خيارات البحث
النتائج 491 - 500 من 576
Microbiological Quality of Drinking Water and Food in a Rural Community النص الكامل
2023
Y. Rapeepan, P. Piyabhorn, P. Phatcharaporn and S. Theethawat
Safe water and food are essential for good human health. The contamination of water with infected fecal bacteria is common in areas with poor standards of hygiene and sanitation. This study investigated total coliform bacteria, fecal coliform bacteria, and E.coli in drinking water and food stalls using water from a rural community, where the rural living conditions increase the risk of water-related diseases. In total, 40 samples of bottled drinking water, 50 water samples from vending machines, 30 samples of household drinking water, 30 food samples were collected from household food, and 60 food samples were collected from food stalls, and coliform bacteria contamination was determined using the most probable number (MPN) technique. The results revealed that all the water and food samples contained coliform bacteria contamination, while all the water samples and 50% of the food samples contained fecal coliform bacteria. The numbers of household food samples contaminated with coliform bacteria and E.coli were 29 (97%) and 12 (40%), respectively. Entrepreneurs should be regularly maintaining clean drinking water vending machines. The government sector should be urgently solving the problem of drinking water standards to ensure suitable consumer safety.
اظهر المزيد [+] اقل [-]Chemistry, Metabolism and Neurotoxicity of Organophosphorus Insecticides: A Review النص الكامل
2023
Ashutosh Singh, Abhishek Singh, Akhilesh Singh, Priti Singh, Vivek Singh, Yogender Singh, Hardeep Singh Tuli, Hadi Sajid Abdulabbas and Abhishek Chauhan
Organophosphorus compounds (OPs) are phosphoric acid derivatives represented by the formula (R2XP=O/S), R as organic groups; however, they need not contain a direct carbon-phosphorus bond. The organophosphorus compounds can be categorized into three classes, viz., organophosphates, carbamates nerve agents. The OPs having application as insecticides are generally phosphorothioates (i.e., containing P=S bond). These sulfur analogs are first bioactivated (in vivo) and converted to oxygen analogs responsible for exerting toxic action. These organophosphorus compounds are esters, fluorides, anhydrides, and amides of phosphoric, phosphorothioate, and phosphorodithioic acids. The toxicity of OPs is related to their molecular structure, metabolism in the targeted organisms, concentration, mode of decomposition, application, ingestion in organisms, etc. Exposure to OPs leads to the appearance of neurological symptoms followed by acute poisoning by targeting the target primarily, acetylcholine (AChE). However, secondary targets and other harmful effects besides nerve system problems are also reported. Organophosphates poison insects and other animals, including birds, amphibians, and mammals. These chemicals can have neural effects (Neurotoxicity), non-neuronal effects, or acute toxicity, which may also result in fatality. Their uncontrollable widespread became a significant threat to the environment; thus, corrective measures have been essential to save living beings and the environment from further damage.
اظهر المزيد [+] اقل [-]Saccharification of Various Wastepaper Materials by Cellulase from Brown Garden Snail (Cornu aspersum) at Different Incubation pH Values النص الكامل
2023
T. M. Ndlovu and J. P. H. van Wyk
Increased solid waste pollution and the negative effect of fossil fuel consumption on the environment are issues that would require more scientific attention and application to deal effectively with these phenomena. Wastepaper, a major component of solid waste, is classified as organic waste due to the presence of cellulose, a glucose-based biopolymer that is part of its structural composition. The saccharification of cellulose into glucose, a fermentable sugar, can be achieved with a hydrolytic enzyme known as cellulase. Although cellulase from fungal species such as Trichoderma, Aspergillus, and Penicillium are well described, knowledge about cellulase isolated from the brown garden snail is limited as it has not been the subject of many research endeavors. The waste paper has been described as a suitable resource for bio-energy development due to cellulose, a structural component of this bio-material that can be degraded into glucose, a fermentable sugar. Although paper materials such as newspaper, office paper, filter paper, Woolworths and Pick and Pay (retailers) advertising paper, as well as foolscap paper, were saccharified by different cellulases, the degradation of these paper materials by garden snail cellulase is a novel investigation from our laboratory. With the effects of temperature and incubation time on this cellulase action when degraded paper materials have already been investigated and reported, this study dealt with the garden snail cellulase action when degraded paper materials at different pH values. Most of the paper materials were degraded optimally at a pH value of 6.0, while optimum saccharification was observed at pH 4.5 when newspaper and brown envelope paper were degraded, with office paper showing maximum bioconversion at pH 7.0. The difference in the structural composition of the paper materials also affects the degree of saccharification, as the amount of sugar released from the various paper materials at optimum pH values is not similar. Together with other catalytic parameters, the pH value of this enzymatic catalysis is also to be considered when designing the development of waste paper as a bio-product resource, with limiting environmental pollution as an additional advantage of this process.
