Ahmed Aidan

Draw solute recovery by metathesis precipitation in forward osmosis desalination.

ABSTRACT Forward osmosis (FO) is a natural osmosis process that is under investigation as a potential means of desalination, wastewater treatment, and energy production. This article presents forward osmosis desalination study on a commercial cellulose acetate membrane. The membrane was tested for high feed concentrations ranging from typical brackish water concentration to seawater concentration. For energy-efficient recovery of product water, a 240,000 ppm of MgSO4 draw solution was used. The membrane achieved an average water flux of 4.06 and 0.60 L/m2 h in case of brackish and seawater, respectively. Pure product water with a salt content of 350 ppm was recovered from the diluted MgSO4 draw solution by reaction with stoichiometric amount of barium hydroxide to remove the soluble draw solute as magnesium hydroxide and barium sulfate precipitates.

Particulates and bacteria removal by ceramic microfiltration, UV photolysis, and their combination

Membrane microfiltration (MF) or ultrafiltration (UF) systems of activated sludge is crucial part of a bioreactor process used in municipal wastewater treatment. In this study, both cylindrical and flat sheet ceramic membranes were used to treat municipal wastewaters. The effects of removing water turbidity and coliform bacteria from an artificial wastewater were studied by performing batch experiments by MF and ultraviolet (UV) photolysis of 254 nm wavelength. It was shown that the microfiltration had a high effect of suspended solid removal. However, the effect of bacteria removal was limited so that the rate of cfu removal was approximately 61%. Combined consecutive processes in the treatment (MF/UV and UV/MF) confirmed that a specific porosity of the ceramic filter for bacteria removal was required. The continuous membrane bioreactor (MBR) tests performed by using a MF membrane with the pore size of 0.2 μ m showed that particulate matter and microorganisms found in municipal wastewater could be effectively removed. Turbidity was decreased from 4.50 to 0.05 NTU, with a removal efficiency of greater than 98%. The permeate total suspended solid (TSS) content for the whole run was below 5 mgL− 1. The density of total coliforms was decreased more than four orders of magnitude (from around 1× 105 mL− 1 to less than 5 mL− 1 in the effluent).

Modeling and dynamic analysis of a membrane bioreactor with backwash scheduling

Abstract A dynamic model, based on mass transport and reaction rate laws of biomass and substrate for a membrane bioreactor (MBR), was successfully developed. Furthermore, an empirical model for flux prediction was used. Key kinetic model parameters were estimated via nonlinear fitting of the model predictions to experimental data obtained from current and previous works. The performance of the MBR was evaluated with different vacuum-to-backwash time ratio. Permeate flux dynamics were shown to be sensitive to the backwash scheduling scenario. The proposed model will enable optimization of MBR operation in an attempt to minimize membrane fouling.

Improved membrane pretreatment of industrial wastewater

AbstractThe main objective of this research was to study the effect of coagulation on membrane performance by assessing the effect of retention of fine suspended and colloidal matter contained in industrial wastewater. Hybrid process was studied to show the improved efficiency of the coagulation–membrane filtration. It was found that some positively charged fine materials are forming a deposit on the inner surface area of the membrane that leads to its fast blockage, lowering the membrane performance life. In aiming to avoid such a fouling, a new technique was made from a combination between microfiltration and ultrafiltration used as a practical solution to overcome the problem. The combined process was named as micro-ultrafiltration (MUF) and investigated to check out the efficiency and the quality through the treatment plant for industrial wastewater of ceramic factory. The results showed (MF) modified devices were able to remove bacteria, cysts, and fine particles while the UF membranes were very effe...