A Pilot-Plant Test of a Membrane Bioreactor with a Novel Membrane Made from Chlorinated Poly (Vinyl Chloride) (CPVC) and Hydroxy-Propyl Cellulose

A pilot-plant test that can treat an amount of 30 ton per day of wastewater is performed. The purpose of this test is to prove the usefulness and applicability of newly developed microfiltration membranes made from chlorinated poly (vinyl chloride) and polyester nonwoven. Here, the hydrophilicity of membranes is important and hydroxyl-propyl cellulose is used to mitigate their hydrophobicity. The membrane consists of the novel structure in which small particles made from hydroxyl-propyl cellulose gel are homogeneously dispersed and attached on the surface of micro fibrils in the structure. The result of the pilot-plant test shows that the newly developed membrane has anti-fouling properties better than that of a conventional membrane made from chlorinated poly (vinyl chloride) by another company. It still shows high hydrophilicity after the use of one year, while the conventional one loses such properties. Saving electricity in producing water is one of important issues in developing membrane bioreactor systems and the case in use of newly-developed membranes is revealed to need 2.0 kWh of electricity to produce 1 m3 of filtered water. This amount is fairly good and reasonable when the pilot-plant test is considered to belong to a medium-size facility

Nanofiltration Hollow Fiber Membranes Made from Sulfonated Polysulfone having a Cyanophenylene Group

A nanofiltration hollow fiber membrane made from sulfonated polysulfone was proposed in this work to meet the demands of having tolerance against chemicals. The sulfonate group in the molecule is a source of highly hydrophilic properties and may increase the inter-molecular force acting between molecules on which it is attached. It also contributes to forming a tight structure in the membrane. The membrane may produce higher water flux than those of commercially available nanofiltration membranes made from polyamides. The state of water in the wet membrane was examined with a nuclear magnetic resonance spectrometer. The bonding force to confine water molecules in the membrane may be considered to control the water flux and salt rejection of membranes. It is revealed that there were two kinds of water in the membrane and the salt rejection was raised when the interaction to the water molecules from sulfonate groups in the sulfonated polysulfone molecule was increased. The salt rejection and water flux is highly correlated with the chemical shift of constrained water

A Relationship between Structure and Property of PBO Fibers

To clarify the relationship between a molecular deformation mechanism and a high Young's modulus of poly p-phenylenebenzobisoxazole (PBO) fiber; structural analyses were carried out. Especially, Raman spectra were measured for fibers subjected to a tensile stress along the chain axis. The Raman shift factor ( the frequency shift caused by 1 GPa tensile stress) depended strongly on the sample production condition. A mechanical series model was adopted, which successfully and quantitatively explained the observed Raman, shif factors