Purple rice bran extract (PRBE), an eco-friendly, inexpensive “green corrosion inhibitor,” was studied on boiler quality (BQ) steel in acidic solution (1 M HCl) to evaluate its ability of corrosion inhibition by various electrochemical techniques: potentiodynamic polarization test (PDP), electrochemical impedance spectroscopy (EIS). From the electrochemical tests, the enhanced inhibition efficiency of PRBE was found to be up to 83
The experiment aimed to grow Chlorella vulgaris in a mixture of Kraft paper effluent and biogas slurry, to treat industrial wastewater and produce biodiesel. Cultivation of Chlorella vulgaris in a batch reactor for 18 days was done in six different proportions of (Kraft paper effluent: biogas slurry, v/v) 20
E-Waste is increasing at an alarming rate of 2 million metric tonnes (Mt) per annum. E-waste covers a wide range of electrical and electronic equipment (EEE), such as mobile phones, laptops and refrigerators. Printed circuit board (PCB) is an indispensable and the most valuable component of any EEE. PCB contributes 2
In this work, the graphene oxide framework (GOF) was synthesized by cross-linking GO with the inorganic borate functional groups of sodium tetraborate using dopamine as a crosslinker. The obtained GOF was further characterized via FTIR, EDX, and XRD. Moreover, the GOF-assisted UF membranes were fabricated using PSF–PEG flat sheets as the substrate via a layer-by-layer (LBL) assembly technique. Further, the separation performance of the fabricated membranes of different GOF compositions was estimated using pure water flux (PWF) and the rejection rate study for heavy metal ions. The GOF-assisted membrane presented better permeability and heavy metal ion rejection rates for Pb2+, Cd2+, and Cr3+ions with 96, 94, and > 90
Flow hydrodynamics in the main channel due to floodplain sand mining is important for a better understanding of maintaining the natural habitat or the reliance between the flood plain and the main channel for the river's long-term survival and also facilitates more effective river restoration engineering. Day by day anthropogenic stresses are increasing in the river corridor system, indiscriminate sand mining is one of them. In this study, a computational fluid dynamics (CFD)-based software Flow-3D hydro (renormalized group K-ε turbulence model used) is used to study the flow hydrodynamics of sinuous (sinuosity index = 1.25) channel 18 m long, 1 m width, and 0.3 m height with floodplain sand mining pit. Sand mining additionally increases the secondary current near the outer bank of the channel, therefore leading to scouring or erosion at the outer bank, as a result, rivers migrate laterally. The turbulence kinetic energy (TKE) is concentrated in the mining pit and near the inner bank. This study result can be used to understand the flow hydrodynamic of the river system due to the series of sand mining.
Wanton degradation of the natural environment caused by various types of pollution has led to disastrous consequences including climate change. In fact, improper management of various types of wastes including household municipal solid wastes (HMSW) has played a significant role in this regard. One means of handling this issue is through disposal of HMSW by segregating such wastes as recyclable waste, toxic/hazardous waste, compostable waste, soiled waste, and wet waste. Increased involvement of people for adopting aforementioned segregation processes of these wastes calls for increased propensity to do so on their part. Therefore, such propensity has been studied in this present research work involving 1018 respondents in individual households across the state Assam in North East India. It was seen that most of these respondents had the idea regarding segregation of HMSW. However, most of these respondents sometimes had the tendency to segregate such wastes into separate bins comprising dry and wet waste, respectively. Also, most of them sometimes had the tendency to segregate such wastes into any other form. Further, it was found that most of these respondents never had similar tendencies to segregate HMSW as recyclable waste, toxic/hazardous waste, compostable organic waste, soiled waste, and wet waste in five separate bins (or any other suitable mode of storage). These findings emphasize the need for increased awareness and knowledge for proper implementation of the aforementioned segregation process for HMSW. It is expected that proper emphasis on the aforementioned findings can help towards having cleaner surroundings and environment in general.
