Dynamics of microbial community and their effects on membrane fouling in an anoxic-oxic gravity-driven membrane bioreactor under varying solid retention time: A pilot-scale study.

Membrane fouling in a membrane bioreactor (MBR) is highly influenced by the characteristics of the influent, the mixed liquor microbial community and the operational parameters, all of which are environment specific. Therefore, we studied the dynamics of microbial community during the treatment of real municipal wastewater in a pilotscale anoxic-oxic (A/O) MBR equipped with a gravity-driven membrane filtration system. The MBR was operated at three different solid retention times (SRTs): 25, 40 and 10 days for a total period of 180 days in Nordic environmental conditions.

Synergy between alkali activation and a salt template in superactive carbon production from lignin.

Due to growing demand, the performance of traditional active carbon is insufficient. An innovative solution is superactive carbon with an ultra-high surface area as high as 3000 m g. However, this material is very costly due to the considerable amount of alkali used in its manufacturing.

Green solvents in recovery of aluminium and plastic from waste pharmaceutical blister packaging.

Pharmaceutical blister packages usually comprise of aluminium and plastic layers. Due to their multi-material structure, the discarded packages are typically landfilled, although when separated, both metallic and polymeric fractions would be recyclable. In the present study, separation of aluminium and polymeric layers of waste pharmaceutical blisters was conducted by exploitation of deep eutectic solvent (DES, lactic acid - choline chloride) and pure lactic acid, both of which are considered green solvents.

Analysis of membrane fouling by Brunauer-Emmet-Teller nitrogen adsorption/desorption technique.

Membrane fouling is the major factor limiting the wider applicability of the membrane-based technologies in water treatment and in separation and purification processes of biorefineries, pulp and paper industry, food industry and other sectors. Endeavors to prevent and minimize fouling requires a deep understanding on the fouling mechanisms and their relative effects. In this study, Brunauer-Emmett-Teller (BET) nitrogen adsorption/desorption technique was applied to get an insight into pore-level membrane fouling phenomena occurring in ultrafiltration of wood-based streams.

Transport of pharmaceuticals during electrodialysis treatment of wastewater.

Electrodialysis (ED) is a promising emerging electrochemical membrane technology for nutrient concentration and recovery from wastewater. However associated environmental safety aspects have to be assessed before utilizing concentrated nutrient produced by ED, for instance as fertilizer. Municipal wastewaters contain various micropollutants that have the potential of being concentrated during the ED treatment processes.

Vanillin as an Antifouling and Hydrophilicity Promoter Agent in Surface Modification of Polyethersulfone Membrane.

Fouling as an intricate process is considered as the main obstacle in membrane technologies, and its control is one of the main areas of attention in membrane processes. In this study, a commercial polyethersulfone ultrafiltration membrane (MWCO: 4000 g/mol) was surface modified with different concentrations of vanillin as an antifouling and hydrophilicity promoter to improve its performance. The presence of vanillin and its increasing adsorption potential trends in higher vanillin concentrations were clearly confirmed by observable changes in FTIR (Fourier transform infrared) spectra after modification.

Utilization of DES-Lignin as a Bio-Based Hydrophilicity Promoter in the Fabrication of Antioxidant Polyethersulfone Membranes.

Enhancement of membrane permeability at no detriment of its other performances, e.g., selectivity, is a goal-directed objective in membrane fabrication.

Visual tool for real-time monitoring of membrane fouling via Raman spectroscopy and process model based on principal component analysis.

Membrane fouling, i.e. accumulation of unwanted material on the surface of the membrane is a significant problem in filtration processes since it commonly degrades membrane performance and increases operating costs.

A Double Transducer for High Precision Ultrasonic Time-Domain Reflectometry Measurements.

Membrane fouling, where unwanted particles accumulate on the membrane surface and reduce its permeability, causes problems in membrane filtration processes. With ultrasonic time-domain reflectometry (UTDR) it is possible to measure the extent of membrane fouling and hence take actions to minimize it. However, the usability of UTDR is very limited to constant filtration conditions if the sonic velocity, which has a great impact on UTDR measurement accuracy, is unknown.

High precision UTDR measurements by sonic velocity compensation with reference transducer.

An ultrasonic sensor design with sonic velocity compensation is developed to improve the accuracy of distance measurement in membrane modules. High accuracy real-time distance measurements are needed in membrane fouling and compaction studies. The benefits of the sonic velocity compensation with a reference transducer are compared to the sonic velocity calculated with the measured temperature and pressure using the model by Belogol'skii, Sekoyan et al.

Enhanced membrane filtration of wood hydrolysates for hemicelluloses recovery by pretreatment with polymeric adsorbents.

In this study adsorption of foulants from birch and pine/eucalyptus wood hydrolysates on two polymeric adsorbents was studied aiming to reduce the membrane fouling. The effect of the pretreatment of hydrolysate on polyethersulphone membrane performance was studied in dead-end filtration experiments. Adsorption pretreatment improved significantly filtration capacity and decreased membrane fouling.

Production and recovery of monosaccharides from lignocellulose hot water extracts in a pulp mill biorefinery.

Processing of hemicelluloses obtained with pressurized hot water extraction (PHWE) from Scots pine to monosaccharides and other chemicals was investigated experimentally. A process scheme consisting of ultrafiltration, acid hydrolysis, and chromatographic separation was proposed and evaluated. A two-stage ultrafiltration was found necessary for efficient fractionation of the wood extract.