Distinctive toxic repercussions of polystyrene nano plastic towards aquatic non target species Nitrobacter vulgaris, Scenedesmus sp and Daphnia magna.

The widespread application of plastics and its eventual degradation to micro-sized or nano-sized plastics has led to several environmental concerns. Moreover, nanoplastics can easily cascade through the food chain accumulating in the aquatic organisms. Thus, our study focussed on investigating the hazardous impact of nano-sized plastics on aquatic species including Nitrobacter vulgaris, Scenedesmus sp, and Daphnia magna. Various concentrations of polystyrene nanoplastics ranging from 0.01 mg/L to 100 mg/L were tested against Nitrobacter vulgaris, Scenedesmus sp, and Daphnia magna. The minimum inhibitory concentration of polystyrene nanoplastics in Nitrobacter vulgaris was found to be 25 mg/L, and in Daphnia magna, the median lethal concentration 50 was observed to be 64.02 mg/L. Exposure of Scenedesmus sp with increasing nanoplastic concentrations showed a significant decrease in total protein (p < 0.001), and chlorophyll content (p < 0.01), whereas the lipid peroxidation increased (p < 0.001) significantly. Similarly, Nitrobacter vulgaris and Daphnia magna showed a significant decrease in catalase activity (p < 0.001) and an increase in lipid peroxidation levels (p < 0.01). Concomitant with lipid peroxidation results, decreased superoxide dismutase levels (p < 0.01) and protein concentrations (p < 0.01) were observed in Daphnia magna. Besides, the increasing concentration of polystyrene nanoplastics displayed an elevated mortality rate in Scenedesmus sp (p < 0.001) and Nitrobacter vulgaris (p < 0.01). Further, scanning electron microscopy analysis substantiated the morphological alterations in Nitrobacter vulgaris and Scenedesmus sp on exposure to polystyrene nanoplastics.

Treatment of industrial wastewaters by algae-bacterial consortium with Bio-H2 production: Recent updates, challenges and future prospects.

Currently, scarcity/security of clean water and energy resources are the most serious problems worldwide. Industries use large volume of ground water and a variety of chemicals to manufacture the products and discharge large volume of wastewater into environment, which causes severe impacts on environment and public health. Fossil fuels are considered as major energy resources for electricity and transportation sectors, which release large amount of CO2 and micro/macro pollutants, leading to cause the global warming and public health hazards. Therefore, algae-bacterial consortium (A-BC) may be eco-friendly, cost-effective and sustainable alternative way to treat the industrial wastewaters (IWWs) with Bio-H2 production. A-BC has potential to reduce the global warming and eutrophication. It also protects environment and public health as it converts toxic IWWs into non or less toxic (biomass). It also reduces 94%, 90% and 50% input costs of nutrients, freshwater and energy, respectively during IWWs treatment and Bio-H2 production. Most importantly, it produce sustainable alternative (Bio-H2) to replace use of fossil fuels and fill the world's energy demand in eco-friendly manner. Thus, this review paper provides a detailed knowledge on industrial wastewaters, their pollutants and toxic effects on water/soil/plant/humans and animals. It also provides an overview on A-BC, IWWs treatment, Bio-H2 production, fermentation process and its enhancement methods. Further, various molecular and analytical techniques are also discussed to characterize the A-BC structure, interactions, metabolites and Bio-H2 yield. The significance of A-BC, recent update, challenges and future prospects are also discussed.

Degradation of the antibiotic ciprofloxacin in urine by electrochemical oxidation with a DSA anode.

Ciprofloxacin (CIP) is a commonly prescribed fluoroquinolone antibiotic that, even after uptake, remains unmetabolized to a significant extent-over 70%. Unmetabolized CIP is excreted through both urine and feces. This persistent compound manages to evade removal in municipal wastewater facilities, leading to its substantial accumulation in aquatic environments. This accumulation raises concerns about potential risks to the health of various living organisms. Herein, we present a study on the remediation of CIP in synthetic urine by electrochemical oxidation in an undivided cell with a DSA (Ti/IrO2) anode and a stainless-steel cathode. Physisorbed hydroxyl radical formed at the anode surface from water discharge and free chlorine generated from Cl- oxidation were the main oxidizing agents. The effect of pH and current density (j) on CIP degradation was examined, and its total removal was easily achieved at pH ≥ 7.0 and j ≥ 60 mA cm-2 due to the action of free chlorine. The CIP decay always followed a pseudo-first-order kinetics. The components of the synthetic urine were also oxidized. The main nitrogenated species released was NH3. A very small concentration of free chlorine was quantified at the end of the treatment, thus demonstrating the good performance of electrochemical oxidation and its effectiveness to destroy all the organic pollutants. The present study demonstrates the simultaneous oxidation of the organic components of urine during CIP degradation, thus showing a unique perspective for its electrochemical oxidation that enhances the environmental remediation strategies.

