scholarly journals Development of Optimal Digesting Conditions for Microplastic Analysis in Dried Seaweed Gracilaria fisheri

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2118
Author(s):  
Rizky Prihandari ◽  
Weeraya Karnpanit ◽  
Suwapat Kittibunchakul ◽  
Varongsiri Kemsawasd
Keyword(s):  
Raman Spectroscopy ◽  
Recovery Rate ◽  
Combination Method ◽  
High Polymer ◽  
Digestion Time ◽  
Digestion Method ◽  
Marine Food Web ◽  
Marine Food ◽  
Digestion Efficiency ◽  
Digestion Methods

Currently, research on the accumulation of microplastics (MPs) in the marine food web is being highlighted. An accurate and reliable digestion method to extract and isolate MPs from complex food matrices has seldom been validated. This study aimed to compare the efficacy of MP isolation among enzymatic-, oxidative-, and the combination of two digestion methods on red seaweed, Gracilaria fisheri. The dried seaweed sample was digested using three different methods under various conditions using enzymes (cellulase and protease), 30% H2O2, and a combination of enzymes and 30% H2O2. The method possessing the best digestion efficiency and polymer recovery rate of MPs was selected, and its effect on spiked plastic polymer integrity was analyzed by Raman spectroscopy. As a result, the enzymatic method rendered moderate digestion efficiency (59.3–63.7%) and high polymer recovery rate (94.7–98.9%). The oxidative method using 30% H2O2 showed high digestion efficiency (93.0–96.3%) and high polymer recovery rate (>98%). The combination method was the most effective method in terms of digestion efficiency, polymer recovery rate, and expenditure of digestion time. The method also showed no chemical changes in the spiked plastic polymers (PE, PP, PS, PVC, and PET) after the digestion process. All the spiked plastic polymers were identifiable using Raman spectroscopy.

scholarly journals An Innovative Digestion Method: Ultrasound-Assisted Electrochemical Oxidation for the Onsite Extraction of Heavy Metal Elements in Dairy Farm Slurry

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4562
Author(s):  
Chenyu Li ◽  
Bin Xue ◽  
Shang Wang ◽  
Xi Zhang ◽  
Chen Zhao ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Particle Size ◽  
Electrochemical Oxidation ◽  
Dairy Farm ◽  
Operating Parameters ◽  
Digestion Time ◽  
Digestion Method ◽  
Ultrasound Assisted ◽  
Digestion Efficiency ◽  
Cu And Zn

Dairy farm slurry is an important biomass resource that can be used as a fertilizer and in energy utilization and chemical production. This study aimed to establish an innovative ultrasound-assisted electrochemical oxidation (UAEO) digestion method for the rapid and onsite analysis of the heavy metal (HM) contamination level of dairy slurry. The effects of UAEO operating parameters on digestion efficiency were tested based on Cu and Zn concentrations in a dairy slurry sample. The results showed that Cu and Zn digestion efficiency was (96.8 ± 2.6) and (98.5 ± 2.9)%, respectively, with the optimal UAEO operating parameters (digestion time: 45 min; ultrasonic power: 400 W; NaCl concentration: 10 g/L). The digestion recovery rate experiments were then operated with spiked samples to verify the digestion effect on broad-spectrum HMs. When the digestion time reached 45 min, all digestion recovery rates exceeded 90%. Meanwhile, free chlorine concentration, particle size distribution, and micromorphology were investigated to demonstrate the digestion mechanism. It was found that 414 mg/L free chorine had theoretically enough oxidative ability, and the ultrasound intervention could deal with the blocky undissolved particles attributed to its crushing capacity. The results of particle size distribution showed that the total volume and bulky particle proportion had an obvious decline. The micromorphology demonstrated that the ultrasound intervention fragmented the bulky particles, and electrochemical oxidation made irregular blocky structures form arc edge and cellular structures. The aforementioned results indicated that UAEO was a novel and efficient method. It was fast and convenient. Additionally, it ensured digestion efficiency and thus had a good application prospect.

scholarly journals Novel AOPs-Based Dual-Environmental Digestion Method for Determination of Total Dissolved Nitrogen in Water

