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A set of python scripts was used for the analysis of molecular dynamics trajectories using minimalist coarse-grained protein-RNA mixture model used in the paper "RNA chain length and stoichiometry govern surface tension and stability of protein-RNA condensates". Python functions are well documented with docstrings and can readily be used both on the command line or in Jupyter-notebooks.

Ecosystem services include conditions and processes that make up natural ecosystems and the species present therein. According to recent studies, wetland ecosystems provide the maximum service value per area by playing a significant role in regulating and purifying water supplies, controlling flood, acting as carbon-sinks, and sustaining human lives and livelihoods. Challenges like wetland loss and degradation, declining freshwater resources, and probable consequences of climate change have attracted significant scientific and public attention towards wetland conservation and restoration. Despite diligent conservation efforts, the global status of wetland security is still alarming. Long-term sustainable management and use of wetlands necessitate active public participation from all sectors. This study reviews the current status of different wetlands in India. It also provides a detailed discussion of different aspects of economic evaluation of ecosystem services, wetland restoration, and public participation for improving wetland policies and governance.

Unplanned and unmonitored growth of civilization and industry recorded in the previous decades have resulted in the introduction of several persistent organic pollutants (POPs) like polyaromatic hydrocarbons, pesticides, pharmaceuticals etc. in adjacent aquatic environments. Bioaccumulation of these pollutants at different stages of the food chain and in potable water has been causing significant alarm across the world. The present chapter reviews and compiles recent reports on membrane bioreactors (MBRs) for separation of POPs from their aqueous phases with emphasis on biodegradation of POPs, advanced configurations of MBRs, ultrafiltration and nanofiltration membranes and application of MBRS for treatments of POP-laden effluents. This study also discusses the cost effectiveness of different processes of nanocomposite-based wastewater treatment discussed herein. This chapter includes a discussion of different strategies of process optimization that ensure efficient treatment of effluents.

Unplanned and unmonitored growth of civilization and industries recorded in the previous decades have resulted in the introduction of several pollutants of emerging concern like pharmaceuticals and antibiotic drugs, endocrine disrupters, personal care products, etc. in adjacent aquatic environments. Moreover, the primary considerations of recent wastewater treatment strategies include energy neutrality and efficient recovery of valuable products as end/byproducts of the concerned process. The present study reviews such recent advances in designs, development, and implementation of algae based photobioreactors for simultaneous CO2 capture and treatment of effluents containing various types of emerging contaminants with negligible energy input. It also discusses the subsequent usage of algal biomass for production of value-added products like bioethanol, alginate, etc. This study has primarily addressed the potential and limitations of such photobioreactors for simultaneous achievement of wastewater remediation, CO2 sequestration, and bioenergy production with a zero-discharge concept.

No one knows what the world would be like by 2050. However, it is apprehended that mankind would be faced with several environmental and social challenges. Few such challenges include providing food for the global population, elimination of poverty and inequality and provision for a life of acceptable quality for all, generation of sufficient energy for maintaining all economic activities without triggering detrimental environmental consequences and arresting the decline of biodiversity while ensuring harmonious co-existence between other species. These are some of the major questions that are recently being addressed by mankind under the broad concept of ‘sustainable development’ (Chambers et al., 2014).

Contamination of water by different emerging pollutants is considered as one of the biggest reasons for global water scarcity. In recent studies, nanotechnology has received significant importance and a wide range of nanomaterials have been investigated for wastewater treatment. This article reviews plant-mediated synthesis of different metal/metal-oxide nanoparticles and their subsequent application for photocatalysis of dye bearing effluents. Special emphasis has been laid upon the mode of synthesis, characterization, and efficiency of dye removal of the reviewed nanoparticles and their composite materials as well. This chapter also discusses the limitations as well as future challenges of application of these nanoparticles and nanocomposites in integrated photocatalysis-based processes for wastewater treatment. The different aspects of these nanocomposite-based water treatment discussed in this chapter will facilitate the potential readers including academicians, environmentalists, and industrialists trying to address issues of water scarcity.

