scholarly journals Sulfation–Roasting–Leaching–Precipitation Processes for Selective Recovery of Erbium from Bottom Ash

2019 ◽  
Vol 11 (12) ◽  
pp. 3461 ◽  
Author(s):  
Josiane Ponou ◽  
Marisol Garrouste ◽  
Gjergj Dodbiba ◽  
Toyohisa Fujita ◽  
Ji-Whan Ahn
Keyword(s):  
Room Temperature ◽  
Treatment Process ◽  
Bottom Ash ◽  
Ammonium Oxalate ◽  
Optimal Conditions ◽  
Selective Recovery ◽  
Sulfation Roasting ◽  
Roasting Temperature ◽  
Pre Treatment ◽  
H 30

Bottom ash (BA) is mainly composed of compounds of Al, Fe, Ca, and traces of rare earth elements (REEs). In this study, the selective recovery of erbium (Er) as REEs by means of sulfation–roasting–leaching–precipitation (SRLP) using BA was investigated. A pre-treatment process of sulfation and roasting of BA was developed to selectively recover REEs using ammonium oxalate leaching (AOL) followed by precipitation. Most of the oxides were converted to their respective sulfates during sulfation. By roasting, unstable sulfates (mostly iron) decomposed into oxides, while the REE sulfates remained stable. Roasting above 600 °C induces the formation of oxy-sulfates that are almost insoluble during AOL. Dissolved REEs precipitate after 7 days at room temperature. The effects of particle size, roasting temperature, leaching time, and AOL concentration were the important parameters studied. The optimal conditions of +100–500 μm particles roasted at 500 °C were found to leach 36.15% of total REEs in 2 h 30 min and 94.24% of the leached REEs were recovered by precipitation. A total of 97.21% of Fe and 94.13% of Al could be separated from Er.

Pozzolanic Reactivity of Coal Bottom Ash after Chemically Pre-Treated with Sulfuric Acid

2019 ◽  
Vol 947 ◽  
pp. 212-216
Author(s):  
Andri Kusbiantoro ◽  
Amalina Hanani ◽  
Rahimah Embong
Keyword(s):  
Construction Industry ◽  
Treatment Process ◽  
Current Trend ◽  
Bottom Ash ◽  
Supplementary Cementitious Materials ◽  
Strength Development ◽  
Coal Bottom Ash ◽  
Cement Replacement ◽  
Pozzolanic Reactivity ◽  
Pre Treatment

Current trend in construction industry has highlighted the use of silica-rich supplementary cementitious materials from industrial wastes in the production of concrete. Numerous studies have validated the pozzolanic properties of these materials, yet coal bottom ash received only infamous reputation as a pozzolanic material, owing to its low reactivity and heavy metals contaminants. Therefore this study was purposed to enhance the pozzolanic reactivity of coal bottom ash through chemical pre-treatment process. Different concentrations of acids and treatment period were studied to obtain optimum parameters for pre-treatment process. Treated ash was characterized for its chemical oxide composition. Its effect on the hydration of cement was studied through the inclusion as cement replacement material in mortar mixtures. From the chemical oxide compositions, a combination of 0.5 M of H2SO4 and 1 hour soaking duration presented the highest SiO2 proportion in the ash. Its inclusion at 5% (by weight of cement) to replace cement proportion in mortar mixtures was able to enhance the compressive strength of mortar at later age, regardless of its slower strength development in the early age. Utilizing treated coal bottom ash as partial cement replacement material has unlocked new achievement for greener future in construction industry.

scholarly journals Nanostructured Black Nickel Coating as Replacement for Black Cr(VI) Finish

2021 ◽  
Vol 11 (9) ◽  
pp. 3924
Author(s):  
Marina M. Mennucci ◽  
Rodrigo Montes ◽  
Alexandre C. Bastos ◽  
Alcino Monteiro ◽  
Pedro Oliveira ◽  
...  
Keyword(s):  
Room Temperature ◽  
Electrochemical Impedance ◽  
Nickel Coating ◽  
Incident Light ◽  
Optimal Conditions ◽  
Nanostructured Surface ◽  
Pre Treatment ◽  
Good Coating ◽  
A Current ◽  
Black Color

This work compares different electrodeposition procedures to produce nickel black coatings as greener and less toxic alternatives to Cr(VI)-based coatings used in different applications. Nickel and nickel-plated brass served as substrates in studies with a Hull cell and polarization curves. After a set of comparative experiments, the best electrodeposition procedure was further studied and optimized. Optimal conditions were found with a bath consisting of 75 g/L NiCl2·6H2O + 30 g/L NaCl and a current density of 0.143 A dm−2 applied for 5 min at room temperature. Furthermore, a pre-treatment with 18.5 vol.% of hydrochloric acid in water was found to be necessary to warrant good coating adhesion to the substrate. The black color is attributed to the development of a nanostructured surface that absorbs the incident light. Corrosion testing was performed in 0.5 M NaCl aqueous solution using electrochemical impedance spectroscopy (EIS) and polarization tests.

