A review on adsorption of heavy metals from wastewater using carbon nanotube and graphene-based nanomaterials.

The rampant rise in world population, industrialization, and urbanization expedite the contamination of water sources. The presence of the non-biodegradable character of heavy metals in waterways badly affects the ecological balance. In this modern era, the unavailability of getting clear water as well as the downturn in water quality is a major concern. Therefore, the effective removal of heavy metals has become much more important than before. In recent years, the attention to better wastewater remediation was directed towards adsorption techniques with novel adsorbents such as carbon nanomaterials. This review paper primarily emphasizes the fundamental concepts, structures, and unique surface properties of novel adsorbents, the harmful effects of various heavy metals, and the adsorption mechanism. This review will give an insight into the current status of research in the realm of sustainable wastewater treatment, applications of carbon nanomaterials, different types of functionalized carbon nanotubes, graphene, graphene oxide, and their adsorption capacity. The importance of MD simulations and density functional theory (DFT) in the elimination of heavy metals from aqueous media is also discussed. In addition to that, the effect of factors on heavy metal adsorption such as electric field and pressure is addressed.

Fe(III)-incorporated porphyrin-based conjugated organic polymer as a peroxidase mimic for the sensitive determination of glucose and H2O2.

Nanozymes, i.e., nanomaterials that possess intrinsic enzyme-like behaviour, have thrived over the past few decades owing to their advantages of superior stability and effortless storage. Such artificial enzymes can be a perfect alternative to naturally occurring enzymes, which have disadvantages of high cost and limited functionality. In this work, we present the fabrication of an Fe(III)-incorporated porphyrin-based conjugated organic polymer as a nanozyme for the efficient detection of glucose through its intrinsic peroxidase activity and the amperometric detection of hydrogen peroxide. The iron-incorporated porphyrin-based conjugated organic polymer (Fe-DMP-POR) possesses a spherical morphology with high chemical and thermal stability. Exploiting the peroxidase-mimicking activity of the material for the determination of glucose, a detection limit of 4.84 µM is achieved with a linear range of 0-0.15 mM. The Fe-DMP-POR also exhibits a reasonable recovery range for the detection of human blood glucose. The as-synthesized material can also act as an H2O2 sensor, with a sensitivity of 947.67 µA cm-2 mM-1 and a limit of detection of 3.16 µM.

Challenges and future solutions for detection of Clostridioides difficile in adults.

There are no established standards for the diagnosis of Clostridioides difficile infection (CDI), even though the importance of this infection in humans is well known. The effectiveness of the commercially available techniques, which are all standardized for use with human feces, is also limited in terms of the accuracy of the tests. Furthermore, the current approach lacks a point-of-care diagnosis with an acceptable range of sensitivity and specificity. This article reviews the challenges and possible future solutions for the detection of CDI in adults. Existing diagnostic methods, such as enzyme-linked immunoassays and microbial culturing for the detection of toxins A and B, appear to work poorly in samples but exhibit great sensitivity for glutamate dehydrogenase. Real-time polymerase chain reaction and nucleic acid amplification tests have been investigated in a few studies on human samples, but so far have shown poor turnaround times. Thus, developing a multiplex point-of-care test assay with high sensitivity and specificity is required as a bedside approach for diagnosing this emerging infection.

Carbon dioxide solubility in choline chloride-based deep eutectic solvents under diverse conditions.

CONTEXT: Global warming is a severe problem experiencing the climate crisis due to rising CO2 emissions. Deep eutectic solvents (DESs) have recently attracted a lot of attention as potential absorbents to mitigate carbon dioxide CO2 emissions because of their large CO2 capacities and stability under diverse conditions. Designing a potent DES requires knowledge of molecular-level understanding including structure, dynamics, and interfacial properties in DESs. In this study, we investigate the CO2 sorption and diffusion in different DESs at different temperatures and pressure using molecular dynamics (MD) simulations. Our results demonstrate that CO2 molecules preferentially concentrate at the CO2-DES interface, and the diffusion of CO2 in bulk DESs increases with increasing pressure and temperature. The solubility of CO2 in the three DESs increases as ChCL-ethylene glycol < ChCL-urea < ChCL-glycerol at high pressure (58.6 bar). METHODS: The initial configuration for MD simulations included DES and CO2 and produced the solvation box using PACKMOL software. The geometries are optimized in the Gaussian 09 software at the theoretical level of B3LYP/6-311 + G*. The partial atomic charges were fitted to an electrostatic surface potential using the CHELPG method. MD simulations were carried out by using the NAMD version 2.13 software. VMD software was used to take the snapshots. TRAVIS software is used to determine spatial distribution functions.

