Outdoor tanks containing the floating aquatic macrophyte water hyacinth [Eichhornia crassipes (Mart) Solms] were provided with diffuse aeration to evaluate its effect on wastewater treatment efficiency and plant growth. Light aeration (0.003 and 0.021 L nr min ') had no effect on the treatment of primary domestic effluent in the batch-fed water hyacinth tanks. Heavy aeration (1.03 and 3.53 L nr...

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) ...

An activated sludge aeration tank (W × L × H = 40 × 40 × 300 cm) with a set of 2 mm orifice air spargers was utilized to treat gas-borne volatile organic compounds (VOCs, toluene, p-xylene, and dichloromethane) in air streams. Effects of liquid depth, aeration intensity (G/A), overall mass transfer coefficient of oxygen in clean water (KLaO2), dimensionless Henry’s law coefficient of the tested...