Comparative study of polyphenol extraction using physical techniques and water as a solvent: a sustainable approach for the valorization of apple pomace.

Apples are among the most commonly cultivated fruits globally. Approximately 65% of annual apple production is transformed into apple juice concentrate generating a large amount of waste material named apple pomace, which includes seeds, skin, and other components. Disposing of apple by-products directly into the environment constitutes a source of environmental pollution due to its high-water content and easily fermentable nature.

Modelling of technical, environmental, and economic evaluations of the effect of the organic loading rate in semi-continuous anaerobic digestion of pre-treated organic fraction municipal solid waste.

The study concerned technical feasibility, economic profitability, and carbon footprint (CF) analysis of semi-continuous anaerobic digestion (sAD) of organic fraction of municipal solid waste (OFMSW). The research assessed the pre-treatment effect on sAD by varying organic loading rates (OLR) from 3.38 to 6.

Simultaneous CO reduction and NADH regeneration using formate and glycerol dehydrogenase enzymes co-immobilized on modified natural zeolite.

In this work, the co-immobilization of formate dehydrogenase (FDH) and glycerol dehydrogenase (GlyDH) enzymes is proposed to reduce CO into formic acid, an important chemical intermediate. The reduction of carbon dioxide is carried out by FDH to obtain formic acid, simultaneously, the GlyDH regenerated the nicotinamide cofactor in the reduced form (NADH) by the oxidation of glycerol into dihydroxyacetone. Natural zeolite was selected as immobilization support given its good properties and low cost.

A practical method for gas changing time estimation using a simple gas-liquid mass transfer model.

The present work explains a practical and simple method to calculate the gas changing time of anaerobic systems. It is substantiated under the physics of gas-liquid transfer theory and allows researchers to obtain an approximate value of gas changing time with few measurements of the gas composition in the outlet of the reactor. The only analytical equipment required is a gas analyzer, and calculations can be done using a spreadsheet.

Covalent Immobilization of Dehydrogenases on Carbon Felt for Reusable Anodes with Effective Electrochemical Cofactor Regeneration.

This study presents the immobilization with aldehyde groups (glyoxyl carbon felt) of alcohol dehydrogenase (ADH) and formate dehydrogenase (FDH) on carbon-felt-based electrodes. The compatibility of the immobilization method with the electrochemical application was studied with the ADH bioelectrode. The electrochemical regeneration process of nicotinamide adenine dinucleotide in its oxidized form (NAD ), on a carbon felt surface, has been deeply studied with tests performed at different electrical potentials.

Synthesis and characterization of ordered mesoporous silicas for the immobilization of formate dehydrogenase (FDH).

This work studied the influence of the pore size and morphology of the mesoporous silica as support for formate dehydrogenase (FDH), the first enzyme of a multi-enzymatic cascade system to produce methanol, which catalyzes the reduction of carbon dioxide to formic acid. Specifically, a set of mesoporous silicas was modified with glyoxyl groups to immobilize covalently the FDH obtained from Candida boidinii. Three types of mesoporous silicas with different textural properties were synthesized and used as supports: i) SBA-15 (D = 4 nm); ii) MCF with 0.

Recovery of humic acids from anaerobic sewage sludge: Extraction, characterization and encapsulation in alginate beads.

Wastewater production is rising all over the world and one of the most difficult problems is the disposal of sewage sludge (SS). It is known that SS contains certain quantities of added-value compounds, such as humic acids (HA) which in turn have beneficial effects on soil quality and plant growth. On the other hand, SS can retain many pollutants, such as heavy metals.

Anaerobic digestates from sewage sludge used as fertilizer on a poor alkaline sandy soil and on a peat substrate: Effects on tomato plants growth and on soil properties.

Anaerobic digestates from sewage sludge (SSADs) are a by-product of the wastewater treatment process that still preserves a certain agronomic interest for its richness in plant nutrients and organic matter. Fertilizing properties of two liquid and two dewatered SSADs were tested on tomato plants (Solanum lycopersicum L.).

Evaluation of anaerobic digestates from sewage sludge as a potential solution for improvement of soil fertility.

Sewage sludge production in European countries has widely raised in the last decade and its fate is currently landfilling, incinerators, composting or land application. To explore its agronomic potential, the main target of this work is to understand the effects of anaerobic digestates from sewage sludge (SSAD). To this aim, four different SSADs (two liquids and two dewatered) were characterized.

Life Cycle Assessment of waste disposal from olive oil production: Anaerobic digestion and conventional disposal on soil.

Extra virgin olive-oil (EVO) production is an important economic activity for several countries, especially in the Mediterranean area such as Spain, Italy, Greece and Tunisia. The two major by-products from olive oil production, solid-liquid Olive Pomace (OP) and the Olive Mill Waste Waters (OMWW), are still mainly disposed on soil, in spite of the existence of legislation which already limits this practice. The present study compares the environmental impacts associated with two different scenarios for the management of waste from olive oil production through a comparative Life Cycle Assessment (LCA).

Anodic microbial community analysis of microbial fuel cells based on enriched inoculum from freshwater sediment.

The characterization of anodic microbial communities is of great importance in the study of microbial fuel cells (MFCs). These kinds of devices mainly require a high abundance of anode respiring bacteria (ARB) in the anode chamber for optimal performance. This study evaluated the effect of different enrichments of environmental freshwater sediment samples used as inocula on microbial community structures in MFCs.

Ureteral double-J stents performances toward encrustation after long-term indwelling in a dynamic in vitro model.

Three different single-lumen double-J ureteral stents of different materials were studied and compared after the insertion into a dynamic in vitro model with sterile artificial urine up to 6 months. The aim was to evaluate, at selected time steps of 1, 3, and 6 months, the material performances of the stents in preventing the formation of inorganic encrustations. Morphological, compositional, and qualitative analyses were carried out both before stent insertion and after stent permanence for the different time steps, showing an increasing level of encrustation which remains particularly low in the case of two polyurethane stents.

New insights in Microbial Fuel Cells: novel solid phase anolyte.

For the development of long lasting portable microbial fuel cells (MFCs) new strategies are necessary to overcome critical issues such as hydraulic pump system and the biochemical substrate retrieval overtime to sustain bacteria metabolism. The present work proposes the use of a synthetic solid anolyte (SSA), constituted by agar, carbonaceous and nitrogen sources dissolved into diluted seawater. Results of a month-test showed the potential of the new SSA-MFC as a long lasting low energy consuming system.

Pyrolytic carbon-coated stainless steel felt as a high-performance anode for bioelectrochemical systems.

Scale up of bioelectrochemical systems (BESs) requires highly conductive, biocompatible and stable electrodes. Here we present pyrolytic carbon-coated stainless steel felt (C-SS felt) as a high-performance and scalable anode. The electrode is created by generating a carbon layer on stainless steel felt (SS felt) via a multi-step deposition process involving α-d-glucose impregnation, caramelization, and pyrolysis.

Additive Manufacturing of a Microbial Fuel Cell--A detailed study.

In contemporary society we observe an everlasting permeation of electron devices, smartphones, portable computing tools. The tiniest living organisms on Earth could become the key to address this challenge: energy generation by bacterial processes from renewable stocks/waste through devices such as microbial fuel cells (MFCs). However, the application of this solution was limited by a moderately low efficiency.