The influence of transient phenomena on the biodegradation of nitrilotriacetic acid in the activated sludge process I: Variations in hydraulic loading and sewage strength

The removal of nitrilotriacetic acid (NTA) following acclimatization in an activated sludge pilot plant has been studied during transient changes in operating conditions. These changes included increases in hydraulic loading and influent chemical oxygen demand (COD) and such phenomena in combination with transient temperature reductions. Short-term increases in hydraulic loading from 1 to 2 dry weather flow (dwf) had a very limited effect on NTA removal. Increasing the influent COD had a slight effect on NTA removal. Short term increases in hydraulic loading combined with transient reductions in temperature significantly reduced NTA removal. The effect of these combined changes on NTA removal was synergistic, rather than additive. Increases in influent COD combined with transient temperature reductions also caused a significant reduction of NTA removal. The effect of such combined changes on NTA removal was at most only additive.     

Sulphur gas emissions in the boreal forest: The west whitecourt case study IV: Air quality and the meteorological environment

A program of atmospheric measurements was carried out in support of the West Whitecourt case study in the summers of 1975 and 1976. Measurements in and around an isolated stand of mature lodgepole × Jack pine trees included temperature, moisture, and wind measurements at a climatological station outside the stand and at several levels on a 30 m radio mast tower within the stand. Sulphur dioxide concentrations were also measured on the tower. A number of short-term, intensive measurements were made to document the meteorological and SO₂ environments in more detail, with special attention given to the transport of S gas from the source to the sink. The major source of SO₂ at the intensive experimental site was very likely the flare stacks at the gas processing plant. Sulphur dioxide events at the study site were typically daytime, low concentration bursts of a few minutes in duration which occurred with westerly winds under fair weather conditions. Air impinging on the stand tended to flow around the edges of the stand, over the canopy, and into the trunk space. This aerodynamic effect, together with the uptake of SO₂ by the vegetation, caused a minimum in SO₂ concentration in the crown of the forest.     

Field evaluation of the synthetic female sex pheromone of the citrus flower moth,Prays Citri (mill.) (Lepidoptera: Yponomeutidae), and related compounds

The synthetic female sex pheromone ofPrays citri, (Z)-7-tetradecenal, proved to be highly attractive to male moths in the field when released from a variety of dispensers in five different designs of sticky trap. When the pheromone was released from impregnated polyethylene vials, a wide range of initial loadings from 10 μg to 20 mg was attractive, and loadings of 40 μg and above were more attractive than a virgin female moth. Initial loadings of 0.5 mg and 1.0 mg remained attractive for at least five months in the field. Release rates of pheromone from the polyethylene vials under constant laboratory conditions were measured for two different initial loadings. Other isomers of the pheromone and a pheromone ‘mimic’, (Z)-5-dodecenyl formate, were unattractive to male moths and did not affect the attractiveness of the synthetic pheromone or of a virgin female moth.     

Effects of treatment with omeprazole or ranitidine on gastric squamous ulceration in racing Thoroughbreds

OBJECTIVE: To compare the effects of oral administration of omeprazole and ranitidine on gastric squamous ulceration in Thoroughbreds in race training. DESIGN: Modified crossover study. ANIMALS: 60 Thoroughbreds in race training with gastric squamous mucosal ulceration. PROCEDURE: Horses were randomly allocated into 3 groups. Group 1 received no treatment for 28 days followed by administration of omeprazole (4 mg/kg [1.8 mg/lb], PO, once daily) for 28 days; group 2 received omeprazole (4 mg/kg, PO, once daily) for 28 days followed by no treatment for 28 days; and group 3 received ranitidine (6.6 mg/kg [3.0 mg/lb], PO, q 8 h) for 28 days followed by administration of omeprazole (4 mg/kg, PO, once daily) for 28 days. Ulceration was assessed endoscopically at days 0, 28, 42, and 56. Lesions were scored from 0 (no ulceration) to 3 (severe ulceration). RESULTS: After the initial 28 days of treatment, the decrease in ulcer severity was significantly greater after omeprazole treatment than after ranitidine treatment. Ulcer severity decreased significantly in group 3 horses after 14 days of treatment with omeprazole. Discontinuation of omeprazole resulted in worsening of ulcer scores; however, ulcer scores at completion of the study were less than at day 0. Horses that received omeprazole after 28 days of ranitidine treatment had a further reduction in ulcer severity. CONCLUSIONS AND CLINICAL RELEVANCE: Omeprazole was more effective than ranitidine in healing gastric squamous ulcers in Thoroughbreds in race training. Improvement was detected by 14 days and persisted in most of the group 2 horses for at least 28 days after omeprazole treatment was discontinued.