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2751
Author(s):  
Rongyao Cai ◽  
Weiqiang Shou ◽  
Xiaochun Hu ◽  
Luyue Xia ◽  
Mengfei Zhou ◽  
...  
Keyword(s):  
Online Monitoring ◽  
Digestion Time ◽  
Digestion Method ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Alkaline Conditions ◽  
Acidic Conditions ◽  
Digestion Efficiency ◽  
N Compounds

Based on a synergistic digestion method of ultraviolet combined with ozone (UV/O3), this article investigates the reaction characteristics of nitrogen-containing compounds (N-compounds) in water and the influence of ions on digestion efficiency. In this respect, a novel and efficient AOPs-based dual-environmental digestion method for the determination of total dissolved nitrogen (TDN) in waters with complex components is proposed, in the hopes of improving the detection efficiency and accuracy of total nitrogen via online monitoring. The results show that inorganic and organic N-compounds have higher conversion rates in alkaline and acidic conditions, respectively. Meanwhile, the experimental results on the influence of Cl−, CO32−, and HCO3− on the digestion process indicate that Cl− can convert to radical reactive halogen species (RHS) in order to promote digestion efficiency, but CO32− and HCO3− cause a cyclic reaction consuming numerous •OH, weakening the digestion efficiency. Ultimately, to verify the effectiveness of this novel digestion method, total dissolved nitrogen samples containing ammonium chloride, urea, and glycine in different proportions were digested under the optimal conditions: flow rate, 0.6 L/min; reaction temperature, 40 °C; pH in acidic conditions, 2; digestion time in acidic condition, 10 min; pH in alkaline conditions, 11; digestion time in alkaline conditions, 10 min. The conversion rate (CR) of samples varied from 93.23% to 98.64%; the mean CR was greater than 95.30%. This novel and efficient digestion method represents a potential alternative for the digestion of N-compounds in the routine analysis or online monitoring of water quality.

Comparison of Digestion Methods for Analysis of Heavy Metals in MSWI Bottom Ash

2011 ◽  
Vol 474-476 ◽  
pp. 1075-1080 ◽  
Author(s):  
Hai Ying Zhang ◽  
Yi Zheng ◽  
Hong Tao Hu ◽  
Jing Yu Qi
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Content ◽  
Bottom Ash ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Digestion Method ◽  
Mswi Bottom Ash ◽  
Digestion Efficiency ◽  
Digestion Methods

This work aims to develop a proper digestion method for measurement of heavy metal content in municipal solid waste incineration (MSWI) bottom. Different digestion methods by HNO3, HNO3/HCl, HNO3/HCl/HClO4, HNO3/HCl/H2O2, HNO3/HClO4, HNO3/H2O2, were compared in digestion efficiency, and Cu, Pb, Zn and Cd were analyzed using atomic absorption spectrum (AAS). The method using mixed HNO3/HCl/HClO4 was recommended for digestion of MSWI slag for measurement of Cu, Pb, Zn, and the method of HNO3/H2O2 recommended for digestion for measurement of Cd.

scholarly journals Complexities of disturbance response in a marine food web

2021 ◽  
Author(s):  
Kristy A. Lewis ◽  
Robert R. Christian ◽  
Charles W. Martin ◽  
Kira L. Allen ◽  
Ashley M. McDonald ◽  
...  
Keyword(s):  
Food Web ◽  
Marine Food Web ◽  
Disturbance Response ◽  
Marine Food

The Role of Ammonites in the Mesozoic Marine Food Web Revealed by Jaw Preservation

Science ◽  
2011 ◽  
Vol 331 (6013) ◽  
pp. 70-72 ◽  
Author(s):  
I. Kruta ◽  
N. Landman ◽  
I. Rouget ◽  
F. Cecca ◽  
P. Tafforeau
Keyword(s):  
Food Web ◽  
Marine Food Web ◽  
Marine Food

scholarly journals Inter-annual cascade effect on marine food web: A benthic pathway lagging nutrient supply to pelagic fish stock

