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Study of Chlorella vulgaris from Different Growth Phases as Biosensor for Detection of Titanium and Silver Nanoparticles in Water Full text
2024
Thenarasu, Arularasi | Chai, Mee Kin | Tan, Yeong Hwang | Wong, Ling Shing | Rajamani, Ranjithkumar | Djearamane, Sinouvassane
The increased use of metallic nanoparticles has led to concern for environmental contamination and disruption in water quality. Therefore, effective screening of metallic nanoparticles is important for detecting metallic nanoparticles in aquatic environments. Biosensors offer several advantages, including high sensitivity to pollutants, short response time, energy efficiency, and low waste generation. In this study, a whole-cell biosensor was developed using microalga Chlorella vulgaris as a recognition element, and its fluorescence response was used as a measuring parameter for detecting the presence of titanium dioxide (TiO2) and silver (Ag) nanoparticles in water. The responses of C. vulgaris at the lag, exponential, and stationary phases to different concentrations of TiO2 and Ag nanoparticles were studied. The results showed that in TiO2 and Ag nanoparticles exposures, the highest fluorescence change (50-150%) was observed at the lag phase, whereas the lowest fluorescence change (40-75%) was observed at the stationary phase. A significant fluorescence change was observed in 15 min. The immobilized C. vulgaris under TiO2 and Ag nanoparticles exposures showed 30-180% higher fluorescence change than the negative control, indicating the potential of C. vulgaris as a biosensor for rapid detection of TiO2 and Ag nanoparticles in water. The mathematical modeling of the responses of C. vulgaris to TiO2 and Ag nanoparticles at 15 min of exposure with high R2 indicated that this biosensor is sensitive to the concentration tested (0.010–10.000 mg.L-1). Taken together, these results reveal that, for the first time, it is possible to detect TiO2 and Ag nanoparticles in water within a very short time using a microalgae-based biosensor. Moreover, no genetic engineering requirement makes this biosensor simple, economical, and free from the restriction on genetically modified microorganisms for environmental applications.
Show more [+] Less [-]Eco-Engineered Low-Cost Carbosorbent Derived from Biodegradable Domestic Waste for Efficient Total Chromium Removal from Aqueous Environment: Spectroscopic and Adsorption Study Full text
2024
Saxena, Vandana | Singh, Ashish Kumar | Srivastava, Atul | Srivastava, Anushree
Chromium contamination in water bodies poses severe risks to both the environment and human health. This research introduces an innovative solution to this challenge by creating a vapor-activated carbosorbent from biodegradable household waste. The efficacy of this adsorbent in removing total chromium through batch methods from aqueous solutions was investigated. Surface analysis using scanning electron microscopy (SEM) exhibited a porous structure, while Fourier-transform infrared spectroscopy (FTIR) identified distinct functional groups on the surface. The point of zero charge (PZC), determined at 6.95, revealed the adsorbent’s surface chemistry. Impressively, the synthesized carbosorbent exhibited significant adsorption capacities of 23.08 mg.g-1 for Cr(III) and 24.84 mg.g-1 for Cr(VI) under optimal conditions. The Langmuir isotherm model illustrated a monolayer adsorption mechanism aligned with the pseudo-second-order kinetic model, confirming chemisorption. Thermodynamic analysis disclosed favorable and spontaneous chromium adsorption. Negative ΔG° values affirmed the spontaneity, while the exothermic nature of the process was signified by the positive ΔH° value, indicating heat release. Increased randomness at the solid-liquid interface, indicated by the positive ΔS° value, underscored the enhanced affinity between the adsorbent and adsorbate. This study exemplifies the potential of the vapor-activated carbosorbent as an efficient and sustainable remedy for chromium-contaminated water bodies.
