Potential Use of Sewage Sludge Ash in Lime-Based Materials
Mamoudou Sall,
Alassane Traoré,
Abdou Ciss Wade,
Prince Momar Gueye,
Saliou Diouf,
Gora Dieye,
Djibril Diop
Issue:
Volume 10, Issue 2, June 2021
Pages:
12-22
Received:
19 May 2021
Accepted:
3 June 2021
Published:
15 June 2021
Abstract: Recycling of wastes and their by-products is attracting increasing interest worldwide because of the high environmental impact in the cement, concrete and other industries. This work deals with the study of the physico-chemical characteristics of binders based on sewage sludge ashes and lime. In a first step, we used X-ray fluorescence to determine the chemical composition of ash, lime and binders. This allowed us to see that the chemical composition of sewage sludge ash is similar to that of cement. We then used X-ray diffraction to identify the main mineralogical phases in the samples. Compressive strengths of mortars containing 20%, 40%, 60% and 80% of SSA showed that SSA has a long-term positive effect which might be related to a slight pozzolanic activity. The L4 binder consisting of 80% fine ash and 20% lime has a higher compressive strength than the others. The binder setting start time is greater than that of cement but shorter than that of lime. The study of the thermophysical properties of the L4 binder shows that it has a higher thermal resistance than cement and clay mortars. Moreover, it heats up less quickly because of its low effusivity compared to the latter two. This analysis highlighted the principal characteristics that must be taken into account to use SSA correctly in lime-based materials.
Abstract: Recycling of wastes and their by-products is attracting increasing interest worldwide because of the high environmental impact in the cement, concrete and other industries. This work deals with the study of the physico-chemical characteristics of binders based on sewage sludge ashes and lime. In a first step, we used X-ray fluorescence to determine...
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Morphological and Structural Elucidation of Room Temperature Catalytic Degradation of Amoxicillin Antibiotic Using Zinc Porphyrin Metal Organic Framework
Shatakshi Saxena,
Punya Saluja,
JBM Krishna,
Tinku Basu
Issue:
Volume 10, Issue 2, June 2021
Pages:
23-30
Received:
7 December 2020
Accepted:
15 December 2020
Published:
13 July 2021
Abstract: Environment is witnessing an extensive increase in persistent and bioactive micro pollutants from the last few decades. Since most clinical modalities are flooded with antibiotics, environmental samples such as sewage treatment effluents, surface water and secondary water drainage etc. reveal the presence of bio-recalcitrant antibiotics worldwide, ergo there is a spurring rise in antibiotic resistant microorganisms. In order to circumvent the escalating concentration of amoxicillin (microgram/liter) we contrived a potential metal organic framework (MOF) and lab tested it for catalytic functionality. A zinc-porphyrin MOF using Tetra (4-carboxyphenyl) porphyrin H2TCPP (>97%) as a ligand and Zinc acetate as a metal salt was solvo-thermally synthesized. The morphological and structural characterization were performed using FESEM, XRD, EDAX, FTIR and UV-Visible spectroscopy. The fabricated MOF catalyst exhibits sterling ability of amoxicillin degradation in a dark environment at room temperature, accounting a degradation efficiency of about 97.3% in a 0.1 mg/ml concentration. 90 minutes of catalyst exposure to the antibiotic shows maximum degradation after which there is no further change in amoxicillin concentration. First time we have exploited electrochemical cyclic voltametric (CV) measurement to monitor the degradation process which was validated by FTIR recording, and noticed that the degradation process followed a first order kinetics. We have also discussed the morphological stability of the fabricated Zn porphyrin MOF after antibiotic exposure and reported a comparative outline between catalytic efficiency of different MOF species. High porosity and effective charge transfer between carboxyphenyl) porphyrin ligand to vacant d orbital of Zn+2 are pivotal factors for effective sorption and degradation of amoxicillin antibiotics dark at room temperature. We would expect the developed Zn porphyrin MOF is very promising for successful commercial application due to its energy efficiency (dark) and simple process for effective degradation of antibiotics.
Abstract: Environment is witnessing an extensive increase in persistent and bioactive micro pollutants from the last few decades. Since most clinical modalities are flooded with antibiotics, environmental samples such as sewage treatment effluents, surface water and secondary water drainage etc. reveal the presence of bio-recalcitrant antibiotics worldwide, ...
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