PLoS ONE ◽  
2017 ◽  
Vol 12 (9) ◽  
pp. e0184512 ◽  
Author(s):  
Lohengrin Dias de Almeida Fernandes ◽  
Eduardo Barros Fagundes Netto ◽  
Ricardo Coutinho ◽  
Keyword(s):  
Food Web ◽  
Nutrient Supply ◽  
Pelagic Fish ◽  
Fish Stock ◽  
Marine Food Web ◽  
Cascade Effect ◽  
Marine Food

Trophic transfer of heavy metals in the marine food web based on tissue residuals

2021 ◽  
Vol 772 ◽  
pp. 145064
Author(s):  
Yongfei Gao ◽  
Ruyue Wang ◽  
Yanyu Li ◽  
Xuebin Ding ◽  
Yueming Jiang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Food Web ◽  
Trophic Transfer ◽  
Web Based ◽  
Marine Food Web ◽  
Marine Food

Phytoplankton in the embayments of King George Island (Antarctic Peninsula): a review with emphasis on diatoms

Polar Record ◽  
2018 ◽  
Vol 54 (2) ◽  
pp. 158-175 ◽  
Author(s):  
Priscila Kienteca Lange ◽  
Ryszard Ligowski ◽  
Denise Rivera Tenenbaum
Keyword(s):  
Antarctic Peninsula ◽  
Early Summer ◽  
Western Antarctic Peninsula ◽  
King George Island ◽  
Accurate Identification ◽  
Phytoplankton Assemblages ◽  
Marine Food Web ◽  
Planktonic Diatoms ◽  
Local Material ◽  
Marine Food

ABSTRACTConsidering that phytoplankton assemblages are good bioindicators of environmental conditions, the sensitivity of the Western Antarctic Peninsula (WAP) to climate change, and the importance of some areas of its islands as Antarctic Specially Managed Areas, this work assembles published datasets on phytoplankton biodiversity and ecology in confined coastal areas (embayments) of King George Island, WAP. Over 33 years (1980–2013), 415 species from 122 genera have been identified to species level, being mostly diatoms (371 species), with 10 new species described with local material (6 diatoms, 4 cyanobacteria). The importance of diatoms was indicated by the frequent occurrence of Corethron pennatum, Pseudogomphonema kamtshaticum, and abundant benthic genera in the plankton (e.g. Navicula, Cocconeis). The increased contribution of dinoflagellates after 2010 suggests marked changes in the water column. Early-summer blooms differ between the bays' eastern and western shores, with terrestrial melting and wind-driven upwelling inducing the dominance of benthic species at eastern shores, whereas planktonic diatoms (Thalassiosira, Pseudo-nizschia, and Chaetoceros) are most abundant along western shores and central areas. The importance of an accurate identification of organisms that are becoming key ecological components of the region is discussed, as recent changes in the microflora may affect the entire marine food web.

scholarly journals Efficiency of acid digestion procedures for geochemical analysis of tungsten mining wastes

2021 ◽  
pp. geochem2021-034
Author(s):  
Z. Han ◽  
M. Edraki ◽  
A. Nguyen ◽  
M. Mostert
Keyword(s):  
Trace Element Analysis ◽  
Major Elements ◽  
Critical Element ◽  
Digestion Method ◽  
Element Analysis ◽  
Geochemical Composition ◽  
Alkali Fusion ◽  
Global Demand ◽  
Complete Digestion ◽  
Digestion Methods

Tungsten is a critical element used in the industry with increasing global demand. There are millions of tons of current and legacy mineral processing tungsten tailings worldwide that can potentially contaminate the environment and pose human health risks. These tailings could also potentially turn into valuable resources if we thoroughly characterise their geochemical composition. In this study, an innovative method was developed to achieve the complete digestion of tungsten tailings. We tested three different digestion methods (hotplate digestion, bomb digestion, and ColdBlockTM digestion) and compared the results. Additionally, an alkali fusion for major element analysis was also applied and tested. The results showed that alkali fusion is the best method for major elements analysis, while bomb digestion is the best method for tungsten and trace element analysis, but volatile chlorite loss was also observed. The hot plate digestion method for tungsten mine tailings was not recommended, because of poor recoveries of trace elements compared to the bomb digestion method. The quick and safer ColdBlockTM digestion method could be used for Bismuth (Bi), Molybdenum (Mo), and several rare earth element analyses indicated by their recoveries being close to the bomb digestion method. 

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