550 individual odour intensity (S) assessments of 62 samples of air polluted with 2-propanol were collected (concentration c = 46-2 1000 mg/m3). The data were used to establish odour detection threshold of 2-propanol by extrapolation to S = 0 in the coordinate system of S-log c. The obtained values were compared with triangular tests results and data published in the literature. A reason for apparent positive deviations from Weber-Fechner law within a range of low odour intensities was indicated,

Searching for dependance of odour intensity on degree of dillution of basic samples with pure air, samples aromatised with citrus oil and containing difTerent amounts of acetone, ethanol, isopropanol, isoamyl acetate were studied. 192 individual odour intensity assesments of 16 samples were collected. Dependence of odour intensity on acetone concentration determined with chromatographic analysis (110-16500 mg/m3) was defined on the basis of 311 individual odour intensity assessments of 24 samples. The measurements' results were elaborated without initial assumptions concerning character of a psychophisical equation and without initial selection of empirical data. Automatic Networks Designer (Statistica Neural Network, StatSoft) was used. Dependence of odour intensity on concentration was described with logistic function resembling Stevens law within a small concentrations range and Weber-Fechner law within a high concentrations range.

Field measurements of the near-ground odorant concentrations were made in surrounding of the mechanical sewage treatment plant with separated digestive chamber. The concentrations downwind the pollutants plume in several different meteorological situations were the basis for the estimations by a process of trial and error. The estimations encompassed the total emission of odorants and emission rates related to the volume of the purified sewage, to the amount of the removed pollutants and to the area of the unorganized emission sources during the autumn. Parallel research concerning other seasons and different surface sources of odorants are planned.

The possibility of applying gas chromatograph to air samples discrimination in regard to odour intensity and hedonic quality was examined. The air samples were arornatised with lemon oil and four admixtures. fourteen distinctive points of a chromatogram were appointed and the distances from the points lo a set basis were measured. The set of h 1-h 14 parameters (inputs) and varied individual sensory estimations of I and H (outputs) was used as a training data set for NN. Possibility of discrimination of the odour quality of the samples situated close to the threshold of odour quality difference detectability was confirmed on the level of approximately one.

Plants under attack of herbivores can emit increased amounts of volatile compounds from their leaves. Similarly, mechanically-injured plants can emit volatile chemicals that differ both quantitatively and qualitatively from undamaged plants. In this experiment, mechanical injury increased the release of the secondary metabolites linalool (3,7-dimethyl-1,6-octadien-3-ol) and linalool oxide (5-ethenyltetrahydro-2-furanmethanol) by wheat plants. The amounts released varied significantly with injury type and the period of time after injury. The time interval for the volatile collection within the photophase also influenced the amount collected for each day. The increased emission of these compounds, as a result of injury, may be explained as a defense mechanism against wounding. The role of these plant volatiles can be further investigated in the context of plant response to mechanical injury, within the broader context of all types of injury.

Evaluations of odour intensity of the air polluted with cyclohexane (A), cyclohexanone (B) and cyclohexane with admixtures of cyclohexanone (mixtures MI, M2 and M3; x8 = 0.14; 0.05 and 0.02 respectively) were made. Empirical parameters of psychophysical equations (Weber-Fechner' and Stevens') were determined. Total concentrations of the mixtures were within the range C = 1500-3500 ppm. The interaction constant av= 115-132° was estimated for the mixtures. Verification of known models of odour interaction led to the conclusion that possible application of the models for prediction of odour intensity of the air polluted with mixtures of cyclohexane and hexane is limited.

In the study the comparative analysis of test results of drainage of municipal wastewater sludge was conducted with the use of flocculant Praestol 855BS and the mixture of flocculant Praestol 855BS 50% + orange essential oil 50%, as the reagents supporting this process. It was also attempted to reduce unpleasant smells exuding from the drained sludge.

The process of drainage of municipal wastewater sludge was conducted in the laboratory setting centrifuge of MPW-350 type. The variable independent parameters were centrifugation time, centrifugation speed, dosage of flocculant Praestol 855BS as well as dosage of mixture in the proportion of flocculant Praestol 855BS (50%) + orange essential oil (50%). The following parameters were subject to assessment: water content in the sludge, dry mass content in the reflux as well as time of maintenance of the oil’s smell in the sludge. The conducted tests demonstrated that the orange essential oil has an impact on drop in resultant quality parameters of the drainage process of municipal wastewater sludge. Batching of the orange essential oil has an impact on considerable reduction of odours exuding from drained wastewater sludge, and thus on improvement of work conditions connected with operation of centrifugal separators. Bearing in mind both the efficient drainage process of wastewater sludge as well as simultaneous reduction of unpleasant smells exuding from the sludge during this process it is assumed and recommended to simultaneously apply both reagents, that is flocculant Praestol 855BS (50%) and orange essential oil, also in the volume of 50%.

This paper deals with the acceptability (AKC) and perceived concentration of pollutants (D) emitted by occupants in relation to the specific enthalpy (h) and relative humidity (qi) of indoor air. Measurements of AKC/D/, described by semilogarithmic function depend significantly on both In h and In (jl. The equation fits to the data published in the literature in a reasonably good way. Therefore, it indicates that the linear function between AKC and h which is commonly used in literature yields rough approximations. The proposed equation allows for the validation of the indoor mieroclimatc and brings an idea how to make measurements of the perceived air quality instrumentally and how to control the air conditioning process.