The current research work focuses on evaluation of workability, compressive strength and microstructure of geopolymer concrete (GPc) made with fly ash (FA) and ground granulated blast furnace slag (GGBFS) and that made with fly ash and OPC. The FA-GGBFS, and FA-OPC based GPc were made by replacing FA with GGBFS and OPC, respectively, at 10
In this study, assessment of water quality of the tributaries of the Brahmaputra River System namely Mora Bharali, Digboi, and Bega Rivers has been carried out. These three rivers have been considered for the study because these rivers flow through urban agglomerations and industrial clusters. The assessment has been made in terms of Water Quality Index (WQI) parameters namely pH, Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), and Fecal Coliform. Further, the catchment characteristics have been studied in order to identify the primary sources of pollutant load in the rivers and subsequently devise a pollution abatement strategy.
The study emphasizes a sustainable approach to addressing the water pollution caused by the textile industries. The wastewater discharged from textile mills is directly released into water bodies which reduces the quality of the water bodies. Plantain pith, a natural and sustainable adsorbent, is experimented for the elimination of a cationic dye present in textile effluent in this paper. The maximum removal efficiency was found by conducting tests with plantain pith and bark. Influence parameters like pH, initial dye concentration in wastewater, the adsorbent amount, and surface area of the adsorbent were investigated. Each experiment was conducted separately in a glass tank, and absorbance was found using a spectrophotometer. The dried samples of plantain pith and plantain pith bark were made and checked for absorbance under various parameters along with the fresh samples. Plantain pith and bar are found to effectively remove methylene blue dye. The contact period, pH, the adsorbent amount, and the dye concentration in the solution were found to be the major parameters that affect the removal efficiency. A rise in pH resulted in a drop in the removal efficiency, and the most effective pH for dye removal was found to be pH 7. The present study suggests that the plantain pith and bark can act as a sustainable alternative for treating textile effluents containing cationic methylene blue dye.
Oil spills are possible accidents that occur sometimes naturally or most often during the transporting oil through pipelines, tanks, etc., or accidents such as blowouts that lead to an adverse impact on the environment and the living beings on it. Various physical, chemical, and biological approaches are utilized to counteract this impact. The Office of Technology Assessment estimates that following a big leak, current mechanical technologies often only recover 10–15% of the oil. Biological methods include bioremediation in which microorganisms or some nutrients are used to degrade the pollutants or the hydrocarbons in soil or water and convert it into less harmful components. Because petroleum hydrocarbons occur naturally in all marine settings, many different microbes have evolved the ability to utilize hydrocarbons as sources of carbon and energy for growth. Bioremediation is a more environmentally friendly method and more cost effective. Bioaugmentation and biostimulation are the two main approaches to oil spill bioremediation. This study highlights the application of bioremediation techniques for oil spill cleanup of two major marine oil spills. Since its successful use during the 1989 Exxon Valdez disaster and BP Deepwater Horizon blowout, in 2010, it has been seen that the alternative treatment for oil removal in these cases could be bioremediation. Natural and expedited biodegradation drastically lowered oil concentrations during the Exxon Valdez and BP Deepwater Horizon oil incidents. Even though they cannot be seen with the human eye, the bacteria did contribute more to the removal of the oil spills that had spread across the environment.
The current study explores a sustainable process involving enhanced production of biomass in association with wastewater treatment. In this study, a mixed culture of a new microalga strain named, Scenedesmus sp. DDVG I and indigenous bacteria that were readily available in rubber wastewater (RWW) were cultivated for concomitant bioremediation of RWW and enhanced lipid production of the biomass. Initially, individual cultures of Scenedesmus DDVG I and indigenous bacteria, viz. Bacillus sp. 0S26, Bacillus Cereus 0S36, Lysinibacillus macroides ST13, Burkholderia cepacia DF12, were cultivated in RWW diluted with distilled water (DI) in varying concentrations ranging from 5 to 100%. The diluted RWW, which showed superior growth of all the strains, was further used for the cultivation of consortium. The species were co-cultivated autotrophically under the inoculation ratios of 1:1, 1:2, 2:1 (Scenedesmus sp. / bacteria) based on cell density for 16 days cultivation period. The consortium's lipid content and productivity of the biomass were analyzed on every 4th day. The maximum biomass productivity of 1.15 g/L.d and having lipid content of 41% were achieved by the microbial consortium of Scenedesmus sp., Bacillus sp. 0S26 and Bacillus cereus 0S36 in RWW. The consortium exhibited maximum biomass harvesting efficiency of 100% compared to the individual cultures. Significant removal of COD, BOD, phosphate, ammonium, and nitrate concentration by the microalga-bacteria consortium from the RWW was observed during the growth. The study results suggested that the consortium cultivation strategy has the potential for sustainable improvement in the environment as well as the generation of oil-rich feedstock.
