The presence of humic substances (HS) in landfill leachate is of great interest because of their structural stability and potential toxicity. This study examined the effects of temperature and waste age on the transformation of HS during in situ aeration of bioreactor landfills. By establishing aerobic conditions, dissolved organic carbon (DOC) rapidly accumulated in the bioreactor leachate. Fr...

Stepped spillwayflows are characterised by significant free-surface aeration downstream of the inception point of air entrainment. The stepped design is advantageous for applications which require large energy dissipation and strong flow aeration. While the energy dissipation rate for embankment stepped spillways was studied previously, the optimum design for aeration and air–water mass transfe...

Ethylene oxide (ETO) sterilization of polyvinyl trays used in an antiviral screening program was initiated to overcome seasonal outbreaks of bacterial and mycotic contamination of tissue culture cells. Trays sterilized by 100% ETO for 5 hr after 48 hr of prehumidification, or by 12% ETO plus 88% Freon 12 for 1, 3, 5 or 18 hr, followed by various methods of aeration, were seeded with several typ...

Soil hydraulic principles suggest that post-infiltration hypoxic conditions would be induced in the plant root-zone for drip-irrigated tomato production in small pots filled with natural soil. No previous study specifically examined the response of tomato plants (Solanum lycopersicum) at different growth stages to low soil aeration under these conditions. A 2 × 6 factorial experiment was conduc...

The emission of greenhouse gases (GHG) during feedlot manure composting reduces the agronomic value of the final compost and increases the greenhouse effect. A study was conducted to determine whether GHG emissions are affected by composting method. Feedlot cattle manure was composted with two aeration methods--passive (no turning) and active (turned six times). Carbon lost in the forms of CO2 ...

INTRODUCTION This study assessed the air exhaustion control of corrugated plate interceptor (CPI) oil separators in a refinery wastewater treatment plant for biodegradation of volatile organic compounds (VOCs) by deep activated sludge aeration systems. Three approaches were used to derive VOC emission factors: * (a) Calculating using the aeration rate and VOC gas-liquid equilibrium concentratio...

Growth of 12 Leuconostoc strains in a broth medium with and without aeration was compared. In general, the aerated cultures grew faster and produced more biomass, at the expense of glucose and other sugars, than unaerated cultures. The more efficient growth correlated well with the production of acetate rather than ethanol as an end-product of metabolism in aerated cultures; unaerated cultures ...

biological removal of lead was observed in this study during treatment of synthetic solutions of this heavy metal by a sample of waste activated sludge (was) having mlss concentration of 10000 mg/l. the objective was determining the capability of was in removal of lead in three different conditions of treatment: without any aeration and feeding, by simultaneous aeration and feeding and by aerat...

Pressure/volume (P/V) curves can be measured by static methods, constant or sinusoidal flow methods and the dynostatic method that allows a breath-to-breath determination of P/V curves. Recent ventilators are equipped with specific flow generators and software aimed at obtaining P/V curves without disconnecting the patient from the ventilator. The most recent generation of computed tomography s...

Inflammation during mechanical ventilation is thought to depend on regional mechanical stress. This can be produced by concentration of stresses and cyclic recruitment in low-aeration dependent lung. Positron emission tomography (PET) with (18)F-fluorodeoxyglucose ((18)F-FDG) allows for noninvasive assessment of regional metabolic activity, an index of neutrophilic inflammation. We tested the h...