Changes in Textural and Geo-Chemical Features of Alluvia in the Western Part of the Lublin Upland Over the Past 1000 Years
In the study the authors analysed the diversity of the textural indices and selected geo-chemical features of sediments that accumulated in the bottoms of valleys in the western part of the Lublin Upland over the past 1000 years. Detailed studies were performed for six profiles with known stratigraphy. The sediments studied varied little in terms of textural features, with a general trend for particle diameters to increase as the depth increased. The characteristics of the sediments indicate a significant role of material supply from the slope systems (mainly gullies) to the bottoms of river valleys. The heavy metal content was characterised by greater vertical variation. In most of the profiles, the youngest deposits were characterised by greater levels of Cd, Cu, Pb and Zn, with enrichment indexes at an average of 1.5-2.5. The observed diversity of the features of sediments, particularly the geo-chemical features, should be attributed to the effect of human activity in the area studied.
The paper presents a study on the possibility of using the laser diffraction method for measuring the size of the activated sludge particles. Susceptibility of the particles to mechanical disintegration, dependent on the programmed value of stirring intensity, was observed (stirring was caused by required dynamic flow of analysed suspension through the measurement unit). According to the conclusions presented in this paper, it may be assumed that the laser diffraction method can be applied for measurement of activated sludge particle diameters under the following conditions: 1) the size of activated sludge particles measured by the laser diffraction method is not a real value, but after standardisation of measurement conditions can be treated as a parameter describing the sludge; 2) the particle diameters of activated sludge should be stabilised before the measurement, eg by mixing in the measurement unit or by ultrasound waves application.
The adaptation of activated sludge from the Hajdow sewage treatment plant in a laboratory SBR was studied. The structure of the ciliate assembly was considered as a criterion. 32 ciliate species were found during the experiment. The composition and changes in the ciliate community structure during the process of activated sludge adaptation was examined. In the process of adaptation, reduction was observed in the number of ciliate species together with an increase in assembly total abundance. The decrease in the Shannon diversity index and equitability index in the adaptation process was observed. In the process of adaptation, two states of ciliate assembly were marked out - unstable transient period and stable period. During the transient period, reduction of ammonium utilization efficiency down to 50% and its subsequent increase up to 80% in the stable period were observed. In the transient period, the Simpson dominance index remained low but increased in the stable period. At a temperature of 10°C, the transient period lasted from six to nine days. After the stabilization process, the diversity of the ciliate assemblage remained at a lower level. Rarefaction methods showed that the number of potential ecological niches of ciliate amounted to 30 in the adaptation period, whereas there were only 15-20 ecological niches in adapted sludge.