Unregulated and unsustainable use of fossil fuels in recent times has caused an unprecedented rise in carbon dioxide emission, which in turn resulted in negative influences (e.g. global climate change, global warming) on this planet. CO2 emissions are supposed to be reduced by the sustainable alternative techniques in order to meet the energy demands for humans. However, owing to the wide global use of carbonaceous fuels as a primary source of energy, these fuels have gained prominence relative to other alternative energy sources. Therefore, the reduction of atmospheric CO2 levels necessitates appropriate upscaling and enhancement of the conventional carbon sequestration and storage approaches. This chapter reviews and compiles various novel composite materials, which are reported in recent studies, used for CO2 fixation as well as the subsequent conversion of the sequestered CO2 to the beneficial products.

Recent research has focused on the synthesis and application of filtration sieves which facilitate fast solute separation during processes of desalination and wastewater treatment. This study reports a simple method for fabrication of Graphene oxide (GO) – nanobentonite (NB) filtration sieves with polyethylene glycol (PEG) interlinkage for efficient removal of mixed cationic dyes and electrolytes from their aqueous solutions. The GO-PEG-NB sieves were characterized for morphology, structural stability and vacuum filtration performance. Insertion of PEG linked NB particles between GO sheets was found to increase capillary size of the former and resist intercalation effects of cations present in effluent. Vacuum filtration processes carried out at moderate pressure (0.7 kg cm− 2) had resulted in simultaneous removal of ~ 99% of 30 mg L− 1 of ternary dyes and 40 g L− 1 of mixed electrolytes with an optimum flux of 5.74 ± 0.62 L m− 2 h− 1. The GO-PEG-NB sieves offered good stability and efficient cation removal and therefore exhibited immense potential for treatment of wide scale real-time wastewaters.

A novel activated carbon with well-developed porous structure was fabricated from waste wood filings using H3PO4 as an activating agent. The activated carbon so prepared was further investigated for adsorption of polyaromatic hydrocarbons like acenapthene and naphthalene from their aqueous solution. Adsorption studies were optimized with response surface methodology. Data obtained in batch adsorption studies were also subjected to analysis of adsorption kinetics, isotherms and thermodynamics. Activated carbon reported in this study was found to be capable of removing 98% (approximately) of both PAHs considered in this study. The adsorption process was found to be guided by Temkin isotherm and pseudo-second-order kinetics. Results also indicated that the process of adsorption was spontaneous, endothermic and chemisorption in nature. Overall results indicated that the activated carbon prepared from waste wood filings could efficiently remove polyaromatic hydrocarbons from their respective aqueous solutions in highly reduced contact time and dosage.

Recent studies have reported graphene-based nanomaterials as novel scaffolds for the development of vigorous biocatalytic systems. The present study investigated polyacrylic acid-linked graphene oxide (GO)–gelatin nanocomposite for the immobilization of moderately halotolerant engineered bacterial consortium consisting of Dietzia sp., Bacillus sp. and Pseudomonas mendocina. This biocatalyst was subsequently applied for treatment of hypersaline textile effluents collected from local textile manufacturing and processing units. Effluent treatment efficiency of this biocatalyst was assessed in terms of its dye, surfactant and salt-removal abilities from collected effluents. High metabolic activity recorded in the case of immobilized bacterial cells indicated that immobilization had stimulated improved growth as well as electrolyte and pH tolerance in bacterial cells. Examination of the treated effluents suggested approximately 99% removal of COD, color (dyes), electrolytes and surfactant. Probable cyto-genotoxic potential and oxidative stress inducing the ability of both untreated and treated effluents was determined with Bellamya bengalensis (fresh water snail). Comet formation in hepatopancreatic cells of snails exposed to untreated effluent was significantly higher than in individuals exposed to treated effluents which in turn were similar to organisms treated as control. Hence, results of this study indicated efficient performance of GO-based biocatalyst in augmenting biodegradation and detoxification of textile effluent. The low cost incurred during the synthesis and application of bacteria-immobilized GO nanocomposite and its reusability potential determined herein established the process of effluent treatment reported in this study as a promising approach for commercial wastewater treatment.