Show more [+] Less [-]Invasive Aquatic Plants as Potential Sustainable Feedstocks for Biochar Production and as an Innovative Approach for Wastewater Treatment Full text
2024
Jayathilake, K. M. P. I. | Manage, P.M. | Idroos, F. S
Biochar (BC) is a well-established physical treatment method. The high-cost BC limits their use as adsorbents in wastewater. Thus, deriving BC from cheap and locally available waste materials is needed to develop a feasible waste removal technology. Nowadays, BC technology makes it possible to envision a new strategy to manage invasive plants by converting them into value-added products like BC. Hence, the present study was designed to evaluate the potential utilization of BC as an efficient filter medium made by invasive aquatic plants, Salvinia spp., and Eichhornia spp. A mass of 50 g of prepared activated and nonactivated BC was incorporated in a sand and gravel filter to treat rubber-manufactured wastewater. Wastewater was passed through the filter, and both raw and treated water samples were analyzed for pH, Total Suspended Solids (TSS), Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Kjeldahl Nitrogen (TKN), Ammoniacal-Nitrogen (NH3-N), Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Phosphates (TP), Nitrate (NO3-N), turbidity and heavy metals (Zinc, Chromium). The control filter was developed only with sand and gravel, excluding BC. Fourier Transform-Infrared Spectroscopy (FT-IR) and Scanning electron microscopy (SEM) were used to analyze BC’s chemical and physical characteristics. A brine shrimp lethality assay was carried out for toxicological evaluation. OH stretching (3,550-3,200 cm−1), C=C aromatic stretching (1400-1660 cm−1), and Phenol-O-H bending (1,300-1,400 cm−1) were recorded in all BC samples that involved the adsorption mechanism. Observed images indicated differences in surface morphology of both activated and nonactivated BC were observed under SEM observation. The study concludes that the filter unit incorporated with activated Eichhornia spp. Gave the best treatment efficiency when compared to filter units incorporated with other activated and nonactivated BC. The toxicity assay revealed 100% mortality in the control setup and raw wastewater but only 60–70% in the nonactivated BC integrated filters. Activated BC-incorporated filters showed no mortalities. Hence, the study’s outcomes suggest a green approach using invasive aquatic plants for sustainable wastewater treatment.
Show more [+] Less [-]Evaluation of an Electrocoagulation Process Modified by Fenton Reagent Full text
2024
López-Ramírez, M. A. | Castellanos-Onorio, O. P. | Lango-Reynoso, F. | Castañeda-Chávez, M. Del R. | Montoya-Mendoza, J. | Díaz-González, M. | Ortiz-Muñiz, B.
This article is oriented to the degradation of nickel in an ionic state at laboratory level from synthetic water made with nickel sulfate, using the electrocoagulation process with aluminum cathodes and modifying this process by the addition of the Fenton reagent, which results from the combination of hydrogen peroxide (H2O2) and ferrous sulfate (FeSO4) being this reagent a catalyst and oxo-coagulant agent, The efficiency of this reagent will be compared with the typical treatment with aluminum sulfate, which is a typical process based on ion exchange/coagulation at the same percentage concentrations as the Fenton reagent. For this purpose, the optimum conditions of the advanced electrocoagulation process were determined, which consisted of determining the concentrations of Fenton’s reagent at concentrations of 150 ppm, 300 ppm, and 450 ppm, in addition to the operating variables such as pH of 8 and 10, voltage of 17.5 V and 19 V and their reaction time, which were compared with aluminum sulfate at 300 ppm, 600 ppm, and 900 ppm. The results obtained with respect to the typical treatment were 0% nickel degradation. However, with the advanced oxidation treatment, an average reduction of 97.5% was found at the conditions of 19 V, pH 10, and Fenton 150 ppm in a time of 30 min.
Show more [+] Less [-]Alleviation of Different Climatic Conditions by Foliar Application of Salicylic Acid and Sodium Nitroprusside and Their Interactive Effects on Pigments and Sugar Content of Maize Under Different Sowing Dates Full text
2024
Devi, Priyanka | Kumar, Prasann
The agricultural sector is seriously impacted by climate change, leading to potential risks to food security. In terms of global food production, maize ranks third. As a result, crop production and food security depend critically on assessing the effects of climate change and developing measures to adapt maize. Regarding adaptability, changing planting dates and using different agrochemicals are more effective than other management. Crop models are part of a global decision support system to help farmers maximize yields despite unpredictable weather patterns. To mitigate yield loss and protect the ecosystem, it is essential to use efficient maize-sowing practices in the field. This experiment was carried out to identify the most favorable sowing dates that maximize yield while ensuring the crop’s productivity and the integrity of the surrounding ecosystem remain intact. The main aim of this experiment was to mitigate the different climatic conditions by exogenous application of salicylic acid (SA) and sodium nitroprusside (SNP) on pigments and sugar content in maize under different sowing dates. A field experiment was carried out in the School of Agriculture, Lovely Professional University, Punjab, India, during the spring season of 2022. The experiment dealt with various maize crops, PMH-10, sourced from the Punjab Agricultural University (PAU), Punjab. The experiment was conducted in an open-air environment. The experimental setup was laid out in a split-plot design. The results stated that foliar application of salicylic acid and sodium nitroprusside successfully influenced high-temperature tolerance and low temperature at the reproductive phase and initial vegetative stages with other growing climatic conditions of maize in early and late sowings when controlled by increasing the chlorophyll index, carotenoids content, and sugar content of maize.
