Recovery of humic acids from anaerobic sewage sludge: Extraction, characterization and encapsulation in alginate beads

Cristina, Giulio; Camelin, Enrico; Ottone, Carminna; Garofalo, Silvia Fraterrigo; Jorquera, Lorena; Castro, Mónica; Fino, Debora; Schiappacasse, M. C.; Tommasi, Tonia

doi:10.1016/j.ijbiomac.2020.07.097

Cited by 34 publications

(19 citation statements)

References 51 publications

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“…The IR spectra of the prepared humates showed the presence of OH groups polymer linked by intermolecular hydrogen bonds (3400 cm −1 ), the presence of СН, СН 2 , and СН 3 groups (stretching vibrations in aliphatic chains at 2870 cm −1 ), the presence of carboxyl groups (1720 cm −1 ) and quinones (1640–1680 cm −1 ), the stretching mode of conjugated double bonds (1650–1620 cm −1 ), the bending mode of СН groups (1420 cm −1 ), and the asymmetric stretching mode inСОС groups (1250 cm −1 ) and the symmetric stretching mode in these groups (1030 cm −1 ). The data obtained indicate the proximity of the selected substances to humates, which is proved by the data presented in the literature 31–40 …”

Section: Resultssupporting

confidence: 60%

“…FA differs from HA in the presence of highly reactive COH groups. Note that, in addition to the peak at 1329 cm −1 , the spectrum contains a well‐read peak at 615 cm −1 , corresponding to the in‐plane stretching mode of the OH group; the aforementioned groups were found by a number of researchers 33,39,40 who characterized these peaks as a part of the HA IR‐spectra structure. As can be seen from Fig.…”

Section: Resultsmentioning

confidence: 99%

“…A compact group of narrow peaks below 3000 cm −1 is formed by antisymmetric and symmetric stretching modes of the CH 2 and CH 3 groups, which are usually present in the side chains of HA. The characteristic spectra of the special functional groups for the liquid extract of chicken droppings were studied and deciphered by a number of workers, [31][32][33][34][35] who showed that the aforementioned absorption peaks are hydroxyl groups, C H, CH 2 , and CH 3 groups, which are usually present in the side chains of HA.…”

Section: Resultsmentioning

confidence: 99%

“…The data obtained indicate the proximity of the selected substances to humates, which is proved by the data presented in the literature. [31][32][33][34][35][36][37][38][39][40] First, the solid phase (filter residue) of the chicken manure obtained after subcritical water extraction is not proposed for future application as a fertilizer. Furthermore, this solid phase was devoid of the most valuable extractable raw material HA, as well as FA.…”

Section: Resultsmentioning

confidence: 99%

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Subcritical water extraction of organic acids from chicken manure

et al. 2020

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BACKGROUND Chicken manure waste has a wide range of organic substances and mineral elements. This enriched source has stimulated great scientific interest in finding cleaner and more environmentally benign nutrient recovery options. This study aimed to determine an effective and eco‐friendly method (i.e. subcritical water extraction) for processing fresh poultry manure. RESULTS The high content of total organic carbon, including humic acids carbon and fulvic acids carbon, in extract was found to release under subcritical conditions. The organic compounds obtained by extraction with subcritical water correspond to humic acid in composition because of the presence in the sample of all the functional groups: polymer bonded by molecular hydrogen bond (3400 cm−1), the presence of CH2 and CH3 groups (2870 cm−1), the presence of carboxyl groups (1720 cm−1) and quinones (1640–1680 cm−1). The solid phase left over was characterized by a high content of organic carbon, phosphorus, potassium, and microelements. The maximum extraction of humic acid and fulvic acid carbon was found between 210 and 250 °C at a pressure of 50–60 atm, and the content was a maximum of 3647.2 × 10−6 g kg−1 at an extraction temperature of 250 °C. CONCLUSION Given the high content of humic acid found in the extracted medium, the proposed subcritical extraction opens up new opportunities for nutrients recovery in the poultry industry. © 2020 Society of Chemical Industry

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Section: Resultssupporting

confidence: 60%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Subcritical water extraction of organic acids from chicken manure

et al. 2020

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“…The SSADs used in this experiment came from a largescale wastewater treatment plant (3,800,000 population equivalents) located in north-west Italy. Two types of digestates were used: a centrifuged solid digestate (C) derived from a mix between primary and secondary digestate and a dried pulverulent digestate (D), obtained by the thermal treatment at 200 °C of C. Physical and chemical analysis were performed on the digestates according to Cristina et al [29], and results are summarized in Table 1.…”

Section: Sewage Sludge and Soil Analysismentioning

confidence: 99%

Time-based evaluation of bioavailable phosphorus in a calcareous soil after the application of anaerobically digested sewage sludge

Cristina

Camelin

Garofalo

et al. 2022

Biomass Conv. Bioref.