Natural polymeric proteins, isolated from sesame meal, had already shown promise as potent nutraceutical. This polymeric protein was employed as a natural alternative surfactant for designing a nanoemulsion based delivery system for ω-3 PUFA rich fish oil (FO) in the present study. The process parameters of the high pressure nanoemulsification were optimized with the CCD guided RSM analysis. Results with highest desirability [cumulative droplet size 125.87 ± 2.54 nm, PdI 0.199 ± 0.01 and D90 Particle size 268.98 ± 13.89 nm] was obtained with 40 Kpsi homogenization pressure and 10 homogenization cycles and upto 1.5% (w/v) FO. The nanoemulsion formulation with SPI at 0.5% (w/v) concentration in combination with Tween 20 and Span 80 (1:1) had minimized the hydrodynamic droplet size to 89.68 ± 2.375 nm and also enhanced the shelf-life stability of the nanoformulations substantially, along an 8 week long storage period. Inclusion of SPI as surfactant also contributed to ≥90% of fatty acid release from the fish oil rich nanoemulsion droplets, at a steady gradient during 120 min of simulated two-step in vitro digestion. The MTT assay had confirmed the formulation to be non-toxic towards rat PBMCs. The informations obtained in this study will facilitate the application of SPI to formulate nutraceuticals-loaded nanoemulsion delivery system with better functional benefits.

This study is the first report of biochar obtained from rice straw biomass as a green precursor for cost effective wide scale synthesis of graphene oxide nanoplatelets (GONps). These GONps were further implemented for adsorption crystal violet (CV) from aqueous solutions. Few selected experimental parameters were optimised using Central Composite Design feature of Response Surface Methodology (RSM). The GONps were characterized with surface SEM, TEM, FTIR, XRD and AFM. Results indicated biochar as a sustainable alternative for graphite in GONP synthesis and GONps to be a clean ecofriendly adsorbent effective in highly reduced dosage and time of contact.

Mixed azo dyes present in various effluents may often impair adsorption efficiency thereby questioning applicability of the same in a real-time scenario. In this study, simultaneous adsorption of acid yellow 36 (AY) and acid blue 74 (AB) from their aqueous solutions was carried out with graphene oxide nanoplatelets embedded in chitosan matrix (GO–Cs–Nc) with assistance of ultrasound exposure. Results obtained were subjected to analysis for process isotherms, kinetics and thermodynamics. This process was also optimized for best results using response surface methodology (RSM) and modelled with artificial neural network (ANN). The nanocomposite was characterised both before and after adsorption using FTIR, SEM, TEM and AFM. Under the experimental conditions prescribed by RSM, 0.50 g L −1 of adsorbent was responsible for 98.18% and 98.80% removal of AY and AB respectively when exposed to 6.48 min of ultrasonic irradiation. Hence, ultrasound assisted GO–Cs–Nc proved to be a cost effective and sustainable adsorbent effective in low dosage and significantly reduced time with possible application for treatment of real industrial effluents rich in mixed dyes.

Ubiquitous occurrence of several pharmaceuticals in discharged sewage effluents has lead to considerable deterioration of life and quality of receiving water bodies. Ibuprofen, an acidic nonsteroid drug, is one such pharmaceutical being widely used for its analgesic, antipyretic and anti-inflammatory properties. The present work investigated the efficiency of graphene oxide nanoplatelets (GONPs) in adsorption of Ibuprofen from its aqueous solutions. The GONPs were characterized by electron microscopy and X-ray diffraction to analyze changes in structure and morphology occurring due to adsorption (if any). The impact of various process parameters on percentage removal (%) of Ibuprofen was determined by batch adsorption experiments. The data obtained were subjected to isotherm and kinetic analysis in order to describe the distribution of ibuprofen between the liquid and solid phases in the batch studies. The results obtained best fitted the Langmuir isotherm model and were determined to be guided by pseudo second-order kinetics. Thermodynamic parameters such as Gibb's free energy, Enthalpy and Entropy were also evaluated and the results revealed the endothermic and spontaneous nature of the process of adsorption of ibuprofen onto graphene oxide. Hence, graphene oxide may be considered as a suitable adsorbent for large scale efficient treatment of water contaminated with ibuprofen and similar other anti-inflammatory drugs.

