mosambi peel. Further, the mass balance analysis of heavy metals is carried out to comprehend the course of expulsion. The study, through a statistical approach, endorses that the SAT in conjunction with adsorbent gives much better removal efficiency than the SAT without adsorbent. Additional removal efficiency of 14% to 30% can be achieved with introduction of adsorbents within the SAT system. The optimal removal efficiency of nickel, copper and zinc was observed to be at 87, 98 and 93% respectively when passed through the combination of SM soil with sawdust.This study aimed to find biosurfactant producing and crude oil-degrading bacteria able to decontaminate crude oil from wastewater. The bacteria that were isolated from contaminated sites in an oil refinery plant in Isfahan, Iran, were identified by 16S rDNA sequencing as Achromobacter kerstersii strain LMG3441, Klebsiella pneumonia strain SKBA6, and Klebsiella variicola strain SKV2. According to the results obtained from different tests for the production of biosurfactant among three strains, only Achromobacter kerstersii strain LMG3441 was selected for further study. The pattern of residual hydrocarbons was analyzed by high-resolution gas chromatography-mass spectrometry (GC-MS). This novel and indigenous strain was capable of producing the highest amount of a glycolipid biosurfactant (7.81 g/L) in MSM (mineral salt medium) with 1% (v/v) crude oil as the only source of carbon and energy. The compound showed high surface activation capacity with reduction of surface tension from 40 mN m-1 in the control to 23.3 mN m-1 by the bacterium. The results of GC-MS for assessment of residual hydrocarbons in the MSM and comparison with crude oil as a control showed that 53% of the hydrocarbons in the crude oil were consumed by this novel strain.Effective treatment of wastewaters laden with heavy metals is critical to the sustainable social and economic growth of metal recycling villages in Vietnam. Currently, most wastewaters from metal recycling villages in Vietnam are directly discharged, posing great threats to the environment and human health. In this study, a small-scale combined coagulation-membrane filtration treatment of wastewater collected from a metal recycling village in Vietnam was experimentally investigated. The experimental results manifested the technical viability of the combined coagulation-membrane filtration process for the treatment of the heavily polluted metal recycling wastewater for beneficial reuse. In this combined treatment process, coagulation using ferric chloride (FeCl2) served as a pre-treatment prior to the microfiltration (MF)/reverse osmosis (RO) process. Under the optimised conditions, coagulation at the dosage of 0.2 g FeCl2 per 1,000 ml wastewater removed more than 90% of heavy metals (i.e. most notably including aluminium and chromium) from the wastewater, reducing the aluminium and chromium concentrations in the wastewater from 548.0 to 52.3 mg/L to 32.6 and 1.7 mg/L, respectively. The MF treatment of the wastewater following the coagulation further removed suspended solids and organic matters, rendering the wastewater safe for the subsequent RO filtration with respect to membrane fouling. Given the efficient pre-treatment of coagulation and MF, the RO process at the controlled water recovery of 50% was able to effectively treat the wastewater to potable water.The continuous growth of the pharmaceutical drug industry has escalated the problem of pharmaceutical waste disposal, and subsequent contamination of aquatic bodies. Paracetamol is one of the most prescribed and purchased drugs that has been widely detected in wastewater and surface water. The present study investigated paracetamol degradation by photocatalytic treatment in a batch system using TiO2 supported on aluminosilicate recovered from waste LED panel (ATiO2). The prepared ATiO2 catalyst was characterized for morphology, elemental composition and crystallinity using scanning electron microscope (SEM) with electron dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD), respectively. ATiO2 was spherical in morphology with a predominance of the anatase phase of TiO2 and an average size of ∼15 nm. Subsequently, the effects of operating parameters, viz., initial paracetamol concentration (1-10 mg/L), catalyst dosage (0.5-4.0 g/L) and pH (4-10) on paracetamol degradation were investigated using central composite design (CCD). A polynomial model was developed to interpret the linear and interactive effect of operating parameters on the paracetamol degradation efficiency. About 99% degradation efficiency of paracetamol was obtained at optimum conditions (Initial paracetamol concentration ∼2.74 mg/L, ATiO2 dosage ∼2.71 g/L and pH ∼ 9.5). The mechanism of paracetamol degradation was adsorption on aluminosilicate and subsequent degradation by TiO2. ATiO2 could be effectively reused up to 3 cycles, with less then 5% decrease in the degradation efficiency.In this study, an excellent phosphate adsorbent was prepared for removing phosphate to an extremely low concentration. The La(OH)3 nano-rods stabilizing in polyacrylonitrile (PAN) nanofibers (PLNFs) were prepared by electrospinning and a subsequent in situ precipitation. PAN nanofibers were employed as the matrix of the composite nanofibers, where the well-dispersed La(OH)3 nano-rods were encapsulated as the active species for highly efficient phosphate capture owing to the strong binding between phosphate and lanthanum. On account of the nano-structure, the maximum phosphate adsorption capacity was 151.98 mg P/g (La), much higher than the result of La(OH)3 nano-crystal, produced by precipitation without PAN or any organic surfactants. Moreover, the PLNFs could remove phosphate (2 mg P/L) to an extremely low concentration within 20 min, which could lead to a nutrient deficient condition to protect water quality and ecosystem. The optimization of PLNFs design was implemented through parameter adjustment of electrospinning. Lanthanum salt content, humidity, concentration of solution and applied voltage were chosen to analyze the influences on the composition, diameter and morphology of the nanofibers, giving the result that the most effective adsorbent was the PLNFs with spider-web-like nano-structures.In order to solve the problems of high energy consumption and low current efficiency in electrochemical oxidation (EO) degradation under the traditional constant output process (COP), a gradient output process (GOP) of current density is proposed in this paper. That is, the current density is gradually reduced in a fixed degradation time, and the Reactive Blue 19 simulated dye wastewater was used as the degradation target. The general applicability of the process was further confirmed by studying the optimal gradient current density output parameters, the dye concentration, electrolyte concentration and other dye compounds with different molecular structures. The corresponding results show that the chemical oxygen demand (COD) removal (78%) and the color removal (100%) under the GOP are similar to those in the COP, and the overall energy consumption is reduced by about 50% compared with that in the traditional constant current mode. Moreover, the current efficiency in the middle and late stages of EO process has increased by 8.