This study focused on three of the most studied PFAS molecules, namely perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutane sulfonate (PFBS). They were compared in terms of their adsorption capacity onto graphite intercalated compound (GIC), a low surface area, highly conductive and cheap adsorbent. The adsorption on GIC followed a pseudo second order kinetics and the maximum adsorption capacity using Langmuir was 53.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
March 2024
Perfluorooctanoic acid (PFOA) is a bioaccumulative synthetic chemical containing strong C-F bonds and is one of the most common per- and polyfluoroalkyl substances (PFAS) detected in the environment. Graphite intercalated compound (GIC) flakes were used to adsorb and degrade PFOA through electrochemical oxidation. The adsorption followed the Langmuir model with a loading capacity of 2.
View Article and Find Full Text PDFThe increasing prevalence of microplastic pollution in aquatic environments has raised concerns about its impact on marine life. Among the different types of microplastics, polystyrene microplastics (PSMPs) are one of the most commonly detected in aquatic systems. Chaetoceros neogracile (diatom) is an essential part of the marine food web and plays a critical role in nutrient cycling.
View Article and Find Full Text PDFPerfluorooctane sulfonate (PFOS) is a highly recalcitrant perfluoro chemical belonging to the family of per- and polyfluoroalkyl substances (PFAS). Its adsorption and degradation was demonstrated in a novel PFAS remediation process involving the adsorption onto graphite intercalated compounds (GIC) and the electrochemical oxidation. The Langmuir type of adsorption was characterized by a loading capacity of 53.
View Article and Find Full Text PDFOn 24 February 2022, Russian military forces invaded Ukraine. The fighting has already caused unimaginable conditions and millions of people were forced to flee their homes. For decades, conflicts have been linked to environmental pollution, exposure to radioactivity and heavy metals as well as infectious diseases.
View Article and Find Full Text PDFDairy products are relevant in the food industries as functional ingredients for several food products and contribute towards human nutrition in ameliorating certain disorders. In this study, set yogurts were produced from raw milk and processed milk combined with 4% LacprodanPL20 concentration and subjected to two-stage pressure homogenization. The total solids concentration of the mixture was raised to 15% using SMP (skim milk powder).
View Article and Find Full Text PDFUltrason Sonochem
November 2018
Ultrasound (ULS), sodium hydroxide (NaOH) and combined ultrasound/NaOH pre-treatment were applied to pre-treat waste activated sludge and improve the subsequent anaerobic digestion. Synergistic effect was observed when NaOH treatment was coupled with ultrasound treatment. The highest synergistic Chemical Oxygen Demand (COD) solubilization was observed when 0.
View Article and Find Full Text PDFThe anaerobic digestion process is a multi - step reaction dependent on concerted activities such as exchange of metabolites among physiologically different microbial communities. This study investigated the impact of iron oxide nanoparticles on the anaerobic sludge microbiota. It was shown there were three distinct microbial phases following addition of the nanoparticles: microbial stress and cell death of approximately one log order of magnitude, followed by microbial rewiring, and recovery.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
February 2018
In this study, the production, composition, and characteristics of dissolved organic matter (DOM) in an anoxic-aerobic submerged membrane bioreactor (MBR) were investigated. The average concentrations of proteins and carbohydrates in the MBR aerobic stage were 3.96 ± 0.
View Article and Find Full Text PDFJ Environ Sci Health A Tox Hazard Subst Environ Eng
September 2017
Zinc Oxide nanoparticles (ZnO NPs) are being increasingly applied in the industry, which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Zinc Oxide NPs and to compare it with its ionic counterpart (as ZnSO). It was found that even 1 mg/L of ZnO NPs could have a small impact on COD and ammonia removal.
View Article and Find Full Text PDFJ Environ Sci Health A Tox Hazard Subst Environ Eng
May 2017
Copper oxide nanoparticles (CuO NPs) are being increasingly applied in the industry which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Copper Oxide NPs at concentrations of 0.1, 1, 10 and 50 mg/L and to compare it with its ionic counterpart (CuSO).
View Article and Find Full Text PDFA biosorption column and a settling tank were operated for 6 months with combined municipal and industrial wastewaters (1 m/hr) to study the effect of dissolved oxygen (DO) levels and Fe dosage on removal efficiency of dissolved and suspended organics prior to biological treatment. High DO (>0.4 mg/L) were found to be detrimental for soluble chemical oxygen demand (COD) removals and iron dosing (up to 20 ppm) did not improve the overall performance.
View Article and Find Full Text PDFIn light of global warming mitigation efforts, increasing sludge disposal costs, and need for reduction in the carbon footprint of wastewater treatment plants, innovation in treatment technology has been tailored towards energy self-sufficiency. The AB process is a promising technology for achieving maximal energy recovery from wastewaters with minimum energy expenditure and therefore inherently reducing excess sludge production. Characterization of this novel sludge and its comparison with the more conventional B-stage sludge are necessary for a deeper understanding of AB treatment process design.