Long-term effect of seasonal and constant low temperatures on mesophilic biomass treating sewage in continuously stirred tank anaerobic granular reactor.

A Continuously Stirred Tank Anaerobic Granular Reactor seeded with mesophilic biomass was studied for 1733 days analysing the impact of seasonal (12-23 °C) and controlled (8-15 °C) low temperatures on anaerobic treatment of sewage. Aided by intermittent dosing of 0.04% (v/v) methanol, the microbiota quickly adapted to temperature fluctuations. Chemical oxygen demand (COD) removal efficiency was high but low temperatures affected methane production. Under low-temperature stress, the Methanomythylovorans and Methanosaeta-dominated methanogenic community shifted focus to cellular repair and transport, with carbon diversion towards assimilative pathways, thereby decreasing methane yields. Specific methanogenic activity at 15 °C and 30 °C increased by five and four times, respectively, from their initial values indicating microbiota retained its mesophilic properties. Despite lower methane yield, stable and high COD removals, along with low dissolved methane and volatile fatty acids indicated that low-temperature anaerobic sewage treatment using mesophilic biomass in the long run is sustainable.

A Novel Study on Anionic Surfactant Degradation Potential of Psychrophillic and Psychrotolerant Pseudomonas spp. Identified from Surfactant-contaminated River Water.

The Yamuna River, a tributary of the holy Ganga, is heavily polluted in the Delhi-NCR region, India and has been gaining attention due to the excessive foaming of the river over the past few years. This can be directly or indirectly related to the overuse of surfactants and the discharge of untreated domestic and textile wastewater into the river. To determine the surfactant load and investigate potential surfactant-degrading bacteria in the region, 96 water samples from four sites in the Okhla Barrage stretch of the river were collected and analysed. The results showed that the selected sites have surfactant concentrations more than the permissible limit (1.00 mgL-1). Also, at most of the sites, the concentration crossed the desirable limit of BIS (0.2 mgL-1) during the period of analysis. The concentration of anionic surfactant reported in the region was found in the range of 0.29 mgL-1 and 2.83 mgL-1. A total of 38 different bacteria were isolated using selective media from the same water samples, out of which 7 bacterial isolates were screened for sodium dodecyl sulphate (SDS) tolerance activity. Based on 16S rRNA gene sequencing, 2 species, namely Pseudomonas koreensis YRW-02 and Pseudomonas songnenensis YRW-05 have been identified and their degradation potential was assessed at different SDS concentrations. The results showed that our strains YRW-02 and YRW-05 degraded 78.29 and 69.24% of SDS respectively. Growth optimization was also performed at different substrate concentrations, pH, and temperature to investigate optimum degradation conditions. This study plays a significant role in assessing the surfactant load and also gives a promising background for future use in in-situ bioremediation experiments.

Copper Immobilized over 2D Hexagonal SBA-15 for Electrochemical and Colorimetric Sulfite Sensing.

Sulfite (SO32-) is considered a highly toxic anion for living organisms. Herein, we report the synthesis of copper immobilized over a 2D hexagonally ordered mesoporous silica material CuMS as an electrochemical and colorimetric dual-technique-based sensing platform for sulfite detection. The immobilization of copper on silica was achieved through the bis[3-(triethoxysilyl)propyl]tetrasulfide (TEPTS) ligand. Morphological and physical properties of the material were confirmed by several characterization techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, N2 sorption, and X-ray photoelectron spectroscopy. The CuMS material retained mesoporosity with a narrow pore size distribution (D ≈ 5.4 nm) and a high Brunauer-Emmett-Teller surface area of 682 m2 g-1 after the immobilization of copper. The prepared catalyst shows promising electrocatalytic activity toward sulfite oxidation. A linear variation in the peak current was obtained for SO32- oxidation in the 0.2-15 mM range with a high sensitivity of 62.08 µA cm-2, under optimum experimental conditions. The limit of detection (LOD) was found to be 1.14 nM. CuMS also shows excellent activity toward colorimetric detection of sulfite anions with an LOD of 0.4 nM. The proposed sensor shows high selectivity toward the sulfite anion, even in the presence of common interferents. The detection of sulfite in white wine with excellent recovery demonstrates the practical applicability of this sensor.

