Membrane bioreactors for sustainable water management
Introduction The Membrane Bioreactor (MBR) process (membrane activated sludge process) is an advanced wastewater treatment technology and constitutes a suspended growth activated sludge system, which instead of secondary clarifiers utilises low-pressure membranes for solid/liquid separation. As opposed to secondary clarification, the quality of solids separation is not dependent upon the mixed liquor suspended solids concentration, or the settling characteristic. Hence the fact that MBRs can operate with much higher mixed liquor suspended solid concentrations, which provides an intensified biological process. Accordingly, the two major benefits of the MBR process are substantially reduced land and space requirements, and the reclamation of water (permeate) of excellent quality, which is a valuable source for higher demand reuse applications.
Pre-Treatment of Municipal MBR Applications in Germany- Current Status and Treatment Efficiency
Since mid 1999 MBR technology is introduced into domestic wastewater treatment in Germany. First wwtps went in operation performing a conventional mechanical treatment (covering screens, grit chambers and grease traps) without any advanced mechanical pre-treatment stage. After a short operation period module-clogging and hence module sludging was observed. Thus, mechanical pre-treatment was upgraded introducing sieves, first of all to reduce hairs and fibrous substances. But today knowledge is relatively poor concerning effectiveness and treatment efficiency of the whole bunch of aggregates that had been brought to market and vary e.g. in gap size and gap geometry. This paper gives the basics of sieving, the current status of mechanical pre-treatment on German municipal MBR plants and exemplifies an investigation to determine treatment efficiency of two different sieve aggregates.
New approach to vision-based BGA package inspection
Ball grid array (BGA) techniques have developed very fast due to the advantages of more I/O ports, small size, and so on. In this paper, a vision-based algorithm for BGA package inspection is proposed to accurately estimate center and diameters of solder-balls of BGA packages, so that defects of BGA packages, such as missing or extra balls, oversize or undersize balls, over-height or under-height balls, and pitch can be detected for ensuring the quality of BGA packages.