Designing of a new transdermal antibiotic delivery polymeric membrane modified by functionalized SBA-15 mesoporous filler.

A new drug delivery system using an asymmetric polyethersulfone (PES) membrane modified by SBA-15 and glutamine-modified SBA-15 (SBA-Q) was prepared in this study by the aim of azithromycin delivery enhancement in both in vitro and ex vivo experiments. The research focused on optimizing membrane performance by adjusting critical parameters including drug concentration, membrane thickness, modifier percentage, polymer percentage, and pore maker percentage. To characterize the fabricated membranes, various techniques were employed, including scanning electron microscopy, water contact angle, and tensile strength assessments. Following optimization, membrane composition of 17% PES, 2% polyvinylpyrrolidone, 1% SBA-15, and 0.5% SBA-Q emerged as the most effective. The optimized membranes demonstrated a substantial increase in drug release (906 mg/L) compared to the unmodified membrane (440 mg/L). The unique membrane structure, with a dense top layer facilitating sustained drug release and a porous sub-layer acting as a drug reservoir, contributed to this improvement. Biocompatibility assessments, antibacterial activity analysis, blood compatibility tests, and post-diffusion tissue integrity evaluations confirmed the promising biocompatibility of the optimized membranes. Moreover, long-term performance evaluations involving ten repeated usages underscored the reusability of the optimized membrane, highlighting its potential for sustained and reliable drug delivery applications.

Concurrent removal of carbon and nutrients in a one-stage dual internal circulation airlift A2O bioreactor from milk processing industrial wastewater: Process optimization, sludge characteristics and operating cost evaluation.

In this work, a one-stage dual internal circulation airlift anaerobic/anoxic/aerobic (DCAL-A2O) bioreactor was continuously operated for concurrent removal of nutrients and organics from milk processing wastewater (MPW). Special configuration of the airlift A2O bioreactor created possibility of the formation of desired anaerobic, anoxic and aerobic zones in a single unit. The process functionality of the bioreactor was examined under three influential operating variables i.e. hydraulic retention time (HRT; 7-15 h), air flow rate (AFR; 1-3 L/min) and aerobic volume ratio (AVR; 0.324-0.464). The optimum region was identified at HRT of 13h, AFR of 2L/min and AVR of 0.437, leading to TCOD, TN and TP removal efficiency of 94.5 %, 59.6 %, and 62.2 %, respectively, and effluent turbidity of 8 NTU. The impact of feed biodegradability on the process performance of the bioreactor treating the MPW, soft drink wastewater (SDW) and soybean oil plant wastewater (SOW) was also assessed. From the results, the feed characteristics affected significantly the nutrients removal. Moreover, the feeding location played an effective role in the nutrient removal while treating the MPW at optimum operating conditions. In this study, the change in residual organic matters as soluble microbial products (SMP) was monitored at various operating conditions. In addition, the impact of SMP extracted from sludge, extracellular polymeric substances (EPS) comprising of loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) was analyzed on sludge characteristics as bio-flocculation and settleability properties. According to the obtained data, the increase in operating variables led to the reduction in contents of effluent SMP, sludge SMP, LB-EPS, turbidity, and SVI, thereby, the enhancement in the sludge characteristics. Meanwhile, analysis of microbial communities verified the presence of various functional bacterial species. The cost operating evaluation confirmed the cost effectiveness of the airlift A2O bioreactor in reduction of energy consumption for the MPW treatment.

Post-treatment of soft drink industrial wastewater using a new antibacterial ultra-filtration membrane prepared of Polyethersulfone blended with boehmite-tannic acid-graphene quantum dot.

