Peak emissions of NO and N(inf2)O are often observed after wetting of soil. The reactions to sudden changes in the aeration of cultures of nitrifying and denitrifying bacteria with respect to NO and N(inf2)O emissions were compared to obtain more information about the microbiological aspects of peak emissions. In continuous culture, the nitrifier Nitrosomonas europaea and the denitrifiers Alcal...

Combination of aerobic and anaerobic processes in constructed wetlands can enhance the treatment performance in textile wastewater. This study assessed the treatment of azo dye Acid Orange 7 (AO7) and nutrients using five laboratory-scale up-flow constructed wetlands (UFCW) with and without supplementary aeration, and with different emergent plants. Supplementary aeration controlled the size of...

Aeration is an essential process in the majority of wastewater treatment processes, and accounts for the largest fraction of plant energy costs. Aeration systems can achieve wastewater oxygenation by shearing the surface (surface aerators) or releasing bubbles at the bottom of the tank (coarse- or fine-bubble aerators). Surfactants accumulate on gas-liquid interfaces and reduce mass transfer ra...

During the past decade, pond aeration systems have been developed which will sustain large quantities of fish and invertebrate biomass. Dissolved Oxygen (DO) is considered to be among the most important water quality parameters in fish culture. Fishponds in aquaculture farms are usually located in remote areas where grid lines are at far distance. Aeration of ponds is required to prevent mortal...

To obtain sustainable aquaculture, developing appropriate treatment processes for wastewater is essential. In this study, two three-stage hybrid wetland systems were configured to treat aquaculture effluent. The two systems added with or without artificial aeration were operated under a high HLR (8.0 m/day) with a short retention time (0.96 h). By the results, COD could be effectively removed b...

AIMS Limited aeration has been demonstrated to cause slowdown in proliferation and delayed budding, resulting eventually in a unique unbudded G2-arrest in the obligate aerobic pathogenic yeast Cryptococcus neoformans. Also, the ability to adapt to decreased oxygen levels during pathogenesis has been identified as a virulence factor in C. neoformans. The aim of this study was to identify and cha...

A 4-m high, 15.24-cm diameter semi-batch bubble column connected to one of three perforated plate gas distributors with open area ratios A = 0.57%, 0.99%, and 2.14% is employed to study gas holdup and flow regime in Rayon and Nylon fiber suspensions. This study determines the effect of superficial gas velocity, fiber type, fiber mass fraction, fiber length, and aeration plate open area ratio on...

In this study we evaluated specific and nonspecific toxic effects of aeration and trichloroethylene (TCE) oxidation on methanotrophic bacteria grown with different nitrogen sources (nitrate, ammonia, and molecular nitrogen). The specific toxic effects, exerted directly on soluble methane monooxygenase (sMMO), were evaluated by comparing changes in methane uptake rates and naphthalene oxidation ...

The present paper attempts to investigate the prediction of air entrainment rate and aeration efficiency of a free overfall jets issuing from a triangular sharp crested weir by using regression based modelling. The empirical equations, Support vector machine (polynomial and radial basis function) models and the linear regression techniques were applied on the triangular sharp crested weirs rela...

Model-based and on-line sensor control schemes in an alternating aerobic/anoxic system for nitrogen removal were applied and compared for system performance. A linear model was developed by simplifying the well known Activated Sludge Model No. 1 and incorporated into an optimization scheme. A program was developed to detect control points on the pH and ORP profiles to control aeration duration ...