New insights into the bioremediation of petroleum contaminants: A systematic review.

Petroleum product is an essential resource for energy, that has been exploited by wide range of industries and regular life. A carbonaceous contamination of marine and terrestrial environments caused by errant runoffs of consequential petroleum-derived contaminants. Additionally, petroleum hydrocarbons can have adverse effects on human health and global ecosystems and also have negative demographic consequences in petroleum industries. Key contaminants of petroleum products, primarily includes aliphatic hydrocarbons, benzene, toluene, ethylbenzene, and xylene (BTEX), polycyclic aromatic hydrocarbons (PAHs), resins, and asphaltenes. On environmental interaction, these pollutants result in ecotoxicity as well as human toxicity. Oxidative stress, mitochondrial damage, DNA mutations, and protein dysfunction are a few key causative mechanisms behind the toxic impacts. Henceforth, it becomes very evident to have certain remedial strategies which could help on eliminating these xenobiotics from the environment. This brings the efficacious application of bioremediation to remove or degrade pollutants from the ecosystems. In the recent scenario, extensive research and experimentation have been implemented towards bio-benign remediation of these petroleum-based pollutants, aiming to reduce the load of these toxic molecules in the environment. This review gives a detailed overview of petroleum pollutants, and their toxicity. Methods used for degrading them in the environment using microbes, periphytes, phyto-microbial interactions, genetically modified organisms, and nano-microbial remediation. All of these methods could have a significant impact on environmental management.

Wastewater generation and treatment by various eco-friendly technologies: Possible health hazards and further reuse for environmental safety.

The discharge of untreated wastewater as a result of various developmental activities such as urbanization, industrialization and changes in lifestyle poses great threats to aquatic ecosystems as well as humans. Currently, ∼380 billion m3 (380 trillion liters) of wastewater is generated globally every year. Around 70% of freshwater withdrawals are used for agricultural production throughout the world. The wastewater generated through agricultural run-off further pollutes freshwater resources. However, only 24% of the total wastewater generated from households and industries is treated before its disposal in rivers or reused in agriculture. The most problematic contaminants associated with ecological toxicity are heavy metals such as Cd, Cr, Cu, Ni, Zn, Fe, Pb, Hg, As and Mn. One of the most important issues linked with wastewater generation is the residual presence of pathogenic microorganisms which pose potential health hazards to consumers when they enter into the food chain. It is estimated that in India almost USD 600 million (48.60 billion INR) is spent per year to tackle waterborne diseases (WBD). In light of this, immediate action is needed to effectively treat wastewater and develop safer reuse prospects. Various wastewater treatment technologies have been established and they work well to provide an alternative water source to meet the growing demand. The main concern towards treating wastewater is to eliminate inorganic and organic substances and lower the nutrient concentration, total solids, and microbial pathogens to prevent freshwater pollution and health risks.

Microbial fuel cell: A green eco-friendly agent for tannery wastewater treatment and simultaneous bioelectricity/power generation.

This review paper emphasised on the origin of hexavalent chromium toxicity in tannery wastewater and its remediation using novel Microbial Fuel Cell (MFC) technology, including electroactive bacteria, which are known as exoelectrogens, to simultaneously treat wastewater and its action in the production of bioenergy and the mechanism of Cr6+ reduction. Also, there are various parameters like electrode, pH, mode of operation, time of operation, and type of exchange membrane used for promising results shown in enhancing MFC production and remediation of Cr6+. Destructive anthropological activities, such as leather making and electroplating industries are key sources of hexavalent chromium contamination in aquatic repositories. When Cr6+ enters the food chain and enters the human body, it has the potential to cause cancer. MFC is a green innovation that generates energy economically through the reduction of toxic Cr6+ to less toxic Cr3+. The organic substrates utilized at the anode of MFC act as electrons (e-) donors. This review also highlighted the utilization of cheap substrates to make MFCs more economically suitable and the energy production at minimum cost.

