scholarly journals Adsorptive and Surface Characterization of Mediterranean Agrifood Processing Wastes: Prospection for Pesticide Removal

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 561
Author(s):  
José A. Fernández-López ◽  
Marta Doval Miñarro ◽  
José M. Angosto ◽  
Javier Fernández-Lledó ◽  
José M. Obón

The sustainable management of biomass is a key global challenge that demands compliance with fundamental requirements of social and environmental responsibility and economic effectiveness. Strategies for the valorization of waste biomass from agrifood industries must be in line with sustainable technological management and eco-industrial approaches. The efficient bioremoval of the pesticides imazalil and thiabendazole from aqueous effluents using waste biomass from typically Mediterranean agrifood industries (citrus waste, artichoke agrowaste and olive mill residue) revealed that these residues may be transformed into cost-effective biosorbents. Agrifood wastes present irregular surfaces, many different sized pores and active functional groups on their surface, and they are abundant in nature. The surface and adsorptive properties of olive mill residue, artichoke agrowaste and citrus waste were characterized with respect to elemental composition, microstructure, crystallinity, pore size, presence of active functional groups, thermal stability, and point of zero charge. Olive mill residue showed the highest values of surface area (Brunauer–Emmett–Teller method), porosity, crystallinity index, and pH of zero point of charge. Olive mill residue showed the highest efficiency with sorption capacities of 9 mg·g−1 for imazalil and 8.6 mg·g−1 for thiabendazole.

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1280
Author(s):  
Domenico Zannini ◽  
Giovanni Dal Poggetto ◽  
Mario Malinconico ◽  
Gabriella Santagata ◽  
Barbara Immirzi

Citrus pomace derived from the industrial processing of juice and essential oils mostly consists of pectin, cellulose, hemicellulose, and simple sugars. In this work, citrus pomace waste from an agricultural company in South Italy was used as source of pectin. The extraction conditions of the polysaccharide were optimized using a suitable combination of time and a concentration of a mild organic solvent, such as acetic acid; thus recovering high Mw pectin and bioactive molecules (flavonoids and polyphenols). The pectin was structurally (GPC, FTIR), morphologically (SEM), thermally (TGA/DTG), and mechanically characterized, while bioactive molecules were separated and the total phenolic content (TPC) and total flavonoids content (TFC) were evaluated. With the aim to develop novel biocomposite-based materials, the pectin extracted from citrus waste was reinforced with different amounts of lignocellulose fractions also recovered from citrus waste after polysaccharide extraction, according to a “zero waste” circular economy approach. The prepared biocomposites were morphologically and mechanically characterized to be used as biodegradable mulching systems for crop protection. Thus, the citrus waste biomass was recovered, fractionated into its main raw materials, and these were recombined to develop novel upgraded biocomposites for mulching applications, by means of a cost-effective and eco-sustainable approach.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3567
Author(s):  
José M. Angosto ◽  
María J. Roca ◽  
José A. Fernández-López

Wastewater treatment is a topic of primary interest with regard to the environment. Diclofenac is a common analgesic drug often detected in wastewater and surface water. In this paper, three commonly available agrifood waste types (artichoke agrowaste, olive-mill residues, and citrus waste) were reused as sorbents of diclofenac present in aqueous effluents. Citrus-waste biomass for a dose of 2 g·L−1 allowed for removing 99.7% of diclofenac present in the initial sample, with a sorption capacity of 9 mg of adsorbed diclofenac for each gram of used biomass. The respective values obtained for olive-mill residues and artichoke agrowaste were around 4.15 mg·g−1. Advanced oxidation processes with UV/H2O2 and UV/HOCl were shown to be effective treatments for the elimination of diclofenac. A significant reduction in chemical oxygen demand (COD; 40–48%) was also achieved with these oxidation treatments. Despite the lesser effectiveness of the sorption process, it should be considered that the reuse and valorization of these lignocellulosic agrifood residues would facilitate the fostering of a circular economy.


2021 ◽  
Author(s):  
KANAT ANURAKPARADORN ◽  
ALAN TAUB ◽  
ERIC MICHIELSSEN

The proliferation of wireless technology calls for the development of cost-effective Electromagnetic Interference (EMI) shielding materials that reduce the susceptibility of high-speed electronic circuits to undesired incoming radiation. Ideally, such materials offer protection over wide frequency ranges and are insensitive to the polarization or angle of incidence of the impinging fields. Here, next-generation EMI shielding materials composed of polymer composites with conductive and magnetic fillers are introduced. It is shown that careful control of the concentration and dispersion of the polymers’ conductive and magnetic constituents permits tuning of the composites’ intrinsic electrical and magnetic properties. The resulting EMI shields are lightweight, cheap and offer greater protection than traditional metal gaskets and foams. In this work, cobalt ferrite magnetic nanoparticles (CoFe2O4) decorated on graphene-based material were dispersed in polylactic acid (PLA) matrix for high EM absorption level in X-band (8-12 GHz). The decoration of the magnetic particles was performed on the as-prepared conductive graphene nanoplatelets (GNP) and reduced graphene oxide (rGO). GNP composites exhibited higher DC conductivity, and permittivity than rGO composites. This is attributed to issues associated with the reduction process, including a lack of conductivity due to the insulated oxygen functional groups and the reduction in the lateral size. Compared with rGOs, the lack of out-plane functional groups causes the cobalt ferrite nanoparticles to agglomerate and not cover the entire surface of the GNPs. These morphological differences improve the magnetization and EM absorption of the composite system. The compatibilizer (pyrene-PLA-OH) was added to the composites to enhance dispersion of the GNPs in the polymer matrix which benefits in higher absorption of the shield. The influence of the compatibilizer on parameter, the reflection loss (RL) of the composite were determined from the characterized intrinsic properties


