Slurry acidification using sulfuric acid reduces ammonia emissions but also affects sulfur (S) cycling. Emission of sulfur is a source of malodor and reduces the sulfur fertilizer value of the slurry. We investigated the effect of sulfate and methionine amendments, alone or in combination with acidification, on sulfur transformations in slurry and emissions of volatile sulfur compounds (VSC) du...

Development of cost-effective amendments for treating dairy slurry has become a critical problem as the number of cows on farms continues to grow and the acreage available for manure spreading continues to shrink. To determine effectiveness and optimal rates of addition of either alum or zeolite to dairy slurry, we measured ammonia emissions and resulting chemical changes in the slurry in respo...

The high hydrophobicity of polycyclic aromatic hydrocarbons (PAHs) strongly reduces their bioavailability in aged contaminated soils, thus limiting their bioremediation. The biodegradation of PAHs in soils can be enhanced by employing surface-active agents. However, chemical surfactants are often recalcitrant and exert toxic effects in the amended soils. The effects of two biogenic materials as...

The melting of a particle-laden slurry in a cylinder is investigated. The slurry consists of neutrally buoyant ceramic hollow spheres suspended in a paraffin wax. Melt front propagation and heat transfer processes during phase change in this particle-laden material is studied. The numerical analysis employs a particle-diffusive model and the enthalpy method. Experiments are carried out to valid...

Biogas yield of mixtures of cattle slurry and cheese whey, rates of production of methane, removal efficiencies of chemical oxygen demand (COD) and biological oxygen demand (BOD) from the mixtures were investigated at 35°C. Four feed regimens (by volume) were studied. Stable biogas production of 621 l/kg Volatile Solids at an Hydraulic Retention Time of 42 days in a mixture containing 50% slurr...

The RheoMetal process (previously called the Rapid Sand RSFprocess) is a novel method to produce cost effective, high quality, semisolid slurries for component casting. The RheoMetal process uses an Enthalpy Exchange Material (EEM) as cooling agent to absorb heat and produce a slurry. Critical process parameters to create a slurry by robust melting of the EEM are alloy content, stirring speed, ...

The effect of impeller speed on the air flow in a selfaerated Denver laboratory flotation cell was investigated using computational modelling. Air is induced into the slurry by the impeller’s rotating action. The rate of air flow is determined by the suction pressure created by the impeller, the hydrostatic head of the slurry and the frictional losses along the delivery shaft from the inlet val...

The objective of this work is to obtain in situ slurry fluid flow data during the chemical mechanical planarization CMP process. Slurry flow affects the material removal processes, the creation of defects, and consumable use during CMP, and therefore impacts the cost and quality of polishing. Wafer-scale flow visualization using seeded slurry was accomplished for a variable applied load 0.3–2.5...

OBJECTIVE The present study aimed to assess the nitrogen (N) use efficiency of acidified pig slurry for regrowth yield and its environmental impacts on perennial ryegrass swards. METHODS The pH of digested pig slurry was adjusted to 5.0 or 7.0 by the addition of sulfuric acid and untreated as a control. The pig slurry urea of each treatment was labeled with 15N urea and applied at a rate of 2...

Acidification of slurry with sulfuric acid is a recent agricultural practice that may serve a double purpose: reducing ammonia emission and ensuring crop sulfur sufficiency. We investigated S transformations in untreated and acidified pig slurry stored for up to 11 mo at 2, 10, or 20 degrees C. Furthermore, the fertilizer efficiency of sulfuric acid in acidified slurry was investigated in a pot...