Potential of eggshell waste derived calcium for sustainable production of biogas from cassava wastewater.

Cassava is a staple crop that plays a significant role in the food security of many countries. However, its processing produces a liquid by-product known as cassava wastewater (CW), which can have adverse environmental consequences if discarded without treatment. Despite its cyanide content, CW has a high organic content and may be profitable when used to produce biogas. In this study, the influence of calcium particles from eggshell residues was investigated on the anaerobic digestion of CW. Moreover, the performance of the bioreactor was remotely monitored. Calcium particles from milled-calcined chicken eggshells were added to the bioreactor, and biogas production was investigated for 21 days. Adding 1 g/L and 3 g/L of calcium particles increased biogas (Bio H2 + Bio CH4) production by 195% and 338%, respectively. Finally, the requirement for digestate post-treatment before use in agriculture was observed after assessing its phytotoxicity through the germination and root growth of L. sativa seeds.

Biodecolorization and Ecotoxicity Abatement of Disperse Dye-Production Wastewater Treatment with Pycnoporus Laccase.

The biological treatment efficiency of dye wastewater using activated sludge (AS) is largely limited to the chromaticity and ecotoxicity of dyestuff. To alleviate this limitation, eleven industrial-grade disperse dyes were obtained from a fiber-dyeing factory, and for the first time, we studied the decolorization and detoxification effects of using the Pycnoporus laccase enzyme. Efficient decolorization was achieved with the following conditions: dye concentration 50 mg/L, 1-hydroxybenzotriazole (HBT) 0.15 mM, temperature 65 °C, pH 4, and laccase 0.33 U/mL. The decolorization rate of disperse dyes, ranging from 51 to 96% in this investigation, was highly dependent on the dye type, concentration, laccase loading, and HBT. The ecotoxicity of dyes was evaluated by studying the germination/growth of wheat seed as well as the respiratory rate of aerobic AS. Laccase treatment mitigated the phytotoxicity of dyes because of the higher wheat germination (e.g., increase of 38% for Black ECT 200%) and growth rate (e.g., increase of 91% for Blue 2BLN 200%). The reduced ecotoxicity of decolorized dye solution towards microorganisms was also confirmed by the finding that the oxygen uptake by aerobic AS was increased relative to that of the untreated samples (e.g., increase of 14 folds for Blue HGL 200%). In addition, the chemical oxygen demand (COD) of decolorized dye solution was slightly lower than that without decolorization during the respiratory test. The experimental results suggest that enzymatic decolorization and detoxification can be potentially used as a pretreatment method for disperse dye wastewater followed by AS treatment.

Effective adsorption of diclofenac and naproxen from water using fixed-bed column loaded with composite of heavy sugarcane ash and polyethylene terephthalate.

The contamination of water by pharmaceutical pollutants is a major issue these days due to excessive use of these ingredients in modern life. This study evaluated the adsorption and effectiveness of a low-cost composite prepared from heavy sugarcane ash (HSA) fused with polyethylene terephthalate (PET) and functionalized with iron (Fe3+) in a dynamic system through a fixed-bed column. The solution of synthetic drugs was prepared and placed in a reservoir, using a peristaltic pump the solution is run onto the fixed bed column at a flow rate of 2 mL min-1. Saturation time and adsorption capacity were evaluated by centrifugation and extraction after a regular interval of 2 h from the adsorption column. The samples were analyzed using high-performance liquid chromatography (HPLC) and the data was modeled for quantification. For DIC removal, an adsorption capacity of 324.34 µg. g-1 and a saturation time of 22 h were observed, while the adsorption capacity of NAP was 956.49 µg. g-1, with a saturation time of 8 h. Thus, the PETSCA/Fe3+ adsorbent proved to be quite efficient for removing the pharmaceutical pollutants, with a longer period of operation for DIC removal. These findings suggested that a highly efficient bed column made from a less expensive waste material and could be used to remove hazardous pharmaceutical contaminants.

Algae bioprocess to deal with cosmetic chemical pollutants in natural ecosystems: A comprehensive review.

