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High-Performance, Eco-Friendly Blocks from Iron Ore Tailings: A Solution for Sustainable Construction Texte intégral
2024
S. A. Kakodkar and Ulhas G. Sawaiker
Goa’s iron ore mining industry has generated over 7.7 million tonnes of iron ore tailings (IOTs) in the past two decades. These IOTs pose a significant environmental threat due to heavy metal contamination, dust generation, and acid mine drainage. While some IOTs are used for backfilling, the majority are stored in tailings storage facilities (TSFs), posing long-term risks to surrounding water resources, ecosystems, and land use. Large-scale utilization technologies are crucial for sustainable IOT management. This study investigates the feasibility of incorporating IOTs in construction block production, aiming for high-volume waste consumption and improved resource efficiency. This approach offers a potential pathway to remediate the environmental impact of IOTs. The proposed method replaces 85% of the cement content with a cementitious material comprising 65% Ground Granulated Blast Furnace Slag (GGBS), 10% Fly Ash, and 10% Lime. It also utilizes IOTs entirely as a substitute for sand, with ceramic waste partially replacing coarse aggregates. While partial substitution of coarse aggregates with ceramic waste was attempted, it decreased workability. The optimal mix design, achieving the highest compressive strength, utilizes 15% cement, 65% GGBS, 10% Fly Ash and Lime, and 100% IOTs as fine aggregate with 100% basaltic aggregates. This formulation successfully demonstrates the potential use of IOTs in manufacturing construction blocks that reach compressive strengths of 10.91 N.mm-² and 15.92 N.mm-² at 7 and 28 days, respectively, satisfying the IS 2185-Part 1 (2005) code requirement. The block density was 2.20 g.cm-³. This research demonstrates the potential to convert a significant environmental challenge into a sustainable solution. By utilizing IOTs in construction block production, we can effectively achieve waste remediation; and create resource-efficient and eco-friendly building materials, offering substantial dual benefits for Goa’s environment and construction sector.
Afficher plus [+] Moins [-]Relative Saccharification of Sawdust Materials at Different Incubation pH-values Texte intégral
2024
N. A. Ndukwe, J. B. M. Seeletse and J. P. H. van Wyk
The uncontrolled production of waste is a daily phenomenon that is experienced by most global communities, and the situation worsens due to the lack of effective waste management procedures. Solid waste such as sawdust is primarily produced by the forestry industry and although it is utilized by certain countries as briquettes to make fire or as an absorbent to clean fluid spillage as well as a component of ceilings, most of the sawdust along the Lagos Lagoon in Nigeria is left unattended as waste, contributing to environmental pollution. Cellulose, composed of glucose units is a structural component of sawdust and when saccharified the resulting glucose can be fermented into renewable substances such as bio-ethanol. The cellulose degradation process can be performed with a cellulase enzyme such as available in the fungus Aspergillus niger and during the current investigation, this enzyme system was used to bio-convert the cellulose component of sawdust from ten different trees along the Lagoon into glucose. To increase the cellulase action all sawdust materials were delignified before cellulase action with the main aim of determining the optimum pH value for maximum degradation of the various sawdust materials. The pH-related saccharification profile of each type of sawdust was constructed as well as the relative percentage of saccharification and it was concluded that all the materials were optimum degraded at acidic pH-values which varied between pH 5.0 and pH 6.0 that are like optimum pH-values reported for the other types of cellulose materials.
Afficher plus [+] Moins [-]A Review on Biosurfactants with their Broad Spectrum Applications in Various Fields Texte intégral
2024
Nazim Uddin, Jyoti Sarwan, Sunny Dhiman, Kshitij, Komal Mittal, Vijaya Sood, Md. Abu Bakar Siddique and Jagadeesh Chandra Bose K.
Because of the superior qualities of biosurfactants over their equivalents derived from fossil fuels, they have recently attracted more attention. Although production costs are still a major barrier to biosurfactants’ superiority over synthetic surfactants, biosurfactants are expected to grow in market share over the next several decades. Glycolipids, a class of low-molecular-weight biosurfactants, are particularly sought-after for a variety of surfactant-related applications due to their effective reduction of surface and interfacial tension. Rhamnolipids, trehalose lipids, sophorolipids, and mannosyl erythritol lipids are the primary types of glycolipids. Glycolipids are made of hydrophilic carbohydrate moieties joined to hydrophobic fatty acid chains by ester bonds. This review addresses the unique glycolipid production and the wide range of goods available in the global market, as well as the present state of the glycolipid industry. Applications include food processing, petroleum refining, biomedical usage, bioremediation, and boosting agricultural productivity. With biosurfactants, their beneficial Ness in releasing oil encased in rock, a need for enhanced oil recovery (EOR). Another crucial biotechnological component in anti-corrosion procedures is biosurfactants, which stop Crude oil transportation in pipelines and are made easier by incrustations and the growth of biofilms on metallic surfaces. They are also employed in the production of emulsifiers and demulsifies and have other cutting-edge uses in the oil sector. Natural surfactants can be used to lessen pollution produced by chemical solvents or synthetic detergents without compromising the oil industry’s financial gains. Consequently, it is imperative to invest in biotechnological processes. It is anticipated that natural surfactants will take over the global market in the not-too-distant future and prove to be economically feasible. It is likely possible to substitute synthetic surfactants used in agricultural product composition with biosurfactants. Because biosurfactants can benefit crops without harming the environment, they hold great potential as a useful tool in the fight against pesticide use. Furthermore, by making hazardous and leftover pesticides more soluble and thus accessible for biodegradation by other microbes, their potential as bioremediation agents can help to improve the health of soil systems. This article is based on the explanation of various applications of Biosurfactants.
