scholarly journals Application of Freeze Concentration Technologies to Valorize Nutrient-Rich Effluents Generated from the Anaerobic Digestion of Agro-Industrial Wastes

2021 ◽  
Vol 13 (24) ◽  
pp. 13769
Author(s):  
Imane Uald-lamkaddam ◽  
Arezoo Dadrasnia ◽  
Laia Llenas ◽  
Sergio Ponsá ◽  
Joan Colón ◽  
...  

The production of biogas through anaerobic digestion implies the generation of 90–95% of digested raw material, namely digestate. A nutrient-rich stream is generally applied to cropland to enhance yields, due to its high abundance of nutrients. Nevertheless, the intensive digestate farming brings about nutrient saturation and groundwater contamination. The application of downstream emerging technologies that focus on the recovery of nutrients from digestate have been studied, yet freeze concentration technology (FC) has never been considered for this purpose. This study evaluates the performance of FC technology applied to concentrate nitrogen (N), phosphorus (P) and potassium (K) from an effluent of a reverse osmosis unit that is treating the digestate of agro-industrial waste effluents. For this aim, two lab-scale methodological approaches were investigated, namely, progressive FC (PFC) and suspension FC (SFC), set through the utilization of different FC configurations. The concentrates obtained in both FC methods agreed with the regulations for fertilizers in terms of nutrients and metals content; meanwhile, the diluted fraction can be delivered as water for irrigation in high-density livestock areas. The application of FC solves the transportation cost side effect of livestock waste on the one hand, and soil contamination with nutrient on the other hand.

2021 ◽  
Vol 5 (6) ◽  
pp. 151
Author(s):  
Mustapha El Kanzaoui ◽  
Chouaib Ennawaoui ◽  
Saleh Eladaoui ◽  
Abdelowahed Hajjaji ◽  
Abdellah Guenbour ◽  
...  

Given the amount of industrial waste produced and collected in the world today, a recycling and recovery process is needed. The study carried out on this subject focuses on the valorization of one of these industrial wastes, namely the fly ash produced by an ultra-supercritical coal power plant. This paper describes the use and recovery of fly ash as a high percentage reinforcement for the development of a new high-performance composite material for use in various fields. The raw material, fly ash, comes from the staged combustion of coal, which occurs in the furnace of an ultra-supercritical boiler of a coal-fired power plant. Mechanical compression, thermal conductivity, and erosion tests are used to study the mechanical, thermal, and erosion behavior of this new composite material. The mineralogical and textural analyses of samples were characterized using Scanning Electron Microscopy (SEM). SEM confirmed the formation of a new composite by a polymerization reaction. The results obtained are very remarkable, with a high Young’s modulus and a criterion of insulation, which approves the presence of a potential to be exploited in the different fields of materials. In conclusion, the composite material presented in this study has great potential for building material and could represent interesting candidates for the smart city.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3411
Author(s):  
Clara Fernando-Foncillas ◽  
Maria M. Estevez ◽  
Hinrich Uellendahl ◽  
Cristiano Varrone

Wastewater and sewage sludge contain organic matter that can be valorized through conversion into energy and/or green chemicals. Moreover, resource recovery from these wastes has become the new focus of wastewater management, to develop more sustainable processes in a circular economy approach. The aim of this review was to analyze current sewage sludge management systems in Scandinavia with respect to resource recovery, in combination with other organic wastes. As anaerobic digestion (AD) was found to be the common sludge treatment approach in Scandinavia, different available organic municipal and industrial wastes were identified and compared, to evaluate the potential for expanding the resource recovery by anaerobic co-digestion. Additionally, a full-scale case study of co-digestion, as strategy for optimization of the anaerobic digestion treatment, was presented for each country, together with advanced biorefinery approaches to wastewater treatment and resource recovery.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 766
Author(s):  
Magdalena Skotnicka ◽  
Kaja Karwowska ◽  
Filip Kłobukowski ◽  
Aleksandra Borkowska ◽  
Magdalena Pieszko

All over the world, a large proportion of the population consume insects as part of their diet. In Western countries, however, the consumption of insects is perceived as a negative phenomenon. The consumption of insects worldwide can be considered in two ways: on the one hand, as a source of protein in countries affected by hunger, while, on the other, as an alternative protein in highly-developed regions, in response to the need for implementing policies of sustainable development. This review focused on both the regulations concerning the production and marketing of insects in Europe and the characteristics of edible insects that are most likely to establish a presence on the European market. The paper indicates numerous advantages of the consumption of insects, not only as a valuable source of protein but also as a raw material rich in valuable fatty acids, vitamins, and mineral salts. Attention was paid to the functional properties of proteins derived from insects, and to the possibility for using them in the production of functional food. The study also addresses the hazards which undoubtedly contribute to the mistrust and lowered acceptance of European consumers and points to the potential gaps in the knowledge concerning the breeding conditions, raw material processing and health safety. This set of analyzed data allows us to look optimistically at the possibilities for the development of edible insect-based foods, particularly in Europe.


