The axial development of calcium sulfate dihydrate (gypsum) scaling on selected reverse osmosis (RO) membrane surfaces was investigated experimentally in a plate-and-frame RO system. Scaling experiments with model solutions demonstrated progressive axial development of surface gypsum crystals along the membrane surface. The impact of surface crystallization was characterized via flux decline me...

Materials and methods: Performance and nutrient digestibility were determined for pigs consuming either water treated by reverse osmosis (RO; 219 mg total dissolved solutes (TDS) per L, 29 mg sulfates per L) or untreated ground water (3078 mg TDS per L, 1650 mg sulfates per L). In each of two experiments, approximately 240 pigs (20 ± 3 days of age, 5.9 ± 1.0 kg) received either RO-treated or un...

Forward osmosis (FO) is a membrane separation technology that has been studied in recent years for application in water treatment and desalination. It can best be utilized as an advanced pretreatment for desalination processes such as reverse osmosis (RO) and nanofiltration (NF) to protect the membranes from scaling and fouling. In the current study the rejection of trace organic compounds (TOr...

Thin-film composite nano-filtration (NF) and reverse osmosis (RO) membranes based NF followed by ROpilot plant at a feed pressure of 20 atm.and flow rate of 10 L/min. was used to remove colour, total dissolved solid (TDS) and chemical oxygen demand (COD) of distillery spent wash. NF was found to be effective for high rejection of TDS, colour and COD by 85%, 99% and 95%, respectively. Furthermor...

The performance of a polyamide-based thin film composite reverse osmosis membrane (RO) in a spiralwound element BW3025 (FilmTec) for the recovery of caprolactam from an aqueous solution have been investigated. The experimental tests of the RO membrane were carried out using pure water (permeate from a nanofiltration system), brackish water (2000 ppm NaCl) and caprolactam solution (1000 ppm) and...

The utility of a laboratory diagnostic approach was investigated for a systematic evaluation of the impact of operating conditions, membrane type, and antiscalant effectiveness on membrane mineral salt scale formation. The study focused on low-pressure reverse osmosis (RO) membrane desalting of brackish water with high potential for scaling by calcium sulfate dihydrate (gypsum). Gypsum scale fo...

We demonstrate theoretically and experimentally that injection of momentum in a region surrounding an object microscale flow can yield both “cloaking” conditions, where the field outside cloaking is unaffected by object, “shielding” hydrodynamic forces on are eliminated. Using field-effect electro-osmosis as mechanism for momentum, we present theoretical framework analytical solutions range geo...

We describe the general phenomenon of ‘induced-charge electro-osmosis’ (ICEO) — the nonlinear electro-osmotic slip that occurs when an applied field acts on the ionic charge it induces around a polarizable surface. Motivated by a simple physical picture, we calculate ICEO flows around conducting cylinders in steady (DC), oscillatory (AC), and suddenly-applied electric fields. This picture, and ...

This paper reports the first investigation of the dependence of AC electro-osmosis (ACEO) on the solution chemistry. It is argued that classical dilute-solution theory breaks down in ACEO, since the large applied voltage leads to ion crowding near the electrode surfaces. A modified theory is proposed with steric effects (finite ion sizes) and a charge-dependent viscoelectric effect, which predi...