View Article and Find Full Text PDFThis study investigated the behaviour and characteristics of soluble microbial products (SMP) in two anoxic-aerobic membrane bioreactors (MBRs): MBRcontrol and MBRpharma, for treating municipal wastewater. Both protein and polysaccharides measured exhibited higher concentrations in the MBRpharma than the MBRcontrol. Molecular weight (MW) distribution analysis revealed that the presence of pharmaceuticals enhanced the accumulation of SMPs with macro- (13,091 kDa and 1587 kDa) and intermediate-MW (189 kDa) compounds in the anoxic MBRpharma, while a substantial decrease was observed in both MBR effluents.
View Article and Find Full Text PDFThis manuscript presents a comparison of the A-stage and B-stage sludges in terms of anaerobic biodegradability and low molecular weight compounds present in the supernatant using Gas Chromatography-Mass Spectrometry (GC-MS). The GC-MS analysis of A-stage and B-stage supernatants identified respectively 43 and 19 organic compounds consisting mainly of aromatics (27.9% and 21%), alcohols (25.
View Article and Find Full Text PDFThe treatment of leachate (Average TCOD=11.97 g/L, 14.4% soluble) from the organic fraction of municipal solid waste was investigated using a Submerged Anaerobic Membrane BioReactor (SAMBR), followed by an aerobic membrane bioreactor (AMBR) to polish this effluent.
View Article and Find Full Text PDFThis paper focuses on the treatment of leachate from the organic fraction of municipal solid waste (OFMSW) in a submerged anaerobic membrane bioreactor (SAMBR). Operation of the SAMBR for this type of high strength wastewater was shown to be feasible at 5 days hydraulic retention time (HRT), 10 L min(-1) (LPM) biogas sparging rate and membrane fluxes in the range of 3-7 L m(-2) hr(-1) (LMH). Under these conditions, more than 90% COD removal was achieved during 4 months of operation without chemical cleaning the membrane.
View Article and Find Full Text PDFImpact of ultrasonication (ULS) and ultrasonication-ozonation (ULS-Ozone) pre-treatment on the anaerobic digestibility of sewage sludge was investigated with semi-continuous anaerobic reactors at solid retention time (SRT) of 10 and 20 days. The control, ULS and ULS-Ozone reactors produced 256, 309 and 348 mL biogas/g CODfed and the volatile solid (VS) removals were 35.6%, 38.
View Article and Find Full Text PDFAcetic acid was used in abiotic experiments to adjust the solution pH and investigate its influence on the chemical hydrolysis of the Organic Fraction of Municipal Solid Waste (OFMSW). Soluble chemical oxygen demand (SCOD) was used to measure the hydrolysis under oxidative conditions (positive oxidation-reduction potential values), and pH 4 allowed for 20% (±2%) of the COD added to be solubilized, whereas only 12% (±1%) was solubilized at pH7. Under reducing conditions (negative oxidation-reduction potential values) and pH 4, 32.
View Article and Find Full Text PDFThis work provides insights on the solubilization products after a simultaneous combination of alkaline and ultrasonic (ALK+ULS) pre-treatment of sewage sludge. Soluble chemical oxygen demand (SCOD) increased from 1200 to 11,000 mg/L after such treatment. Organics with molecular weight around 5.
View Article and Find Full Text PDFIn this study, a fungal mash rich in hydrolytic enzymes was produced by solid state fermentation (SSF) of waste cake in a simple and efficient manner and was further applied for high-efficiency hydrolysis of mixed food wastes (FW). The enzymatic pretreatment of FW with this fungal mash resulted in 89.1 g/L glucose, 2.
View Article and Find Full Text PDFJ Environ Sci Health A Tox Hazard Subst Environ Eng
June 2015
This article focuses on the combination of ultrasonic and thermal treatment of sewage sludge (SS). The combination involved ultrasonicating a fraction of the sludge and thermal treatment at various temperatures and this resulted in solubilization of proteins and carbohydrates, and so contributing to increased COD solubilization. During the treatment, SCOD, soluble proteins and carbohydrates increased from 760 mg L(-1) to 10,200 mg L(-1), 110 mg L(-1) to 2,900 mg L(-1) and 60 mg L(-1) to 630 mg L(-1), respectively.
View Article and Find Full Text PDFThe sequential combination of ultrasonication and ozonation as sewage sludge treatment prior to anaerobic digestion was investigated. Synergistic volatile suspended solids (VSS) solubilization was observed when low energy ultrasonication (⩽12kJg(-1) TS) was followed by ozonation. 0.
View Article and Find Full Text PDFThis paper focuses on a novel process for adding value to algae residue. In current processes oleaginous microalgae are grown and harvested for lipid production leaving a lipid-free algae residue. The process described here includes conversion of the carbohydrate fraction into glucose prior to lipid extraction.
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