Reuse of Wastewaters in Agriculture by Means of Sprinkler Irrigation on a Farmland Area of 3000 ha – Large Scale Experience in Germany

1986 ◽  
Vol 18 (9) ◽  
pp. 163-173
Author(s):  
R. Boll ◽  
R. Kayser
Keyword(s):  
Large Scale ◽  
Treatment Process ◽  
Treatment Plant ◽  
Sprinkler Irrigation ◽  
Paper Briefly ◽  
Treatment Results ◽  
Sewage Farm ◽  
Western Germany ◽  
Pre Treatment ◽  
Main Components

The Braunschweig wastewater land treatment system as the largest in Western Germany serves a population of about 270.000 and has an annual flow of around 22 Mio m3. The whole treatment process consists of three main components : a pre-treatment plant as an activated sludge process, a sprinkler irrigation area of 3.000 ha of farmland and an old sewage farm of 200 ha with surface flooding. This paper briefly summarizes the experiences with management and operation of the system, the treatment results with reference to environmental impact, development of agriculture and some financial aspects.

Vivianite Occurrence and Remediation Techniques in Biosolids Pre-treatment Process

2018 ◽  
Vol 2018 (4) ◽  
pp. 103-117
Author(s):  
Bipin Pathak ◽  
Ahmed Al-Omari ◽  
Scott Smith ◽  
Nicholas Passarelli ◽  
Ryu Suzuki ◽  
...  
Keyword(s):  
Treatment Process ◽  
Pre Treatment

scholarly journals Bioethanolic yeasts from dung beetles: tapping the potential of extremophilic yeasts for improvement of lignocellulolytic feedstock fermentation

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Anita Ejiro Nwaefuna ◽  
Karl Rumbold ◽  
Teun Boekhout ◽  
Nerve Zhou
Keyword(s):  
Treatment Process ◽  
Dung Beetles ◽  
Production Costs ◽  
Industrial Wastes ◽  
Major Drawback ◽  
Renewable Fuel ◽  
Extreme Stress ◽  
Pre Treatment ◽  
The Cost ◽  
Simultaneous Saccharification

AbstractBioethanol from abundant and inexpensive agricultural and industrial wastes possesses the potential to reduce greenhouse gas emissions. Bioethanol as renewable fuel addresses elevated production costs, as well as food security concerns. Although technical advancements in simultaneous saccharification and fermentation have reduced the cost of production, one major drawback of this technology is that the pre-treatment process creates environmental stressors inhibitory to fermentative yeasts subsequently reducing bioethanol productivity. Robust fermentative yeasts with extreme stress tolerance remain limited. This review presents the potential of dung beetles from pristine and unexplored environments as an attractive source of extremophilic bioethanolic yeasts. Dung beetles survive on a recalcitrant lignocellulose-rich diet suggesting the presence of symbiotic yeasts with a cellulolytic potential. Dung beetles inhabiting extreme stress environments have the potential to harbour yeasts with the ability to withstand inhibitory environmental stresses typically associated with bioethanol production. The review further discusses established methods used to isolate bioethanolic yeasts, from dung beetles.

Bioethanol Production of Cellulase Producing Bacteria from Soils of Agrowaste Field

2021 ◽  
Vol 13 (2) ◽  
pp. 643-655
Author(s):  
A. Thomas ◽  
M. Laxmi ◽  
A. Benny
Keyword(s):  
Treatment Process ◽  
Agricultural Waste ◽  
Cellulase Production ◽  
Cellulolytic Enzymes ◽  
Bioethanol Production ◽  
Ethanolic Fermentation ◽  
Cellulose Bioconversion ◽  
Congo Red Staining ◽  
Pre Treatment ◽  
And Staphylococcus Aureus

With decades of studies on cellulose bioconversion, cellulases have been playing an important role in producing fermentable sugars from lignocellulosic biomass. Copious microorganisms that are able to degrade cellulose have been isolated and identified. The present study has been undertaken to isolate and screen the cellulase producing bacteria from soils of agrowaste field. Cellulase production has been qualitatively analyzed in carboxy methylcellulose (CMC) agar medium after congo red staining and NaCl treatment by interpretation with zones around the potent colonies. Out of the seven isolates, only two showed cellulase production. The morphogical and molecular characterization revealed its identity as Escherichia coli and Staphylococcus aureus. The potential of organisms for bioethanol production has been investigated using two substrates, namely, paper and leaves by subjecting with a pre-treatment process using acid hydrolysis to remove lignin which acts as physical barrier to cellulolytic enzymes. Ethanolic fermentation was done using Saccharomyces cerevisiae for 24-48 h and then the bioethanol produced was qualitatively proved by iodoform assay. These finding proves that ethanol can be made from the agricultural waste and the process is recommended as a means of generating wealth from waste.