Author(s):  
Sebastian Ponce ◽  
Stefanie Wesinger ◽  
Daniela Ona ◽  
Daniela Almeida Streitwieser ◽  
Jakob Albert

AbstractThe selective oxidative conversion of seven representative fully characterized biomasses recovered as secondary feedstocks from the agroindustry is reported. The reaction system, known as the “OxFA process,” involves a homogeneous polyoxometalate catalyst (H8PV5Mo7O40), gaseous oxygen, p-toluene sulfonic acid, and water as solvent. It took place at 20 bar and 90 °C and transformed agro-industrial wastes, such as coffee husks, cocoa husks, palm rachis, fiber and nuts, sugarcane bagasse, and rice husks into biogenic formic acid, acetic acid, and CO2 as sole products. Even though all samples were transformed; remarkably, the reaction obtains up to 64, and 55% combined yield of formic and acetic acid for coffee and cocoa husks as raw material within 24 h, respectively. In addition to the role of the catalysts and additive for promoting the reaction, the influence of biomass components (hemicellulose, cellulose and lignin) into biogenic formic acid formation has been also demonstrated. Thus, these results are of major interest for the application of novel oxidation techniques under real recovered biomass for producing value-added products. Graphical abstract


Mining Revue ◽  
2021 ◽  
Vol 27 (3) ◽  
pp. 40-44
Author(s):  
Eugen Traistă ◽  
Camelia Bădulescu ◽  
Maria Lazăr ◽  
Camelia Traistă

Abstract Metallurgical slag is one of the most common industrial wastes. Many of these wastes are not stable over time, by reacting with water and air, continuously generating emissions of heavy metals. Metallurgical slag processing is necessary for at least two reasons: reducing pollutant emissions and broadening the raw material base. The recovery of these slags is very difficult because they are the result of metallurgical processes that aimed to fix metals considered impurities in chemical matrices as stable as possible. This paper presents the initial research on the behavior of metallurgical slags against different leaching technologies.


2015 ◽  
Vol 77 (3) ◽  
Author(s):  
Anuar Othman ◽  
Nasharuddin Isa ◽  
Rohaya Othman

Precipitated calcium carbonate (PCC) chemically can be synthesized in the laboratory. In this study, hydrated lime or calcium hydroxide was used as raw material with sucrose as additive to produce PCC. The process was compared with the one without additive. PCC produced was observed based on morphology, mineral composition and size by using Fesem-Edx and LPSA, respectively. PCC products without additive demonstrated fine and more uniform size of calcite PCC as compared to the one with additive. Nevertheless, the process with additive produced more PCC product than without additive.


2016 ◽  
Vol 697 ◽  
pp. 433-436
Author(s):  
Shi Chao Zhang ◽  
Yu Feng Chen ◽  
Wei Wu ◽  
Hao Ran Sun ◽  
Guang Hai Wang ◽  
...  

In this paper, fumed nano-silica as the main raw material, nano-silica insulation materials were prepared by the dry processing. Research on humidity-reinforcement of nano-Silica insulation materials has been carried out and analyzed. When hygroscopicity of samples reach to 23%, the compressive strength 1.65MPa is at twice the one without high humidity-reinforcement, while the thermal conductivities are almost the same. Then, the action mechanism of high humidity-reinforcement method was analyzed. In humidity-reinforcement method, as vapor enters, silica sol is formed in the gap between one aggregate particle and another, and various condensation polymerization occurred in the drying process, which lead to aggregates connection and compressive strength improvement.


