Comparative evaluation of osmotically-driven cleaning methods for organic-inorganic fouling in pressure retarded osmosis (PRO)

Pressure retarded osmosis (PRO) is a promising technique of desalination techniques. However, one of the major problems is permeate flux decline by fouling. This study investigates the mitigation of organic and inorganic fouling in PRO by osmotically driven cleaning methods. This study comparatively evaluates the effective cleaning methods: (i) Osmotic Backwashing (OB), (ii) Reverse Osmosis Flushing (ROF), and (iii) Pressure Assisted Osmotic Backwashing (PAOB). The results showed that PAOB was a more effective method than the others in terms of cleaning efficiency and permeability. CaCO3 solution of 1000 mg/L and humic acid 100 mg/L were used as a representative inorganic and organic foulant, respectively. After cleaning, cleaning efficiency and flux decline rate were compared. The PAOB method showed the higher performance compared to other cleaning methods, had 92% recovery rate and lower flux decline after cleaning. Also, by using instrumental analysis-scanning electron microscope (SEM), it was proven to find out the proper cleaning method in PRO. Keywords: Membrane fouling, Cleaning method, PAO

CFD modelling of cyclonic-DAF (dissolved air flotation) reactor for algae removal

The purpose of this study is to simulate the Cyclonic-DAF tanks using CFD techniques for the optimal design. CFD simulations were performed on two different Cyclonic-DAF reactor shapes either having or not having a cone shaped settled sludge removal unit in the bottom area of the inlet in the Cyclonic-DAF reaction tank. An average flow of less than 10% within the Cyclonic-DAF was rarely found in both shapes while areas of less than 20% were only slightly found near the central concentrate waste pipe. Areas having an average flow of less than 50% were found around the concentrate waste pipe and were observed at a rate of less than 5% of the total volume. Efficiency test results of different Cyclonic-DAF (CDAF) tank height to diameter ratios set at 1:1, 1:35:1, 1.6:1, and 1.85:1 indicated similar efficiencies with turbidity at 91.9% and chlorophyll-a at 94.7%. Keywords: Algae removal, Dissolved air flotation, DAF, Cyclonic-DAF, Computational fluid dynamics (CFD

First test-beam results obtained with IDEA, a detector concept designed for future lepton colliders

IDEA (Innovative Detector for Electron\u2013positron Accelerators) is a detector concept designed for a future leptonic collider operating as a Higgs factory. It is based on innovative detector technologies developed over years of R&D. In September 2018, prototypes of the proposed sub-detectors have been tested for the first time on a beam line at CERN. The preliminary results from this test of a full slice of the IDEA detector and standalone measurements of dual read-out calorimeter prototypes are presented