Show more [+] Less [-]The Passive Environmental Effect of the Fungicide Benomyl on Soil Promoting Bacteria and Concentration of Some Important Soil Elements Full text
2024
Abbas, Zaid Raad | Al-Ezee, Aqeel Mohammed Majeed | Authman, Sawsan Hassan | Shafeeq, Maan Abdul Azeez
Loam examples were gathered through the 2020-2021 rising periods, and the following measurements were made: Viable bacterial count by reducing root colonization. The outcomes of reviewing the impact of the fungicide Benomyl on development and viable microflora count revealed that the highest microbial count was in Al-Madaein 80 ×103 CFU/mL was recorded ., and the lowest count was 60 ×103 CFU/mL for the Aushtar area, The microbial viable count values for the affected microorganisms with Benomyl were decrease to 27×103 and 65 × 103 CFU/mL respectively. Those consequences specify that Benomyl has a robust choosiness contrary to microflora, especially when compared to the benomyl effect as folded dose, the microflora l count decreases to 25 ×103 CFU /mL in the Aushtar area and increases to 60 ×103 CFU/mL in Al-Madaein area. Whereas the study estimated the level of eight elements in soil (Mn, Fe, Cu, Zn, NO3, P, K, and NH4) cultured with Cyperus rotundus L. Which mentioned the effect of benomyl on these levels after three days of treatment. Mn concentration ranged between 5.96 to 9.11 ppm, while after fungicide benomyl, it decreased to 5.63 -6.53 ppm similar results were observed for other elements. The highest affected element was Mn in the Aushtar area. Those consequences designate that Benomyl has a stout fussiness in contrast to soil nutrients. The greatness of benomyl impacts on loam ingredients and procedures were minor, qualified to impact on mycorrhizal root foundation (reduction through benomyl).
Show more [+] Less [-]Enhanced Natural Attenuation Technique, Edaphic and Microbiological Changes in Oil-Impacted Soil of Odhiaje Community, Rivers State Full text
2024
Muonye, P. N. | Nnaji, C. C.
Oil spills in the Niger Delta could exert environmental pressures on the soil component. We investigated the impacts of oil spills and the effect of the Enhanced Natural Attenuation (ENA) remediation method on contaminated soil and resident microbial populations in the Odhiaje community in Rivers State, Nigeria. Soil samples for microbiological studies were collected weekly during a 17-week remediation period, while those for edaphic parameters were taken before and after remediation, all at 4 sampling points (SPs). Serial dilution of the oil-impacted soils for microbial density enumeration was carried out according to standard methods. Results revealed that mean concentrations of Total Petroleum Hydrocarbon Contents (THC) (Sig.value = 0.009), SO42- ions (Sig.value = 0.001), and sand compositions (Sig.value = 0.045) all differed markedly across the sampling points at p<0.05. Mean levels of EC (Sig.tvalue = 0.039) and ΣN (Sig.tvalue = 0.058) & K+ ions (Sig.tvalue = 0.004) differed significantly before and after the remediation exercise at the 95% confidence interval. Application of nutrients was rapidly accompanied by microbial population increases, leading to the consumption of oil contaminants in soils to levels comparable to control over the remediation period. Total Heterotrophic Bacteria counts correlated with pH (r = 0.501) and SO42- ions (r = 0.500) (p<0.05), and K+ ions (r = -0.800) (p<0.01); Total Heterotrophic Fungi correlated with pH (r = 0.520) (p<0.05), and Mg2+ ions (r = 0.820) (p<0.01); Hydrocarbon Utilizing Bacteria correlated with available P (r = 0.530) and silt composition (r = -0.504) (p<0.05), and K+ (r = 0.626) and Mg2+ ions (r = 0.733) (p<0.01); and Hydrocarbon Utilizing Fungi correlated with K+ (r = 0.500) & Mg2+ ions (r = 0.506) (p<0.05). Results indicate improvement in C/N ratios and effectiveness of the current cost-effective bioaugmentation technique in the restoration of arable soil productivity in the Odhiaje community.
Show more [+] Less [-]Techno-Economic Analysis of Solar, Wind, and Biomass Hybrid Renewable Energy Systems to Meet Electricity Demand of a Small Village in Bihar State of India Full text
2024
Patil, Anant Arun | Arora, Rajesh | Arora, Ranjana | Sridhara, S. N.