Afficher plus [+] Moins [-]Forward Osmosis Process for Concentration of Treated Tannery Effluent Texte intégral
2024
S. U. Sayyad
Forward Osmosis is a suitable pretreatment process for reverse osmosis for secondary-treated sewage reuse and secondary-treated industrial effluents. In this study, the FO process is investigated for concentrating synthetic secondary treated tannery effluents using 24 g.L-1 and 38 g.L-1 of NaCl solution as draw solution. Results showed that 38 g.L-1 NaCl solution when used, provided higher flux and lower flux decline ratio as compared to 24 g.L-1 NaCl solution. The solute rejection by FO membrane was more in FO experiments using 38 g.L-1 NaCl solution as DS as compared to 24 g.L-1 NaCl solution. Contact angle, Fourier transform infrared spectroscopy, and scanning electronic microscopy tests on pristine and chemically cleaned membranes indicated the change in membrane structure and the presence of foulants on the membrane surface, indicating insufficient chemical cleaning. Findings signify implications on the concentration of DS and the cleaning method adopted for concentrating treated tannery effluent efficaciously using the FO process.
Afficher plus [+] Moins [-]Assessment of 40K and Heavy Metal Levels in Euphrates River of Al-Qadisiyah Governorate Texte intégral
2024
S. K. Ibrahiem and H. A. Walli
The objective of the current research is to measure the specific activity of 40K and heavy metals in the water samples collected from the Al-Diwaniyah River in Al-Qadisiyah Governorate, Iraq. The activity of 40K in water samples was ascertained using High Purity Germanium Spectrometer (HPGe) detector technology, which is based on a high-resolution gamma spectrometry system, and by using an atomic absorption spectrometer (A.A.S.) to determine the heavy metals of Ni, Cd and Pb, as well as measure some of the physical properties of water samples. The results indicated the concentration of 40K in the water was presented in different concentrations. The lowest value was 2.6±0.5 Bq/L Al-Muhanawiyah, while the highest value was in Al-Diwaniyah center 24.6± 4.0Bq/L. On the other hand, the highest results of Pb, Cd and Ni have been 0.1247, 0.0652 and 0.157 ppm, respectively. While, the results of physics properties were from 7.05 to 8.3 for total dissolved solids (T.D.S.) values were from 2100 to 756.6 mg/L, electrical conductivity values were between 1140 and 3500 μs/cm, and turbidity values were between 7.0 and 54.5. Based on the results, the concentrations of the 40K and heavy metals indicated that the results are almost slight compared to internationally accepted values.
Afficher plus [+] Moins [-]Optimizing Community Health Center Effluent Treatment with Moving Bed Biofilm Reactor Technology Combined with Activated Carbon and Chlorine Texte intégral
2024
Budirman, Muhammad Farid Samawi, Fahruddin, Paulina Taba, Mahatma Lanuru and Agus Bintara Birawida
Community Health Centers are small-scale hospitals that serve community medicine in Indonesia. These activities generate wastewater containing various contaminants, such as pathogens, chemicals, and nutrients, which can pollute the environment and endanger human health. So, efforts are needed to reduce their impact through wastewater treatment. This research applies an anaerobic-aerobic biofilter system with Moving Bed Biofilm Reactor (MBBR) technology combined with activated carbon and chlorine in treating wastewater. The treatments in the study were different service capacities and wastewater treatment, with three replicates in each treatment. The residence time of wastewater in the system is 4 h. The results showed that combining MBBR technology, activated carbon, and chlorine could reduce temperature, TSS, pH, BOD5, COD, NH3, and Coliform values in wastewater in three Community Health Center services. Thus, it can be concluded that the different services and wastewater treatment efforts, combined with MBBR, activated charcoal, and chlorine, have been proven to affect and improve the quality of wastewater from the Community Health Center to meet the effluent quality standards.
