scholarly journals Influence of Leachate Matrix on Oxidation Performance of Ozonation and AOPs

2021 ◽  
Vol 12 (6) ◽  
pp. 7903-7913

Landfill leachate is a critical environmental issue that should be adequately treated to prevent it from spreading to the environment. This study explored the influence of raw leachate matrix and treated leachate matrix on O3, O3/H2O2, and O3/PS performance. O3 and AOPs were conducted in a laboratory-scale batch reactor. The findings showed the degradation of p-cresol, COD, and humic substances was much slower in treated leachate matrix than in raw leachate matrix. However, color was found easier to remove in treated leachate. The results revealed a synergic effect between molecular O3 and dissolved organic matter in the raw leachate as the O3 performance was enhanced in the presence of raw leachate matrix, except for color removal. The highest degradation of more than 90% was achieved in O3/H2O2 to remove COD, p-cresol, and humic substances, although it is the most affected by the leachate matrix. This study provides vital insight into the notable performance of O3/PS in color removal regardless of the influence of leachate matrix, suggesting that the sulfate radical-induced oxidation outperformed O3 and O3/H2O2 in reducing nitrogen-containing compounds.

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1067
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Romualda Bejger ◽  
Guillaume Debaene ◽  
Bożena Smreczak

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.


2018 ◽  
Vol 205 ◽  
pp. 244-252 ◽  
Author(s):  
Zi Jun Yong ◽  
Mohammed J.K. Bashir ◽  
Choon Aun Ng ◽  
Sumathi Sethupathi ◽  
Jun-Wei Lim

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Devendra P. Tekale ◽  
Ganapati D. Yadav ◽  
Ajay K. Dalai

Value addition to glycerol, the sole co-product in biodiesel production, will lead to reform of the overall biodiesel economy. Different valuable chemicals can be produced from glycerol using heterogeneous catalysis and these valuable chemicals are useful in industries such as cosmetics, pharmaceuticals, fuels, soap, paints, and fine chemicals. Therefore, the conversion of glycerol to valuable chemicals using heterogeneous catalysis is a noteworthy area of research. Etherification of glycerol with alkenes or alcohols is an important reaction in converting glycerol to various value-added chemicals. This article describes reaction of glycerol with benzyl alcohol in solvent-free medium by using a clay supported modified heteropolyacid (HPA), Cs2.5H0.5PW12O40/K-10 (Cs-DTP/K-10) as solid catalyst and its comparison with other catalysts in a batch reactor. Mono-Benzyl glycerol ether (MBGE) was the major product formed in the reaction along with formation of di-benzyl glycerol ether (DBGE). The effects of different parameters were studied to optimize the reaction parameters. This work provides an insight into characterization of Cs2.5H0.5PW12O40/K-10 catalyst by advanced techniques such as surface area measurement, X-ray analysis, ICP-MS, FT-IR, and SEM. Reaction products were characterized and confirmed by using the GCMS method. The kinetic model was developed from an insight into the reaction mechanism. The apparent energy of activation was found to be 18.84 kcal/mol.


Cellulose ◽  
2021 ◽  
Author(s):  
Iris Amanda A. Silva ◽  
Osmir Fabiano L. de Macedo ◽  
Graziele C. Cunha ◽  
Rhayza Victoria Matos Oliveira ◽  
Luciane P. C. Romão

AbstractUrea-based multi-coated slow release fertilizer was produced using water hyacinth, humic substances, and chitosan, with water rich in natural organic matter as a solvent. Elemental analysis showed that the nitrogen content of the fertilizer (FERT) was around 20%. Swelling tests demonstrated the effectiveness of the water hyacinth crosslinker, which reduced the water permeability of the material. Leaching tests showed that FERT released a very low concentration of ammonium (0.82 mg L−1), compared to the amount released from urea (43.1 mg L−1). No nitrate leaching was observed for FERT, while urea leached 13.1 mg L−1 of nitrate. In water and soil, FERT showed maximum releases after 30 and 40 days, respectively, while urea reached maxima in just 2 and 5 days, respectively. The results demonstrated the promising ability of FERT to reduce nitrogen losses, as well as to minimize environmental impacts in the soil–plant-atmosphere system and to improve the efficiency of nitrogen fertilization. Graphic abstract


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