Molecularly Imprinting Microfiltration Membranes Able to Absorb Diethyl Phthalate from Water

Environmentally friendly molecularly imprinted polymers as an insert for SPE type columns in the gentamicin monitoring process

The quantity and variety of micro-pollutants infiltrating water resources have increased rapidly in recent times. The appearance of many harmful substances in the waters has resulted in so-called chemical cocktails which significantly contribute to the deterioration of water quality. Additionally, the variety of these compounds, often similar to each other in terms of molecular weights, makes their separation and identification very difficult. In this paper we present the possibility of using self-regenerating mechanism of molecularly imprinted polymers to measure the concentration of micropollutants in the aquatic environment. Molecularly imprinted polymers toward gentamicin were prepared by monomer polymerization in aqueous solution at ambient temperature. Results from computer-based molecular modelling demonstrated potential binding sites between gentamicin and functional monomers in water. Various compositions of polymerization mixtures were tested. The ratio of monomers to each other was 1.1:1.4:0.0015 and 1:1:1 for N-isopropylacrylamine:acrylamide:acrylic acid, respectively. For each composition, various amounts of the standard were tested: 0, 3, 5, 7, 10,15 mol% in relation to monomers. The best results were obtained for 5 % gentamicin with an excess of acrylamide in relation to the other monomers. Sorption for this system was 0.783 mg/g at ambient temperature and desorption 0.593 at 4 °C. The synthesized materials, thanks to the incorporation of thermosensitive poly(N-isopropylacrylamide) into their structures, were able to release 89 % of adsorbed gentamicin. This made it possible to use the designed SPE columns repeatably with similar efficiency. The prepared materials were selective in the presence of other antibiotics like amoxicillin and norfloxacin.

Synthesis and functional mechanism evaluation of novel polymer-graphene oxide-biochar nanocomposite for efficient removal of diethyl phthalate

Phthalates, categorized as a main constituent of endocrine-disrupting chemicals (EDCs), are present in polymeric products. These substances can enter the environment through several pathways, including improper handling, which leads to their presence in toilet water, floor washings, surface runoff, and landfill leachate. This study focuses on the performance analysis of nanocomposite materials made of polymer (polypyrrole), quasi-metal (graphene oxide), and biochar (from palmyra seed) for the elimination of diethyl phthalates (DEP) from aqueous environments. Scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) were used to describe the nanocomposite characteristics. The experimental results supported a chemisorption process by agreeing well with the pseudo-second order. The Langmuir isotherm explained the DEP sorption data, which aligned to monolayer DEP adsorption on the nanocomposite surface. With a binding affinity of -13.36 (kcal/mol) and the highest docking score, Diethyl phthalates and graphene oxide interaction is validated. The produced nanocomposite is suggested as a possible alternative for the sorption of DEP. Future applications could benefit from the higher adsorption capacity, and environmental friendliness of nanocomposites.

Bioselective PES Membranes Based on Chitosan Functionalization and Virus-Imprinted NanoMIPs for Highly Efficient Separation of Human Pathogenic Viruses from Water

Waterborne viruses are a public health concern due to relatively small infection doses. Particularly, adenoviruses (AdVs) are more resistant than RNA viruses to water purification treatments in terms of ultraviolet (UV) irradiation, pH, and chlorination tolerance. Moreover, AdVs are one of the most predominant waterborne viruses. Membrane separations have proven superior removal capabilities of waterborne pathogens over other separation methods. However, virus removal at ultratrace levels is still a significant challenge for current membrane technology. This study successfully addressed this challenge by developing a bioselective polyethersulfone (PES) membrane by a joint strategy involving chitosan hydrophilic surface modification and the immobilization of adenovirus-specific molecularly imprinted nanoparticles (nanoMIPs). The topological and chemical changes taking place on the membrane surface were characterized by using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Furthermore, hydrophilicity and membrane performance were investigated in terms of swelling behavior, permeation flux, and surface fouling studies. The membrane efficacy was evaluated by filtration experiments, where the virus concentration of the loading solution before filtration and the permeates after filtration was quantified. The novel bioselective membrane showed excellent virus removal capabilities by separating 99.99% of the viruses from the water samples.