Heavy metals present in water environments, such as copper, lead, iron, and others, may cause substantial risk owing to their toxic effect, which may pose a risk to diverse human body systems. These metals come in contact with the water bodies due to their various applications such as medical, industrial, technological, and agricultural industries. A technical report submitted to Meghalaya Basin Management Agency, Shillong, confirms that the metal concentration of mining discharge of the Jaintia Hill coalfield (Basin and Agency in Study on mining affected areas and its impact on livelihood, 2019) [5] is having significant relation with the metal composition presented by Morcali et al. (J Environ Chem Eng 2:1655–1662, 2014) [13]. Both conventional and novel separation schemes exist for the resolution of such stiff prepositions. Notable processes among these can be formally classified into three categories, namely schemes involving greater usage of chemical media, sorptive approaches, and biomaterials and processes. Multiple heavy metal containing wastewater streams (with Cu, Zn, Pb, and Fe) can be characterized to be with lower metal concentrations. For such systems, chelating and ion exchange resins that follow the combined principles of physisorption and chemisorption are highly promising. Thereby, according to HSAB theory, Amberlite IR 120H (containing sulfonic acid functional group) and Lewatit TP 260 (containing aminomethyl phosphonic acid functional group) commercial ion exchange resins have been identified to gain useful insights into the competence of the resins to address cyclic adsorption–desorption characteristics using simple acid and base eluents. The adsorption studies were performed for adsorbent loading (0.2–2 g L−1), adsorption time (5–660 min), and solution concentration ranges (187.7–563.1 mg L−1 Cu+2 and 194.9–584.7 mg L−1 Zn+2). Finally, various basic (KOH, NaOH) and acidic (HCl, HNO3, and H2SO4) eluents were deployed in variant concentration ranges (0.1–2.0 M) to potentially evaluate the adsorption–desorption characteristics of 3 cycles. A comparative assessment of obtained findings has been considered with best prior art data.
Petroleum can be substituted by producing biofuels such as biodiesel from microalgae, a unicellular organism that has proven to be a viable cell factory. Triacylglycerols (TAGs) obtained from microalgae by the transesterification process can be used for biofuel and other biomaterials. The current study focuses on the development of the microalgae Chlorella vulgaris in low-cost media (cow urine), with the goal of increasing biomass and lipid content while decreasing the cost of the final product (biodiesel). Using a natural culture media for growing algae has decreased the cost incurred for nutrients essential for the growth of algae. Batch cultivations of 18 days were carried out in ten different concentrations of cow urine and BG11 media in the proportions of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% (v/v). Below 40% of cow urine produced satisfactory results, whereas concentrations above 50% were eliminated due to the culture's toxicity. The maximum biomass yield of 90.21 mg/L/day was monitored in 10% cow urine followed by 63.42 mg/L/day in 20% cow urine. And the maximum lipid content of 25.23% was noticed in 30% of cow urine. Transesterification of the lipid extract resulted in the formation of fatty acid methyl ester (FAME). The respective peaks of the +HNMR and 13CNMR spectra confirmed the synthesis of FAME or biodiesel from cow urine-grown cells. The conversion efficiency of triglycerides to methyl esters was found to be 87%. Therefore, the present study proves the feasibility of using cow urine alone for culturing microalgae and producing biofuel.
