PAPER PRESENTATION - Sritama Mukherjee 27.08.2016 Membrane for - PowerPoint PPT Presentation

PAPER PRESENTATION - Sritama Mukherjee 27.08.2016

Membrane for UNIVERSAL water purifjcation?  Prevalent techniques:  Chemical precipitation- ~99% effjciency, causes secondary pollution, expensive, treats high contamination.  Sorbents and Ion Exchange resins- 60-90% SPECIFICTY!! effjciency, costly, treat small volume waste water, secondary pollution  Floatation or electrochemical treatment of waste water  Membrane purifjcation- ~99% effjciency but high intrinsic costs, membrane fouling, limiting feed fmows

The background Science involved…  Rufo and colleagues suggested that amyloid-forming peptides have a binding capability for zinc metal ions, which can catalyse fjbril formation.  It has also been proposed that the toxicity of protein aggregates is due to binding of heavy metal ions to the peptides.

So, what they did is..  Hybrid membrane development  amyloid fjbrils and activated Carbon  Waste water purifjcation (heavy metal and nuclear waste)  Simultaneous ion removal mode  β-Lactoglobulin  cheap edible milk protein  amyloid fjbrils  vacuum fjltration method.  Sticky and stifg-enable assembly of amyloid fjbrils with carbon-based materials  Mechanically strong composite membranes

Schematically, Heavy metal pollutants stud (KAu(CN) 2 ), (HgCl 2 ), (Pb(C 2 H 3 O 2 ) 4 ) a (Na 2 PdCl 4 )

Results and discussion: 50mL, 0.1L/min, 1.8 cm 2 area

Cont d.

Highlights: 10 × 50 mL = 0.5 L volume of water contaminated by mercury was processed using a 77 mg membrane containing only 7.4 wt% protein, that is, 5.7 mg, nearly 90,000 times less than the quantity of processed contaminated water. By extrapolating, 1 kg of protein could be used to treat 90,000 L of contaminated water. Fitting Parameters to fjt Metal adsorption isotherm

Recovery: Pollutant to valuable material

Summary:  Development of a hybrid composite membrane incorporating inexpensive and environmentally friendly β-lactoglobulin amyloid fibrils and activated carbon, and show that it can be used as a tool for the effjcient removal of heavy metal ion pollutants and radioactive waste from water.  Demonstrated the case of expensive metal pollutants, the recovered ions can even be converted into valuable materials, turning a global risk challenge into a unique opportunity.

Characterization Band gap=1.55 eV

FLV-MoS 2 disinfection performance

Summary:  Effjcient harvesting of visible light for photocatalytic water disinfection with a novel material, FLV-MoS2.  By decreasing the domain size, the band gap of MoS2 was increased from 1.3 eV (bulk material) to 1.55 eV (FLV- MoS2).  This enabled the FLV-MoS2 to generate ROS successfully for bacteria inactivation in water. The FLV-MoS2 showed a faster disinfection than the most-studied photocatalyst, TiO2.  With the additional deposition of Cu or Au to assist electron–hole pair separation and also to catalyse the ROS production reactions, FLV-MoS2 showed a rapid inactivation of >99.999% bacteria in only 20 or 60 min, respectively.

What can be done.. • Our material is specifjc towards Arsenic. Can we achieve multiple ion trapping by incorporating some cheap fjbrils to our composite? • Also, our material has no light sensitivity, so our material can be given visible light disinfection property, apart from Ag disinfection. Thank You.