Effect of advanced oxidation processes on the toxicity of municipal landfill leachates

2004 ◽  
Vol 49 (4) ◽  
pp. 273-277 ◽  
Author(s):  
B. Slomczynska ◽  
J. Wasowski ◽  
T. Slomczynski
Keyword(s):  
Organic Compounds ◽  
Advanced Oxidation Processes ◽  
Vibrio Fischeri ◽  
Advanced Oxidation ◽  
Optimal Conditions ◽  
Toxicity Evaluation ◽  
Landfill Leachates ◽  
Oxidation Processes ◽  
Municipal Landfill ◽  
Pre Treatment

The aim of the present study was to assess the effect of advanced oxidation processes (AOPs) (oxidation ozone and peroxide/ozone) on the toxicity of leachates from municipal landfill for Warsaw, Poland, using a battery of tests. AOPs used to pre-treat leachates were carried out in laboratory conditions after their coagulation with the use of FeCl3. The effects of the pre-treatment of leachates using the method of coagulation with FeCl3 depended on the concentration of organic compounds and with optimal conditions of the process ranged from 40 to 70%. Further pre-treatment of the leachates after coagulation, involving the use of oxidation with O3 and H2O2/O3, did not cause significant decrease of leachate toxicity. The data of this study demonstrated the usefulness of the battery of tests using Daphnia magna, Artemia franciscana, Scenedesmus quadricauda and Vibrio fischeri for the toxicity evaluation of raw and pre-treated leachates.

Utilization of open pit burned household waste ash – a feasibility study in Dhaka

2014 ◽  
Vol 32 (5) ◽  
pp. 397-405
Author(s):  
Md. Obaidul Haque ◽  
Ahmed Sharif
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Bottom Ash ◽  
Open Pit ◽  
Household Waste ◽  
Chemical Compositions ◽  
Muffle Furnace ◽  
Clay Bricks ◽  
Peripheral Area

Informal incineration or open pit burning of waste materials is a common practice in the peripheral area of Dhaka, one of the fastest growing mega-cities in the world. This study deals with the effect of open pit burned (i.e. open burned) household waste bottom ash on fired clay bricks. Between 0 to 50% (by weight) of open pit burned household waste bottom ash was mixed with clay to make bricks. The molded specimens were air-dried at room temperature for 24 h and then oven dried at 100 °C for another 24 h to remove the water. The raw bricks were fired in a muffle furnace to a designated temperature (800, 900 and 1000 °C, respectively). The firing behaviour (mechanical strength, water absorption and shrinkage) was determined. The microstructures, phase compositions and leachates were evaluated for bricks manufactured at different firing temperatures. These results demonstrate that open pit burned ash can be recycled in clay bricks. This study also presents physical observations of the incinerated ash particles and determination of the chemical compositions of the raw materials by wet analysis. Open pit burned ash can be introduced easily into bricks up to 20% wt. The concentrations of hazardous components in the leachates were below the standard threshold for inert waste category landfill and their environmental risk during their use-life step can be considered negligible.

2. Adhesion of the plasma-polymerized fluorocarbon films to silicon substrates The adhesion properties of the plasma-polymerized FC coatings were determined by using a test, already employed by Yasuda and Sharma [13] (see Fig. 1 and Table 1) in which the silicon substrates coated with plasma FC-films were boiled in a0.9% sodium chloride solution. The FC thin films produced in the processes 1 and 2 were lifted after a very short time (15 minutes). Coatings generated in process 3 were lifted after the second cycle of boiling. The films produced in processes 4 and 5 withstood the complete test procedure. The results are shown in Fig. 3. The poor adhesion of the polymerized films in the first two processes is due to the fact that these processes do not involve a plasma pre-treatment process. The difference between processes 1 and 3 is only in the plasma pre-treatment (process 1 does not contain the pre-treatment step of the silicon surface). The fluorocarbon films deposited by processes 4 and 5 have shown the best adhesion. These test results indicate that the plasma pre-treatment is very important and necessary for a good adhesion of the FC coatings to the silicon surfaces. 2.3. Patterning of FC films 2.3.1. Patterning through resist mask. The patterning of the FC films through a photoresist mask (conventional All resist AR-P351) was examined after deposition for process No. 5. Different coating parameters were investigated to improve the adhesion of the resist to the FC surface. The best adhesion results were obtained using the process parameters, shown in Table 3. Differences in the thickness uniformity of so-deposited resists were in a range below 5%. The samples were etched in a pure oxygen plasma in an RIE-system after the lithography steps (pre-bake, exposure, development, post-bake). A resolution of 2 /xm was obtained. A significant increase in the surface energy was not observed after resist stripping. The sessile contact angle of water was 103°. 2.3.2. Lift-off process for patterning thin plasma polymerized FC films. A lift-off process was also examined to pattern the thin FC films. The lithography steps were used before the plasma polymerization process was carried out (Fig. 2). A standard resist AR-P351 was coated directly onto the Si substrates. After all lithography

2014 ◽  
pp. 275-278
Keyword(s):  
Treatment Process ◽  
Test Procedure ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
Fluorocarbon Films ◽  
Si Substrates ◽  
Complete Test ◽  
The Difference ◽  
Pre Treatment ◽  
Lift Off
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