In the last decade, the outbreak of Covid-19, swine flu and bird flu have increased the use of medicines in humans and other animal species, especially livestock animals. Over 1.3 lakh tons of antibiotics are used in animal feed globally, and India is 4th highest user of antibiotics. As a result, the production of Pharmaceutically Active Compounds (PhACs) containing waste has increased alarmingly. Expansion of the antimicrobial resistance microbes is a major concern that can give rise to some lethal microbes. India has > 30% of the global pharma industries and generates a massive amount of PhACs containing effluents. Herein, we have reviewed the reported studies over the last decade to illustrate the contamination of many PhACs in various water bodies, their toxic impact on the environment, and several degradation methods and trends for future research are also suggested. The national and global distribution of PhACs confirmed their spreading throughout the world in surface (rivers, lakes, ponds) and groundwater (wells). PhACs not only affect aquatic organisms, microbes, and humans but also hinder the activity of wastewater treatment plants (WWTPs). Most of PhACs (with at least 10% of initial concentration) can escape the WWTPs, which results in augmentation of PhACs contamination. Most water bodies with history of PhACs contamination are reported as hubs for antimicrobial resistant microbes. Hence, PhACs containing wastewater must be treated before throwing away in the environment. Methods used to degrade PhACs are highlighted, and a highly efficient degradation method is suggested for the complete normalization of PhACs.
Water soluble and fluorescent C-dots were synthesized from biomass wastes such as Camellia sinensis (tea), tea leaves; Terminalia chebula (silikha), silikha leaves; Carica papaya (papaya) leaves; Piper betle (paan), and peel of Citrus paradise (grape fruit) through pyrolysis and microwave process. The dynamic light scattering measurements show the size of the C-dots within the range 8.9–1.8 nm, all having negative zeta potentials within the range −13.4 to −18.9. The negative zeta potential is due to the presence of COO– group as evidenced by the IR spectroscopy. The photoluminescence study was conducted for all carbon dots in which all exhibited excitation-dependent fluorescence. The synthesized C-dots have been embedded in previously synthesized MCM-41. Blank MCM-41 and C-dot MCM-41 composite was characterized with the help of XRD, which confirms the presence of carbon dots in the MCM-41. The decrease in the heavy metal concentration was monitored with atomic absorption spectroscopy (AAS) which shows efficient adsorption in the composite. The study found that lead adsorption was more effective when papaya C-dot embedded MCM-41 was used as an adsorbent.
Landfill contains a liner system to arrest the movement of contaminants into the groundwater. Nowadays, geosynthetic clay liners (GCLs) are adapted as a liner due to its ease in workability and less air pollution during the operation. GCLs contain a 5–7 mm layer of granular bentonite in between two geotextiles. The initial hydraulic conductivity of GCLs is generally high due to the presence of granules. On hydration, the voids of granular bentonite seals and have very low hydraulic conductivity. The presence of salts in the leachate influences the hydraulic behaviour of granular bentonites. There are very few studies on the behaviour of air-dried granular bentonite under loading conditions for various salt environments. For the long-term application of granular bentonite as a liner, a complete analysis of hydro-mechanical behaviour under the influence of various salt environments is required to analyse under loading conditions. In this study, volume change and hydraulic behaviour of commercially available granular bentonite exhumed from GCL were investigated. Granular bentonite was compacted at natural compaction condition of GCL (i.e. 1.2 gm/cc). Three different commonly available salts (i.e. NaCl, KCl, and CaCl2) in leachate were used. The laboratory oedometer was used for hydro-mechanical behaviour of compacted bentonite under the overburden stress of 50 kPa, to simulate the waste load. Test results of the current study showed that the presence of pore fluid influences the swelling and sealing ability of granular bentonite. Mechanisms influencing volume change and hydraulic behaviour will be presented.
