Most of the water treatment plants applying the DAF process are faced with off-flavors control problems. For simultaneous control of particles of impurities and dissolved organics that cause pungent taste and odor in water, an effective method would be the simple application of powdered activated carbon (PAC) in the DAF process. A series of experiments were carried out to explore the feasibility for simultaneous removal of kaolin particles and organic compounds that produce off-flavors (2-MIB and geosmin). In addition, the flotation efficiency of kaolin and PAC particles adsorbing organics in the DAF process was evaluated by employing the population balance theory. The removal efficiency of 2-MIB and geosmin under the treatment condition with kaolin particles for simultaneous treatment was lower than that of the individual treatment. The decrease in the removal efficiency was probably caused by 2-MIB and geosmin remaining in the PAC particle in the treated water of DAF after bubble flotation. Simulation results obtained by the population balance model indicate, that the initial collision-attachment efficiency of PAC particles was lower than that of kaolin particles.

ABSTRACT:Here we describe a unique uterine mass in a dog with granulomatous lesions caused by filarial larvae from the family Onchocercidae. An 8-year-old female Maltese was presented to a local animal hospital with anorexia, depression, and vaginal discharge. A markedly distended uterus was observed on lateral abdominal radiographs, leading to a clinical diagnosis of pyometra or uterine mass of an unknown origin. During surgery, the left uterine horn contained a 5 cm diameter mass adhered to adjacent soft tissue. On gross inspection, the mass contained numerous white nematodes. Microscopically, this mass was characterised by a granulomatous inflammation of the myometrium and endometrium. Because all of the nematodes were dead, definitive species identification was not possible. However, based on the histologic appearance, these nematodes were tentatively identified as Dirofilaria immitis larvae.