Lignin peroxidase (LiP) seems to be a catalyst for cleaving high-redox potential non-phenolic compounds with an oxidative cleavage of CC and COC bonds. LiP has been picked to seek a practical and ...cost-effective alternative to the sustainable mitigation of diverse environmental contaminants. LiP has been an outstanding tool for catalytic cleaning and efficient mitigation of environmental pollutants, including lignin, lignin derivatives, dyes, endocrine-disrupting compounds (EDCs), and persistent organic pollutants (POPs) for the past couple of decades. The extended deployment of LiP has proved to be a promising method for catalyzing these environmentally related hazardous pollutants of supreme interest. The advantageous potential and capabilities to act at different pH and thermostability offer its working tendencies in extended environmental engineering applications. Such advantages led to the emerging demand for LiP and increasing requirements in industrial and biotechnological sectors. The multitude of the ability attributed to LiP is triggered by its stability in xenobiotic and non-phenolic compound degradation. However, over the decades, the catalytic activity of LiP has been continuing in focus enormously towards catalytic functionalities over the available physiochemical, conventional, catalyst mediated technology for catalyzing such molecules. To cover this literature gap, this became much more evident to consider the catalytic attributes of LiP. In this review, the existing capabilities of LiP and other competencies have been described with recent updates. Furthermore, numerous recently emerged applications, such as textile effluent treatment, dye decolorization, catalytic elimination of pharmaceutical and EDCs compounds, have been discussed with suitable examples.
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The leather industry is a major source of environmental pollution in India. The wastewater generated by leather industries contains very high pollution parameters due to the presence of a complex ...mixture of organic and inorganic pollutants even after the treatment at a Common Effluent Treatment Plant (CETP) and disturbs the ecological flora and fauna. The nature, characteristics and toxicity of CETP treated wastewater is yet to be fully elucidated. Thus, this study aims to characterize and evaluate the toxicity of CETP treated tannery wastewater collected from the Unnao district of Uttar Pradesh, India. In addition to measuring the physico-chemical parameters, the residual organic pollutants was identified by GC-MS analysis and phytotoxicity, cytotoxicity and genotoxicity of the treated wastewater was evaluated using Vigna radiata L. and Allium cepa L. Results showed that the treated wastewater contained very high pollution parameters (TDS 3850 mg/L, BOD 680 mg/L, COD-1300 mg/L). GC-MS analysis revealed the presence of various types of residual organic pollutants including benzoic acid, 3-4,-(T-butyl) Phenyl furan-2-5-dione, benzeneacetamide, resorcinol, dibutyl phthalate, and benzene-1,2,4-triol. Further, toxicological studies showed the phytotoxic nature of the wastewater as it inhibited seed germination in V. radiata L. and root growth of A. cepa. Genotoxicity was evidenced in the root tip cell of A. cepa where chromosomal aberrations (stickiness, chromosome loss, C-mitosis, and vagrant chromosome) and nuclear abnormalities like micronucleated and binucleated cells were observed. Thus, results suggested that it is not safe to discharge these wastewater into the environment.
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•Tannery wastewater rich in organic and inorganic pollutants.•Tannery wastewater possesses genotoxic and cytotoxic pollutants.•Phytotoxic nature of tannery wastewater was evaluated by Vigna radiata seeds.•Allium cepa chromosomal tests revealed genotoxic nature of treated tannery wastewater.•Wastewater also induced chromosomal aberrations and nuclear abnormalities in cells.
The incessant accumulation of pharmaceutically active compounds (PhACs) in various environmental compartments represents a global menace. Herein, an equimolar high entropy alloy (HEA), i.e., ...FeCoNiCuZn, is synthesized via a facile and scalable method, and its effectiveness in eliminating four different PhACs from aqueous matrices is rigorously examined. Attributing to its relatively low bandgap and multielement active sites, the as-synthesized quinary HEA demonstrates more pronounced photocatalytic decomposition efficiency, towards tetracycline (86%), sulfamethoxazole (94%), ibuprofen (80%), and diclofenac (99%), than conventional semiconductor-based photocatalysts, under visible light irradiation. Additionally, radical trapping assays are conducted, and the dissociation intermediates are identified, to probe the plausible photocatalytic degradation pathways. Further, the end-products of FeCoNiCuZn-mediated photocatalysis are apparently non-toxic, and the HEA can be successfully recycled repeatedly, with no obvious leaching of heavy metal ions. Overall, the findings of this study testify the applicability of FeCoNiCuZn as a visible light-active photocatalyst, for treating wastewaters contaminated with PhACs.
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•An equimolar FeCoNiCuZn high entropy alloy (HEA) is synthesized by induction melting.•The quinary HEA can effectively degrade pharmaceutical residues under visible light.•The plausible photocatalytic degradation mechanism is investigated and proposed.•The photocatalysis end-products do not present any imminent threat to human health.•The HEA exhibits extraordinary stability for repeated usage.
