Sherub Phuntsho

Bio: Sherub Phuntsho is an academic researcher from University of Technology, Sydney. The author has contributed to research in topics: Forward osmosis & Membrane. The author has an hindex of 38, co-authored 151 publications receiving 5189 citations.

A review of draw solutes in forward osmosis process and their use in modern applications

Abstract: Forward osmosis (FO) is one of the emerging membrane technologies which has gained renewed interest recently as a low energy desalination process. The central to FO process is the draw solution (DS) and the membrane because both play a substantial role on its performance. Hence, the selection of an appropriate DS is crucial for the process efficiency. Many DS have been tested so far for a wide range of modern applications and this paper aims to review the various aspects of the DS in the process performance and provides valuable information regarding the selection criteria of suitable DS. Several general DS properties such as the osmotic pressure and the water solubility can affect the process performance. Other intrinsic properties to specific novel DS such as the emerging magnetic nanoparticles (MNPs) can also have an impact on the process efficiency and have to be evaluated. Separation and recovery of the DS are one of the major challenges facing the development of FO process. The recovery pro...

Nanofiltration for water and wastewater treatment – a mini review

Abstract: . The application of membrane technology in water and wastewater treatment is increasing due to stringent water quality standards. Nanofiltration (NF) is one of the widely used membrane processes for water and wastewater treatment in addition to other applications such as desalination. NF has replaced reverse osmosis (RO) membranes in many applications due to lower energy consumption and higher flux rates. This paper briefly reviews the application of NF for water and wastewater treatment including fundamentals, mechanisms, fouling challenges and their controls.

What a Waste 2.0: A Global Snapshot of Solid Waste Management to 2050

Abstract: By 2050, the world is expected to generate 340 billion tons of waste annually, increasing drastically from today’s 201 billion tons What a Waste 20: A Global Snapshot of Solid Waste Management to 2050 aggregates extensive solid waste data at the national and urban levels It estimates and projects waste generation to 2030 and 2050 Beyond the core data metrics from waste generation to disposal, the report provides information on waste management costs, revenues, and tariffs; special wastes; regulations; public communication; administrative and operational models; and the informal sector

A Review: Desalination by Forward Osmosis

Abstract: Rapid population growth increases the demand for freshwater. Membrane technology is playing a dynamic role in the production of clean water from seawater and wastewater. The desalination of seawater using forward osmosis (FO) is an emerging technology to produce freshwater, as it is energy efficient than the conventional processes. In recent days, a significant amount of work has been carried out to produce high-performance FO membrane for desalination. In this chapter, usage of different types of membranes for FO desalination application and their performances enhancement by suitable modification has been discussed.

Tunable sieving of ions using graphene oxide membranes

Abstract: Ion permeation and selectivity of graphene oxide membranes with sub-nm channels dramatically alters with the change in interlayer distance due to dehydration effects whereas permeation of water molecules remains largely unaffected. Graphene oxide membranes show exceptional molecular permeation properties, with promise for many applications1,2,3,4,5. However, their use in ion sieving and desalination technologies is limited by a permeation cutoff of ∼9 A (ref. 4), which is larger than the diameters of hydrated ions of common salts4,6. The cutoff is determined by the interlayer spacing (d) of ∼13.5 A, typical for graphene oxide laminates that swell in water2,4. Achieving smaller d for the laminates immersed in water has proved to be a challenge. Here, we describe how to control d by physical confinement and achieve accurate and tunable ion sieving. Membranes with d from ∼9.8 A to 6.4 A are demonstrated, providing a sieve size smaller than the diameters of hydrated ions. In this regime, ion permeation is found to be thermally activated with energy barriers of ∼10–100 kJ mol–1 depending on d. Importantly, permeation rates decrease exponentially with decreasing sieve size but water transport is weakly affected (by a factor of <2). The latter is attributed to a low barrier for the entry of water molecules and large slip lengths inside graphene capillaries. Building on these findings, we demonstrate a simple scalable method to obtain graphene-based membranes with limited swelling, which exhibit 97% rejection for NaCl.