Ecotoxicological and health concerns of persistent coloring pollutants of textile industry wastewater and treatment approaches for environmental safety

Textile industry wastewater (TIWW) is considered as one of the worst polluters of our precious water and soil ecologies. It causes carcinogenic, mutagenic, genotoxic, cytotoxic and allergenic threats to living organisms. TIWW contains a variety of persistent coloring pollutants (dyes), formaldehyde, phthalates, phenols, surfactants, perfluorooctanoic acid (PFOA), pentachlorophenol and different heavy metals like lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), zinc (Zn) and nickel (Ni) etc. TIWW is characterized by high dye content, high pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS), total organic carbon (TOC), chlorides and sulphates. Thus, requires adequate treatment before its final discharge into the water bodies to protect public health and environment. The treatment of TIWW is a major challenge as there is no particular economically feasible treatment method capable to adequately treat TIWW. Therefore, there is a need to develop a novel, cost-effective and eco-friendly technology for the effective treatment of TIWW. This review paper emphasizes on the different textile industry processes, wastewater generation, its nature and chemical composition, environmental impacts and health hazards and treatment approaches available for TIWW treatment. It also deals various analytical techniques used to detect and characterize TIWW pollutants and their metabolites, challenges, key issues and future prospectives

Dark fermentative hydrogen production: from concepts to a sustainable production

ABSTRACT: The use of renewable sources and environmentally friendly processes is considered a priority for the construction of a sustainable energy future. The harmful impact of fossil fuels and the fact that we are reaching a disrupting point regarding environmental damage require the rapid implementation of new energy systems and a substantial increase in the use of alternative, unconventional energy sources. Hydrogen (H2) is considered one of the most promising sources as a clean energy vector, because of its high energy density (120 MJ/kg) and carbon-free combustion (Argun and Kargi, 2011). Hydrogen is the simplest and most abundant element on earth; however, it barely exists in nature in its molecular state. Instead, it is almost always found as part of other compounds from which it should be separated, either by thermochemical processes or through biological conversion.info:eu-repo/semantics/publishedVersio

Exploiting antidiabetic activity of silver nanoparticles synthesized using Punica granatum leaves and anticancer potential against human liver cancer cells (HepG2).

This study first time reports the novel synthesis of silver nanoparticles (AgNPs) using a Punica granatum leaf extract (PGE). The synthesized AgNPs were characterized by various analytical techniques including UV-Vis, Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy and energy-dispersive spectra (FESEM-EDS) and high-resolution transmission electron microscopy (HRTEM). FTIR analysis revealed that the involvement of biological macromolecules of P. granatum leaf extract were distributed and involved in the synthesis and stabilization of AgNPs. A surface-sensitive technique of XPS was used to analyse the composition and oxidation state of synthesized AgNPs. The analytical results confirmed that the AgNPs were crystalline in nature with spherical shape. The zeta potential study revealed that the surface charge of synthesized AgNPs was highly negative (-26.6 mV) and particle size distribution was ranging from ∼35 to 60 nm and the average particle size was about 48 nm determined by dynamic light scattering (DLS). The PGE-AgNPs antidiabetic potential exhibited effective inhibition against α-amylase and α-glucosidase (I

Phytoremediation of heavy metal-contaminated sites: Eco-environmental concerns, field studies, sustainability issues and future prospects

Environmental contamination due to heavy metals (HMs) is of serious ecotoxicological concern worldwide because of their increasing use at industries. Due to non-biodegradable and persistent nature, HMs cause serious soil/water pollution and severe health hazards in living beings upon exposure. HMs can be genotoxic, carcinogenic, mutagenic, and teratogenic in nature even at low concentration. They may also act as endocrine disruptors and induce developmental as well as neurological disorders and thus, their removal from our natural environment is crucial for the rehabilitation of contaminated sites. To cope with HM pollution, phytoremediation has emerged as a low-cost and eco-sustainable solution to conventional physico-chemical cleanup methods that require high capital investment and labor alter soil properties and disturb soil microflora. Phytoremediation is a green technology wherein plants and associated microbes are used to remediate HM-contaminated sites to safeguard the environment and protect public health. Hence, in view of the above, the present paper aims to examine the feasibility of phytoremediation as a sustainable remediation technology for the management of metals-contaminated sites. Therefore, this paper provides an in-depth review on both the conventional and novel phytoremediation approaches, evaluate their efficacy to remove toxic metals from our natural environment, explore current scientific progresses, field experiences and sustainability issues and revise world over trends in phytoremediation research for its wider recognition and public acceptance as a sustainable remediation technology for the management of contaminated sites in 21st century

Bioelectrochemical systems using microalgae − A concise research update

Excess consumption of energy by humans is compounded by environmental pollution, the greenhouse effect and climate change impacts. Current developments in the use of algae for bioenergy production offer several advantages. Algal biomass is hence considered a new bio−material which holds the promise to fulfil the rising demand for energy. Microalgae are used in effluents treatment, bioenergy production, high value added products synthesis and CO2 capture. This review summarizes the potential applications of algae in bioelectrochemically mediated oxidation reactions in fully biotic microbial fuel cells for power generation and removal of unwanted nutrients. In addition, this review highlights the recent developments directed towards developing different types of microalgae MFCs. The different process factors affecting the performance of microalgae MFC system and some technological bottlenecks are also addressed

Probing the mechanism of simultaneous bioenergy production and biodegradation process of Congo red in microbial fuel cells