Elevated demand and extensive exploitation of cosmetics in day-to-day life have hiked up its industrial productions worldwide. Organic and inorganic chemicals like parabens, phthalates, sulfates, and so forth are being applied as constituents towards the formulations, which tend to be the mainspring ecological complication due to their enduring nature and accumulation properties in various sections of the ecosystem. These cosmetic chemicals get accrued into the terrestrial and aquatic systems on account of various anthropogenic activities involving agricultural runoff, industrial discharge, and domestic effluents. Recently, the use of microbes for remediating persistent cosmetic chemicals has gained immense interest. Among different forms of the microbial community being applied as an environmental beneficiary, algae play a vital role in both terrestrial and aquatic ecosystems by their biologically beneficial metabolites and molecules, resulting in the biobenign and efficacious consequences. The use of various bacterial, fungal, and higher plant species has been studied intensely for their bioremediation elements. The bioremediating property of the algal cells through biosorption, bioassimilation, biotransformation, and biodegradation has made it favorable for the removal of persistent and toxic pollutants from the environment. However, the research investigation concerned with the bioremediation potential of the algal kingdom is limited. This review summarizes and provides updated and comprehensive insights into the potential remediation capabilities of algal species against ecologically hazardous pollutants concerning cosmetic chemicals.

Efficient degradation and detoxification of methylene blue dye by a newly isolated ligninolytic enzyme producing bacterium Bacillus albus MW407057.

In present work, a LiP enzyme producing bacterium was isolated form textile wastewater and sludge sample and identified as Bacillus albus by 16S rRNA gene sequencing analysis. This bacterium decolorized 99.27 % MB dye and removed 83.87 % COD within 6 h at 30 °C, pH 7, 100 rpm and 100 mg/l of dye concentration in presence of glucose and yeast extract as carbon and nitrogen source, respectively. The bacterium also produced LiP enzyme of molecular weight ∼48 kDa, characterized by SDS-PAGE analysis. Different metabolites like monomethylthionine, thionin, (E)-2-(3-Oxopropylidene)-2H-benzo[b][1,4] thiozine-3-carboxylic acid, N-(3,4-dihydroxyphenyl)-N-methylformamide, ethylamine, water and carbon dioxide produced during treatment process were characterized by FT-IR and LC-MS analysis. Further, the toxicity assessment results showed that the toxicity of bacteria treated dye solution was reduced significantly allowing 90 % seed germination indicating that the isolated bacterium B. albus has high potential to decolorize and detoxify MB dye for environmental safety.

Detection and characterization of refractory organic and inorganic pollutants discharged in biomethanated distillery effluent and their phytotoxicity, cytotoxicity, and genotoxicity assessment using Phaseolus aureus L. and Allium cepa L.

The color effluent discharged by alcohol distilleries comprises very high pollution loads due to the plethora of refractory chemicals even after anaerobic treatment and causing adverse effects to the environment. The present study aimed to examine the phytotoxic, cytotoxic, and genotoxic potential of the identified refractory organic and inorganic pollutants discharged in bio-methanated distillery effluent (BMDE). Physico-chemical analyses revealed that BMDE retains high BOD, COD, TDS along with heavy metals like Fe (572.64 mg L-1), Mn (4.269 mg L-1), Cd (1.631 mg L-1), Zn (2.547 mg L-1), Pb (1.262 mg L-1), (Cr 1.257 mg L-1), and Ni (0.781 mg L-1) beyond the permissible limits for effluent discharge. GC-MS analysis revelaed the presence of hexadecanoic acid, TMS ester; octadecanoic acid, TMS ester; 2,3 bis[(TMS)oxy]propyl ester; stigmasterol TMS ether; ß-sitosterol TMS ester; hexacosanoic acid; and tetradecanoic acid, TMS ester as major refractory organic pollutants, which are listed as potential endocrine disruptor chemicals (EDCs) as per USEPA. Furthermore, phytotoxicity assessment with Phaseolus aureus L. showed the toxic nature of BMDE as it inhibited various seedling growth parameters, seed germination, and suppression of α-amylase activity in seed germination experiment. Moreover, genotoxicity and cytotoxicity evaluation of the discharged BMDE evidenced in root-tip meristematic cells of Allium cepa L. where chromosomal aberration such as disturbed metaphase, c-mitosis, laggard chromosomes, sticky chromosomes, prolonged prophase, polyploid cells, and apoptotic bodies etc. were observed. Thus, this study's results suggested that BMDE discharged without adequate treatment poses potential risk to environment and may cause a variety of serious health threats in living beings upon exposure.