Polymeric membranes have garnered great interest in wastewater treatment; however, fouling is known as their main limitation. Therefore, the blending of hydrophilic nanoparticles in polymeric membranes' structure is a promising approach for fouling reduction. Herein, a hydrophilic boehmite-tannic acid-graphene quantum dot (BM-TA-GQD) nanoparticle was synthesized and blended in a polyethersulfone polymeric membrane in different percentages. The fabricated membranes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) images, water contact angle, porosity measurement, and antibacterial and antifouling properties. Surface SEM images of the modified membranes showed good dispersion of nanoparticles up to 0.5 wt%, which resulted in hydrophilicity and pure water flux enhancement. Based on AFM images, the mean roughness (Sa) of the fabricated membranes decreased from 2.07 to 0.84 nm for the bare and optimum membranes, respectively. In terms of performance, increasing the nanoparticle percentages up to 0.5 wt% resulted in the flux recovery ratio developing from 44.58% for the bare membrane to 71.35% for the 0.5 wt% BM-TA-GQD/PES membrane (optimum membrane). The antibacterial property of fabricated membranes was studied against biologically treated soft drink industrial wastewater (BTSDIW) as a bacterial source. The results showed that the turbidity of solutions containing permeated wastewater from the modified membranes (0.1, 0.5, and 1 wt% of BM-TA-GQD) was lower than that obtained from the unmodified membrane. These results confirmed the antibacterial properties of fabricated membranes. Finally, the optimal membrane (0.5 wt% BM-TA-GQD) was examined for post-treatment of the BTSDIW. An effluent COD of 13 mg/L and turbidity of 2 NTU showed a successful performance of the filtration process. PRACTITIONER POINTS: Ultrafiltration PES membranes were modified by different loadings of BM-TA-GQD. Hydrophilicity improvement was achieved by adding BM-TA-GQD nanoparticles. Expansion of size and number of macro-voids in modified membranes was confirmed. Membrane roughness was reduced in the BM-TA-GQD blended membranes. The optimum membrane was efficient in COD and turbidity removal.

Enhancing nitrogen removal from wastewater in a low C/N ratio using an air-lift bio-electrochemical reactor (ALBER).

This study focuses on the development of an air-lift bio-electrochemical reactor (ALBER) with a continuous feeding regime. The objective is to enhance nitrogen removal from synthetic wastewater with a low carbon-to-nitrogen (C/N) ratio. The chemical oxygen demand (COD) and total nitrogen (TN) of the influent wastewater were 500 and 200 mg/L, respectively. The effect of four independent variables, i.e., temperature, hydraulic retention time (HRT), N-NH4+/TN ratio and current density in the range of 16-32 °C, 6-12 h, 25-75%, and 2-10 A/m2, respectively, at three levels on the bio-electrochemical reactor performance were investigated during the bio-electrochemical reactor operation. The Face Center Cube (FCC) of response surface methodology (RSM) was used for design of experiments and model of obtained data. The ALBER achieved the maximum TN removal of 73% (146 mg/l) using external voltage and zeolite/plastic medium at temperature of 16 °C, HRT of 6 h, current density of 2 A/m2 and N-NH4+/TN ratio of 75%. The results indicated that shortening the HRT from 12 to 6 h, reducing the temperature from 32 °C to 24 °C, increasing the current density from 2 to 6 A/m2 and the reduction of nitrate concentration caused an increase in the TN removal. The results indicated that the performance of air-lift bio-electrochemical for nitrogen removal could be attributed to autotrophic denitrification (AD) and simultaneous nitrification/denitrification (SND). The research findings suggest that the ALBER should be further studied for potential use in treating industrial wastewater at low temperatures.

Arsenic and total dissolved solids removal using antibacterial/antifouling nanofiltration membranes modified by functionalized graphene oxide and copper ferrodioxide.

