We study stable circular orbits (SCO) around static spherically symmetric configuration of general relativity with a nonlinear scalar field (SF). The configurations are described by solutions the Einstein-SF equations monomial SF potential $V(\ensuremath{\phi})=|\ensuremath{\phi}{|}^{2n}$, $n>2$, under conditions asymptotic flatness and behavior $\ensuremath{\phi}\ensuremath{\sim}1/r$ at spa...

Snow cover is an important part of the Earth’s surface and its changes affect local even global climates due to high albedo heat insulation. However, it difficult directly compare results previous studies on in snow Northern Hemisphere mainland (NH) use different datasets, research methods, or study periods, a lack comparison terms differences similarities at latitudes altitudes. By using depth...

The aim of this study was to investigate the effectiveness of anaerobic digestion for the treatment of wool scouring wastes. The experiments design comprised three ratios of waste (W) to seed(S) (W:S) of 25:75, 50:50 and 75:25, corresponding to 1.9. 1.7 and 1.5g tCOD/g TS, respectively, with or without chemicals addition. NH4Cl was added to the reactors as a source for nitrogen to achieve C:N:P...

In order to ascertain the effects of different carbon sources (methanol, glucose, starch and NaHCO(3)) on denitrification in BESs, the experiment was conducted in a constant current, 3.5 of chemical oxygen demand to nitrate ratio in a greenhouse. Among the four carbon sources investigated in BESs, NaHCO(3) showed the highest nitrite accumulation and the ratio of soluble microbial products to so...

This work provides insights on the solubilization products after a simultaneous combination of alkaline and ultrasonic (ALK+ULS) pre-treatment of sewage sludge. Soluble chemical oxygen demand (SCOD) increased from 1200 to 11,000 mg/L after such treatment. Organics with molecular weight around 5.6 kDa were solubilized because of the synergistic effect of ultrasound and alkali. Organics with mole...

Using internal carbon source contained in waste activated sludge (WAS) is beneficial for nitrogen removal from wastewater with low carbon/nitrogen ratio, but it is usually limited by sludge disintegration. This study presented a novel strategy based on free nitrous acid (FNA) pretreatment to intensify the release of organic matters from WAS for enhanced denitrification. During FNA pretreatment,...

a study was performed in hybrid up flow anaerobic sludge blanket (huasb) and anaerobic filter (af) reactors to compare the start-up time and optimum hrt required for the treatment of poultry slaughterhouse wastewater under similar loading conditions. initially, the reactors were started at an olr of 0.77 kg cod/m3.d and hrt of 36 h. loading rates were increased by reducing hrt 24, 16, 12, 10 an...

Additional enzymes pretreatment technology can promote the hydrolysis of excess activated sludge, while increasing gas production. Single enzyme pretreatment of sludge, alkaline protease has a better effect of hydrolysis. The optimum working conditions for alkaline protease: pH value of 8.0, the solid-liquid ratio of 1:4, the enzyme concentration of 2%, the working temperature of 55°C, reaction...

The purpose of this research was develop a biological nutrient removal (BNR) system which has low energy consumption, sludge production, and land usage. These indicate that BNR system could be a alternative of future wastewater treatment in ubiquitous city(U-city). Organics and nitrogen compounds could be removed by this system so that secondary or tertiary stages of wastewater treatment satisf...