•Here TiOx was developed as a highly efficient and novel anti-viral surface coating.•This TiOx is found to be highly defective, non-stoichiometric and amorphous.•This showed significantly higher ...efficacy against the viral strain than anatase.•This is transparent, non-cytotoxic, durable, stable and has high surface adherence.•RF magnetron sputtering was used here to synthesize this film at room temperature.
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This study focuses on the development of a highly defective, non-stoichiometric and amorphous TiOx as an efficient anti-viral surface coating. This amorphous phase is found to be significantly more effective against the baculovirus as compared to the conventionally used anatase modification. Moreover, the coating is found to be highly transparent in the entire visible-near infrared range. Radio frequency (RF) magnetron sputtering, one of the industrial scale techniques is used here to synthesize this film at room temperature. Furthermore, this film is found to be non-cytotoxic, durable, chemically stable and has strong adhesiveness with that of the substrate. Being cost-effective and environment friendly, this anti-viral surface coating holds huge promises of commercialization.
Various chemical compounds emerged including kraft lignin (KL) during the processes of papermaking. These chemical compounds in effluent of the paper industry have hazardous environmental impacts. KL ...is liable for causing pollution of aquatic and water bodies; hence, it must be minimized in order to maintain a healthy and sustainable environment. In the present study, KL degradation was performed with ligninolytic bacterium
and we confirmed biotransformation of KL to various less polluted or harmless compounds. KL being degraded as 1000 mg/L
concentration with incubating 30°C for 72, 168, and 240 h, shaking at 120 rpm under laboratory conditions. We found 65% maximum degradation of KL and 62% decolorization by the treatment with
for 240 h (10 days). After being the treatment of KL, clear changes were observed in its morphology (using scanning electron microscopy and stereo microscopy), hydrodynamic size (using dynamic light scattering), and the functional groups using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR). Biotransformation of KL monitored by Gas Chromatography-Mass Spectrometry (GC-MS) revealed formation of various metabolites. In addition to degradation of KL, detoxification (involving biotransformation into various metabolites) was assessed using cytotoxicity assays 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide MTT and calcein-acetoxymethyl (AM) assays using a human kidney cell line (NRK-52E), which indicated improved cell survival rates (74% for the bacteria-treated KL solution treated for 240 h) compared to the control (27%). Thus, the present study suggests that bacteria
ciens might be useful in reducing the pollution of KL by transforming it into various metabolites along with cytotoxicity reduction for environmental protection.
Synthesis of 2D materials from natural resources, and having unique functionalities have created enormous research interest among material scientists. Such 2D materials can be used as impetus for ...light scattering to generate continuous wave (CW) pumped random laser (RL) emission at room temperature. In this work, defects-free 2D yellow pearl (2D-YP) has been synthesized from bulk south sea pearl using liquid-phase exfoliation (LPE) technique. Thereafter, 2D-YP has been employed as a passive scatterer to achieve CW pumped RL emission from a conventional gain molecule. Compared to other semiconductor (TiO2) and 2D (Graphene and hBN) passive scatterers, ∼25 times improvement in gain volume is observed for the disordered system consisting of 2D-YP, and is due to the formation of a large refractive index gradient via thermal nonlinear optical (NLO) interaction. Hence, incoherent RL (ic-RL) emission ∼591 nm is reported at a lowest threshold input pump power and a linewidth of 65 mW and 3 nm, respectively. Additionaly, a clear transition from ic-RL to mode tunable coherent RL (c-RL) emission is also demonstrated by altering the pump configuration. Therefore, the newly designed van der Waals heterostructure, i.e., 2D-YP with intrinsic photon trapping capability may pave an avenue towards developing exciting optoelectronic devices.
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•2D yellow pearl is synthesized from its bulk form using liquid phase exfoliation.•Structural and linear optical properties of 2D-YP is explored.•The 2D-YP is employed as passive scatterer to achieve RL emission under CW pumping.•NLO effect induced boosting of gain volume over other scatterers is demonstrated.•Incoherent RL emission of linewidth of ∼3 nm, and ThPin of ∼65 mW is reported.
•
Isolation of a functional lignin-degrading
Bacillus aryabhattai
.
•
Production of growth-associated LiP and MnP enzymes.
•
Almost 84% KL degradation at 500 mg
L
−1
KL concentration.
•
KL ...biodegradation process was revealed by chemical analysis.
Kraft lignin (KL), is the major pollutant in pulp and paper effluent and due to its heterogeneous structure, it is resistant to the depolymerization process. It has drawn much attention from the researcher due to its challenging degradation process. In this study, a KL-degrading bacterium was isolated and screened from paper mill sludge. This bacterium was identified as ligninolytic
Bacillus aryabhattai
using biochemical and 16SrRNA gene analysis.
B. aryabhattai
showed maximum activities of lignin peroxidase-LiP (0.74 IU mL
−1
) and manganese peroxidase-MnP (9.2 IU mL
−1
) on the 4th day, and 5th day, respectively. A total 84% of KL (500 mg
L
−1
) reduction was observed after 14 days. The KL bio-degradation was confirmed based on changes in chemical stracture of KL and new metabolites identification using FTIR and GC–MS, respectively. The study concluded that
B. aryabhattai
maybe becomes a potential biological agent in KL biodegradation and treatment of other lignin-containing industrial effluents.
