scholarly journals Hazardous Components of Landfill Leachates and Its Bioremediation

2021 ◽  
Author(s):  
Menaka Salam ◽  
Namdol Nilza
Keyword(s):  
Organic Compounds ◽  
Biological Treatment ◽  
Low Cost ◽  
Chemical Properties ◽  
Industrial Effluents ◽  
Physical Method ◽  
Cost Effective ◽  
Toxic Substances ◽  
Landfill Leachates ◽  
Assessment And Treatment

Landfill leachates contain both dissolved and suspended material and may pose a threat to the environment because of the toxic substances that it carries and contaminates surface water and groundwater. They are composed of several different categories of components out of which many of them are recalcitrant and highly toxic. Major components of landfill leachates are dissolved organic compounds, inorganic macro compounds, heavy metals such as copper, lead, cadmium, chromium, nickel etc. and xenobiotic compounds such as polychlorinated biphenyls. Complex organic compounds which are released from industrial effluents like perfluorooctanoic acid and benzothiazole are also common in many of the landfill leachates. Biological treatment is a low cost effective method for the treatment of landfill leachates which can act as an accelerator for further treatment by either chemical or physical method. Improved strategies have been developed in the biological treatment of leachates which shows the efficiency of the system. But, as leachate characteristics vary depending on the rainfall and other environmental factors, it is important to first thoroughly analyze the physical and chemical properties of the landfill under study. A combined effort involving proper analysis of the leachate components, monitoring leachate flow, risk assessment, and treatment of the leachate before its release is required to efficiently control its impact to the environment.

scholarly journals CHARACTERISTICS OF LEACHATE AT IHIAGWA DUMPSITE, IMO STATE NIGERIA AND THEIR IMPLICATIONS FOR SURFACE WATER POLLUTION

2021 ◽  
pp. 1-11
Author(s):  
CT Nelson ◽  
GT Amangabara ◽  
CO Owuama ◽  
CN Nzeh ◽  
CN Uyo
Keyword(s):  
Heavy Metals ◽  
Chemical Properties ◽  
Total Solid ◽  
Toxic Substances ◽  
Landfill Leachates ◽  
Total Chloride ◽  
Metal Cyanide ◽  
Physico Chemical ◽  
High Concentrations ◽  
Total Dissolved Solid

Open dumpsite is the most common way to eliminate solid urban wastes in this part of the world. An important problem associated to landfills and open dumpsite is the production of leachates. The leachates from these dumpsites have many toxic substances, which may adversely affect the environmental health. Thus in order to have a better management of characteristics of Ihiagwa-Nekede waste dump leachates, representative leachate samples were collected and analyzed for Physico-chemical properties and levels of heavy metals in them. Results indicate pH7.38, temperature 28.30 ℃ - 28.40℃, total dissolved solid 124.01mg/l-125.45mg/l, magnesium hardness 4.40mg/l-7.32mg/l, sulphate 3.60mg/l-3.70mg/l, and nitrate 27.00mg/l-27.60mg/l. Other parameters indicated as follows Conductivity1910𝜇𝑠/𝑐𝑚-1930.00 𝜇𝑠/𝑐𝑚, total chloride 891.72mg/l-891.74mg/l, carbonate 1708.00mg/l-1904.00mg/l, Ammonia 9.39mg/l-9.40mg/l, calcium hardness 373.17mg/l-375.61mg/l, total solid 2423.00mg/l-2454.00mg/l, phosphate 13.52mg/l-13.54mg/l. The heavy metal: cyanide 2.25mg/l-2.33mg/l, zinc 18.08mg/l-18.38mg/l, copper 19.90mg/l20.48mg/l, iron10.67mg/l-10.82mg/l, lead 1.27mg/l-1.41mg/l, and manganese 3.00mg/l-3.61mg/l, all these exceeded the WHO standards. The obtained results showed that the landfill leachates are characterized by high concentrations of heavy metals and other disease causing elements and therefore require urgent treatment to forestall the contamination of groundwater system and the nearby Otamiri River.

scholarly journals PtOEP–PDMS-Based Optical Oxygen Sensor

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5645
Author(s):  
Camila M. Penso ◽  
João L. Rocha ◽  
Marcos S. Martins ◽  
Paulo J. Sousa ◽  
Vânia C. Pinto ◽  
...  
Keyword(s):  
Oxygen Sensor ◽  
Low Cost ◽  
Chemical Properties ◽  
Cost Effective ◽  
Luminescent Properties ◽  
Low Oxygen ◽  
Pdms Film ◽  
Sensing Applications ◽  
Optical Oxygen Sensor

