Search results for "Waste"
showing 10 items of 2580 documents
Valorization of winery and oil mill wastes by microbial technologies
2015
Agro-food industrial wastes represent a serious environmental problem in producing countries. In addition to the traditional irrigation with wastewaters, application of solids to the land, and the extraction of valuable compounds for the pharmaceutical, cosmetics and food industries, a microbiological approach is also available. In this review, the most promising microbiological processes for the valorization of wine and oil by-products are presented. Recently, there has been an upsurge in the exploitation of the waste materials generated by the wine and olive oil industries. Treatments by physical and chemical methods are generally expensive, and they do not often provide complete solution…
Towards the first proof of the concept of a Reverse ElectroDialysis - Membrane Distillation Heat Engine
2019
Abstract The coupling of Reverse Electrodialysis with Membrane Distillation is a promising option for the conversion of waste heat into electricity. This study evaluates the performances of the integrated system under different operating conditions, employing validated model and correlations. This work provides a detailed description of the behaviour of a real RED-MD heat engine and indicates the set of inlet concentrations, velocities and equipment size which returns the highest cycle exergy efficiency. These operating conditions were selected for the pilot plant developed within the EU-funded project RED Heat to Power. For the first time, a perspective analysis was also included, consider…
Thermolytic reverse electrodialysis heat engine: model development, integration and performance analysis
2019
Abstract Salinity gradient heat engines represent an innovative and promising way to convert low-grade heat into electricity by employing salinity gradient technology in a closed-loop configuration. Among the aqueous solutions which can be used as working fluid, ammonium bicarbonate-water solutions appear very promising due to their capability to decompose at low temperature. In this work, an experimentally validated model for a reverse electrodialysis heat engine fed with ammonium bicarbonate-water solutions was developed. The model consists of two validated sub-models purposely integrated, one for the reverse electrodialysis unit and the other for the stripping/absorption regeneration uni…
Protection concepts from optical radiation used in places of danger from explosion of gases, vapour or cloud of particles
2005
Use of optical systems in hazardous locations can result in ignition of surrounding explosive atmosphere. The conducted research work allowed to propose three protection concepts. The primary protection concept - inherently safe optical radiation - consists in use of optical radiation with power, energy or irradiance incapable of causing ignition of surrounding explosive atmosphere. However, the arbitrary determination of values of these parameters is considered as excessively rigorous. The work presents the proposed protection concepts in relation to zone classification. The author describes his own method to determine safe values based on probability mathematics that can be used not only …
Energy harvesting by waste acid/base neutralization via bipolar membrane reverse electrodialysis
2020
Bipolar Membrane Reverse Electrodialysis (BMRED) can be used to produce electricity exploiting acid-base neutralization, thus representing a valuable route in reusing waste streams. The present work investigates the performance of a lab-scale BMRED module under several operating conditions. By feeding the stack with 1 M HCl and NaOH streams, a maximum power density of ~17 W m−2 was obtained at 100 A m−2 with a 10-triplet stack with a flow velocity of 1 cm s−1, while an energy density of ~10 kWh m−3 acid could be extracted by a complete neutralization. Parasitic currents along feed and drain manifolds significantly affected the performance of the stack when equipped with a higher number of t…
A simulation tool for ion exchange membrane crystallization of magnesium hydroxide from waste brine
2021
Abstract Increasing attention is nowadays paid to the management and valorisation of industrial waste brines aiming also at the recovery of raw materials. Magnesium has been listed as a Critical Raw Material by EU, prompting researchers to investigate novel routes for its recovery. Within this framework, a novel Crystallizer with Ion Exchange Membrane (CrIEM), is proposed as an innovative way to recover magnesium from industrial waste brines exploiting low-cost alkaline reactants. In the present work, a novel mathematical model of the CrIEM process is proposed to provide a useful tool for its design in different working conditions. Batch and feed & bleed continuous configurations have been …
Thermo-mechanical volume change behaviour of Opalinus Clay
2016
The paper examines the thermo-mechanical volume change behaviour of Opalinus Clay in relation to different stress conditions and overconsolidation ratio (OCR) values and evaluates the impact of temperature on some hydro-mechanical properties of this material. To this aim, a focused experimental campaign consisting in high-temperature/high-pressure oedometric tests has been carried out. The results show that the thermo-mechanical volume change behaviour of Opalinus Clay is heavily affected by the OCR: thermal expansion is found when the heating is carried out at high OCR, whereas irreversible thermal compaction is observed when heat is applied at a vertical effective stress that is sufficien…
From waste to resource for a sustainable future
2023
Every day we produce waste that constitutes an environmental and economic problem. A quantity of this waste is recycled, reused or composted and a quantity is sent to landfills. How can we produce less waste and using waste as a resource? Reducing waste is one of the objectives of the circular economy and their recycle asks us to rethink production and consumption models, this implies that design is a strategic element. In fact, in recent years design played a key role in the transition from a linear to a circular economy with a design based on the efficient use of materials, the reduction of the amount of waste generated, intervening on durability, repairability, the possibility of updatin…
Bezatkritumu dzīvesveids Rīgā
2019
Bakalaura darba mērķis ir noskaidrot, kā un kāpēc Rīgas iedzīvotāji piekopj bezatkritumu dzīvesveidu. Pētījuma problēma: kādas izmaiņas ir jāveic ikdienā, lai veiksmīgi piekoptu bezatkritumu dzīvesveidu. Darbā tika izmantota racionālās izvēles teorija, kā arī veikta iepriekš veikto pētījumu par Zero Waste un bezatkritumu dzīvesveidu analīze. Darba gaitā tika veiktas 11 daļēji strukturētās intervijas ar Rīgas iedzīvotājiem, kas piekopj bezatkritumu dzīvesveidu. Rezultātā tika secināts, ka bezatkritumu dzīvesveida piekopšana notiek caur iepirkšanās paradumu maiņu, videi draudzīgāku alternatīvu meklēšanu un patēriņa samazināšanu. Savukārt, galvenie piekopšanas iemesli ir plašākas informācijas …
Electrodialysis for wastewater treatment—Part I: Fundamentals and municipal effluents
2020
Abstract Selectivity, high recovery, and chemical-free operation are strengths of electrodialysis. Different configurations have been proposed for several applications. Effluents from municipal wastewater treatment plants (including sludge and supernatants), desalination plants, and animal farms can be treated for recovering water, nutrients, salts, and acids/bases. Although many applications are technoeconomically feasible and competitive with other zero liquid discharge systems, only a few real plants have been installed. However, the research is currently very active, thus paving the way for a widespread use at large scale in the next future.