Copper(II)-Incorporated Porphyrin-Based Porous Organic Polymer for a Nonenzymatic Electrochemical Glucose Sensor.

To date, the fabrication of multifunctional nanoplatforms based on a porous organic polymer for electrochemical sensing of biorelevant molecules has received considerable attention in the search for a more active, robust, and sensitive electrocatalyst. Here, in this report, we have developed a new porous organic polymer based on porphyrin (TEG-POR) from a polycondensation reaction between a triethylene glycol-linked dialdehyde and pyrrole. The Cu(II) complex of the polymer Cu-TEG-POR shows high sensitivity and a low detection limit for glucose electro-oxidation in an alkaline medium. The characterization of the as-synthesized polymer was done by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and 13C CP-MAS solid-state NMR. The N2 adsorption/desorption isotherm was carried out at 77 K to analyze the porous property. TEG-POR and Cu-TEG-POR both show excellent thermal stability. The Cu-TEG-POR-modified GC electrode shows a low detection limit (LOD) value of 0.9 µM and a wide linear range (0.001-1.3 mM) with a sensitivity of 415.8 µA mM-1 cm-2 toward electrochemical glucose sensing. The interference of the modified electrode from ascorbic acid, dopamine, NaCl, uric acid, fructose, sucrose, and cysteine was insignificant. Cu-TEG-POR exhibits acceptable recovery for blood glucose detection (97.25-104%), suggesting its scope in the future for selective and sensitive nonenzymatic glucose detection in human blood.

Celebrating 50 years of microbial granulation technologies: From canonical wastewater management to bio-product recovery.

Microbial granulation technologies (MGT) in wastewater management are widely practised for more than fifty years. MGT can be considered a fine example of human innovativeness-driven nature wherein the manmade forces applied during operational controls in the biological process of wastewater treatment drive the microbial communities to modify their biofilms into granules. Mankind, over the past half a century, has been refining the knowledge of triggering biofilm into granules with some definite success. This review captures the journey of MGT from inception to maturation providing meaningful insights into the process development of MGT-based wastewater management. The full-scale application of MGT-based wastewater management is discussed with an understanding of functional microbial interactions within the granule. The molecular mechanism of granulation through the secretion of extracellular polymeric substances (EPS) and signal molecules is also highlighted in detail. The recent research interest in the recovery of useful bioproducts from the granular EPS is also emphasized.

Ni(II)-Incorporated Porphyrin-Based Conjugated Porous Polymer Derived from 2,6-Diformyl-4-methylphenol as a Catalyst for the Urea Oxidation Reaction.

The urea oxidation reaction (UOR) is an excellent alternative to the sluggish oxygen evolution reaction (OER) as an anode reaction for hydrogen generation via electrochemical water splitting. Here, a porphyrin-based conjugated porous polymer (CPP) has been developed through the polycondensation reaction of 2,6-diformyl-4-methylphenol and pyrrole (DMP-POR). The nickel(II) complex of this conjugated polymer Ni-DMP-POR shows efficient UOR in an alkaline medium. The as-synthesized materials were characterized by solid-state 13C CP-MAS, thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The porous property of the materials was characterized by N2 adsorption/desorption isotherms at 77 K. Both DMP-POR and Ni-DMP-POR showed excellent thermal stability. The Ni-DMP-POR exhibits very good UOR in 1 M KOH and 0.33 M urea with an overpotential of 260 mV at 10 mA cm-2 and a Tafel slope of 48 mV dec-1. The catalyst also shows excellent chronoamperometric and chronopotentiometric stability, suggesting its future scope in sustainable hydrogen production from wastewater resources.

Design and preliminary techno-economic assessment of a pilot scale pharmaceutical wastewater treatment system for ammonia removal and recovery of fertilizer.

