scholarly journals The use of cardboard factory sludge in the remediation of zinc contaminated sediment

2012 ◽  
Vol 77 (8) ◽  
pp. 1097-1107
Author(s):  
Miljana Prica ◽  
Milena Dalmacija ◽  
Bozo Dalmacija ◽  
Jelena Trickovic ◽  
Snezana Maletic
Keyword(s):  
Leaching Tests ◽  
Contaminated Sediment ◽  
Paper Production ◽  
Stabilizing Agent ◽  
Stabilization Treatment ◽  
Polluted Sediment ◽  
Leaching Behaviour ◽  
Leaching Mechanism

Paper and cardboard factory sludges are generated by various processes during pulp, cardboard and paper production, and the increasing quantities produced make the disposal of this sludge a problem. This study investigates the use of cardboard factory sludge as a stabilizing agent in the solidification/stabilization (S/S) treatment of zinc polluted sediment. Semidynamic and toxicity leaching tests were conducted to assess the effectiveness of the solidification/stabilization treatment and long-term zinc leaching behaviour. A diffusion-based model was used to elucidate the controlling leaching mechanisms. The applied S/S treatment was effective in immobilizing zinc, and the controlling leaching mechanism appeared to be diffusion, which indicates that a slow leaching of zinc could be expected when cardboard mill sludge is applied as a S/S agent.

scholarly journals Evaluation of Strength Properties of Subgrade Materials Stabilized with Bio-Enzyme

2020 ◽  
Vol 5 (5) ◽  
pp. 607-610
Author(s):  
Bamidele S. Raheem ◽  
G. F. Oladiran ◽  
D. A. Oke ◽  
S. A. Musa
Keyword(s):  
Laboratory Experiments ◽  
Strength Properties ◽  
Dry Density ◽  
Sand Sample ◽  
Stabilizing Agent ◽  
Filling Materials ◽  
Base Materials ◽  
Long Term Effect ◽  
Enzyme Dosage

In the recent studies many chemical have been emerged and used as stabilizing agent. One of such chemical (Bio-enzyme) was used in this study as a stabilizing agent. Bio-enzyme is prepared locally from fermented vegetable and fruits waste. These products are natural, nontoxic, non-corrosive, nonflammable liquid and environmentally harmless. In this research, Bio-enzyme was prepared and used in varying proportion to stabilize laterite samples collected from different locations. Detailed laboratory experiments (Classification tests and CBR) were conducted to evaluate the effects of Bio-enzyme at varying dosage after 24 hours of curing of specimens. The percentage passing through sieve No. 200(75 micron) was less than 35%., according to ASHTO and clause 6201 of Federal Ministry of Works and Housing (F.M.W & H) Specification Requirements, sample A is (A-2-5), sample B is (A-2-4) while sample C is classified as A-2-6 and they are silty or clayed gravel and sand. Sample A is a good subgrade, subbase or base materials based on highest CBR values (at 20% bio-enzyme dosage, Sample A (102.50%) and sample B (69.40%) & at 10% sample C (33.2%). Sample B can also be used as subgrade or subbase materials where light traffic is considered and sample C is suitable as filling materials as evident in their CBR value. It has been observed that Bio-enzyme treated soil shows significant improvement in terms of the dry density and CBR value. Presence of Bio-enzyme in the soil samples led to increase in the C.B.R by 10-20% as compared to the control). However, it is recommended that assumption should not be made that Bio-enzyme is considered suitable for all type of soil and long term effect of it should also be examined.

scholarly journals Co-Disposal of Coal Gangue and Red Mud for Prevention of Acid Mine Drainage Generation from Self-Heating Gangue Dumps

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1081
Author(s):  
Zhou Ran ◽  
Yongtai Pan ◽  
Wenli Liu
Keyword(s):  
Acid Mine Drainage ◽  
Red Mud ◽  
Mine Drainage ◽  
Coal Gangue ◽  
Leaching Tests ◽  
Self Heating ◽  
Acid Mine ◽  
Acid Pollution ◽  
Dynamic Leaching