Xylanases have important industrial applications but are most extensively utilized in the pulp and paper industry as a pre-bleaching agent. We characterized a xylanase from
Bacillus amyloliquefaciens
...strain SK-3 and studied it for kraft pulp bleaching. The purified enzyme had a molecular weight of ~50 kDa with optimal activity at pH 9.0 and 50 °C. The enzyme showed good activity retention (85%) after 2 h incubation at 50 °C and pH 9.0. This enzyme obeyed Michaelis–Menten kinetics with regard to beechwood xylan with
K
m
and
V
max
values of 5.6 mg/ml, 433 μM/min/mg proteins, respectively. The enzyme activity was stimulated by Mn
2+
, Ca
2+
and Fe
2+
metal ions. Further, it also showed good tolerance to phenolics (2 mM) in the presence of syringic acid (no loss), cinnamic acid (97%), benzoic acid (94%) and phenol (97%) activity retention. The thermostability of xylanase was increased by 6.5-fold in presence of sorbitol (0.75 M). Further, pulp treated with 20U/g of xylanase (20IU/g) alone and with sorbitol (0.75M) reduced kappa number by 18.3 and 23.8%, respectively after 3 h reaction. In summary, presence of xylanase shows good pulp-bleaching activity, good tolerance to phenolics, lignin and metal ions and is amenable to thermostability improvement by addition of polyols. The SEM image showed significant changes on the surface of xylanase-treated pulp fiber as a result of xylan hydrolysis.
Distillery industries are the key contributor to the world's economy, but these are also one of the major sources of environmental pollution due to the discharge of a huge volume of dark colored ...wastewater. This dark colored wastewater contains very high biological oxygen demand, chemical oxygen demand, total solids, sulfate, phosphate, phenolics and various toxic metals. Distillery wastewater also contains a mixture of organic and inorganic pollutants such as melanoidins, di-n-octyl phthalate, di-butyl phthalate, benzenepropanoic acid and 2-hydroxysocaproic acid and toxic metals, which are well reported as genotoxic, carcinogenic, mutagenic and endocrine disrupting in nature. In aquatic resources, it causes serious environmental problems by reducing the penetration power of sunlight, photosynthetic activities and dissolved oxygen content. On other hand, in agricultural land, it causes inhibition of seed germination and depletion of vegetation by reducing the soil alkalinity and manganese availability, if discharged without adequate treatment. Thus, this review article provides a comprehensive knowledge on the distillery wastewater pollutants, various techniques used for their analysis as well as its toxicological effects on environments, human and animal health. In addition, various physico-chemicals, biological as well as emerging treatment methods have been also discussed for the protection of environment, human and animal health.
•Endocrine disrupting chemicals of distillery wastewater.•Environmental and health hazards of distillery wastewater pollutants.•Analytical techniques used for distillery wastewater pollutants analysis.•Physico-chemical, biological and emerging treatment methods of distillery wastewater.•Merits and demerits of various distillery wastewater treatment approaches.
The azo dyes in textile industry are a major source of environmental pollution and cause serious threat to aquatic flora and fauna. The present study aims to evaluate the potential of previously ...isolated lignin peroxidase (LiP) enzyme producing Serratia liquefaciens in degradation of Azure-B (AB) dye. S. liquefaciens showed rapid decolourisation of AB dye (100 mg L−1) in mineral salt medium (MSM) supplemented with 0.2% glucose and yeast extract, and more than 90% dye decolourisation was observed at 48 h when incubated at 30 °C. Decolourisation conditions were optimized by Response Surface Methodology (RSM) using Box-Behnken Designs (BBD). The dye degradation was further confirmed by ATR-FTIR and GC-MS analysis. Toxicological studies of untreated (UT) and bacterial treated (BT) AB dye solutions were studied by using phytotoxicity, genotoxicity and cytotoxicity endpoints. Phytotoxicity assay using Vigna radiata indicated that bacterial treatment led to detoxification of AB dye. Genotoxicity assay with Allium cepa showed that pure AB dye solutions significantly reduced mitotic index (MI) and induced various chromosomal abnormalities (CAs) like c-mitosis, stickiness, chromosome break, anaphase bridges, vagrant chromosomes and binucleated and micronucleated cell in the root tip cells, whereas, bacterial treated solutions induced relatively less genotoxicity in nature. Improved cell survivability (%) was also noted in kidney cell line (NRK-52E) after S. liquefaciens treated dye solutions than the pure dye solutions. The findings suggest that S. liquefaciens could be a potential bacterium for azo dye degradation, as it is effective in lowering of toxic effects of AB dye.
•Bacterial treatment led rapid decolourisation of Azure-B dye.•ATR-FTIR and GC-MS analysis confirmed dye degradation.•Pure dye exhibited phytotoxic, cytotoxic and genotoxic effects.•Bacterial treated dye solution was less toxic in nature.
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