With rapid expansion in economy and increased human demand for a healthy living environment, study of air pollutants (particularly Particulate Matter 2.5) has gained a lot of attention in India. Such pollutants cause foggy weather and acute health issues, thus being an urgent environmental issue. It has therefore become necessary to precisely predict PM2.5 concentrations and formulate their diffusion models to accurately monitor and control air pollution. In our work, fractional calculus has been discussed, which is used to obtain the 'Anomalous Diffusion Equation' for various places in the north-eastern states. Moreover, by using the 'Grunwald–Letnikov' fractional derivative, the variation of diffusion coefficients in North-East India has been calculated explicitly which will be used for the modelling of PM2.5 concentration and diffusion which will be used in weather forecasting and climate analysis.
The present work aims to reduce the decomposition temperature of cured epoxy resins in carbon fiber reinforced polymer (CFRP) composite during pyrolysis through a pre-treatment process. The CFRP was treated with different concentrations (5–40 w/v%) of ZnCl2-Ethanol solution at 80 °C for 2 h under magnetic stirring. The overall temperature range at which resin decomposition occurs was reduced by 87 °C and the temperature at which the maximum decomposition shows a 32 °C decrease. The simultaneous effect of swelling and catalytic action provided by the Ethanol-ZnCl2 solution effectively reduces the decomposition temperature of epoxy resins in the CFRP.
Malaria has long been a cause of human suffering and mortality in Sub-Saharan Africa, particularly in Ethiopia. The objective of this study was to assess the spatial distribution of malaria risk using MCE (Multi-Criteria Evaluation). To analyze and generate a spatial malaria risk level distribution map. Factors that affect the spatial malaria hazard and risk distribution have been considered. Such as; temperature, rainfall, altitude, slope, distance from the river, population density, and land use land cover factors were selected to produce a malaria risk map of the Didessa district area. GIS based multi-criteria evaluation method applied using weighted overlay analysis by considering three map layer factors (i.e. malaria hazard map layer, element at risk map layer, and vulnerability map layer), an optimum malaria risk map is produced. The malaria risk map result shows that 0.68%, 36.2%, 30.1%, 27.52% 5.5% of the study area falls under very high, high, moderate, low, and very low spatial malaria risk levels respectively. Our findings indicate that malaria is heavily influenced by major environmental parameters and socio-economic factors and these factors play a vital role either directly or indirectly in the occurrence of this vector-borne disease. In conclusion, 36.88% (31034.88 ha) of the study area has a high potential risk of malaria disease manifestation and occurrence. The result of this report indicates that there are high malaria risk areas in the district. This ascertains the communities living in those areas are prone to the disease. Therefore, there is an urgent need to prevent and progressively reduce malaria disease distribution through policy formulation and health care implementation in prioritized areas. This study is useful to use as a guideline for further research study in combating malaria distribution, particularly in developing countries.
This study aimed at evaluating the potential biogas production from four main sources, in terms of the volume of methane for energy production and the equivalent avoidable carbon dioxide emissions in 2020 through to 2030. It was based on the projection of methane production from common livestock and poultry manure, possible landfills, wastewater treatment plants, and palm oil mill effluent. This paper uses sound and reliable methodology to estimate the biogas potential of these major resources, which could lead to significant achievement in environmental sustainability via biogas generation and carbon dioxide emission reduction. The results showed that a total of 690.7 million m3 and 848.74 7 million m3 of methane could be obtained from all the sources considered in 2020 and in 2030, respectively, which translates to about 1.84 TWhel and 2.28 TWhel. It also meant that a total carbon dioxide equivalent emission of 12.36 million tCO2-eq and 15.82 million tCO2-eq could be avoided in 2020 and 2030, respectively. The results of this study therefore, show the remarkable contribution that biogas technology can make, as well as serve as an immediate technical information for policies makers, government agencies, and potential investors on the development of biogas technology in Ghana. Significant achievements can be made when comprehensive attempts are made so as to provide sustainable energy by integrating and improving livestock rearing, application of comprehensive solid and liquid waste management system and usage of best practices for managing agro-processing residues, which are integral part of the socio-economic activities in Ghana.