The advanced and widespread use of microfluidic devices, which are usually fabricated in polydimethylsiloxane (PDMS), requires the integration of many sensors, always compatible with microfluidic fabrication processes. Moreover, current limitations of the existing optical and electrochemical oxygen sensors regarding long-term stability due to sensor degradation, biofouling, fabrication processes and cost have led to the development of new approaches. Thus, this manuscript reports the development, fabrication and characterization of a low-cost and highly sensitive dissolved oxygen optical sensor based on a membrane of PDMS doped with platinum octaethylporphyrin (PtOEP) film, fabricated using standard microfluidic materials and processes. The excellent mechanical and chemical properties (high permeability to oxygen, anti-biofouling characteristics) of PDMS result in membranes with superior sensitivity compared with other matrix materials. The wide use of PtOEP in sensing applications, due to its advantage of being easily synthesized using microtechnologies, its strong phosphorescence at room temperature with a quantum yield close to 50%, its excellent Strokes Shift as well as its relatively long lifetime (75 µs), provide the suitable conditions for the development of a miniaturized luminescence optical oxygen sensor allowing long-term applications. The influence of the PDMS film thickness (0.1–2.5 mm) and the PtOEP concentration (363, 545, 727 ppm) in luminescent properties are presented. This enables to achieve low detection levels in a gas media range from 0.5% up to 20%, and in liquid media from 0.5 mg/L up to 3.3 mg/L at 1 atm, 25 °C. As a result, we propose a simple and cost-effective system based on a LED membrane photodiode system to detect low oxygen concentrations for in situ applications.

scholarly journals Sustainable Application of Biosorption and Bioaccumulation of Persistent Pollutants in Wastewater Treatment: Current Practice

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1696
Author(s):  
Cătălina Filote ◽  
Mihaela Roșca ◽  
Raluca Maria Hlihor ◽  
Petronela Cozma ◽  
Isabela Maria Simion ◽  
...  
Keyword(s):  
Life Cycle ◽  
Scientific Literature ◽  
Industrial Effluents ◽  
Cost Effective ◽  
Point Of View ◽  
Toxic Substances ◽  
Efficient Operation ◽  
Treatment Processes ◽  
Persistent Pollutants ◽  
Microbial Bioremediation

Persistent toxic substances including persistent organic pollutants and heavy metals have been released in high quantities in surface waters by industrial activities. Their presence in environmental compartments is causing harmful effects both on the environment and human health. It was shown that their removal from wastewaters using conventional methods and adsorbents is not always a sustainable process. In this circumstance, the use of microorganisms for pollutants uptake can be seen as being an environmentally-friendly and cost-effective strategy for the treatment of industrial effluents. However, in spite of their confirmed potential in the remediation of persistent pollutants, microorganisms are not yet applied at industrial scale. Thus, the current paper aims to synthesize and analyze the available data from literature to support the upscaling of microbial-based biosorption and bioaccumulation processes. The industrial sources of persistent pollutants, the microbial mechanisms for pollutant uptake and the significant results revealed so far in the scientific literature are identified and covered in this review. Moreover, the influence of different parameters affecting the performance of the discussed systems and also very important in designing of treatment processes are highly considered. The analysis performed in the paper offers an important perspective in making decisions for scaling-up and efficient operation, from the life cycle assessment point of view of wastewater microbial bioremediation. This is significant since the sustainability of the microbial-based remediation processes through standardized methodologies such as life cycle analysis (LCA), hasn’t been analyzed yet in the scientific literature.

scholarly journals Ironmaking and Steelmaking Slags as Sustainable Adsorbents for Industrial Effluents and Wastewater Treatment: A Critical Review of Properties, Performance, Challenges and Opportunities

2020 ◽  
Vol 12 (5) ◽  
pp. 2118 ◽  
Author(s):  
James Manchisi ◽  
Elias Matinde ◽  
Neil A. Rowson ◽  
Mark J. H. Simmons ◽  
Geoffrey S. Simate ◽  
...  
Keyword(s):  
Low Cost ◽  
Chemical Properties ◽  
Toxic Metal ◽  
Industrial Effluents ◽  
Metal Species ◽  
Adsorption Sites ◽  
Post Process ◽  
Steelmaking Slags ◽  
Challenges And Opportunities ◽  
Performance Challenges

This paper critically discusses the structure, properties and applications of ironmaking and steelmaking slags and their silicate-based variants as low-cost adsorbents for removing cations and anions from industrial effluents and wastewater. Undoubtedly, the performance of slag-based adsorbents depends on their physical, chemical and phase chemical properties. The presence of crystalline phases, for example, has a significant effect on the adsorption capacity. However, despite their low cost and ubiquity, their chemical and geometric heterogeneity significantly affects the performance and applications of slag-based adsorbents. These challenges notwithstanding, the efficacy of slag-based adsorbents can be significantly enhanced through purposeful activation to increase the specific surface area and density of adsorption sites on the surfaces of adsorbent particles. The synthesis of functionalised adsorbents such as geopolymers, zeolites and layered double hydroxides from silicate and aluminosilicate precursors can also significantly increase the performance of slag-based adsorbents. In addition, the ability to stabilise the dissolved and/or entrained toxic metal species in stable phases in slags, either through controlled post-process fluxing or crystallisation, can significantly enhance the environmental performance of slag-based adsorbents. Most critical in the design of future slag-based adsorbents is the integration of the engineered properties of molten and solidified slags to the recovery and stabilisation of dissolved and/or entrained metals.