Afficher plus [+] Moins [-]The Synthesis of AgNPs/SAC Using Banana Frond Extract as a Bioreducing Agent and its Application as Photocatalyst in Methylene Blue Degradation Texte intégral
2024
Anti Kolonial Prodjosantoso, Tengku Khadijah Nurul Hanifah, Maximus Pranjoto Utomo, Cornelia Budimarwanti and Lis Permana Sari
Silver nanoparticles (AgNPs) were synthesized utilizing various methods, including bioreducing agents. The synthesis involved the use of silver nitrate (AgNO3) as the precursor and banana frond extract as the bioreducing agent, with different volume ratios being tested. Subsequently, the most optimal variant of AgNPs was immobilized onto activated carbon (AC) derived from soybean seeds. The AgNPs/SAC composite was subjected to thorough characterization using UV-Vis diffuse reflectance spectroscopy and X-ray diffraction (XRD). A series of degradation experiments were then conducted using methylene blue, with the reaction duration following a specific protocol. A comparison of methylene blue concentrations before and after the photodegradation process was made to assess the reaction’s efficacy. The findings revealed that the ideal ratio between the bioreducing agent and precursor was 9:30 (v/v). The AgNPs/SAC composite exhibited a peak absorption at a wavelength of 420-440 nm. The UV-DRS characterization of AgNPs/SAC unveiled a band gap energy of 1.52 eV. The AgNPs supported on AC displayed a peak absorption wavelength of 5,438.5 nm, showcasing a face-centered cubic (FCC) structure. The AgNPs/SAC effectively decreased the concentration of methylene blue through a combination of adsorption and photodegradation mechanisms, achieving efficiencies of 35.3813% and 81.1636%, respectively. The AgNPs/SAC composite demonstrates significant potential for efficient and sustainable water treatment.
Afficher plus [+] Moins [-]A Review on Extended Producer Responsibility Schemes for Packaging Waste Management and Research Gaps in the Field Texte intégral
2024
T. T. Y. Anh, S. Herat and K. Prasad
Recently, Extended Producer Responsibility (EPR) schemes have been considered as potential policies for solid waste management and many countries have applied them. Researchers, authorities, and producers need a comprehensive and up-to-date understanding of EPR. Therefore, this literature review aims to review the current research status of EPR implementation on packaging, to highlight actual experiences conducting EPR, and to find research gaps. Results indicate that during the last 5 years, there has been an increase in the amount of research on EPR in packaging and that packaging waste recycling under this scheme is the most considered activity. Additionally, the primary metrics used to assess the efficacy of EPRs are recycling and reducing packaging waste. According to the lessons learned, applying EPR to packaging should take stakeholder engagement, policy design, transparency, and incentive strategy into account. Additionally, knowing the economic effectiveness problems small- and medium-sized packaging companies face, the effectiveness of EPR methods on various materials and geographical areas, and the efficacy of monitoring methods are the main areas that need to be researched.
Afficher plus [+] Moins [-]Using Azospirillum Bacteria Isolated from Soil as Bioremediation Agent in Wastewater Contaminated with Cadmium in Iraq Texte intégral
2024
Z. R. Abbas, A. M. Al-Ezee, B. T. Al-Shandah and M. A. Shafeeq
Bioremediation is an important technique to remove heavy metals from wastewater. The current research aimed to use Azospirillum bacteria in removing cadmium ions from wastewater. The source of Azospirillum bacteria was the soil of Al-Mishkhab in Al-Najaf province, Iraq (rice fields), while the source of wastewater was taken from the Al-Rustamia wastewater treatment plant, in Baghdad in October 2020. All the experiments were carried out in Soil and Water Research Center, Ministry of Science and Technology. After collecting the soil, the microorganisms were isolated through the Immunomagnetic beads (IMB) process and were incubated on a certain synthesized medium. The concentration of cadmium ion was determined through the Absorption Spectrophotometer (AAS) technique. The Azospirillum colonies were identified and characterized as white colonies while the concentration of cadmium ion ranged from 0.03-1.6 mg/L and applying the microorganism on the wastewater will decrease the concentration up to 99.9% in a process called biosorption. Treatment time was also studied for 24, 48, 72, and 168 hours. The statistical analysis shows that increasing time will enhance the removal of cadmium. Cadmium is one of the heavy metals responsible for soil contamination; bacteria play a crucial role in bioremediation, demonstrating stability in decomposing various compounds and materials. Azospirillum is employed for soil decontamination purposes; increasing incubation time will enhance the removal of the trace element; also further investigate the effect of other factors such as temperature, pH, and the effect of using other microorganisms.
Afficher plus [+] Moins [-]The Utility of Synthetic Biology in the Treatment of Industrial Wastewaters Texte intégral
2024
Monica Joshi and Jai Gopal Sharma
Effective treatment of industrial wastewater effluents before discharging them to the soil and water bodies has always been one of the paramount environmental concerns. The pollutants in untreated wastewater effluents have hazardous implications for human health and the ecosystem. Conventional physical and chemical processes of industrial wastewater treatment have many complications and they often fall short in the treatment of new and diverse varieties of pollutants. Several microbial strains in nature have shown their remediation property, but they possess limited efficiency in breaking down pollutants into non-toxic components. Synthetic biology is a perfect amalgam of two fields – biological science and engineering, and it has transformed our ways of understanding the functioning of complex biological systems. Researchers have reported that some engineered microbes can achieve remediation efficiency of up to 100% in specific pollutants such as heavy metals and hydrocarbons. For example, microbes like Pseudomonas veronii have been shown to reduce cadmium concentrations by up to 100%, and Pseudomonas putida has been shown to reduce phenol concentrations by 92%. Synthetic biology-based biosensors are also being developed for pollution monitoring and control of industrial wastewater. In this review, we discuss these advancements of synthetically engineered microorganisms in the treatment of industrial wastewater.
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