Campylobacter is one of the most commonly reported bacterial causes of human foodborne infections in the United States. Recent evidence has demonstrated that Campylobacter is present in poultry semen and may contribute to the vertical transmission between the breeder hen and offspring. As Campylobacter is considered sensitive to oxygen and cold temperature, the objective of this study was to de...

Most river systems are impacted by sewage effluent. It remains unclear if there is a lower threshold to the concentration of sewage effluent that can significantly change the structure of the microbial community and its mobile genetic elements in a natural river biofilm. We used novel in situ mesocosms to conduct replicated experiments to study how the addition of low-level concentrations of se...

A direct relationship has been shown between the maximum cell concentration and aeration efficiency with aerobic microorganisms (Maxon and Johnson, 1953; Smith and Johnson, 1954). Since the antibiotic titer generally varies directly with the weight of mycelium in streptomycete fermentations, it is imperative to define the dependence of antibiotic and mycelial syntheses on the aeration efficienc...

Under intensive aeration (1.3 l/l min) the associated growth of Rhodotorula rubra GED2 and Lactobacillus casei subsp. casei in cheese whey ultrafiltrate (55 g lactose/l) proceeded effectively for both cultures with production of maximum carotenoids (12.4 mg/l culture fluid). For maximum amount of carotenoids synthesized in the cell, the yeast required more intensive aeration than the aeration n...

This paper describes an improvement to the aeration control at the Ljubljana wastewater treatment plant. Several changes were made to the existing aeration control. An adjustment to the parameters of the common air pressure controller contributes to a more responsive operation of the compressors. The introduction of the air pressure set-point controller adjusts the air pressure in the common ai...

This study was carried out to investigate the effect of different waters; tap water (control), sewage effluent (100 % & 50 %), sewage effluent with Scenedesmus quadricauda and sewage effluent with Nostoc sp. on plant growth, leaf chlorophyll and Assessment of hygienic (fungi) of wheat and alfalfa plants. The obtained results showed that plant height, herb weight (fresh and dry), total chlorophy...

When primary domestic sewage sludge was combined with settled sewage or secondary-treatment plant effluent, synergism resulted. The activity (measured by oxygen uptake, and the removal of Kjeldahl nitrogen and orthophosphate from solution) which resulted from incubating sludge together with settled sewage exceeded the sum of the activities when these components were incubated separately. A simi...

Pathogens and antibiotics enter the aquatic environment via sewage effluents and may pose a health risk to wild life and humans. The aim of this study was to determine the levels of faecal bacteria, and selected antibiotic residues in raw wastewater and treated sewage effluents from three different sewage treatment plants in the Western Cape, South Africa. Sewage treatment plant 1 and 2 use old...

Membrane bioreactor (MBR) is a promising alternative to conventional wastewater treatment methods. However this process is still under-used due to its high running costs. Its main power requirement comes from aeration, which is used to supply dissolved oxygen to the micro-organisms and to maintain the solids in suspension. In addition, in submerged MBRs, aeration is used for membrane cleaning. ...

A study was undertaken to investigate the effect of liquid nitrogen aeration on mortalities of adult Cryptolestes furrugineus, rusty grain beetles, in a prototype cardboard grain bin equipped with an aeration system. The grain bin was filled with Hard Red Spring wheat and liquid nitrogen was introduced from the bottom of the bin. The survival of both cold acclimated and unacclimated C. furrugin...