BACKGROUND: Many approaches have been employed to increase the understanding and consequently the performance of Microbial Fuel Cells to obtain simultaneous power production and biodegradation. This study uses recombinant Escherichia coli K-12 with MtrA, MtrC and MtrCAB inserts previously prepared using synthetic biology to evaluate the involvement of each of these genes in bioenergy production and biodegradation of Congo red using a double chamber microbial fuel cell. RESULTS: MtrC was the key gene required for energy production corresponding to an average voltage of 360 mV (external resistance 1 K&) and power density of 59 mW/m2, while E. coli with MtrCAB insert showed the highest decolourisation which reached 80% in 36 h under microbial fuel cells conditions. Coloumbic efficiency was 1.2% for E.coli with MtrCAB compared to 2.5% and 2.3% for MtrC and MtrA inserts, respectively. Riboflavin seems to be involved in the electron transferring, its concentration was highest for E.coli with MtrA insert despite its poor performance in both bioenergy production and dye degradation. CONCLUSION: This study suggests that electrons are mutually exclusive between electricity production, dye degradation and other cellular activities. This study helps us improve our understanding of the dual bioenergy/decolourisation process taking place in MFCs in order to maximize the outcome

Isolation and characterization of lignin-degrading bacterium Bacillus aryabhattai from pulp and paper mill wastewater and evaluation of its lignin-degrading potential

This study reports the degradation and decolourization capability of a manganese peroxidase enzyme producing bacterium isolated from pulp and paper mill wastewater. The isolate was identified as Bacillus aryabhattai based on biochemical analysis and 16S rRNA gene sequencing. The strain was designated MG966493. This bacterium was able to reduce 67% and 54% colour and lignin, respectively from the pulp and paper mill wastewater after 144 h of treatment at 32 °C, pH 7.6 and 120 rpm. Further, FT-IR analysis showed that during the lignin degradation process a number of metabolites were produced comprising different functional groups such as carbonyl (C = C), carboxyl (-COOH), alkene (C=C), amines (-NH2), sulphonic (-SO3) and nitro (-NO2). In addition, the SEM analysis showed that the bacterial cells exposed to pulp and paper mill wastewater have rough surfaces with reduced size as compared to the unexposed cells with smooth surfaces. This study concluded that the isolated bacterium B. aryabhattai has significant potential for the bioremediation of pulp and paper mill wastewater and thus, can be applied for their treatment at an industrial scale

Phytotoxicity, cytotoxicity and genotoxicity evaluation of organic and inorganic pollutants rich tannery wastewater from a Common Effluent Treatment Plant (CETP) in Unnao district, India using Vigna radiata and Allium cepa

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 3850mg/L, BOD 680mg/L, COD-1300mg/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

Enhancement of fermentative hydrogen production from Spirogyra sp by increased carbohydrate accumulation and selection of the biomass pretreatment under a biorefinery model

ABSTRACT: In this work, hydrogen (H-2) was produced through the fermentation of Spirogyra sp. biomass by Clostridium butyricum DSM 10702. Macronutrient stress was applied to increase the carbohydrate content in Spirogyra, and a 36% (w/w) accumulation of carbohydrates was reached by nitrogen depletion. The use of wet microalga as fermentable substrate was compared with physically and chemically treated biomass for increased carbohydrate solubilisation. The combination of drying, bead beating and mild acid hydrolysis produced a saccharification yield of 90.3% (w/w). The H-2 production from Spirogyra hydrolysate was 3.9 L H-2 L-1 , equivalent to 1463 mL H-2 g(-1) microalga dry weight. The presence of protein (23.2 +/- 0.3% w/w) and valuable pigments, such as astaxanthin (38.8% of the total pigment content), makes this microalga suitable to be used simultaneously in both food and feed applications. In a Spirogyra based biorefinery, the potential energy production and food-grade protein and pigments revenue per cubic meter of microalga culture per year was estimated on 7.4 MJ, US $412 and US S15, respectively, thereby contributing to the cost efficiency and sustainability of the whole bioconversion process.info:eu-repo/semantics/publishedVersio

Environment friendly degradation and detoxification of Congo red dye and textile industry wastewater by a newly isolated Bacillus cohnni (RKS9)

Textile industry wastewater (TIWW) is a major source of environmental pollution causing serious threats to all life forms and thus, it must be adequately treated before its final discharge for the safety of environment and public health. In the present study, a potential bacterial strain (RKS9) was isolated from textile (wastewater & sludge) sample for the effective treatment of TIWW resulting in a significant reduction in pollution parameters such as ADMI color (93.87%), COD (77.35%), BOD (86.02%), TDS (66.75%), TOC (67.25%), TSS (60.34%), and phenol (68.55%) within 48 h. This bacterium also decolorized 99% of Congo red dye (100 mg L−1) within 12 h and removed 59.76%, 40.51%, 52.71% and 26.51% cadmium, chromium, lead and nickel, respectively from the TIWW. The activities of azoreductase, laccase, lignin peroxidase (LiP) and manganese peroxidase (MnP) was monitored and metabolites produced during the treatment of dye and TIWW were also analyzed by FT-IR and GC–MS. The phytotoxicity of the untreated and treated TIWW was assessed by seed germination and seedling growth parameters of Phaseolus mungo L. and results showed a significant reduction in the toxicity of the treated TIWW, suggesting that the isolated bacterium RKS9 has a remarkable potential to effectively decolorize/detoxify TIWW