اظهر المزيد [+] اقل [-]Defluoridation of Water by Biowaste Material – A Study of Adsorption Kinetics and Isotherms النص الكامل
2023
K. Kiran Kumar, Ratnakaram Venkata Nadh, Kaza Somasekhara Rao and G. Krishnaveni
Human beings experience adversative effects due to the large fluoride concentrations present in potable water. Because of the low cost and simple operation, the extensively acknowledged process is adsorption. The objective of this study is to investigate the performance of some of the prepared carbons from bio-waste materials viz., Citrus limon, Citrus nobilis, Pithecellobium dulce, and Bombax malabaricum sheaths in defluoridation. Initial concentration, particle size, agitation time, adsorbent dose, and pH were the different parameters chosen to study their effect on adsorption. Studied the adsorption kinetics. Further suitability to adsorption isotherms was reviewed.
اظهر المزيد [+] اقل [-]Wastewater Treatment Technologies Selection Using Analytical Hierarchy Process and VIKOR Methods: A Case Study النص الكامل
2023
Gnanasekaran Sasikumar, A. Sivasangari and S. Ravibabu
Due to the ever-increasing water scarcity problem across the globe, the treatment of wastewater is an important public health and socio-economic issue. Treating wastewater through proper technology is vital to protect the ecosystem from unsafe and contaminated matter available in wastewater. Identification of suitable wastewater treatment technologies is a complex Multi-Criteria Decision Making (MCDM) problem since it includes many conflicting assessment criteria. The objective of the paper is to construct an integrated model using the Analytical Hierarchy Process (AHP) and VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) for evaluating wastewater treatment technologies (WWTTs). AHP is applied to calculate criteria weights, and the VIKOR method is applied to prioritize and select the best WWTTs. The proposed model is applied to selecting the best WWTT among four alternatives and seven criteria. It is found that the proposed model yields better results when compared with other MCDM solutions.
اظهر المزيد [+] اقل [-]Carbon Emission and Industrial Structure Adjustment in the Yellow River Basin of China: Based on the LMDI Decomposition Model النص الكامل
2023
J. Song , W. J. Du and F. Wang
In the context of promoting high-quality development in the Yellow River Basin (YRB) of China, urgent action is needed to achieve the “Dual Carbon” goal through energy savings, emission reductions, and industrial upgrading. This study measures carbon emissions from eight types of energy consumption across 43 industries from 2000 to 2019. Using the Kaya-LMDI model, factors affecting carbon emissions are analyzed, and the relationship between industrial structure and carbon emissions is explored through the coefficient of variation (CV). The findings reveal that coal consumption remains significantly higher than other energy sources, and the effect of energy structure adjustment on carbon emission reduction is limited compared to the impact of energy consumption increase on carbon emission growth. Moreover, the economic output effect is identified as the primary driving factor of carbon emissions, while energy utilization rate is crucial in achieving energy savings and emission reductions. Finally, the CV of carbon emissions across 43 industries is increasing. Based on these results, we suggest several policy recommendations, including prioritizing ecological concerns, developing comprehensive and scientifically sound plans, optimizing energy consumption structure, improving energy utilization efficiency, and adjusting industrial structure to promote sustainable development in the YRB.
اظهر المزيد [+] اقل [-]Multivariant Assessment of Metals Using Liverworts as an Appealing Tool in Catchment Sites of Uttarakhand, India النص الكامل
2023
Priyank Chaturvedi, Shivom Singh and Kajal S. Rathore
This study aimed to conduct a systematic review to analyze heavy metals seasonal concentrations in Uttarakhand tourist hotspot cities (Almora, Nainital, Ranikhet, Mussoorie, and Dhanaulti). A total of 45 samples of liverwort Dumotiera hirsuta were collected from five different cities during winter (Dry deposition) and monsoon (Wet deposition) in the year 2021. The concentrations of Zn, As, Cd, and Pb due to anthropogenic pollution load in the selected locations were analyzed by active biomonitoring using Inductive Coupled Plasma Mass Spectrometry (ICP-MS). Concentration loading of zinc, arsenic, cadmium, and lead was observed to be 79%, 71%, 48%, and 33%, respectively, higher during the dry (winter) season when compared with the monsoon dataset. Multivariant data were analyzed using Principal Component Analysis (PCA) with three components explaining maximum variation in data by factor loading through varimax rotation. The rapid growth and development have connected tourists to the mountain of the western Himalayas. Thus, a monitoring program is needed in these areas for further assessment. So that necessary action can be taken to conserve the eco-sensitive zones of Uttarakhand.