This study examines the potential use of Hybrid Renewable Energy Systems (consisting of photovoltaic, wind, bio, and diesel sources) both with and without the inclusion of battery storage in the eastern region of India. An evaluation is conducted to determine the economic viability of several system configurations, and the most efficient system is selected using HOMER software. The investigation focused on six distinct scenarios to meet the energy needs of a village community. The goal was to satisfy a daily load need of 1093.7 kWh, with a peak demand of 153.63 kW. The study examined many factors, such as system efficiency, financial viability, and ecological consequences. The primary aim of the research was to compare the power costs associated with different designs of HRES. Detailed techno-commercial assessments were carried out to examine the energy production, consumption, and financial impacts of each scenario. This research provides valuable insights for individuals and organizations seeking reliable and long-lasting energy solutions by analyzing the potential benefits and drawbacks of implementing HRES in rural areas. An evaluation is conducted to determine the energy contribution of each element within an RES, as well as the influence of HRES on energy expenses and net present value. The findings of this study reveal that the optimized hybrid system comprises 133 kW photovoltaic arrays, a 130-kW wind turbine, a 0.2 kW biogas generator, a 100-kW diesel generator, a 540-kWh battery bank with nominal capacity, and a 58-kW converter. This system has a minimum COE of 0.347$/kWh and NPC of $1.71M. The research offers useful insights for designers, scholars, and policymakers on the existing design constraints and policies of biomass-based hybrid systems.
Show more [+] Less [-]Characterization of the Bacterial Microbiome Structure and Identification of the Beneficial Genera in the Leaf Litter Compost for its Potential Application as a Bioorganic Fertilizer Full text
2024
Mahongnao, Sophayo | Sharma, Pooja | Ahamad, Arif | Dohare, Neeraj | Dhamija, Neeru | Garg Mangla, Anita | Nanda, Sarita
This study investigates the potential of leaf and various organic waste composts as bio-organic fertilizers using 16S rRNA metagenomics. The microbial richness and diversity analysis, employing alpha and beta diversity indices, reveal substantial variations influenced by organic substrates during composting. The leaf compost had a high total OTU (70,554) but low microbial diversity (Chao 1 index = 272.27). The kitchen waste compost had the highest microbial diversity (Chao 1 index = 429.18). Positive correlations between microbial biomass, diversity, and compost quality highlighted the pivotal role of microbial activity. The beneficial genera identified across all the bio-composts were Lactobacillus, Leuconostoc, Sphingobacterium, Paenibacillus, Pseudomonas, and Clostridium. Some pathogenic genera were also detected in all the composts analyzed, viz. Prevotella, Agrobacterium, Fusobacterium, and Streptococcus. Nonetheless, the ratio of beneficial to the pathogenic genera was generally high in all compost, highlighting the enrichment with beneficial microorganisms. The leaf compost demonstrated the highest proportion of beneficial genera, about 92%, indicating significant bio-fertilizing potential, with a low % level of pathogenic genera of about 3%. Thus, the leaf compost has excellent potential to be used as a bio-organic fertilizer. Understanding the microbial composition of organic waste composts is crucial for its application as bio-fertilizer for promoting sustainable agriculture.
Show more [+] Less [-]Saccharification of Different Delignified Sawdust Masses from Various Trees Along the Lagos Lagoon in Nigeria Full text
2024
Ndukwe, N. A. | Seeletse, J. B. M. | Van Wyk, J. P. H.
Sawdust, a major waste product of the forestry industry, is accumulating along the Lagos Lagoon in Lagos, Nigeria, without it being effectively managed. Besides its use in The saccharification of sawdust could contribute to the development of renewable energy sources and feedstock for bioproduct development. The process is, however, not that straightforward as variables such as the type of cellulase enzyme, pretreatment of the cellulose substrate, and optimizing of cellulase to cellulose ratio are a few that need to be optimized for the process to be effective in terms of glucose production.manufacturing sound-absorbing boards to reinforce concrete beams and for energy purposes, its potential as a renewable energy source and feedstock for bio-product development has not yet been realized. Cellulose, a glucose biopolymer and structural component of cellulose can be hydrolyzed by a hydrolytic enzyme known as cellulase. During the process, the enzyme breaks the B-1,4-glucosidic bond, which keeps the glucose units together, and by acting on this bond, numerous glucose units are released. As part of sawdust, the cellulose molecule is not freely available for the degradation action of the cellulase enzyme as it is strongly associated with lignin, which acts as bio-glue, keeping cellulose and hemicellulose together. Delignification is an effective technique that was used to make the sawdust from ten different trees along the Lagos Lagoon in Nigeria more susceptible to saccharification by cellulase isolated from the fungus Aspergillus niger. Delignified and non-delignified sawdust masses between 2 mg and 10 mg were incubated with the A. niger cellulase solution (2 mg.mL-1), whereafter, the amount of sugar produced by the cellulase action was determined. The percentage saccharification of each sawdust material was also linked with the amount of sugar produced during cellulase action. From these investigations was concluded that delignification increased sugar production when almost all the masses of different sawdust materials were degraded. It was also observed that the ratio of sawdust mass to enzyme concentration is an important variable that influences the effectiveness of the saccharification process. The percentage saccharification of the various sawdust materials was also determined, and it indicated that the highest percentage of saccharification was not obtained when the highest amount of sawdust was degraded, producing the highest amount of sugar.
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