Search results for "Fouling"
showing 10 items of 150 documents
Potentiation of the cytotoxic activity of copper by polyphosphate on biofilm-producing bacteria: A bioinspired approach
2012
Adhesion and accumulation of organic molecules represent an ecologically and economically massive problem. Adhesion of organic molecules is followed by microorganisms, unicellular organisms and plants together with their secreted soluble and structure-associated byproducts, which damage unprotected surfaces of submerged marine structures, including ship hulls and heat exchangers of power plants. This is termed biofouling. The search for less toxic anti-biofilm strategies has intensified since the ban of efficient and cost-effective anti-fouling paints, enriched with the organotin compound tributyltin, not least because of our finding of the ubiquitous toxic/pro-apoptotic effects displayed b…
Utilization of enzymatic detergents to clean inorganic membranes fouled by whey proteins
2005
In this work inorganic membranes used for whey protein fractionation were cleaned with enzymatic detergents. The inorganic membrane Carbosep ® M1 (Orelis S.A., France), of 150 kg/mol molecular weight cut-off and ZrO2 filtering layer, was used and the commercial detergent P3-Ultrasil ® 62 (Henkel IbS.A., Spain) was selected for the cleaning. Hydraulic and chemical methods were considered to characterize the membrane cleanliness. Cleaning efficiency was observed to be a function of the operating conditions: recycling versus non-recycling of permeate, cleaning solution pH, enzymatic agent concentration and cleaning time. The optimum conditions to perform the cleaning were related to the optimu…
Functional Enzyme Mimics for Oxidative Halogenation Reactions that Combat Biofilm Formation
2017
Transition-metal oxide nanoparticles and molecular coordination compounds are highlighted as functional mimics of halogenating enzymes. These enzymes are involved in halometabolite biosynthesis. Their activity is based upon the formation of hypohalous acids from halides and hydrogen peroxide or oxygen, which form bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities in follow-up reactions. Therefore, enzyme mimics and halogenating enzymes may be valuable tools to combat biofilm formation. Here, halogenating enzyme models are briefly described, enzyme mimics are classified according to their catalytic functions, and current knowledge about th…
The fouling community as an indicator of fish farming impact in Mediterranean
2007
Fouling species richness, abundance and composition and biomass were chosen as the descriptors of effect of fish farm organic enrichment. The study was carried out in September 2004 in the Gulf of Castellammare (South Tyrrhenian, Mediterranean). The fouling species were sampled from plastic buoys spaced throughout the study area both up- [UP] and down-stream [DOWN]. The results showed that fouling community responded to the chronic input of allochthonous organic matter experiencing local changes more or less significantly with regard to abundance, species composition and general community diversity. Upper fouling would work as a first filter naturally opposed by environment resistance assim…
Impact of surface state on polyethylene glycol conformation confined inside a nanopore.
2021
Solid-state nanopores are a promising platform for characterizing proteins. In order to improve their lifetime and prevent fouling, Polyethylene Glycol (PEG) grafting is one of the most efficient and low-cost solutions. Different models to calculate the PEG thickness do not consider their interaction with the nanopore inner surface nor the effect of confinement. Here, we investigate by molecular dynamic simulation the PEG conformation inside a nanopore in the case of hydrophobic and hydrophilic nanopores. Our results reveal that the nanopore inner surface plays a role in the PEG organization and, thus, in the speed of the salt constituent. The resulting pair interaction between PEG and its …
Energy and environmental impact of an anaerobic membrane bioreactor (AnMBR) demonstration plant treating urban wastewater
2020
Abstract In order to assess the environmental feasibility of anaerobic membrane bioreactor (AnMBR) technology for urban wastewater (UWW) treatment at ambient temperature, a demonstration plant was operated within the LIFE MEMORY project ( http://www.life-memory.eu/en/ ). This plant incorporates full-scale hollow-fiber membrane modules and was fed with the effluent from the pre-treatment of the “Alcazar de San Juan” WWTP (Alcazar de San Juan, Ciudad Real, Spain). Because of the dimensions of this plant, the system can be regarded as a previous step to the scale-up of AnMBR technology for full-scale UWW treatment. High-energy recovery potentials were achieved treating medium-/high-loaded UWW …
Water level regulation in winter triggers fouling of fishing nets by the diatom Aulacoseira islandica in a boreal lake
2015
Water level regulation related to hydroelectric power production and flood prevention is an important hydro-morphological pressure on many watercourses around the world. Fouling of fishing nets in autumn during the open water period and in winter under the ice is a common phenomenon in large Finnish lakes where the water level is regulated. This fouling of fishing nets can sometimes be so extensive that fishing has to be stopped. Based on the practical experiences of fishermen, the main cause for the under-ice fouling has been proposed to be the winter draw-down of water causing low water level and stronger currents in lakes, but no conclusive relationship between fouling and water level re…
Impianto perfezionato per il trattamento di acque reflue
2019
Negli ultimi anni, a causa dell’incremento dei costi di smaltimento dei fanghi prodotti nel corso dei processi depurativi basati su metodi biologici, si va diffondendo sempre più la tendenza e la necessità di ridurne la produzione direttamente alla fonte, ovvero nel corso dello stesso processo che li genera. Diversi metodi sono proposti in letteratura e molti di essi sono già coperti da brevetto (OSA®, Cannibal®, Biminnex®), applicati ai processi biologici a fanghi attivi convenzionali (CAS). Il limite di questi processi è che una riduzione molto spinta della produzione di fango di supero, ottenuta sottoponendo la biomassa a stress biologico, comporta significativi peggioramenti della quali…
Real-time optimization of the key filtration parameters in an AnMBR: Urban wastewater mono-digestion vs. co-digestion with domestic food waste
2018
[EN] This study describes a model-based method for real-time optimization of the key filtration parameters in a submerged anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) and UWW mixed with domestic food waste (FW). The method consists of an initial screening to find out adequate filtration conditions and a real-time optimizer applied to a periodically calibrated filtration model for minimizing the operating costs. The initial screening consists of two statistical analyses: (1) Morris screening method to identify the key filtration parameters; (2) Monte Carlo method to establish suitable initial control inputs values. The operating filtration cost after implementing the…
Power Production from Produced Waters via Reverse Electrodialysis: A Preliminary Assessment
2022
Wastewaters generated by crude oil extraction processes, called “produced waters” (PWs), are complex solutions that contain organic compounds, mainly hydrocarbons, and often exhibit high salinity. The large amounts of PWs represent a global issue because of their environmental impact. An approach widely used in the oil industry is the reinjection of this wastewater into the extraction wells after a suitable treatment. The high salt concentration of such solutions may be used in salinity gradient technologies to produce green electricity. Among these technologies, reverse electrodialysis (RED) is one of the most promising. In this work, the application of RED for energy generatio…