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Nowadays, phosphorus natural reserves are being depleted, while P fertilizers demand is increasing. Phosphorus is well contained in waste materials such as sewage sludge. Only a small amount (1–3%) of the soil total phosphorus is bioavailable for plant nutrition. More in detail, the present study focuses on the determination of the kinetics of bioavailable phosphorus concentrations in a sandy calcareous soil after the application of sewage sludge. A centrifuged (C) and dried (D) anaerobic digestate from sewage sludges obtained from the same wastewater treatment plan were separately tested to fertilize a calcareous sandy soil. Falcon tubes (50 mL) containing negative control (T) and soil treated with C and D were incubated from 1 to 90 days. Soil phosphorus fractionation was performed with the SMT method and bioavailable-P was extracted through the Olsen method. Phosphorus was spectrophotometrically quantified by the molybdovanadate method. Lastly, kinetics of bioavailable-P on soils were evaluated using four kinetic models. Phosphorus fractions were constant throughout the experiment. Conversely, the bioavailable-P significantly decreased from day 1 to day 90 in C treatment (from 34.9 ± 2.9 to 23.8 ± 1.5 ppm) and T treatment (from 4.2 ± 1.2 to 0.3 ± 0.6 ppm). This decrease might be due to the precipitation of P with calcium; in fact, high concentration of Ca2+ ions and the alkaline soil pH can induce the sequential formation of calcium phosphates, even less soluble over time. Whereas D treatment showed a peak of bioavailable-P concentration on day 14 (26.6 ± 3.0). This trend could be due to organic carbon compounds, competitive sorption and metal bridging. The fitting of experimental data revealed that the Elovich model best described the adsorptive-precipitate process of bioavailable-P in T (r2 = 0.90) and C (r2 = 0.93). Conversely, none of the models satisfactorily described the behavior of bioavailable-P in D samples. This study increases the knowledge on P-related phenomena for designing and optimizing fertilizers and reducing their drawbacks such as eutrophication.

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Partition of humic acids using alkaline aqueous two‐phase systems constituted of alcohol and hydroxides

Vieira,

Buarque,

Gomes

et al. 2024

J of Chemical Tech & Biotech

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BACKGROUNDHumic acids (HAs) are macromolecules classified within the group of humic substances that are mainly related to the agricultural and environmental sectors, but they have attracted interest from the medicine, pharmaceutical, and cosmetic industries. However, these latter sectors depend on developing extraction and purification technologies for adequate use. Thus, this paper aims to study the partitioning and recovery of HA using alkaline two‐phase aqueous systems (ATPSs) based on alkali metal‐based hydroxides and alcohols. Initially, the influence of alcohols (methanol, ethanol, 1‐propanol, and 2‐propanol) and hydroxides (NaOH, KOH, and LiOH) in the phase diagrams construction was addressed.RESULTSThe phase formation is correlated to an increase in the hydrophobicity of alcohols and hydroxides, which allows for the enlargement of the biphasic region. In the proposed systems, HA is always partitioned to the hydroxide‐rich phase. Increasing the hydrophobicity of the alcohol favors the migration of HA to the opposite phase, while increasing the hydrophilicity of the hydroxides leads to better partition and recovery values. It was observed that increasing TLL favors the recovery of HA. Furthermore, there was a decrease in alcohol concentration in the hydroxide‐rich phase with an increase in the alkyl chain and TLL, improving the recovery. Finally, the best reached‐recovery value was 98.18 ± 0.41% (KHA = 0.038 ± 0.02) for ATPS formed by 1‐propanol + NaOH with TLL ≈ 55 at 298 K.CONCLUSIONSThe alkaline systems can be a novel route for recovering humic substances from the environment.This article is protected by copyright. All rights reserved.

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Recovery of humic acids from anaerobic sewage sludge: Extraction, characterization and encapsulation in alginate beads

Cited by 34 publications

References 51 publications

Subcritical water extraction of organic acids from chicken manure

Subcritical water extraction of organic acids from chicken manure

Time-based evaluation of bioavailable phosphorus in a calcareous soil after the application of anaerobically digested sewage sludge

Partition of humic acids using alkaline aqueous two‐phase systems constituted of alcohol and hydroxides

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