Recovery of nutrients from wastewater has a paramount importance for a sustainable and safe environment. In this study removal of ammonia and recovery of resources in the form of struvite from a complex pharmaceutical acidic wastewater having high concentration of ammoniacal nitrogen (NH4-N > 40 g/L) and other co-existing contaminants (magnesium, phosphorous, phenol etc.) was explored. Response Surface Methodology (RSM) was employed for design of experiments and process optimization. RSM results revealed that removal of ammoniacal nitrogen, i.e., struvite precipitation was found to be maximum in alkaline pH (10.5-11.0) at a N:Mg molar ratio (1:0.030 to 1:0.035) and N:P molar ratio (1:0.025 to 1:0.030). X-Ray diffraction, thermo-gravimetric analysis and Fourier transform-infrared spectroscopy confirmed the presence of struvite crystals in the obtained precipitate. Techno-economic assessment (TEA) based on mass energy balance principle and market equipment specifications revealed that a pilot-scale plant set up would have a break-even period of 1.06 years with a return on investment as 94.28%. This clearly elucidated the economic viability of the developed process for industrial applications for management of high ammonia laden pharmaceutical wastewater. While further specific technological improvements are needed for reduction of cost, this study will guide researchers and industries for careful selection of target markets to reduce the cost for successful implementation.

Molecular dynamics simulations and COSMO-RS method for CO2 capture in imidazolium and pyrrolidinium-based room-temperature ionic liquids.

The solubility of CO2 in different ionic liquids (ILs) was determined using molecular dynamics (MD) simulations and quantum calculations. MD simulation was used to study the interaction between IL and CO2 molecules at the interface. The solubility of CO2 is found to be higher in ILs containing [TF2N]- anion. The COSMO-RS model was used to determine the Henry's law constants for CO2 in different ILs. With increasing molar volume of ILs, the Henry's law constant of CO2 drops, which is in good accord with the solubility data obtained from MD simulations. The Henry's law constants follow the sequence of [BMIM][PF6] > [PMIM][TF2N] > [BMIM][TF2N] > [BMPY][TF2N] > [HMIM][TF2N] > [OMIM][TF2N]. The MD simulations and quantum calculations have shown that [TF2N]- has a higher impact on CO2 solubility than [PF6]-; this information is useful for screening and designing of ILs for CO2 absorption.

Surfactant pollution, an emerging threat to ecosystem: Approaches for effective bacterial degradation.

The use of surfactants in households and industries is inevitable and so is their discharge into the environment, especially into the water bodies as effluents. Being surface-active agents, their utilization is mostly seen in soaps, detergents, personal care products, emulsifiers, wetting agents, etc. Anionic surfactants are the most used class. These surfactants are responsible for the foam and froth in the water bodies and cause potential adverse effects to both biotic and abiotic components of the ecosystem. Surfactants are capable of penetrating the cell membrane and thus cause toxicity to living organisms. Accumulation of these compounds has been known to cause significant gill damage and loss of sight in fish. Alteration of physiological and biochemical parameters of water decreases the amount of dissolved oxygen and thus affecting the entire ecosystem. Microbes utilizing surfactants as substrates for energy form the basis of the biodegradation of these compounds. The main organisms for surfactant biodegradation, both in sewage and natural waters, are bacteria. Several Pseudomonas and Bacillus spp. have shown efficient degradation of anionic surfactants namely: sodium dodecyl sulphate (SDS), linear alkylbenzene sulphonate (LAS), sodium dodecylbenzenesulphonate (SDBS). Also, several microbial consortia constituting Alcaligenes spp., Citrobacter spp., etc. have shown efficacy in the degradation of surfactants. The biodegradation efficiency studies of these microbes/microbial consortia would be of immense help in formulating better solutions for the bioremediation of surfactants and help to reduce their potential environmental hazards.

Clostridioides difficile epidemiology in India.

Clostridioides difficile infection (CDI) continues to affect hospitalized patients and community populations worldwide. In contrast to the substantial resources invested in the diagnosis and prevention of CDI in high-income countries, this anaerobic toxigenic bacterium has been largely overlooked in low-and-middle-income countries (LMICs) such as India, where there remains a paucity of epidemiologic data evaluating the burden of CDI. Extensive multi-institutional studies describing C. difficile epidemiology in India have not yet been performed. Given recent economic growth in many Asian countries, with aging populations, increased access to healthcare and widespread inappropriate use of antimicrobials, C. difficile is likely to be highly prevalent and causing significant disease burden. Greater efforts are required to enhance awareness of this neglected pathogen, through educating healthcare practitioners to test for CDI. There is also an urgent need to strengthen laboratory capacity, and ideally establish a national reference laboratory, to help facilitate a greater understanding of the molecular epidemiology of CDI in India and other LMICs. This mini-review aims to summarize the existing research evaluating the burden of CDI in humans and the environment in India.