The seepage and diffusion of acid mine drainage (AMD) generated from self-heating coal gangue tailings caused acid pollution to the surrounding soil and groundwater. Red mud derived from the alumina smelting process has a high alkali content. To explore the feasibility of co-disposal of coal gangue and red mud for prevention of AMD, coal gangue and red mud were sampled from Yangquan (Shanxi Province, China), and dynamic leaching tests were carried out through the automatic temperature-controlled leaching system under the conditions of different temperatures, mass ratios, and storage methods. Our findings indicated that the heating temperature had a significant effect on the release characteristics of acidic pollutants derived from coal gangue, and that the fastest rate of acid production corresponding to temperature was 150 °C. The co-disposal dynamic leaching tests indicated that red mud not only significantly alleviated the release of AMD but also that it had a long-term effect on the treatment of acid pollution. The mass ratio and stacking method were selected to be 12:1 (coal gangue: red mud) and one layer was alternated (coal gangue covered with red mud), respectively, to ensure that the acid-base pollution indices of leachate reached the WHO drinking-water quality for long-term discharge. The results of this study provided a theoretical basis and data support for the industrial field application of solid waste co-treatment.

Simfuel Leaching Studies in Granitic Groundwater Under Oxidizing Conditions

1995 ◽  
Vol 412 ◽  
Author(s):  
J. Garcia-Serrano ◽  
J. A. Serrano ◽  
P. P. Diaz-Arocas ◽  
J. Quiñones ◽  
J. L. R. Almazan
Keyword(s):  
Elemental Analysis ◽  
Particle Sizes ◽  
Leaching Tests ◽  
Minor Components ◽  
High Release ◽  
Synthetic Groundwater ◽  
Granitic Groundwater ◽  
Good Agreement

AbstractSimulated high-bumup nuclear fuel (SIMFUEL) has been leached in synthetic groundwater under oxic conditions. SIMFUEL pellets were ground and sieved to two particle sizes (50–100 and 100–315 μm). An extensive solid characterization of the fragments was carried out by various techniques. Elemental analysis has also been performed prior to the leaching tests.The release of U and the minor components (Mo, Ba and Sr) was monitored during the long term dissolution experiments (350 days). These minor components exhibit a trend similar to uranium, high release at the beginning followed by a plateau. The M/U calculated ratios show different behavior although after a period of time, depending on the particle sizes, constant ratios were observed.SIMHUEL powder was used in order to simulate the physical effect of bum-up on the fuel structure. This fact seems to play an important role on the uranium release. A comparison with the results given in the literature for SIMFUEL pellet leaching tests shows good agreement with the values reported.

The influence of stabilization treatment on long-term corrosion resistance and microstructure in Er and Zr containing 5083 aluminum alloy

2020 ◽  
Vol 161 ◽  
pp. 110143 ◽  
Author(s):  
Yusheng Ding ◽  
Xiaolan Wu ◽  
Kunyuan Gao ◽  
Cheng Huang ◽  
Xiangyuan Xiong ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Stabilization Treatment ◽  
5083 Aluminum Alloy

scholarly journals Identification of biodegradation products of biphenyl and 2,3-dihydroxybiphenyl (2,3-DHB)

2014 ◽  
Vol 7 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Slavomíra Murínová ◽  
Katarína Dercová ◽  
Peter Tarábek ◽  
Peter Tölgyessy
Keyword(s):  
Degradation Products ◽  
Pseudomonas Stutzeri ◽  
Dienoic Acid ◽  
Transformation Rate ◽  
Contaminated Sediment ◽  
Bacterial Strains ◽  
Fission Rate ◽  
Transformation Pathway ◽  
Biphenyl Degradation