Environmental aspects of hormones estriol, 17ß-estradiol and 17α-ethinylestradiol: Electrochemical processes as next-generation technologies for their removal in water matrices.

Hormones as a group of emerging contaminants have been increasingly used worldwide, which has increased their concern at the environmental level in various matrices, as they reach the water bodies through effluents due to the ineffectiveness of conventional treatments. Here we review the environmental scenario of hormones estriol (E3), 17ß-estradiol (E2), and 17α-ethinylestradiol (EE2), explicitly their origins, their characteristics, interactions, how they reach the environment, and, above all, the severe pathological and toxicological damage to animals and humans they produce. Furthermore, studies for the treatment of these endocrine disruptors (EDCs) are deepened using electrochemical processes as the remediation methods of the respective hormones. In the reported studies, these micropollutants were detected in samples of surface water, underground, soil, and sediment at concentrations that varied from ng L-1 to µg L-1 and are capable of causing changes in the endocrine system of various organisms. However, although there are studies on the ecotoxicological effects concerning E3, E2, and EE2 hormones, little is known about their environmental dispersion and damage in quantitative terms. Moreover, biodegradation becomes the primary mechanism of removal of steroid estrogens removal by sewage treatment plants, but it is still inefficient, which shows the importance of studying electrochemically-driven processes such as the Electrochemical Advanced Oxidation Processes (EAOP) and electrocoagulation for the removal of emerging micropollutants. Thus, this review covers information on the occurrence of these hormones in various environmental matrices, their respective treatment, and effects on exposed organisms for ecotoxicology purposes.

Fungal biosynthesis of lignin-modifying enzymes from pulp wash and Luffa cylindrica for azo dye RB5 biodecolorization using modeling by response surface methodology and artificial neural network.

This study demonstrates the evaluation between the artificial neural network technique coupled to the genetic algorithm (ANN-GA) and the response surface methodology (RSM) for prediction of Reactive Black 5 (RB5) decolorization by crude enzyme from Pleurotus. sajor-caju. Fungal lignin-modifying enzymes (FLME) were synthesized using pulp wash (PW) as an inducing substrate, and L. cylindrica (L.C) for cell immobilization. When grown in PW, the fungus showed higher Lac activity (126.5 IU. mL-1), whereas when immobilized a higher MnP activity was achieved (22.79 IU. mL-1), but both methods were capable of decolorizing the dye in about 89.4 % and 75 %, respectively. This indicates applicability of PW as an alternative substrate for FLME induction and viability of immobilization for MnP synthesis. For RB5 decolorization, the action of the crude enzyme extract was considered as a function of pH, dye concentration, temperature, and reaction time. The models are well adjusted to predict the efficiency of biodecolorization, with no statistical difference between ANN-GA and RSM, which indicates potential for green enzymes prospecting application in bioprocess industry.

Electrochemical oxidation of indanthrene blue dye in a filter-press flow reactor and toxicity analyses with Raphidocelis subcapitata and Lactuca sativa.

Alternative routes to degrade dyes are of crucial importance for the environment. Hence, we report the electrochemical removal of indanthrene blue by using a boron-doped diamond anode, focusing on the toxicity of the treated solutions. Different operational conditions were studied, such as current density (5, 10, and 20 mA cm-2) and electrolyte composition (Na2SO4, Na2CO3, and NaNO3). Besides, the pH was monitored throughout the experiment to consider its direct influence on the ecotoxicity effects. The highest electrochemical oxidation efficiency, measured as color removal, was seen in the 180 min condition of electrolysis in 0.033 M Na2SO4, applying 20 mA cm-2, resulting in a color removal of nearly 91% and 40.51 kWh m-3 of energy consumption. The toxicity towards Lactuca sativa depends solely on pH variations being indifferent to color removal. While the inhibition concentration (IC50) for Raphidocelis subcapitata increases 20% after treatment (in optimized conditions), suggesting that the byproducts are more toxic for this specific organism. Our data highlight the importance of analyzing the toxicity towards various organisms to understand the toxic effect of the treatment applied.

