Multi-step forecasting of dissolved oxygen in River Ganga based on CEEMDAN-AdaBoost-BiLSTM-LSTM model.

Accurate prediction of Dissolved Oxygen (DO) is an integral part of water resource management. This study proposes a novel approach combining Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) with AdaBoost and deep learning for multi-step forecasting of DO. CEEMDAN generates Intrinsic Mode Functions (IMFs) with different frequencies, capturing non-linear and non-stationary characteristics of the data. The high-frequency and medium-frequency IMFs, characterized by complex patterns and frequent changes over time, are predicted using Adaboost with Bidirectional Long Short-Term Memory (BiLSTM) as the base estimator. The low-frequency IMFs, characterized by relatively simple patterns, are predicted using standalone Long Short-Term Memory (LSTM). The proposed CEEMDAN-AdaBoost-BiLSTM-LSTM model is tested on data from ten stations of river Ganga. We compare the results with six models without decomposition and four models utilizing decomposition. Experimental results show that using a tailored prediction technique based on each IMF's distinctive features leads to more accurate forecasts. CEEMDAN-AdaBoost-BiLSTM-LSTM outperforms CEEMDAN-BiLSTM with an average improvement of 25.458% for RMSE and 37.390% for MAE. Compared with CEEMDAN-AdaBoost-BiLSTM, an average improvement of 20.779% for RMSE and 28.921% for MAE is observed. Diebold-Mariano test and t-test suggest a statistically significant difference in performance between the proposed and compared models.

Emission inventory of inorganic trace gases from solid residential fuels over the National Capital Territory of India.

In developing nations, solid residential fuels are the major sources of primary energy for various domestic activities. To date, the emission inventory of inorganic trace gases over National Capital Territory (NCT) was prepared using either default or country-specific emission factors. In this paper, we report (for the first time) the spatial variation of emission factors (EFs) of inorganic trace gases (SO2, NO, NO2, CO, CO2, and CH4) from the residential fuels used in slums and rural areas of NCT determined using dilution chamber in the laboratory. 147 residential fuel samples, including fuelwood, dung cake, crop residues, coal, etc., were collected at 149 NCT locations out of 675 slum clusters and 146 rural villages. The range of EF(s) of SO2 (0.02 ± 0.01 to 0.04 ± 0.01 g kg-1), CH4 (0.10 to 0.34 g kg-1), NO2 (0.01 to 0.02 g kg-1) is lower than the CO (3.55 ± 1.72 to 6.07 ± 1.53 g kg-1) and CO2 (0 to 129.45 ± 46.94 g kg-1). The north and north west districts of NCT are emission hotspots for CH4, NO, and NO2 emissions, whereas, the southern and northern areas of NCT are for CO2. These citywide emission inventories (0.05° × 0.05°) of inorganic trace gases are prepared using laboratory-determined EFs and available consumption data determined by recent survey information. Among solid residential fuels, fuel wood, and dung cake are two major contributors to inorganic trace gases in NCT.

Recent innovation and impacts of nano-based technologies for wastewater treatment on humans: a review.

Sustainable wastewater management requires environment-friendly, efficient, and cost-effective methods of water treatment. The ever-growing list of emerging contaminants in municipal wastewater requires advanced, efficient, and cost-effective techniques for its treatment to combat the increasing water demand. The nano-based technologies hold great potential in improving water treatment efficiency and augmenting the water supply. However, the environmental effects of these technologies are still questionable among the public and scientific community. The present review discusses risks to human health due to the use of nano-based technology for the removal of emerging contaminants in water. The discussion will be about the impacts of these technologies on humans. Recommendations about safe and environmentally friendly options for nano-based technology for water treatment have been included. Safest options of nano-based technologies for water treatment and steps to minimize the risk associated with them have also been incorporated in this article. Since all biological systems are different, separate risk analyses should be performed at the environmentally relevant concentration for different durations. There is little/no information on the quantitative impact on humans and requires more understanding. The quantitative measurement of the cellular uptake of nanoparticles is usually difficult. We hope this article will serve its purpose for water researchers, medical researchers, environmentalists, policymakers, and the government.

Ultrafine particle number concentration and its size distribution during Diwali festival in megacity Delhi, India: Are 'green crackers' safe?