Multiomics Profiling Reveals Signatures of Dysmetabolism in Urban Populations in Central India.

BACKGROUND: Non-communicable diseases (NCDs) have become a major cause of morbidity and mortality in India. Perturbation of host-microbiome interactions may be a key mechanism by which lifestyle-related risk factors such as tobacco use, alcohol consumption, and physical inactivity may influence metabolic health. There is an urgent need to identify relevant dysmetabolic traits for predicting risk of metabolic disorders, such as diabetes, among susceptible Asian Indians where NCDs are a growing epidemic. METHODS: Here, we report the first in-depth phenotypic study in which we prospectively enrolled 218 adults from urban and rural areas of Central India and used multiomic profiling to identify relationships between microbial taxa and circulating biomarkers of cardiometabolic risk. Assays included fecal microbiota analysis by 16S ribosomal RNA gene amplicon sequencing, quantification of serum short chain fatty acids by gas chromatography-mass spectrometry, and multiplex assaying of serum diabetic proteins, cytokines, chemokines, and multi-isotype antibodies. Sera was also analysed for N-glycans and immunoglobulin G Fc N-glycopeptides. RESULTS: Multiple hallmarks of dysmetabolism were identified in urbanites and young overweight adults, the majority of whom did not have a known diagnosis of diabetes. Association analyses revealed several host-microbe and metabolic associations. CONCLUSIONS: Host-microbe and metabolic interactions are differentially shaped by body weight and geographic status in Central Indians. Further exploration of these links may help create a molecular-level map for estimating risk of developing metabolic disorders and designing early interventions.

Metagenomics reveals impact of geography and acute diarrheal disease on the Central Indian human gut microbiome.

BACKGROUND: The Central Indian gut microbiome remains grossly understudied. Herein, we sought to investigate the burden of antimicrobial resistance and diarrheal diseases, particularly Clostridioides difficile, in rural-agricultural and urban populations in Central India, where there is widespread unregulated antibiotic use. We utilized shotgun metagenomics to comprehensively characterize the bacterial and viral fractions of the gut microbiome and their encoded functions in 105 participants. RESULTS: We observed distinct rural-urban differences in bacterial and viral populations, with geography exhibiting a greater influence than diarrheal status. Clostridioides difficile disease was more commonly observed in urban subjects, and their microbiomes were enriched in metabolic pathways relating to the metabolism of industrial compounds and genes encoding resistance to 3rd generation cephalosporins and carbapenems. By linking phages present in the microbiome to their bacterial hosts through CRISPR spacers, phage variation could be directly related to shifts in bacterial populations, with the auxiliary metabolic potential of rural-associated phages enriched for carbon and amino acid energy metabolism. CONCLUSIONS: We report distinct differences in antimicrobial resistance gene profiles, enrichment of metabolic pathways and phage composition between rural and urban populations, as well as a higher burden of Clostridioides difficile disease in the urban population. Our results reveal that geography is the key driver of variation in urban and rural Indian microbiomes, with acute diarrheal disease, including C. difficile disease exerting a lesser impact. Future studies will be required to understand the potential role of dietary, cultural, and genetic factors in contributing to microbiome differences between rural and urban populations.

A gold nanoparticle-intercalated mesoporous silica-based nanozyme for the selective colorimetric detection of dopamine.

Highly dispersed aggregation-free gold nanoparticles intercalated into the walls of mesoporous silica (AuMS) were synthesized using thioether-functionalized silica as a nanozyme, which exhibited an excellent peroxidase mimic activity. The AuMS material was characterized via XRD, N2 adsorption-desorption, FESEM, SEM-EDS particle mapping, TEM, and XPS. The peroxidase-like activity of the AuMS material was studied thoroughly, and the effect of pH and temperature was evaluated. The reproducibility of the peroxidase mimic activity and long-term stability of the AuMS catalyst were also studied. Furthermore, the AuMS catalyst was successfully utilized for the detection and quantification of dopamine, an important neurotransmitter, colorimetrically with a linear range of 10-80 µM and a limit of detection (LOD) value of 1.28 nM. The determination of dopamine concentration in commercially available dopamine hydrochloride injection showed high accuracy, good reproducibility, and high selectivity in the presence of uric acid, ascorbic acid, glucose, tryptophan, phenylalanine, and tyrosine.

