scholarly journals Characterisation of Metal Retention Agents and Study of their Application in Liquid Wastes

2013 ◽  
Vol 5 (1) ◽  
pp. 29-37
Keyword(s):  
Experimental Study ◽  
Fly Ash ◽  
Metal Uptake ◽  
Waste Treatment ◽  
Liquid Waste ◽  
Uptake Capacity ◽  
Metal Retention ◽  
Lignite Fly Ash ◽  
Liquid Wastes

A procedure that should be implemented for the evaluation of materials suitability, in terms of their use as metal retention agents, is presented. It derives from a review of materials and waste treatment mechanisms, which has been studied and is also presented. Lignite fly ash, agricultural ashes, lime and sawdust were chosen for the experimental study of their metal uptake capacity, according to the proposed stages, during the treatment of an acidic liquid waste loaded with metals (Cu, Zn, Fe, Ni, Cd, Cr). Fly ash, agricultural ashes and lime exhibited increased metal retention percentages through adsorption and precipitation, as it was expected due to their structure, while sawdust acted as sorbent.

scholarly journals Management of hospital radioactive liquid waste: treatment proposal for radioimmunoassay wastes

2021 ◽  
Vol 8 (5) ◽  
pp. 449-464
Author(s):  
María Sancho ◽  
◽  
José Miguel Arnal ◽  
Gumersindo Verdú-Martín ◽  
Cristina Trull-Hernandis ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Waste Treatment ◽  
Liquid Waste ◽  
Radiological Hazard ◽  
Radioactive Liquid Waste ◽  
Low Concentrations ◽  
Liquid Wastes ◽  
Clearance Level ◽  
Activity Decay ◽  
Direct Discharge

<abstract> <p>Radioactive liquid wastes are produced at hospitals from diagnostic and therapeutic applications of radionuclides. The most usual management of these wastes is temporary storage at the hospital for radioactivity decay and, then, discharge into sewage if not other pollutants are present in waste, always after authorization of the corresponding institution. In some cases, radioactive wastes have other hazards, such as chemical or biological ones, which can be more dangerous than radiological hazard, and do not allow direct discharge into sewage in spite of decaying activity below the clearance level. Therefore, these wastes have to be treated and condition before discharge in spite of activity decay below discharge limit. This is the case of liquid wastes from radioimmunoassay (RIA), a laboratory technique that allows to determine human substances in very low concentrations (below 10<sup>-12</sup> g/mL), like hormones, using <sup>125</sup>I as radionuclide. This study summarizes the usual management of radioactive liquid wastes from hospitals, including conventional and recent treatments applied. Furthermore, based on experimental results obtained with real RIA wastes, this work exposes a proposal of treatment with ultrafiltration and reverse osmosis membranes, and determines the most suitable application of this treatment according to radiological and operational considerations.</p> </abstract>

scholarly journals The Solidification/Stabilization of Wastewater (From a Landfill Leachate) in Specially Designed Binders Based on Coal Ash

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5610
Author(s):  
Carmen-Lidia Oproiu ◽  
Georgeta Voicu ◽  
Alina Bădănoiu ◽  
Adrian-Ionuţ Nicoară
Keyword(s):  
Fly Ash ◽  
Complex Analysis ◽  
Waste Treatment ◽  
Bottom Ash ◽  
Liquid Waste ◽  
Coal Ash ◽  
X Ray Diffraction ◽  
Pozzolanic Reactivity ◽  
Calcium Silicate Hydrates ◽  
Cementitious Systems

The aim of this study is to assess the possibility to solidify/stabilize a liquid waste from a municipal waste landfill using binders based on coal ash (fly ash and bottom ash) and specially designed cements for waste treatment (INERCEM). The leaching test proved that all cementitious systems are efficient for the solidification/stabilization of the studied wastes and can reduce the leaching potential of heavy metals present in both liquid waste and coal ash. Therefore, these wastes cease to be a source of environmental pollution. X-ray diffraction (XRD) and thermal complex analysis (DTA-TG) were used to assess the nature and amount of compounds formed in these cementitious systems during the hydration and hardening processes; ettringite, calcium silicate hydrates and CaCO3 were the main compounds formed in these systems assessed by these methods. The microstructure of hardened specimens was assessed by scanning electronic microscopy (SEM); the presence of hydrate phases, at the surface of cenospheres present in fly ash, proved the high pozzolanic reactivity of this phase.

Experimental Study on Mechanical Property of Concrete Based on Seawater and Sea Sand

2013 ◽  
Vol 641-642 ◽  
pp. 574-577 ◽  
Author(s):  
Ying Tao Li ◽  
Ling Zhou ◽  
Mao Jiang ◽  
Yu Zhang ◽  
Jun Shao
Keyword(s):  
Mechanical Property ◽  
Experimental Study ◽  
Fly Ash ◽  
Raw Materials ◽  
Growth Trend ◽  
Sea Sand ◽  
Significant Strength ◽  
Dry Conditions ◽  
Early Strength ◽  
Better Than

In this paper, the mechanical property experiments of concrete based on the seawater and sea sand have been carried in different raw materials preparation and different conservation environments. The results show that the early strength and late strength of concrete based on seawater and sea sand are better than concrete based on freshwater and sand. There is no significant strength decreased for concrete based on seawater and sea sand under accelerated alternating wet and dry conditions. For concrete based on seawater and sea sand mixed with admixture, the downward trend of late strength is significantly delayed, the late strength of concrete based on the seawater and sea sand mixed with slag gets the most obvious growth trend, while the late strength of seawater and sea sand concrete mixed with fly ash gets the largest increment.

scholarly journals Effect of Lignite Fly Ash on the Growth and Reproduction of Earthworm Eisenia fetida

2009 ◽  
Vol 6 (2) ◽  
pp. 511-517 ◽  
Author(s):  
S. Sarojini ◽  
S. Ananthakrishnasamy ◽  
G. Manimegala ◽  
M. Prakash ◽  
G. Gunasekaran
Keyword(s):  
Fly Ash ◽  
Eisenia Fetida ◽  
Power Plants ◽  
Thermal Power ◽  
Biological Properties ◽  
Cow Dung ◽  
Physical Chemical ◽  
Lignite Fly Ash ◽  
Agricultural Use ◽  
Growth And Reproduction

Fly ash is an amorphous ferroalumino silicate, an important solid waste around thermal power plants. It creates problems leading to environmental degradation due to improper utilization or disposal. However, fly ash is a useful ameliorant that may improve the physical, chemical and biological properties of soils and is a source of readily available plant macro and micronutrients when it is used with biosolids. Supply of nutrients from fly ash with biosolids may enhance their agricultural use. The growth and reproduction ofEisenia fetidawas studied during vermicomposting of fly ash with cowdung and pressmud in four different proportions (T1,T2,T3& T4) and one controli.e.,cow dung and pressmud alone. The growth, cocoon and hatchlings production were observed at the interval of 15 days over a period of 60 days. The maximum worm growth and reproduction was observed in bedding material alone. Next to that the T1was observed as the best mixture for vermiculture.

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