Since the air pollution and noise generated from fireworks are related to air quality and human health, the regulatory bodies had implemented the eco-friendly "Green Crackers" in megacity Delhi, India, to celebrate Diwali 2019 with the permission of a specific time slot (8:00 p.m. to 10:00 p.m.). The present study was conducted on a residential educational institute campus to evaluate the particle number size distribution (PNSD) of green cracker emissions. During the Diwali event period, the high peak of particle number concentration (PNC) reached 1.7 × 105 # cm-3 with a geometric mean diameter (GMD) of ∼44 nm. The average PNC increment on Diwali day was 138% and 97% compared to pre (October 26, 2019) and post (October 28, 2019) Diwali period, respectively, including 468%, 142%, 65%, 75% on pre-Diwali and 485%, 110%, 32%, 26% on post- Diwali 2019 period in terms of Nucleation mode (10 nm < Dp < 20 nm), Small Aitken mode (20 nm < Dp < 50 nm), Large Aitken mode (50 nm < Dp < 100 nm), and Accumulation mode (100 nm < Dp < 1000 nm), respectively. Unlike traditional firework emissions, green crackers had a high UFP/Ntotal ratio of 0.72, including Nucleation mode-0.35, Aitken mode-0.30, and Accumulation mode 0.35, distinguishing it from other pre-and post-Diwali particle number size distribution-dN/dlogDp curves. These observations indicate that green crackers emit more particles with smaller diameters than traditional crackers. Recommendations for using green crackers for Diwali celebrations may be an option if lower size-diameter particle emission could be controlled by changing the material composition of the green crackers. More research studies need to be conducted to assess atmospheric emissions of green crackers and their health impacts to evaluate whether they are better or worse than traditional crackers.

Assessment of the effect of the judicial prohibition on firecracker celebration at the Diwali festival on air quality in Delhi, India.

Diwali (the festival of lights and crackers) is celebrated grandly, resulting in a significant drop in the city's air quality. To study the impact of the judicial prohibition in Delhi to improve air quality, a comprehensive and comparative analysis was conducted over two consecutive years, namely 2015-2016 (when no significant regulations on the sale or usage of firecrackers were imposed) and 2017-2018 (when radically different regulations were implemented). Data on PM10, PM2.5, NOx, and CO were analysed, and their trends and levels with various regulations in place were compared. In 2017, the concentrations of PM10, PM2.5, NOx, and CO were reduced by 50%, 50%, 71%, and 64%, respectively, compared to 2016. However, in 2018, there was an increase of 32% in PM10 and PM2.5 concentrations, as well as a 25% increase in CO concentrations, with the exception of NOx, which decreased to 25% on Diwali day. The data was also examined in conjunction with the entire timeline of the various court rulings and regulations imposed in Delhi. The questionnaire survey study revealed that, despite the legislation in place, ambient air quality continued to deteriorate, necessitating a deeper dive into the policy's structure and implementation to fine-tune its feasibility and applications. Air pollution-related health effects were recognized by 82% of participants. Despite this, only 13% of people were observed without a mask, and only 12% of people were aware of green crackers as of 2018. To combat this deteriorating situation, the national capital must enact radical and well-thought-out legislation and regulations governing firecrackers, as well as raise public awareness amongst its citizens.

Spatio-temporal variations of indoor air quality in a university library.

The present study aims to assess the air quality status in the central library of Indian Institute of Technology Roorkee, India. Pollutants concentrations (i.e. PM10, PM2.5, PM1 and TVOC) and comfort parameters i.e. CO2, temperature and relative humidity were monitored across all floors of the library. Air quality was found to vary significantly (P < 0.05) among the different floors of the library. The average concentration of PM10, PM2.5 and PM1 was found to be highest at the first floor. On the other hand, the highest concentration of TVOC (51.7 ± 30 ppb) and CO2 (838.4 ± 99 ppm) was observed at the ground floor. Pollutant concentration was higher in the morning hours. The indoor pollutants were found positively correlated with each other except relative humidity. Indoor to outdoor ratio for PM1, TVOC and CO2 was found to be greater than 1, which indicate a substantial contribution from indoor sources. Exceedance of WHO guidelines was observed for the daily average PM2.5 concentration.Abbreviation: IAQ: indoor air quality; ASHRAE: American Society of Heating, Refrigerating, and Air-Conditioning Engineers; WHO: World Health Organization; PM: particulate matter; VOC: volatile organic carbon; CO2: carbon dioxide; TVOC: Total volatile organic compound; RH: relative humidity; HVAC: heating ventilation and air-conditioning; PID: Photo Ionization Detector; PTFE: Polytetrafluoroethylene; NDIR: Non-dispersive infra-red.

Characterization of dye-decolorizing peroxidase from Bacillus subtilis.

The dye-decolorizing peroxidases (DyPs) belong to a unique heme peroxidase family for their biotechnological potential to detoxify synthetic dyes. In this work, we have biochemically and structurally characterized the dye-decolorizing peroxidase from Bacillus subtilis (BsDyP). The biochemical studies of BsDyP demonstrate that pH 4.0 is optimum for the oxidation of malachite green (MG) and methyl violet (MV). However, it oxidizes the MG with higher catalytic efficiency (kcat/Km = 6.3 × 102 M-1s-1), than MV (kcat/Km = 5.0 × 102 M-1s-1). While reactive black 5 (RB5) is oxidized at pH 3.0 with the catalytic efficiency of kcat/Km = 3.6 × 102 M-1s-1. The calculated thermodynamic parameters by isothermal titration calorimetry (ITC) reveal the feasibility and spontaneity of dyes binding with BsDyP. Further, the crystal structures of a HEPES bound and unbound of BsDyP provide insight into the probable binding sites of the substrates. In BsDyP-HEPES bound structure, the HEPES-1 molecule is found in the heme cavity at the γ-edge, and another HEPES-2 molecule is bound ~16 Å away from the heme that is fenced by Ile231, Arg234, Ser235, Asp239, Glu334, and surface-exposed Tyr335 residues. Furthermore, the molecular docking, simulation, and MMPBSA studies support the binding of dyes at both the sites of BsDyP and produce lower-energy stable BsDyP-dyes complexes. Here, the BsDyP study allows the identification of its two potential binding sites and shows the oxidation of a variety of dyes. Structural and functional insight of BsDyP will facilitate its engineering for the improved decolorization of dyes.