Alkali Metal Ion Partitioning with Calix[4]arene-benzo-crown-6 Ionophore in Acidic Medium: Insights from Experiments, Statistical Mechanical Framework, and Molecular Dynamics Simulations.

The current work reports the experimental and predicted interfacial behavior of metal ion extraction from aqueous phase-diluent system using a newly synthesized calix-benzo-crown-6 (CBCBGA) ionophore. Conductor-like screening model for real solvents was used to predict the selectivity at infinite dilution for the metal ion complexes in both aqueous and diluent phases. The selectivity for Cs+-CBCBGA extraction was found to be higher than that of other metal ions, namely, K+, Na+, and Rb+. This was confirmed by the experimental distribution coefficients obtained in the diluents system at 3 M HNO3 along with 0.01 M CBCBGA/organic solvents. The high selectivity of Cs+-CBCBGA complex over other complexes (K+, Rb+, and Na+) in nitrobenzene was also confirmed and validated by the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap (i.e., 0.13114 > 0.12411 > 0.11719 > 0.11561 eV) and interaction energy (i.e., -68.25 > -57.11 > -55.52 > -52.37 kcal/mol). The interaction and free energies of the extraction were found to increase with the dielectric constant of the organic solvents, namely, nitrobenzene > o-nitrophenyl hexyl ether > 1-octanol > chloroform. Overall, a higher selectivity of Cs+ ion over that of other metal ions (K+, Na+, and Rb+) was obtained for the newly synthesized CBCBGA ionophore in a radioactive waste solution.

Interfacial Behavior of Cs+, K+, Na+, and Rb+ Extraction in the Presence of Dibenzo-18-Crown-6 from the Nitrobenzene-Water Biphasic System: Experimental, Quantum Chemical, and Molecular Dynamic Studies.

Extraction of metal ions (i.e., Cs+, K+, Na+, and Rb+) in the presence of ionophore such as dibenzo-18-crown-6 (DB18C6) from the nitrobenzene-water biphasic system is reported by COSMO-RS (conductor-like screening model for real solvents) predictions, molecular dynamics simulation, along with experimental validation. The predicted values of selectivity as obtained for the Na+-DB18C6 complex were 4.571, 4.877, and 4.947 at 298.15, 308.15, and 318.15 K, respectively. This was then confirmed by the experimental distribution coefficient (D) as obtained in the diluent systems along with by varying the metal ion to crown ether ligand (M-L) mole ratios: 10:1 (0.1 M M+ and 0.01 M DB18C6), 1:1 (0.01 M M+ and 0.01 M DB18C6), and 1:10 (0.001 M M+ and 0.01 M DB18C6). The experimentally determined values of D Na (i.e., 0.059, 0.060, and 0.056) were found to be very large as compared to the values of D Cs (i.e., 0.001, 0.010, and 0.024) in the nitrobenzene phase. It indicates an excellent extraction ability of DB18C6 for Na+. The rate of phase separation for the Cs+NO3 - system was slow as compared to other metal ion systems. The binding energies, free energies, and nonbonded interaction energies of the complexed metal ion in solution were calculated with both explicit and implicit solvent models. A higher interaction energy between Na+-DB18C6 complex and nitrobenzene was observed (i.e., -289.92 in the explicit model and -143.12 kcal/mol in the implicit model) when compared with other metal ions (i.e., Cs+, K+, and Rb+).

Methanol induces low temperature resilient methanogens and improves methane generation from domestic wastewater at low to moderate temperatures.

Low temperature (<20 °C) limits bio-methanation of sewage. Literature shows that hydrogenotrophic methanogens can adapt themselves to low temperature and methanol is a preferred substrate by methanogens in cold habitats. The study hypothesizes that methanol can induce the growth of low-temperature resilient, methanol utilizing, hydrogenotrophs in UASB reactor. The hypothesis was tested in field conditions to evaluate the impact of seasonal temperature variations on methane yield in the presence and absence of methanol. Results show that 0.04% (v/v) methanol increased methane up to 15 times and its effect was more pronounced at lower temperatures. The qPCR analysis showed the presence of Methanobacteriales along with Methanosetaceae in large numbers. This indicates methanol induced the growth of both the hydrogenotrophic and acetoclastic groups through direct and indirect routes, respectively. This study thus demonstrated that methanol can impart resistance in methanogenic biomass to low temperature and can improve performance of UASB reactor.