اظهر المزيد [+] اقل [-]Carbon Emissions from Energy Use in India: Decomposition Analysis النص الكامل
2023
Sebak Kumar Jana and Wietze Lise
To become the fastest-growing large economy in the world, India has set a target growth rate of 9%, reaching an economy of $5 trillion by 2024-25. It is an immense challenge to meet the growth target and keep the CO2 emissions under control. The present paper aims to discover the determinants for explaining CO2 emissions in India by conducting a complete decomposition analysis, where the residuals are fully distributed to the determinants for the country from 1990-2018. The analysis reveals that the biggest contributor to the rise in CO2 emissions in India is the expansion of the economy (scale effect). The intensity of CO2 and the change in the composition of the economy, which nearly move in tandem, also contribute to the rise in CO2 emissions, although more slowly. A declining energy intensity of the Indian economy is responsible for a considerable reduction in CO2 emissions. As a typical result for an upcoming economy, this paper did not find evidence for an environmental Kuznets curve. This implies that continued economic growth will lead to increased CO2 emissions.
اظهر المزيد [+] اقل [-]Evaluation of Cr(VI) Reducing Capability of Bacillus licheniformis DAS1 Using a Multifactor Experimental Approach النص الكامل
2023
Md. Saduzzaman, Kumari Mini, Shardendu Shardendu and S. Rehan Ahmad
The current study is about detoxifying soil and water contaminated with toxic Cr(VI). To ensure that DAS1 could develop as well as possible, the pH was changed between 4 and 10. DAS1 showed its highest growth at pH 8, and at the same pH, it had an 85% potential to remediate by converting Cr(VI) to Cr(III). Immobilized bacteria increased the reduction of Cr(VI) to Cr(III) from the culture medium to 90.4%. The impact of glucose concentrations between 0.5 and 2.5 g.L-1 was examined. The greatest development was seen at pH 8 and 2 g.L-1 glucose concentration. The remediation potential was improved by up to 96% when the growing medium contained 200 mg.L-1 Cr(VI). The value of ks (0.434 g.L-1) demonstrated the substrate’s affinity for bacteria in accordance with the Monod equation, while μ max (0.090 h) demonstrated that DAS1 required 11.11 h for maximal growth. The multifactor experimental design was used to analyze mixed cultures of DAS1 and DAS2 in a 1:1 ratio, and it was determined that the X3Y2Z1 experiment design was best for completely removing Cr(VI) from the growing medium. By making pores using Na2EDTA, it was determined that the cell membrane’s impermeability did not cause Cr(VI) resistance in DAS1. The delayed lag phase indicated that the enzyme activity was inductive rather than constitutive.
اظهر المزيد [+] اقل [-]State-of-the-art Overview of Biological Treatment of Polluted Water from Rice Mills and Imminent Technologies with Green Energy Retrieval النص الكامل
2023
R. K. Singh and S. Bajpai
Rice milling involves shelling and polishing paddy grains to produce rice- both raw and parboiled. Parboiled rice production requires a massive quantity of freshwater for soaking, which, in turn, generates a large amount of wastewater. If this wastewater is not properly ameliorated, it can cause tremendous troubles of surface water pollution, land pollution, and, ultimately, groundwater pollution. Therefore, proper treatment of polluted water from rice mills (PWRM) as per the effluent discharge norms is necessary to protect the surface and subsurface water resources for sustainable development. There are two methods for remediating rice mill wastewater- physicochemical and biological. The biological methods produce comparatively less sludge and are cost-effective. Moreover, these processes are capable of retrieving green energy in the form of biomethane, biohydrogen, and bioelectricity to augment bio-fuel production, aiming to meet the ever-increasing fuel demands caused by rapid industrialization, motorization, and urbanization. The focus on green energy production is gaining momentum day by day due to the adverse effects of conventional energy derived from fossil fuel combustion in terms of enhanced Air Pollution Index (API) in the ambient atmosphere. In this paper, anaerobic biodegradation, phytoremediation, phyco-remediation, and microbial fuel cell techniques adopted by various researchers for remediating the polluted water from rice mills have been well addressed and critically discussed. The pros and cons of these biological methods have been well addressed to assess the socio-technoeconomic feasibility of each method.
اظهر المزيد [+] اقل [-]