A novel approach using low-cost Citrus limetta waste for mixotrophic cultivation of oleaginous microalgae to augment automotive quality biodiesel production.

The present study reports the use of Citrus limetta (CL) residue for cultivating Chlorella sp. mixotrophically to augment production of biodiesel. The cultivation of Chlorella sp. using CL as media was carried out by employing a fed-batch technique in open tray (open tray+CL) and in software (BioXpert V2)-attached automated photobioreactor (PBR+CL) systems. Data showed the limit of nitrogen substituent and satisfactory organic source of carbon (OSC) in CL, causing > 2-fold higher lipid content in cells, cultivated in both the systems than in control. For the cells grown in both the systems, ≥ 3-fold enhancement in lipid productivity was observed than in control. The total fatty acid methyl ester (FAME) concentrations from lipids extracted from cells grew in PBR+CL and in open tray+CL techniques were calculated as 50.59% and 38.31%, respectively. The PBR+CL system showed improved outcomes for lipid content, lipid and biomass productivity, FAME characteristics and physical property parameters of biodiesel than those obtained from the open tray+CL system. The physical property parameters of biodiesel produced from algal cells grown in PBR+CL were comparable to existing fuel standards. The results have shown lower cold filter plugging point (- 6.57 °C), higher cetane number (58.04) and average oxidative stability (3.60 h). Collectively, this investigation unveils the novel deployment of CL as a cost-effective feedstock for commercialisation of biodiesel production.

Assessment of GHG mitigation and CDM technology in urban transport sector of Chandigarh, India.

The increase in number of vehicles in metropolitan cities has resulted in increase of greenhouse gas (GHG) emissions in urban environment. In this study, emission load of GHGs (CO, N2O, CO2) from Chandigarh road transport sector has been estimated using Vehicular Air Pollution Inventory (VAPI) model, which uses emission factors prevalent in Indian cities. Contribution of 2-wheelers (2-w), 3-wheelers (3-w), cars, buses, and heavy commercial vehicles (HCVs) to CO, N2O, CO2, and total GHG emissions was calculated. Potential for GHG mitigation through clean development mechanism (CDM) in transport sector of Chandigarh under two scenarios, i.e., business as usual (BAU) and best estimate scenario (BES) using VAPI model, has been explored. A major contribution of GHG load (~ 50%) in Chandigarh was from four-wheelers until 2011; however, it shows a declining trend after 2011 until 2020. The estimated GHG emission from motor vehicles in Chandigarh has increased more than two times from 1065 Gg in 2005 to 2486 Gg by 2011 and is expected to increase to 4014 Gg by 2020 under BAU scenario. Under BES scenario, 30% of private transport has been transformed to public transport; GHG load was possibly reduced by 520 Gg. An increase of 173 Gg in GHGs load is projected from additional scenario (ADS) in Chandigarh city if all the diesel buses are transformed to CNG buses by 2020. Current study also offers potential for other cities to plan better GHG reduction strategies in transport sector to reduce their climate change impacts.

A risk-based model to establish threshold planning quantities of hazardous substances.

The Threshold Planning Quantity (TPQ) is the minimum quantity of any hazardous substance stored or processed at an industry that can pose a defined level of risk up to a certain distance from the industrial premises should an accidental release occur. These are recommended by the concerned government departments of the respective countries. Often, concerned regulatory authorities focus on simple screening tools to prescribe TPQs of hazardous chemicals rather than on more detailed technical aspects. This is illustrated with the help of TPQs presently administered in India, which are followed based on Control of Industrial Major Accident Hazard regulations of the United Kingdom. In this paper, the risk ranking matrix (RRM) approach is described to evaluate the recommended TPQs and prescribe these for some extremely hazardous chemicals (EHS) commonly used in industries. The RRM presented here is unique in the sense that various acceptable risk criteria are reviewed to appropriately rank the risk potential and provide suitability criteria in terms of individual risk factors and geosocietal risk factors (GSRF). Based on this concept, an attempt has been made to develop a risk-based model to determine the TPQs of various EHS (acrolein, ammonia, chlorine, hydrogen fluoride, and phosgene).