scholarly journals Comparative study of Malaysian and Nigerian kaolin-based ceramic hollow fiber membranes for filtration application

2020 ◽  
Vol 16 (2) ◽  
pp. 182-185
Author(s):  
Jamilu Usman ◽  
Mohd Hafiz Dzarfan Othman ◽  
Ahmad Fauzi Ismail ◽  
Mukhlis A Rahman ◽  
Juhana Jaafar ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Ceramic Membrane ◽  
Mechanical Stability ◽  
Sintering Temperature ◽  
Low Cost ◽  
Water Flux ◽  
Chemical Properties ◽  
Cost Effective ◽  
High Water ◽  
Membrane Morphology

Ceramic membrane has gained increasing interest in water filtration application due to its inherent characteristics. Low-cost clay materials are preferred to fabricate an efficient and cost-effective ceramic membrane. Among the ceramics, kaolin displays better mechanical, thermal, and chemical properties. However, natural properties of kaolin vary from different studies. Hence, cost-effective Nigeria (NK) and Malaysia (MK) kaolins were compared to study the fabrication of kaolin hollow fiber ceramic membrane for filtration application. The effects of kaolin loading concentration (34 and 37 wt. %) and sintering temperature (1200, 1350, 1400, and 1500 °C) on kaolin membrane fabrication were also studied. XRF studies indicated that the hydroxyl silica and alumina compositions were 56.76wt.% and 41.97wt% for NK and 55.21wt.% and 40.33wt% for MK. MK exhibited intense kaolinite peak with a broad range of particle size distribution. The mechanical stability of kaolin ceramic membrane increased with the increase of sintering temperature and kaolin loading concentration. Membrane morphology also varied with MK and NK. Interestingly, 34wt% kaolin at a sintered temperature of 1350 °C produced ceramic membrane with a high water flux. A similar trend was observed in both MK and NK, where the flux of 34wt% MK and NK are 565 and 460 L/m2h, respectively.

scholarly journals Cashew nut shell (Anarcadium accidentale L) charcoal as bioadsorbent to remove Cu2+ and Cr3+

2021 ◽  
Vol 10 (2) ◽  
pp. e0510212238
Author(s):  
Karine Fonseca Soares de Oliveira ◽  
Joemil Oliveira de Deus Junior ◽  
Talita Lorena da Silva do Nascimento ◽  
Raoni Batista dos Anjos ◽  
Dulce Maria de Araújo Melo ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Low Cost ◽  
Chemical Properties ◽  
Industrial Effluents ◽  
Second Order ◽  
Point Of Zero Charge ◽  
Cashew Nut ◽  
Pseudo Second Order ◽  
Cashew Nut Shell ◽  
Removal Of Metal Ions

Lignocellulosic materials have been used as bioadsorbents for contaminants removal from industrial effluents due to their physical-chemical properties, renewable source, low-cost and efficiency that make them competitive to commercial activated carbon. The objective of this work is to develop an efficient and low cost bioadsorbent reusing the cashew nut shell (Anarcadium accidentale L), CNS, for the removal of metal ions (Cu2+ and Cr3+). The CNS was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), the point of zero charge (pHpzc) and the Boehm titration. The kinetics and adsorption equilibrium experiments were carried out in a monoelementary system, in batch runs at room temperature. The adsorption kinetics was evaluated by the mathematical models of pseudo first-order, pseudo second-order and intraparticle diffusion, while the adsorption isotherm was adjusted according to the Langmuir, Freundlich and Redlich-Peterson models. The removal percentage was 91% (Cu2+) and 96% (Cr3+) and adsorption kinetics was better adjusted to the pseudo second-order model, suggesting the predominance of chemisorption. The fit of the Langmuir isotherm was better for the experimental data of Cu2+ and Cr3+ ions, indicating adsorption in monolayers. It is concluded that the bioabsorbent produced from the cashew nut shell has a high potential for the removal of metals, in addition to being an abundant product in nature, is renewable and biodegradable and its reuse contributes to the reduction of environmental pollution, the production of waste and improves the local circular economy through the valorization of the byproduct.