The intrinsic hydrophilicity of metal compounds, such as copper ferrite (CuFe2 O4 ), and organic compounds, including graphene oxide (GO) and triethylenetetramine (TETA), make them promising adsorbents for heavy metals removal. The presence of lone pairs in these compounds is observed in modified polyethersulfone membranes used for the separation of arsenic (As) and total dissolved solids (TDS), including mono and divalent salts from aqueous solutions. The objective of this study was to investigate the performance of GO-TETA-CuFe2 O4 membranes for wastewater treatment applications. The membranes were characterized for their optimal mechanical strength (tensile strength) and high negative charge (zeta potential) on the surface. Separation tests were conducted at different pressures and pH levels to evaluate the membrane's effectiveness in removing contaminants. In addition, the membranes were examined for their antibacterial properties. The modified membrane exhibited superior performance compared with the control membrane, with TDS removal rates of 93.8%, As3+ removal rates of 81.2%, and As5+ removal rates of 87.9%. The contact angle of the modified membrane was reduced, resulting in an increase in pure water flux from 13.11 to 27.87 L/m2 .h. The modified membrane also demonstrated significantly higher resistance to fouling than the control membrane, with a resistance increase from 6.78 × 10+12 to 2.07 × 10+12  m-1 . This contributed to the improved separation performance of As and TDS in a cross-flow setup. The results suggest that the GO-TETA-CuFe2 O4 modified membrane has great potential for use in water treatment applications. PRACTITIONER POINTS: GO-TETA-CuFe2 O4 was successfully used for modification of PES NF membrane structure. The efficiency of blended NF membranes with GO-TETA-CuFe2 O4 significantly increased. The modified membranes exhibited significant water flux and antifouling properties. The GO-TETA-CuFe2 O4 /PES membranes showed high rejection of heavy metal ions and TDS than PES. The GO-TETA-CuFe2 O4 /PES membranes exhibited desirable antibacterial activity.

Design of a new polyethersulfone nanofiltration membrane with anti-fouling properties using supported protic ionic liquid modification for dye/salt removal.

Facile techniques to fabricate the nanofiltration membranes with ideal molecular sieving is one of the most interesting subjects in membrane separation technology. In this study, the application of modified graphene oxide (GO) with triethylenetetramine (TETA), CuFe2 O4 , and acetic acid (AC) (supported GO-TETA-CuFe2 O4 @AC) as a supported protic ionic liquid (PIL) modifier for polyethersulfone (PES) membrane was evaluated to approve the improvement of anti-fouling properties and wastewater rejection of the fabricated membranes. To enhance the key properties of graphene oxide, it was modified by hydrophilic nanomaterials (TETA-CuFe2 O4 ). High flux and promising flux recovery ratio (up to 95% compared to the unmodified membrane) can be observed in the modified membranes. The modified membranes by GO-TETA-CuFe2 O4 @AC were studied at optimum concentrations (0.5 wt.%) for salt rejection and different dyes. The obtained data indicated that the modified membranes by GO-TETA-CuFe2 O4 @AC indicated higher salt removal (up to 97% for BaCl2 than the unmodified membrane), which was related to the efficient modification. The obtained pure water flux (PWF) for bare and optimal modified membrane from 13.11 to 27.87 kg/m2 ·h, respectively. To exact evaluate the effect of membrane modification on performance examination, the modified membranes were evaluated for chlorine resistance testing. This study aimed to develop cost-effective nanofiltration (NF) membranes with high anti-fouling properties and to determine the maximum filtration capacity of in-time dyes and salts in effluents. PRACTITIONER POINTS: A GO-TETA-CuFe2O4 mixed matrix membrane was prepared for removal of salts and dyes. The effect of GO-TETA-CuFe2O4 enhanced the hydrophilicity and porosity. The membrane exhibited superior antifouling properties and ions rejection.

Color removal from wastewater using a synthetic high-performance antifouling GO-CPTMS@Pd-TKHPP/polyether sulfone nanofiltration membrane.