2020 ◽  
Author(s):  
P.A. Kozlov ◽  
A.M. Panshin ◽  
L.I. Leontiev

The increasing demand for zinc and a range of zinc-related metals (for example: lead; indium; tin; cadmium; and copper) in the Russian Federation cannot be satisfied by the existing production plants due to the lack of raw materials. At the same time, ferrous and non-ferrous metallurgy and the chemical industry have accumulated hundreds of millions of tons of zinc wastes (falling into the hazard categories 2 to 4), the processing of which could not only make up the raw material base, but also improve the environmental situation. In the world, over 85% of ferrous dust is recycled using the Waelz process. The Waeltz process is used for distilling separation of elements under reducing conditions. In this study, a block diagram for production of the following elements from industrial wastes is proposed: zinc, cadmium and indium in form of massive metals; zinc and indium in the form of fine powders; and clinker as a raw material for cement production. The technical and scientific details of this new process have been patented in the Russian Federation and abroad. For the first time, the following operations have been implemented with the use of large-sized Waelz kilns: vapour-oxidized Waeltz treatment of polymetallic wastes; recycling of heat from gases and solid products with generation of process fumes; and implementation of alternative flux (dolomite) and alternative fuel (petroleum coke). Keywords: Waelz process, industrial wastes, heat recycling, vapour-oxidized Waelz processing


Author(s):  
Maria V. Morar

In our country, the developments of the measures for the prevention of the environmental pollution are aligning to the UE Directives. The costs for the treatment of the water wastes are continuously increasing, following to the also increasing of the investments costs. Therefore it is necessary to accord attention for the alternatives of cleaning, treating, respective recycling of the agro-industrial wastes and their reintroduction in the natural circuit. At the processing of the food results wastes with high organic charge. The effluents form the processing of dairy products, sugar, starch, beer yeasts as well as breweries or distilleries are getting fast into acids fermentation, finally resulting organic acids. Such process water wastes can be released in the canalization by dilution or by a suitable treating. As an example, for the distillery wastes (distillery slops) with a high dry matter contents (4-20%), the waste water treatment plant shall be designed properly (with mechanical separation step and biological treatment) to ensure the capacity of purifying according to the high flow and increased concentration, due to the high CBOD5 concentration. The treatment of such water wastes can be realized with aerobic processes, which suppose a high energetic consumption. While in the aerobic purifying processes 50 % of the CBOD5 is involved in the forming of biomass and slurry in excess, in the anaerobic treatment processes (anaerobic or methane digestion) a high part of the substrate (until 70 %) is metabolized through the metabolic transformation of bacterial flora, with production of biogas. Therefore, the concentrated water wastes, with potential for the energy production could offer a possibility of energy replacement in the own processing units. The paper presents a review of the anaerobic digestion for different wastes from the agro-industrial processing and their potential for the biogas production. There are presented possibilities of mixture, respectively of co-digestion of different wastes the agro-industrial processing with other wastes from the agriculture (from cereals processing, biomass, manure etc). Simultaneously biogas plants from the praxis with functioning characteristics are presented.


2021 ◽  
pp. 37-46
Author(s):  
Fredy Torres Mejía ◽  
Juan Alexander Torres Mejía ◽  
Henry Edgardo Maradiaga Galeano ◽  
Claudia López Toro

The aim of this work is to evaluate the performance of the extraction and mechanical filtering of Jatropha curcas oil and to evaluate the primary energy of the raw material resulting from the process, this is a qualitative-quantitative study of transversal order based on measurements and analysis of the process in situ: The following factors were evaluated as factors: weight of oil per seed processed, weight of pressed cake, and measurements in the filtering process, from which a balance of matter of the process used was constructed, and the energy valuation of the oil and pressed cake, energy was used as the response variable, measured in Tons of Oil Equivalent (TEP), Barrels of Oil Equivalent (BEP), and tons of Carbon Dioxide Equivalent (Ton CO2eq). The seed used is Creole, the one existing in the area, the extraction was carried out in a KEK-P0101 press, and a KEK-F0090 filter. The collected seeds were dried and then discarded, the average shell weight is 40% of the total weight of the dry seed, from the oil extraction process a yield of 18.6% was obtained using seed with 5.8% humidity, and from the oil filtering process, when it passed through the filter, no weight loss in kg was obtained; finally, the equivalent primary energy valuation of one ton of oil is 39076. 39 MJTon-1, which is equivalent to 0.94 TEP, 2.90 Ton CO2 eq, and 20.87 BEP; in the same way one ton of Jatropha cake represents 15969.30 MJ, equivalent to 0.38 TEP, 1.18 Ton CO2 eq, and 8. 53 BEP, and the total primary energy between one ton of oil and one ton of Jatropha cake after oil extraction together contain 55045.61 MJTon-1, equivalent to 1.32 TEP, 4.08 Ton CO2 eq, and 29.41 BEP.


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