Ref ID : 4607
Stoica Godeanu; [Contributii la Cunoasterea Rotiferilor Intilniti in Instalatiile de Epurare Biologica a Apelor Reziduale] (Contributions to Knowledge of Rotifera found in Biological Wastewaters Treatments Plants). Studii de Protectia si Epurarea Apelor VII:569-599, 1966
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In the literature it was stated the absence of some works analysing the rotifera these being organisms which constitute one of the last links of the trophic chains appearing in the biological treatment plants. The research presented in the paper was effected during the years 1963-1965 on 21 treatment plants supplied with 11 various types of wastewaters. For being able to explain, as a consequence of the morphological, philogenetic and ecological complexity degree, the existing possibilities and the part played by these animals in the treatment plants, a concise characterization of the rotifera is made. From the author's own observations effected on rotifera found in the treatment plants, a systematic list has been drawn up. For every species, morphology and observed variability elements have been given. The biotop mentioned in literature, the plants supplied with various types of wastewaters where these were found the periods when these were met and whether they are common or accidental forms for treatment plants, have been shown. Precarious living conditions offered to rotifera by wastewaters are illustrated in the Table 1. The wastewater effects on the organisms reaching these waters and the manner in which are developed those for whom this biotop is propitious briefly analysed. On the basis of rotifera frequency in various wastewaters, a division into four groups is made. 1) Species found in plants supplied with 1-2 types of wastewaters that occured here accidentally and survive in a low number and for a short period (of time). 2) Species found in plants supplied with 1-2 types of wastewaters that have reached here also accidentally and survive for a little time but very numerous. 3) Species found in plants supplied with more types of waters that survive here in a reduced number. 4) Species characteristic to treatment plants: they develop massively, are found during long periods and suffer various types of wastewaters and high loadings. The rotifera capacity to live in media rich in organic substances, is underlined. It is shown, that rotifera exist in plants especially in summer period. In winter only a little species survive at a temperature of + 10 degrees C. All rotifera found in biological treatment plants are cosmopolit. Analysis of the rotifera feeding manner is made, by showing at the same time that most of them are not predatory "stricto sensu" but bacterivore; the most predatory for small organisms are flagellata, amoebae, small ciliate. The necessity to reconsider the place of rotifera and the correlations between nematode rotifera within the trophic chains installed in the plants are underlined. Analysing the efficiency of rotifera during the process of the water treatment in biological treatment plants it is concluded that these rotifera in addition to ciliate, but in a much smaller extent, are useful to clarify the effluent. By their motions they favour the feed exchange, catabolits and air between the liquid and bacterial mass and replace functionally the ciliate when these are absent.