Modified graphene oxide with 5,10,15,20-tetrakis-(4-hexyloxyphenyl)-porphyrin and palladium (II) (signified by GO-CPTMS@Pd-TKHPP) prepared as a novel antifouling polyether sulfone (PES) blended nanofiller membrane. The membrane efficiency has been analyzed such as pure water flux (PWF), hydrophilicity, and antifouling features. By increasing of modified graphene oxide percentage from 0 to 0.1 wt.% in the polymer matrix, the PWF was incremented from 14.35 to 37.33 kg/m2·h at 4 bar. The membrane flux recovery ratio (FRR) has been investigated by applying powdered milk solution; the FRR results indicated that the 0.1 wt.%-modified graphene oxide membrane showed a positive effect on fouling behavior with Rir and FRR value 8.24% and 91.76%, respectively. The nanofiltration membrane performance was assessed applying the Direct Red 16 dye rejection. It was demonstrated that the optimal membranes (0.1 wt.%-modified graphene oxide) had notable dye removal (99.58% rejection). The results are also verified by measuring the scanning electron microscopy (SEM), water contact angle (WCA), and atomic microscopy analysis (AFM).

A new anti-fouling polysulphone nanofiltration membrane blended by amine-functionalized MCM-41 for post treating waste stabilization pond's effluent.

Developing an effective and stable separation membrane for water treatment is of much interest while challenging because of the restrictions of membrane fouling and water flux reduction. To minimize this problem, in this work, highly porous and hydrophilic nanostructure of NH2-modified MCM-41 (NH2-MCM-41) was embedded successfully into the nanofiltration (NF) membrane body via commonly used phase inversion method. The unmodified and modified nanofiller was analyzed by Fourier Transform Infrared (FTIR) spectroscopy, X-Ray powder diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and nitrogen adsorption-desorption. Furthermore, the modified membranes were characterized through surface and cross section FE-SEM images, the membrane surface roughness, hydrophilicity, antifouling properties and dye rejection. Benefiting from porous networks and enhanced hydrophilicity, the mixed matrix membranes (MMMs) revealed more prominent hydrophilic property as well as higher pure water flux (PWF) compared with naked membrane. The polysulphone (PSf) membrane modified with NH2-MCM-41-1.0 exhibited the highest pure water flux (PWF) of 65.43 kg/m2.h and superior antifouling characteristics with a flux recovery ratio (FRR) of around 97.0% and an irreversible fouling resistance (Rir) of 3.2%. Furthermore, the optimal membrane possessed high dye rejection (100%) and antifouling capacity (FRR of 97%) while filtering a field sample, effluent from a local stabilization pond treating municipal wastewater. The fabricated membrane in this study is believed to pave pathways for constructing NF membranes with superior effectiveness for other municipal and industrial wastewaters treatment.

A novel L-Histidine (C, N) codoped-TiO2-CdS nanocomposite for efficient visible photo-degradation of recalcitrant compounds from wastewater.

The aim of current study is to synthesis novel visible driven photocatalysts (L-Histidine (C, N) codoped-TiO2-CdS) with different loadings of L-Hisitdine (1, 2, and 3 wt.%) and CdS (1:9, 7:1, and 1:5 mass ratios of CdS to TiO2). Then, their application for photo-degradation of methyl orange (MO) and biologically treated palm oil mill effluent (POME) were studied. The structure, optical properties, and morphology of the prepared nanocomposites were also characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR), photoluminescence spectroscopy (PL), and diffuse reflectance spectra (DRS). DRS results indicated that all the modified samples with different L-Hisitdine and CdS loadings showed a red shift to visible region. The results of photo-degradation experiments showed that L-Hisitdine with a weight fraction of 2% and mass ratio of TiO2 to CdS of 7:1 were the optimum amount of the modifiers in the photocatalyst network. The PL intensity of the photocatalyst decreased with addition of L-Hisitdine and CdS nanoparticles due to a decrease in e-/h+ recombination. The effects of organic pollutant concentration, initial pH, catalyst concentration, and irradiation time on the photo-degradation process of MO and POME were studied using full faced centered central composite design (CCFD) under response surface methodology (RSM). The obtained results showed that MO was completely removed at initial concentration of 10 mg/L, acidic pH, and catalyst loading of 1.5 g/L after 120 min. The complete degradation of biologically treated POME was achieved at original pH, 300 mg/L of chemical oxygen demand (COD) concentration, catalyst loading of 2 g/L, and irradiation time of 2 h.