ASSESSMENT OF THE PLATELET COUNT IN THE PREGNANT WOMEN IN IGIMS, PATNA, BIHAR

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Tanwi Singh ◽  
Anshuman Sinha
Keyword(s):  
Platelet Count ◽  
Pregnant Women ◽  
Screening Test ◽  
Low Cost ◽  
Medical Science ◽  
Cost Effective ◽  
Platelet Indices ◽  
Increased Risk ◽  
Low Platelet Count ◽  
Severity Of The Disease

The major risk associated with low platelet count in pregnancy is the increased risk of bleeding during the childbirth or post that. There is an increased blood supply to the uterus during pregnancy and the surgical procedure requires cutting of major blood vessels. Women with thrombocytopenia are at increased risk of losing excessive blood. The risk is more in case of caesarean delivery as compared to vaginal delivery. Hence based on above findings the present study was planned for Assessment of the Platelet Count in the Pregnant Women in IGIMS, Patna, Bihar. The present study was planned in Department of Pathology, Indira Gandhi Institute of Medical Science, Patna, Bihar, India. The present study was planned from duration of January 2019 to June 2019. In the present study 200 pregnant females samples received for the platelet estimation were enrolled in the present study. Clinically platelet indices can be a useful screening test for early identification of preeclampsia and eclampsia. Also platelet indices can assess the prognosis of this disease in pregnant women and can be used as an effective prognostic marker because it correlates with severity of the disease. Platelet count is a simple, low cost, and rapid routine screening test. Hence the data generated from the present study concludes that platelet count can be used as a simple and cost effective tool to monitor the progression of preeclampsia, thereby preventing complications to develop during the gestational period. Keywords: Platelet Count, Pregnant Women, IGIMS, Patna, Bihar, etc.

Janus – A New Approach to Air Combat Pilot Training

2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Training System ◽  
Embedded Sensors ◽  
Pilot Training ◽  
New Approach ◽  
Combat Aircraft ◽  
Air Combat ◽  
The Cost

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.

Two-stage chemical-biological treatment at Thessaloniki greater area WWTP - experiences and potentials

1995 ◽  
Vol 32 (9-10) ◽  
pp. 75-84 ◽  
Author(s):  
A. D. Andreadakis ◽  
G. H. Kristensen ◽  
A. Papadopoulos ◽  
C. Oikonomopoulos
Keyword(s):  
Biological Treatment ◽  
Treatment Plant ◽  
Cost Effective ◽  
Primary Treatment ◽  
Effective Control ◽  
Two Stage ◽  
Effluent Quality ◽  
Filamentous Microorganisms ◽  
Sludge Settling ◽  
The City

The wastewater from the city of Thessaloniki is discharged without treatment to the nearby inner part of the Thessaloniki Gulf. The existing, since 1989, treatment plant offers only primary treatment and did not operate since the expected effluent quality is not suitable for safe disposal to the available recipients. Upgrading of the plant for advanced biological treatment, including seasonal nitrogen removal, is due from 1995. In the mean time, after minor modifications completed in February 1992, the existing plant was put into operation as a two-stage chemical-biological treatment plant for 40 000 m3 d−1, which corresponds to about 35% of the total sewage flow. The operational results obtained during the two years operation period are presented and evaluated. All sewage and sludge treatment units of the plant perform better than expected, with the exception of the poor sludge settling characteristics, due to severe and persistent bulking caused by excessive growth of filamentous microorganisms, particularly M. Parvicella. Effective control of the bulking problem could lead to more cost-effective operation and increased influent flows.

Motivating Compliance: Firm Response to Mandatory Disclosure Policies

2018 ◽  
Vol 32 (2) ◽  
pp. 103-119
Author(s):  
Colleen M. Boland ◽  
Chris E. Hogan ◽  
Marilyn F. Johnson
Keyword(s):  
Conflict Of Interest ◽  
Low Cost ◽  
Cost Effective ◽  
Data Availability ◽  
Policy Adoption ◽  
Future Research ◽  
Regulated Firms ◽  
Firm Response ◽  
Disclosure Rules ◽  
The Impact

SYNOPSIS Mandatory existence disclosure rules require an organization to disclose a policy's existence, but not its content. We examine policy adoption frequencies in the year immediately after the IRS required mandatory existence disclosure by nonprofits of various governance policies. We also examine adoption frequencies in the year of the subsequent change from mandatory existence disclosure to a disclose-and-explain regime that required supplemental disclosures about the content and implementation of conflict of interest policies. Our results suggest that in areas where there is unclear regulatory authority, mandatory existence disclosure is an effective and low cost regulatory device for encouraging the adoption of policies desired by regulators, provided those policies are cost-effective for regulated firms to implement. In addition, we find that disclose-and-explain regulatory regimes provide stronger incentives for policy adoption than do mandatory existence disclosure regimes and also discourage “check the box” behavior. Future research should examine the impact of mandatory existence disclosure rules in the year that the regulation is implemented. Data Availability: Data are available from sources cited in the text.

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