The primary driver for a successful biological nutrient removal is the availability of suitable carbon source, mainly in the form of volatile fatty acids (VFA). Several methods have been examined to increase the amount of VFAs in wastewater. This study investigates the mechanism of mechanical disintegration of thickened surplus activated sludge by a deflaker technology for the production of org...

A control law based on Fuzzy Logic was developed and validated for an anaerobic wastewater treatment process. The controlled variable was the concentration of Volatile Fatty Acids (VFA) in the reactor and the manipulated variable was the input flow rate. In order to use it as the input of the fuzzy sets, the controlled variable was treated using an algorithm of interpolation, extrapolation and ...

work evaluating nutritional mitigation strategies. However, much of this work has been conducted on a small scale using intensive techniques such as respiration chambers or head boxes. Therefore, a method of gas collection and analysis was developed to allow evaluation of methane emissions by a large number of growing cattle under conditions that more closely mimic a production setting. The obj...

Twelve Suffolk×Small-tail-Han male sheep (body weight 21-26 kg), aged four months, were used to study the effects of volatile fatty acids (VFA) on IGF-I (insulin-like growth factor-I) , IGFBP-3 (insulin-like growth factor binding protein-3), GH (growth hormone), insulin and glucagon in plasma, and IGF-I and IGFBP-3 in different tissues. The sheep were randomly divided into four groups with 3 sh...

Adult male pigs were fed on a diet containing (% of energy) fat 25 starch 55 from white rice and providing 20 g fibre/pig d (diet WR). In two other groups rice bran was added to the diet to provide 43 g fibre/d. One group received the diet unmodified (diet RB), but in another (diet RO) heat-stabilized unrefined rice oil replaced the palm oil. In a further group brown rice replaced white rice an...

Virtual Force Algorithm (VFA) is becoming a main solution to area coverage forhomogeneous wireless sensor networks with random distribution of mobile sensor nodes.Consider the factors of the convergence, the boundary in Region Of Interest (ROI), effec-tive distance of acting force and useless moving, etc, VFA is improved to overcome the aboveproblems. Furthermore, an expression of exponential f...

Results: In the fi eld study, average daily gain of antibiotic-fed pigs was larger than that of DFM-fed pigs. Other growthperformance parameters, fecal Escherichia coli concentrations, and prevalence of Salmonella serovars were similar among treatment groups. Under experimental conditions, total fecal coliform concentration was signifi cantly lower in the antibiotic-fed group than in the two ot...

Fecal coliform bacteria were isolated from three herbivores (cattle, horse, and red panda) and shown to produce primarily the D-form of lactate, plus acetate and ethanol when grown anaerobically in 1.0% glucose broth. To evaluate coliform contribution to D-lactate acidosis in cattle, experiments involving a forage-adapted steer (fasted or normally fed) and four 500-ml fermentors were compared d...

As a primary energy source for ruminants, volatile fatty acids (VFA) have been estimated to provide up to 75% of the total metabolizable energy (Bergman, 1990). Thus, it is not surprising that diets promoting fermentation and greater production of VFA also promote greater levels of productivity (e.g. milk production) than less fermentable diets (Kolver and de Veth, 2002; Oba and Allen, 2003a,b)...