scholarly journals New Materials Synthesized by Sulfuric Acid Attack Over Power Plant Fly Ash

2020 ◽  
Vol 71 (7) ◽  
pp. 48-58 ◽  
Author(s):  
Loredana Forminte (Litu) ◽  
Gabriela Ciobanu ◽  
Gabriela Buema ◽  
Nicoleta Lupu ◽  
Horia Chiriac ◽  
...  

In the current work, the preparation of a complex wastewater coagulant based on polymeric sulfates of aluminum/iron from fly ash is presented. The performance of the coagulation�flocculation process is mostly influenced by the coagulant type, which enhances the aggregation of particles and leads to formation of fast-settling flocs by charge neutralization or chain-bridging mechanisms. Within the preparation process, the reaction temperature was controlled at 80�C and 90�C for 4 h, the synthesized materials being characterized through different techniques (SEM, EDAX, FTIR, and XRD) and further used as coagulants for real wastewater treatment. As a novelty of this study, it can be mentioned that there were analyzed the possibilities of capitalization of Romanian fly ash collected from Iasi area and its transformation into complex based on aluminum - iron sulfates. Fly ash containing different concentrations of Fe2O3 and Al2O3 was successfully used in producing complex coagulants by reacting with 10% technical sulfuric acid solution. The produced complex coagulants contain both polymeric ferric sulfate (PFS) and polymeric aluminum sulfate (PAS) (demonstrated by complex characterization) and proved to be effective in wastewater treatment. These sustainable materials exhibited a good performance in coagulation�flocculation process (e.g. it was obtained a TSS removal efficiency of 84% at the coagulant dosage of 60 mg/L).

2018 ◽  
Vol 111 ◽  
pp. 23-40 ◽  
Author(s):  
Timothy A. Aiken ◽  
Jacek Kwasny ◽  
Wei Sha ◽  
Marios N. Soutsos

2020 ◽  
Vol 331 ◽  
pp. 05002
Author(s):  
Andi Arham Adam ◽  
Suci Amalia Namira ◽  
Atur PN Siregar ◽  
Mustofa

One of the significant characteristic material needed to consider is durability. Sulphate ion contained in soil is one of aggressive agents that could cause degradation of concrete members which led to loss of compressive strength. The current research is to elaborate the effect of activator to binder ratio on the compressive strength of the fly ash based geopolymer mortar in the sulphate environment. Two different types of geopolymer mortar were casted i. e. mortar made of 100% fly ash and mortar contained 95% fly ash + 5% slaked lime. The fly ash used in this research is classified as F fly ash from the Mpanau power plant the variation of activator to binder ratio of 0. 40; 0. 50; and 0. 60, and water/solid ratio variations of 0. 32, 0. 34 and 0. 36. The composition of sulfuric acid was by 5% of the sample volume. Geopolymers mortar compressive strength test is conducted on the immersed samples in a solution of 5% sulfuric acid with age of 0, 7, 14, 28, 56, and 84 days, respectively. The compressive strength test results showed that the highest compressive strength of geopolymers mortar (resistant to sulfuric acid attack) was geopolymers mortar made from fly ash with activator to binder ratio 0. 60, water / solid ratio 0. 32, and percentage of lime to binder 5% at the age of 84 days.


2011 ◽  
Vol 183-185 ◽  
pp. 1596-1599
Author(s):  
Juan Tan ◽  
Yan Zhen Yu ◽  
Yong Sun

Ploy-high-ferric-silicic coagulant was prepared using the fly ash extract and potassium ferrate. The flocculation process of treatment lead wastewater by this coagulant with various Si/FeO42- ratios and salt-basicity at different pH and dosage were studied by jar test. The results showed that color, turbidity and Pb2+ removal efficiency are excellent and treatment effects are stable in treatment lead wastewater, especially the removal of Pb2+ has been up to 96% more. The comparison on coagulation between poly-high-ferric-silicic and other coagulants, the poly-high-ferric-silicic dosage is low and adapt to a wide PH. Therefore, by comparison, the poly-high-ferric-silicic is a superior coagulant in lead wastewater treatment.


2016 ◽  
Vol 15 (3) ◽  
pp. 521-526
Author(s):  
Narcis Barsan ◽  
Mariana Turcu ◽  
Emilian Mo.negu.u ◽  
Mihaela Dascalu ◽  
Dana Chitimus ◽  
...  

2021 ◽  
Vol 11 (5) ◽  
pp. 2344
Author(s):  
Srikanth Vuppala ◽  
Riyaaz Uddien Shaik ◽  
Marco Stoller

Olive oil production is one of the important industrial sectors within the agro-food framework of the Mediterranean region, economically important to the people working in this sector, although there is also a threat to the environment due to residues. The main wastes of the olive oil extraction process are olive mill wastewater (OMW) and olive husks which also require proper treatment before dismissal. In this research work, the main goal is to introduce grey relational analysis, a technique for multi-response optimization, to the coagulation and flocculation process of OMW to select the optimum coagulant dosage. The coagulation and flocculation process was carried out by adding aluminum sulfate (Alum) to the waste stream in different dosages, starting from 100 to 2000 mg/L. In previous research work, optimization of this process on OMW was briefly discussed, but there is no literature available that reports the optimal coagulant dosage verified through the grey relational analysis method; therefore, this method was applied for selecting the best operating conditions for lowering a combination of multi-responses such as chemical oxygen demand (COD), total organic carbon (TOC), total phenols and turbidity. From the analysis, the 600 mg/L coagulant dosage appears to be top ranked, which obtained a higher grey relational grade. The implementation of statistical techniques in OMW treatment can enhance the efficiency of this process, which in turn supports the preparation of waste streams for further purification processes in a sustainable way.


2016 ◽  
Vol 866 ◽  
pp. 99-105 ◽  
Author(s):  
Smita Singh ◽  
M.U. Aswath ◽  
R.V. Ranganath

The present investigation is on the effect of red mud on the mechanical properties and durability of the geopolymer paste in sulphuric and acetic acid solution. Red mud and fly ash were used to form the geopolymer paste along with the alkalies. The variation of red mud in the paste composition was from 0% to 90%. Cylindrical shaped specimens of 1 inch diameter and 1 inch height were prepared. The specimens were immersed in 5% sulphuric acid and 5% acetic acid for 1, 7, 14, 28, 56 and 84 days and tested for weight loss, visual deformation, strength loss and colour of the solvent, based on the procedure specified by ASTM C 267 – 01. SEM/EDX Tests were performed on the geopolymer specimens. Test results show that initially, the strength of the geopolymer increased upon the addition of red mud. The strength was maximum when the percentage of red mud was 30%. The maximum strength obtained was 38 MPa for the paste containing 30% red mud using 10M alkali solution as against 31.69 MPa, when only fly ash was used. Geopolymer paste containing 30% and 50% red mud showed better resistance to acid attack. The strength loss was minimum for the samples containing 30% red mud in both inorganic and organic acid i.e. sulphuric and acetic acid.


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