Environmental threatening concern and efficient removal of pharmaceutically active compounds using metal-organic frameworks as adsorbents.

An alarming number of contaminants of emerging concern, including active residues from pharmaceuticals and personal care products (PPCPs), are increasingly being introduced in water systems and environmental matrices due to unavoidable outcomes of modern-day lifestyle. Most of the PPCPs based contaminants are not completely eliminated during the currently used water/wastewater treatment processes. Therefore, highly selective and significant removal of PPCPs from environmental matrices remains a scientific challenge. In recent years, a wide range of metal-organic frameworks (MOFs) and MOF-based nanocomposites have been designed and envisioned for environmental remediation applications. MOF-derived novel cues had shown an adsorptive capability for the extraction and removal of an array of trace constituents in environmental samples. Noteworthy features such as substantial surface area, size, dispersibility, tunable structure, and repeated use capability provide MOFs-derived platform a superiority over in-practice conventional adsorptive materials. This review provides a comprehensive evaluation of the efficient removal or mitigation of various categories of PPCPs by diverse types of MOF-derived adsorbents with suitable examples. The growing research investigations in this direction paves the way for designing more efficient porous nanomaterials that would be useful for the elimination of PPCPs, and separation perspectives.

Sequential degradation of raw vinasse by a laccase enzyme producing fungus Pleurotus sajor-caju and its ATPS purification.

This study evaluated simultaneously the raw vinasse degradation, an effluent from the sugar-alcohol industry, the laccase production by Pleurotus sajor-caju and its purification using aqueous two-phase systems (ATPS). To improve laccase production, different concentrations of inducers (ethanol and CuSO4) were added. The higher laccase production promoted an increase of 4-fold using 0.4 mM of CuSO4 as inducer, with maximum enzymatic activity of 539.3 U/L on the 3rd day of fermentation. The final treated vinasse had a decolorization of 92% and turbidity removal of 99% using CuSO4. Moreover, the produced laccase was then purified by ATPS in a single purification step, reaching 2.9-fold and recovered ≈ 99,9 %, in the top phase (PEG-rich phase) using 12 wt% of PEG 1500 + 20 wt% of citrate buffer + enzyme broth + water, at 25 °C. Thus, an integrated process of vinasse degradation, laccase production and purification with potential industrial application was proposed.

Mycoremediation of vinasse by surface response methodology and preliminary studies in air-lift bioreactors.

This work evaluated the degradation of sugarcane vinasse with the production of biomass by Pleurotus sajor-caju CCB020, considering the combination of temperature and pH effects, using surface response methodology (RSM). A 22 complete central factorial composite experiment was used to analyze the results. The optimum temperature and pH values were respectively 27 °C and 5.6 for maximum decolorization yield and 20 °C and 6.8 for maximum biomass production. In parallel, scale-up experiments under conditions of 30 °C and initial pH 5.0 were evaluated in two different air-lift bioreactors of 7.0 L. Under these conditions, reductions of 53% and 58% in chemical oxygen demand (COD) and 71% and 58% in biological oxygen demand (BOD) were obtained respectively with the concentric tube type air-lift bioreactor with an increased degassing zone and without an increased degassing zone. Under these conditions, this study concluded that the systematic combination of P. sajor-caju and vinasse can be applied in the biodegradation process of refractory compounds contained in vinasse, concomitant to obtaining biomass and laccase and manganese peroxidase enzymes. Due to the good performance of the air-lift bioreactors, they can be used in scale studies in future industrial vinasse applications, besides it is possible to emphasize that different configurations in the bioreactor can affect the efficiency of the process.

Pineapple crown delignification using low-cost ionic liquid based on ethanolamine and organic acids.

Pineapple fibre was treated with protic ionic liquids (PILs) and the effects on the structure, composition, and properties of the fibres were evaluated. Treatment with PILs efficiently exposed the fibre surface, as confirmed by scanning electron microscopy. The chemical composition analysis revealed reductions in the lignin and hemicellulose contents in the treated fibres, promoting exposure of cellulose. The results correlated with the crystallinity index, which was greater in the treated fibres compared with that in the untreated fibres. The generated residue from the treatment of fibres with PIL (1%, v/v) showed lower levels of toxic compounds, demonstrating the advantages of this treatment over conventional biomass treatments.