An investigation on effect of ultrasound waves on sludge treatment

Mehrdadi, Naser; Kootenaei, Farshad Golbabaei

doi:10.1016/j.egypro.2018.10.042

Cited by 9 publications

(7 citation statements)

References 12 publications

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“…Variations observed in pH values could be related to the sonolysis of water that dissociates the water molecule, releasing hydrogen atoms during cavitation (Koda et al., 1999). Moreover, Mehrdadi and Kootenaei (2018) have reported that with sonication time, the temperature increases resulting in pHdecrement. Anaya‐Esparza, Velázquez‐Estrada, et al.…”

Section: Resultsmentioning

confidence: 99%

Optimal thermoultrasound processing of jackfruit ( Artocarpus heterophyllus lam.) nectar: Physicochemical characteristics, antioxidant properties, microbial quality, and fatty acid profile comparison with pasteurized nectar

Cruz-Cansino

Ariza‐Ortega

Alanís-García

et al. 2020

J Food Process Preserv

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The objective of this study was to determine the optimal thermoultrasound processing conditions for jackfruit nectar by applying response surface methodology and comparing the physicochemical parameters, antioxidant properties, microbiology, and fatty acid profile with pasteurized jackfruit nectar. Optimal condition was 80% of amplitude at 45 ± 1°C for 20 ± 1 min, allowing physical stability of 68%, 60% of pectin methylesterase activity, ascorbic acid of 420 mg AA/L, total phenolic of 134 mg GAE/L, ABTS, DPPH, and chelating activity of 3,510 µmol TE/L, 75 µmol TE/L, and 96%, respectively. The thermoultrasonicated jackfruit nectar had lower microbial load and higher total soluble solids, ascorbic acid content, total phenolic content, antioxidant activity than pasteurized, and similar unsaturated fatty acids to the untreated sample. Our results demonstrated that thermoultrasound could be an option for processing jackfruit nectar as an alternative to pasteurization that allows successful inactivation of microorganisms, inactivation of enzymes, and good quality parameters. Practical applications Based on consumer demand for more natural or fresh‐like products, alternative technologies have been evaluated by research works looking to reduce the effects of heat treatments in the Food Industry. Among these technologies, thermoultrasound technology have gained relevance and seems to be a good replacement to inactivate microorganisms and enzymes without affecting the quality parameters, maintaining the unsaturated fatty acids content, and even increasing bioactive compounds. For example, the thermoultrasound application in jackfruit nectar has been demonstrated as a viable preservation technique to develop an innocuous nectar without affecting their food quality. Nevertheless, in order to solve the challenges about potential applications of ultrasound technology, further research is needed to obtain optimal processing conditions according to the food matrix quality required.

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Section: Resultsmentioning

confidence: 99%

Optimal thermoultrasound processing of jackfruit ( Artocarpus heterophyllus lam.) nectar: Physicochemical characteristics, antioxidant properties, microbial quality, and fatty acid profile comparison with pasteurized nectar

Cruz-Cansino

Ariza‐Ortega

Alanís-García

et al. 2020

J Food Process Preserv

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“…Although information about the degradation of pharmaceuticals by such combination is still scarce, it is widely reported that the sonication enhances the performance of biological treatments, especially for the nutrient substrate removals. The ultrasonic process increases the enzymatic activity, and thus decreases the detention time and time of hydrolysis (which is a limiting factor in digestion step), also this may limit the sludges accumulation [189] , [190] . Additionally, ultrasound increases the removal of pollutants by improving the biological activity sludges, changing the cell membrane permeability, enhancing cell growth and biosynthesis [191] .…”

Section: Combined Systemsmentioning

confidence: 99%

A review on pharmaceuticals removal from waters by single and combined biological, membrane filtration and ultrasound systems

Alfonso-Muniozguren

Serna-Galvis

Bussemaker

et al. 2021

Ultrasonics Sonochemistry

106

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“…During ultrasonication, microbubbles and free radicals are generated which could efficiently destroy microbial cells, breakdown complex organic compounds and release nutrients to the supernatant [ 36 ]. It was reported that the release of organic matters and the increase of SCOD with the ultrasonic density and ultrasonic intensity followed the first-order reaction [ 15 , 24 , 30 , 48 ]. It has been reported that a neglectable amount of organic matter was oxidized during the ultrasonication pretreatment, and soluble materials were mainly transferred from the solid phase to the liquid phase [ 20 ].…”

Section: Resultsmentioning

confidence: 99%

Pretreatments for enhancing sewage sludge reduction and reuse in lipid production

Chen

Zhang

et al. 2020

Biotechnol Biofuels

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Background Converting wastewater sludge to lipid is considered as one of the best strategies of sludge management. The current problem of lipid production from wastewater sludge is the low yield (0.10–0.16 g lipid/g dry sludge) due to the low availability of easily uptaken materials (such as soluble monosaccharide and oligosaccharide) in sludge to oleaginous microorganism (Rhodotorula glutinis, Trichosporon oleaginosus, Lipomyces starkeyi). Pretreatments are efficient methods to improve sludge bioavailability. This study is aimed to achieve high lipid production from sludge and high sludge reduction. Results In this study, it was observed that the soluble chemical oxygen demand (SCOD) had significantly increased after different pretreatment. The SCOD in the supernatant was increased from 32.64 to 180.25 mg/L, 924.16 mg/L, 1029.89 mg/L and 3708.31 mg/L after acidic (pH 2 for 2 h), alkaline (pH 12 for 2 h), microwave irradiation (15 min with 5 min interval), and ultrasonication (30 min at 450 W and 20 kHz frequency with 5 s on and 2 s off mode) pretreatment, respectively. Pretreatments have also increased the release of total nitrogen (TN) and total phosphorus (TP) from solids. The sludge after different pretreatments were used as a medium for lipid production, and the highest lipid content (36.67% g/g) was obtained in the fermentation with ultrasonication pretreatment sludge, and the sludge reduction was 63.10%. For other pretreatments, the lipid content and sludge reduction were 18.42% and 32.63% in acid pretreatment case, 21.08% and 36.44% in alkaline pretreatment case, and 26.31% and 43.03% in microwave pretreatment case, respectively. Conclusion It was found that ultrasonication pretreatment was the most efficient way to increase the sludge biodegradability (SCOD) and to release TN and TP from solid phase to liquid phase. Pretreated sludge for lipid production achieved significant improvement in lipid yield and sludge reduction. Lipids produced from pretreated sludge were transesterified to biodiesel and the analysis showed that biodiesel had a similar composition as commercial biodiesel. The study reveals that pretreatment on sludge is a promising method for enhancing biological sludge management efficiency.

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An investigation on effect of ultrasound waves on sludge treatment

Cited by 9 publications

References 12 publications

Optimal thermoultrasound processing of jackfruit ( Artocarpus heterophyllus lam.) nectar: Physicochemical characteristics, antioxidant properties, microbial quality, and fatty acid profile comparison with pasteurized nectar

Optimal thermoultrasound processing of jackfruit ( Artocarpus heterophyllus lam.) nectar: Physicochemical characteristics, antioxidant properties, microbial quality, and fatty acid profile comparison with pasteurized nectar

A review on pharmaceuticals removal from waters by single and combined biological, membrane filtration and ultrasound systems

Pretreatments for enhancing sewage sludge reduction and reuse in lipid production

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