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6636
Author(s):  
Muna Abu-Dalo ◽  
Jehad Abdelnabi ◽  
Abeer Al Bawab

Olive oil production generates solid and liquid wastes that cause various environmental problems due to their high phenols and polyphenols load. Although many treatment methods were investigated to manage these wastes, more research is still needed to identify simple and cost-effective approaches. In this study, activated carbon (AC) was prepared from olive cake waste and functionalized with Cu/Cu2O/CuO for efficient and selective removal of phenolic content from olive mill wastewater (OMW). AC media were characterized by scanning electron/dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, and Brunauer–Emmett–Teller (BET) surface area analysis. The optimum adsorption parameters were investigated, and the adsorption isotherms, thermodynamics, and kinetics were determined. The adsorption of phenols onto copper oxide AC was best described by the Langmuir adsorption with maximum adsorption capacity of 13.9, 12.7, and 9.9 mg/g at 311, 302, and 293 K, respectively. The adsorption reaction was found to be spontaneous and endothermic where ∆H° and ∆G° were found to be 30.104 kJ/mol and −1.765, −2.839, and −3.723 (kJ/mol) at 311, 302, and 293 K, respectively. In addition, the kinetics data were perfectly fit by the pseudo-second-order model. The activated product derived from recyclable olive cake and enriched with inorganic functionality can offer a cost-effective treatment solution for OMW; thus, reducing both the liquid and solid waste generated from the olive mill industry.


2019 ◽  
Vol 17 (2) ◽  
pp. 204-218 ◽  
Author(s):  
Ampai Soros ◽  
James E. Amburgey ◽  
Christine E. Stauber ◽  
Mark D. Sobsey ◽  
Lisa M. Casanova

Abstract Turbidity reduction by coagulation-flocculation in drinking water reduces microbes and organic matter, increasing effectiveness of downstream treatment. Chitosan is a promising household water coagulant, but needs parameters for use. This study tested the effects of chitosan dose, molecular weight (MW), degree of deacetylation (DD), and functional groups on bentonite and kaolinite turbidity reduction in model household drinking water. Higher MW or DD produced greater reductions. Highest reductions were at doses 1 and 3 mg/L by MW >50,000 or >70% DD (residual turbidity <5 NTU). Higher doses did not necessarily continually increase reduction. For functional groups, 3 mg/L produced the highest reductions by lactate, acetate, and HCl, and lower reductions of kaolinite than bentonite. Doses where the point of zero charge was observed clustered around 3 mg/L. Chitosan reduced clay turbidity in water; effectiveness was influenced by dose, clay type, MW, DD, and functional groups. Reduction did not necessarily increase with MW. Bentonite had a broader effective dose range and higher reduction at the optimal dose than kaolinite. Chitosans with and without functional groups performed similarly. The best of the studied doses was 3 mg/L. Chitosans are promising for turbidity reduction in low-resource settings if combined with sedimentation and/or filtration. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.


2020 ◽  
Vol 7 (7) ◽  
pp. 200065 ◽  
Author(s):  
Siti Nur Aishah Mat Yusuf ◽  
Che Nurul Azieyan Che Mood ◽  
Nor Hazwani Ahmad ◽  
Doblin Sandai ◽  
Chee Keong Lee ◽  
...  

Background : Silver nanoparticles (AgNPs) are widely used in food industries, biomedical, dentistry, catalysis, diagnostic biological probes and sensors. The use of plant extract for AgNPs synthesis eliminates the process of maintaining cell culture and the process could be scaled up under a non-aseptic environment. The purpose of this study is to determine the classes of phytochemicals, to biosynthesize and characterize the AgNPs using Clinacanthus nutans leaf and stem extracts. In this study, AgNPs were synthesized from the aqueous extracts of C. nutans leaves and stems through a non-toxic, cost-effective and eco-friendly method. Results : The formation of AgNPs was confirmed by UV-Vis spectroscopy, and the size of AgNP-L (leaf) and AgNP-S (stem) were 114.7 and 129.9 nm, respectively. Transmission electron microscopy (TEM) analysis showed spherical nanoparticles with AgNP-L and AgNP-S ranging from 10 to 300 nm and 10 to 180 nm, with average of 101.18 and 75.38 nm, respectively. The zeta potentials of AgNP-L and AgNP-S were recorded at −42.8 and −43.9 mV. X-ray diffraction analysis matched the face-centred cubic structure of silver and was capped with bioactive compounds. Fourier transform infrared spectrophotometer analysis revealed the presence of few functional groups of phenolic and flavonoid compounds. These functional groups act as reducing agents in AgNPs synthesis. Conclusion : These results showed that the biogenically synthesized nanoparticles reduced silver ions to silver nanoparticles in aqueous condition and the AgNPs formed were stable and less toxic.


Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 847 ◽  
Author(s):  
Ahmed Ragab ◽  
Inas Ahmed ◽  
Dina Bader

Nanocomposites of natural bone that show some benefits in terms of both composition and microstructure were synthesized by an in situ precipitation method. Hydroxyapatite (Hap) was prepared from cost-effective precursors within chitosan (CS) dissolved in aqueous acetic acid solution. The nanocomposite was synthesized for the removal of brilliant green dye (BG) from a contaminated water solution. The compositional and morphological properties of the nanocomposite were studied by means of FTIR spectroscopy, X-ray diffraction (XRD), SEM, and TEM analysis. Batch experiments were carried out to investigate the effects of pH, contact time, and initial concentration, as well as the adsorbent dosage and zero point charge for the sorbent to determine a suitable medium for the adsorption process. The sorption models using Mories-Weber, Lagrange, and Bangham equations were used to identify the mechanism and reaction order. The isotherm model was carried out using Langmuir, Freundlich, and Dubinin-Radusekevisch-Kanager equations to calculate the adsorption capacity and type of adsorption. Thermodynamic parameters, enthalpy change (∆Ho), entropy change (∆So), and Gibbs free energy (∆Go) were evaluated. All of the results suggest the feasibility of using nanocomposites as a sorbent for brilliant green dye removal.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chiara Pennesi ◽  
Alessia Amato ◽  
Stefano Occhialini ◽  
Alan T. Critchley ◽  
Cecilia Totti ◽  
...  

AbstractThe biosorption capacities of dried meal and a waste product from the processing for biostimulant extract of Ascophyllum nodosum were evaluated as candidates for low-cost, effective biomaterials for the recovery of indium(III). The use of indium has significantly grown in the last decade, because of its utilization in hi-tech. Two formats were evaluated as biosorbents: waste-biomass, a residue derived from the alkaline extraction of a commercial, biostimulant product, and natural-biomass which was harvested, dried and milled as a commercial, “kelp meal” product. Two systems have been evaluated: ideal system with indium only, and double metal-system with indium and iron, where two different levels of iron were investigated. For both systems, the indium biosorption by the brown algal biomass was found to be pH-dependent, with an optimum at pH3. In the ideal system, indium adsorption was higher (maximum adsorptions of 48 mg/g for the processed, waste biomass and 63 mg/g for the natural biomass), than in the double metal-system where the maximum adsorption was with iron at 0.07 g/L. Good values of indium adsorption were demonstrated in both the ideal and double systems: there was competition between the iron and indium ions for the binding sites available in the A. nodosum-derived materials. Data suggested that the processed, waste biomass of the algae, could be a good biosorbent for its indium absorption properties. This had the double advantages of both recovery of indium (high economic importance), and also definition of a virtuous circular economic innovative strategy, whereby a waste becomes a valuable resource.


2015 ◽  
Vol 6 (41) ◽  
pp. 7333-7341 ◽  
Author(s):  
M. S. Chisholm ◽  
I. K. Martin ◽  
A. T. Slark

Branched acrylic copolymers were synthesised via facile conventional free-radical polymerisations taken to high conversion using comonomers containing 2-6 acrylate functional groups and chain transfer agents containing 1-8 thiol functional groups.


2019 ◽  
Vol 2 (2) ◽  
pp. 81-82
Author(s):  
Rong Wu ◽  
Muhammad Zubair ◽  
Aman Ullah

More than 100 million tons of banana peels are produced annually, and about 40 million banana peels (40% of total weight) remain greatly unused. Hence, exploring banana peels’ ability to clean contaminated water would bring an additional value to the current “waste” product. One of the most common aspects of water pollution currently is heavy metal contamination, which is particularly dangerous for humans due to its high toxicity. Banana peels contain a high concentration of carbohydrates, the two most abundant being cellulose and starch, which has multiple hydroxyl and carboxyl functional groups. Banana peels are an easily available and cost-effective adsorbent that can adsorb different kinds of heavy metal ions. This research primarily focuses on improving the current efficiency of this technique through the development of a banana peel/graphene oxide hybrid adsorbent. The cross-linking graphene oxide possess numerous hydroxyl, carbonyl, carboxyl, and epoxide functional groups that can be used to induce chemical reactions with banana peel carbohydrates, providing the graphene oxide with additional functional groups. This modification can potentially increase the adsorption capacity of banana peel derived adsorbents. It is evident through FTIR analysis that banana peel powder and graphene oxide have many functional groups of similar types. Thus, reactions can readily occur to combine the two substances. The TGA analysis of both compounds, however, indicates different patterns of thermal decomposition. Further thermal analysis is required for the hybrid adsorbent. After the development and characterization of this hybrid adsorbent, the next step is to complete a water purification analysis. In the future, banana peel/graphene oxide derived adsorbent may serve as a sustainable and efficient solution for water purification.


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