Aeration devices are introduced along chute spillways and at bottom outlets to prevent cavitation damage in high velocity flows. Bottom aerators are characterised by large quantities of air entrained along the jet interfaces but also by a strong de-aeration process near the impact of the water jet with the spillway bottom. In this paper, the aeration and de-aeration occurring respectively in th...

Low efficiency of conventional aeration techniques and the excessive production and disposal of sludge are great concerns in biological wastewater treatment systems. The present study aimed to evaluate the active sludge method using batch reactors under continuous operation to determine the efficiency of aeration and sludge production through microbubble and nanobubble aeration. The results ind...

Aeration using automatic controllers was compared with manually‐activated aeration (manual aeration) in bins of farm‐stored rice in Nome, Texas, from 17 September 2002 through the end of the year. Manual aeration was defined as the farm owner manually activating the fans in mid‐October, while automatic aeration employed activation temperatures of 23.9 C, 15.6 C, and 7.2 C for three discreet coo...

Ethanol fermentation requires oxygen to maintain high biomass and cell viability, especially under very-high-gravity (VHG) condition. In this work, fermentation redox potential (ORP) was applied to drive the aeration process at low dissolved oxygen (DO) levels, which is infeasible to be regulated by a DO sensor. The performance and characteristics of flocculating yeast grown under 300 and 260 g...

The aims of these experiments were treating tapioca processing waste water to produce polyhydroxyalkanoates (PHAs) and removal of chemical oxygen demand (COD). The experiments were conducted in a sequencing batch reactor with a volume of 6 L. The entire experimental condition was anaerobic-aerobic-anaerobic. Experiment 1, 2 and 3 had the first 2 h for feeding time while Experiment 4 had 3 h. Th...

(a) The treatment efficiency in MBR was observed under different aeration rates. It was found that the optimal rate of aeration for removal efficiency was 3m/h.Increasing aeration rate resulted in shear stress, which caused elevated rates of sludge floc breakage, and consequently, supernatant COD. Excessive aeration rate could consequently also affected nitrogen removal by destructing anoxic co...

Biowaste composting at several plants in Scandinavia has been troubled by low pH in the collected waste as well as after the composting process. Our hypothesis was that increased aeration would give a higher and faster rise in pH during the composting process, and that this would give a higher decomposition rate. The objective was to test this hypothesis by experiments in full scale, with an em...

The aim of this work was to study the production of the bioinsecticide using the aerobic cultivation. Two-stage cultivation process was used: aerobic vegetative growth and end-phase of sporulation (with aeration and without aeration). The cuts of working volume evaluated were 20, 40, 60 and 80 %. The highest value of spore concentration (2.17x10 CFU/mL) and spore productivity (7.2x10 CFU/mL.h) ...

This study investigated the effects of 4 aeration levels (varied by injection of air to the soil through subsurface irrigation lines) at two subsurface irrigation line depths (15 and 40 cm) on plant growth, yield and nutritional quality of greenhouse tomato. In all experiments, fruit number, width and length, yield, vitamin C, lycopene and sugar/acid ratio of tomato markedly increased in respon...

BACKGROUND AND OBJECTIVES The aim of our study was to evaluate postoperative mastoid aeration according to the preoperative middle ear disease and investigate the factors affecting it. SUBJECTS AND METHODS We retrospectively reviewed the high-resolution computed tomography (CT) scans of temporal bones that were taken 1 year after surgery. The postoperative mastoid aeration was evaluated accor...