Extensive usage of pharmaceutical and personal care products (PPCPs) and their discharge through domestic sewage have been recently recognized as a new generation environmental concern which deserves more scientific attention over the classical environmental pollutants. The major issues of this type of effluent addressed in this study were its colour, triclosan and anionic surfactant (SDS) content. Samples of cosmetic effluent were collected from different beauty treatment salons and spas in and around Kolkata, India and treated in bioreactors containing a bacterial consortium isolated from activated sludge samples collected from a common effluent treatment plant. Members of the consortium were isolated and identified as Klebsiella sp., Pseudomonas sp., Salmonella sp. and Comamonas sp. The biotreated effluent was subjected to ultrafiltration (UF) involving indigenously prepared ceramic membranes in both side-stream and submerged mode. Analysis of the MBR treated effluent revealed 99.22%, 98.56% and 99.74% removal of colour, triclosan and surfactant respectively. Investigation of probable acute and chronic cyto-genotoxic potential of the untreated and treated effluents along with their possible participation in triggering oxidative stress was carried out with Heteropneustes fossilis (Bloch). Comet formation recorded in both liver and gill cells and micronucleus count in peripheral erythrocytes of individuals exposed to untreated effluent increased with duration of exposure and was significantly higher than those treated with UF permeates which in turn neared control levels. Results of this study revealed successful application of the isolated bacterial consortium in MBR process for efficient detoxification of cosmetic effluent thereby conferring the same suitable for discharge and/or reuse.

This is the first report on utilization of modified Hummers' method for in-situ synthesis of novel graphene oxide-cellulose nanocrystals nanocomposite in a single reaction vessel. Cellulose used for nanocomposite preparation was extracted from waste jute. The synthesized nanocomposite was characterized with FTIR, XRD, SEM, EDX, DLS, and Zeta potential analyzer. It was applied as an adsorbent for the removal of toxic dye methylene blue from aqueous solutions. Around 98 % MB removal was achieved in 135 min. Under optimum experimental conditions recommended by response surface methodology, adsorption capacity of the nanocomposite was found to be 334.19 mg g-1 while the maximum adsorption capacity as determined by Langmuir isotherm 751.88 mg g-1. Further analysis revealed that the process was guided by both Langmuir and Freundlich isotherm and followed pseudo-second-order kinetics. This cost-effective synthesis route and efficient adsorption capacity of the nanocomposite indicate its immense potential for large-scale application in wastewater treatment.

Of various aquatic pollutants, azo dyes are inevitable toxicants appearing in almost all major streams of effluents. Besides being potent mutagens and carcinogens, azo dyes are also often of biorecalcitrant nature. In this study, co-implementation of adsorption and biodegradation has been carried out to achieve complete removal of Direct Red 21 from effluents. This study investigated the potential of graphene oxide as support material for azo dye-degrading bacterial strain (Pseudomonas mendocina). Application of immobilized microorganism offered a number of advantages like higher percentage of dye removal (~99.78%), rise in metabolic activity, and stronger resistance to toxicants. Moreover, this combined approach was cost-effective and re-utilizable without significant loss of activity. The experimental parameters were optimized and modeled using Central Composite Design of Response Surface Methodology. The immobilized GO sheets were characterized using SEM. Toxicity effects of effluents were determined using chickpea seeds (Cicer arietinum). Results proved that the treated water is biologically safe and fit for discharge or reuse in agricultural processes.