Abstract We investigated the degradation of biphenyl and identified main degradation products. Biphenyl and 2,3-dihydroxybiphenyl (2,3-DHB) was added to cultivation media to identify whole collection of degradation products of four bacterial strains isolated from long-term PCB contaminated soil (Alcaligenes xylosoxidans and Pseudomonas stutzeri) and long-term PCB contaminated sediment (Ochrobactrum anthropi and Pseudomonas veronii). Cultivation flasks were processed in different time after inoculation to determine biphenyl fission rate. Alcaligenes xylosoxidans was revealed as the most appropriate strain for bioremediation process with the highest biphenyl transformation rate. Biphenyl degradation led to the formation of benzoic acid. However, as the presence of 2-hydroxy-6-oxo-6-phenylhex-2,4-dienoic acid (HOPDA) was not confirmed, the transformation pathway common for many other bacteria is probably modified.

scholarly journals Long-term leaching behaviours of cement composites prepared by hazardous wastes

RSC Advances ◽  
2018 ◽  
Vol 8 (49) ◽  
pp. 27602-27609
Author(s):  
Zhenzhou Yang ◽  
Ji Ru ◽  
Lili Liu ◽  
Xidong Wang ◽  
Zuotai Zhang
Keyword(s):  
Environmental Impact ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Saline Water ◽  
Hazardous Wastes ◽  
Cement Composites ◽  
Leaching Tests ◽  
Water Conditions

In order to evaluate the long-term environmental impact of Eco-Ordinary Portland Cement (EOPC) prepared by hazardous wastes, long-term leaching tests were conducted on the EOPC composites under deionized and saline water conditions.

Leaching Studies of Non-Metallic Materials for Nuclear Fuel Immobilization Containers

1984 ◽  
Vol 44 ◽  
Author(s):  
M. Onofrei ◽  
D. K. Raine ◽  
L. Brown ◽  
F. Stanchell
Keyword(s):  
Nuclear Fuel ◽  
Ceramic Surface ◽  
Weight Losses ◽  
Concentration Of Ions ◽  
Ceramic Components ◽  
Leaching Experiments ◽  
Leaching Behaviour ◽  
Static Conditions ◽  
Nuclear Fuel Waste

AbstractThe leaching behaviour of various ceramics was studied as part of a program to evaluate their potential use as container material for very long term containment of nuclear fuel waste under conditions of deep geologic disposal.Samples of four grades of Al2O3, stabilized ZrO2, TiO2, a cermet (70% A12O3- 30% TiC) and porcelain have been leached in deionized distilled water, Standard Canadian Shield Saline Solution (SCSSS), and SCSSS plus 20% Na-bentonite under static conditions at 100°C for periods up to 120 d.The results of these ongoing leaching experiments suggest that the controlling features of the ceramic leaching process were leachant composition, and the presence and concentration of ions in the solution capable of preferentially precipitating on the ceramic surface, i.e., silicon, Mg2+, Ca2+, etc. Weight losses were determined after leaching. The initial leach rates showed a dependence upon ceramic purity and the processing used to prepare the ceramics, as well as the leachant composition. Also, it was apparent that the decrease of leach rates with time occurred as a result of the ceramic components in the leachant approaching their saturation limits.

Mechanism of Immobilization of Toxic Elements in Special Binders

2015 ◽  
Vol 1124 ◽  
pp. 3-9 ◽  
Author(s):  
Theodor Staněk ◽  
Petr Sulovský
Keyword(s):  
Electron Microscopy ◽  
Research Methods ◽  
Toxic Elements ◽  
Basic Component ◽  
Cement Stone ◽  
Leaching Tests ◽  
Optical And Electron Microscopy

The paper deals with development of cementitious binders that would be able to efficiently immobilize toxic elements contained in various types of wastes. The basic component of the proposed binders are clinkers with phosphorus incorporated into the structure of clinker silicates, mixtures of cement with ash containing hydroxylapatite and belite-rich clinkers activated with sulfate anions. The prepared binders were mixed with water doped with various toxic elements; after a defined period of cement stone hydration the test beams were subjected to long-term testing of leachability of individual toxic elements. The research methods involved besides leaching tests also optical and electron microscopy.

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