Wastewater Treatment by Novel Polyamide/Polyethylenimine Nanofibers with Immobilized Laccase

Abstract

Endocrine-disrupting chemicals are highly resistant organic compounds, commonly occurring in the aquatic environment, that can interfere with the endocrine system of animals and humans, causing serious chronic diseases. In recent decades, enzymes from oxidoreductases have been studied for their potential to degrade these compounds effectively. In order to use such enzymes repeatedly, it is necessary to ensure their insolubility in water, a method termed enzyme immobilization. We developed novel polyamide/polyethylenimine (PA/PEI) nanofibers as a promising support material for the immobilization of various biomolecules. Our nanofibers are highly suitable due to a unique combination of mechanical endurance provided by polyamide 6 and their affinity toward biomolecules, ensured by numerous PEI amino groups. Enzyme laccase was successfully immobilized onto PA/PEI nanofibers using a simple and fast method, providing exceptional activity and stability of the attached enzyme. We then tested the degradation ability of the PA/PEI-laccase samples on a highly concentrated mixture of endocrine-disrupting chemicals in real wastewater with adjusted pH. The results indicate that the samples were a suitable material for wastewater treatment by degrading a highly concentrated mixture of bisphenol A, 17α-ethinylestradiol, triclosan, and diclofenac, in real wastewater effluent.

Comparison of Acetaminophen Degradation by Laccases Immobilized by Two Different Methods via a Continuous Flow Microreactor Process Scheme

“…Currently, it is very challenging to remove such pollutants from wastewaters due to their high stability and resistance to physicochemical and biological degradation. Some of the most worrisome micropollutants include pharmaceuticals, personal care products, industrial chemicals, and pesticides [ 20 , 39 ]. Acetaminophen has become one of the most consumed pharmaceutical and personal care products in many countries; it is excreted in both native and metabolized forms to sewer systems, wastewater treatment plants, and natural environments [ 19 ].…”

“…This results in substrate oxidation and in the generation of polymerization prone phenoxy free radicals [ 4 ]. Through this mechanism, Laccase, LiP and MnP have been previously shown to decompose phenolic and aromatic compounds, which usually show relatively low redox potential [ 4 , 6 , 20 ]. Furthermore, their applicability has been expanded to non-phenolic or non-aromatic substrates, including dyes, active residues from pharmaceuticals, pesticides, surfactants, and hormones [ 4 , 21 ].…”

Suitability of Immobilized Systems for Microbiological Degradation of Endocrine Disrupting Compounds

“…The level of the removal rate is still notable and could be relevant in potential use in the industry, however, it still requires more research. Laccase from T. versicolor immobilized on novel polyamide/polyethylenimine (PA/PEI) nanofibers also shows great reusable properties [ 76 ] with 100% initial activity after five cycles of 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) oxidation. Removal efficiency against triclosan, 17α-ethinylestradiol and bisphenol-A was 73.6, 47.3 and 27.9%, respectively.…”

“…Whereas, the storage stability of immobilized laccase after 30 days of storage retained 52% of its initial activity. Despite an almost 50% decrease of immobilized system activity during storage, Maryškova et al [ 76 ] shows great potential to reuse the PA/PEI carrier in continuous cycles of oxidation. It makes PA/PEI polymer potentially useful in EDCs and other pollutant removal.…”

Electrochemical Detection of Bisphenol A by Tyrosinase Immobilized on Electrospun Nanofibers Decorated with Gold Nanoparticles

“…The continuous discharge of highly toxic chemicals in the aquatic environment is a global concern due to their adverse effects on human health and the environment [1,2]. Pollutants with endocrine-disrupting activity, in particular, may damage the endocrine system of animals (including humans), even at such low concentrations as ng L −1 [3][4][5]. Regulatory agencies have established safe exposure limits, which are often low because the hormone systems are sensitive to these compounds [6][7][8].…”