This study focuses on the investigation of removal of textile dye (Reactive Yellow) by a combined approach of sorption integrated with biodegradation using low cost adsorbent fly ash immobilized with Pseudomonas sp. To ensure immobilization of bacterial species on treated fly ash, fly ash with immobilized bacterial cells was characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and fluorescence microscopy. Comparative batch studies were carried out using Pseudomonas sp, fly ash and immobilized Pseudomonas sp on flyash and were observed that immobilized Pseudomonas sp on flyash acted as better decolourizing agent. The optimized pH, temperature, and immobilized adsorbent dosage for highest percentage of dye removal were observed to be pH 6, 303 K, 1.2 g/L in all the cases. At optimum condition, the highest percentage of dye removal was found to be 88.51%, 92.62% and 98.72% for sorption (flyash), biodegradation (Pseudomonas sp) and integral approach (Pseudomonas sp on flyash) respectively. Optimization of operating parameters of textile dye decolourization was done by response surface methodology (RSM) using Design Expert 7 software. Phytotoxicity evaluation with Cicer arietinum revealed that seeds exposed to untreated dye effluents showed considerably lower growth, inhibited biochemical, and enzyme parameters with compared to those exposed to treated textile effluents. Thus this immobilized inexpensive technique could be used for removal of synthetic dyes present in textile wastewater.

A two level three factor (23) central composite design (CCD) was applied for optimization of the selected biodegradation process variables, i.e. initial solution pH (4–8), initial dye concentration (150–400 mg L−1), and time consumed for degradation (14–48 h) for studying the biodegradation of Congo red (CR) and Indigo carmine (IC) using the isolated novel bacterial strain, Dietzia sp. PD1. This is the first report of dye degradation for the genus Dietzia obtained so far. The optimum dye degradation efficiency of Dietzia sp. PD1, obtained from RSM modeling for CR, was found to be 99.97% (at 177.63 mg L−1 of initial dye concentration at pH 5.56 for 42.64 h) and for IC it was found to be 99.95% (at pH 5.85, concentration of dye 135.62 mg L−1 and time 43.29 h) at temperature 303 K and stirring speed 150 rpm. A strong correlation existed between the input process variables and the output parameter for degradation of dye using Artificial Neural Network (ANN). The model developed using Response Surface ...

Soil is widely used as adsorbent for removing toxic pollutants from their aqueous solutions due to its wide availability and cost efficiency. This study investigates the potential of soil and soil composites for removal of crystal violet (CV) dye from solution on a comparative scale. Optimisation of different process parameters was carried out using a novel approach of response surface methodology (RSM) and a central composite design (CCD) was used for determining the optimum experimental conditions, as well as the result of their interactions. Around 99.85 % removal of CV was obtained at initial pH 6.4, which further increased to 99.98 % on using soil and cement composite proving it to be the best admixture of those selected. The phenomenon was found to be represented best by the Langmuir isotherm at different temperatures. The process followed the pseudo-second-order kinetic model and was determined to be spontaneous chemisorption in nature. This adsorbent can hence be suggested as an appropriate liner material for the removal of CV dye.

Graphene nanosheets were used as adsorbent for the removal of crystal violet dye from its aqueous solution. The equilibrium kinetic data were analyzed using pseudo-second-order kinetic model. A comparison between linear and non-linear methods of estimating the kinetic parameters was examined. Four pseudo-second-order kinetic linear equations have been discussed here. The coefficient of determination and chi-square test were employed as methods of error analysis for determining the best-fitting equation. The results revealed that the non-linear method proved to be a significantly better alternative for obtaining the kinetic parameters in comparison with the linear form of the model. In addition, the test was found to be a better method for determination of the best-fitting model.

A bacterial consortium isolated from activated sludge was identified to be Bacillus sp., Pseudomonas sp., Shigella sp. and E. coli. and was found capable of 98.62 % decolourization of highly toxic textile effluent, when applied in an ultrafiltration (UF) membrane bioreactor (UMBR). Ceramic capillary UF membranes prepared over low cost support proved to be highly efficient in adverse experimental conditions. The UMBR permeate and untreated textile effluent (40 % (v/v)) was then used to treat Heteropneustes fossilis for a comparative assessment of their toxicity. Micronucleus count in peripheral blood erythrocytes and comet assay carried out in liver and gill cells showed significantly lower nuclear and tissue specific DNA damage respectively in organisms exposed to membrane permeate and was further supported by considerably lower oxidative stress response enzyme activities in comparison to raw effluent treated individuals. The results indicate efficient detoxification of textile effluent by the UMBR treatment using the isolated bacterial consortium.