Wpływ obciążenia osadu ładunkiem zanieczyszczeń organicznych na wzrost wybranych grup bakterii podczas procesu oczyszczania odcieków ze składowiska odpadów w SBR 443

Celem badań bakteriologicznych było określenie wpływu obciążenia osadu czynnego ładunkiem zanieczyszczeń organicznych (Bx) na rozwój w nim wybranych grup bakterii będących wskaźnikami stopnia rozkładu związków organicznych i zanieczyszczenia pod względem sanitarnym. Założeniem tych badań było ustalenie zakresu Bx, przy którym zachodzi eliminacja tych bakterii z odcieków połączona z ich akumulacją w kłaczkach osadu oraz oszacowanie stopnia zagrożenia sanitarnego dla środowiska przy jego ewentualnym wykorzystaniu do celów rolniczych. Wskaźnikami stopnia rozkładu zanieczyszczeń organicznych występujących w odciekach, była ogólna liczba heterotroficznych bakterii psychrofilnych (HBP) i bakterii sporowych (BS), a zanieczyszczenia pod względem sanitarnym: bakterie mezofilne (BM), bakterie z rodziny Enterobacteriaceae, termotolerancyjne bakterie grupy coli (TBGC) oraz Clostridium perfringens.

Assessment of the influence of activated sludge loading with organic contaminants (Bx) on the development in it of selected groups of bacteria, which are indexes of decomposition degree of organic compounds and sanitary contamination, was the aim of conducted biological investigations. Determination of Bx range, in which elimination from leachate of those bacteria connected with their accumulation in floccules of activated sludge takes place as well as estimation of level of sanitary threat for the environment when it is used in agriculture were aims was of these investigations. Indexes of degree of organic contaminants decomposition occurring in leachates were: general number of heterotrophic psychrophilic bacteria (HBP) and sporeforming bacteria (BS), and sanitary contamination were: mesophilic bacteria (BM), bacteria from Enterobacteriaceae family, thermotolerant bacteria of cola group (TBGC) and Clostridium perfringens. Leachate used in investigations were piped off with drainage system to cumulative well located near landfill of wastes other than inert and dangerous, so-called municipal situated in the south-east part of Otwock city. Landfill functions from 1998 and the planned end of exploitation is anticipated in the year 2012. Municipal wastes in the quantity over 20 Mg per day are deposited in it. Dominating group of bacteria both in leachates and activated sludge adapted to their pretreatment constituted heterotrophic psychrophilic (HPB) and mesophilic bacteria (MB). Less numerous were sporeforming bacteria (BS) and the bacteria from the class Enterobacteriaceae. The greatly lower numbers of thermotolerant coliform bacteria (TCB) and Cl. perfringens were stated. Among the studied groups of bacteria - HPB, BM, TCB and bacteria from class Enterobacteriaceae showed the most stable growth in activated sludge. The washing out of these bacteria occurred at the maximal studied Bx = 1.64 mgCOD mg-1 d-1. Less stable growth characterized Cl. perfringens (washing out at Bx = 0.96 mgCOD mg-1 d-1). Fast washing out of SB (Bx = 0.34 mgCOD mg-1 d-1) took place. The number of these groups of bacteria in activated sludge and effluent from SBR don't constitute a sanitary impedence for environment. Conducted investigations allow to state, that both leachates outflowing from SBR as well as excessive activated sludge coming into being in the process of treatment, taking into consideration size of investigated bacteria groups does not make up sanitary threat for the environment. However full distinguishing in this issue may be made just after executing investigations on occurrence and size in those biotopes of bacteria and microscopic fungi pathogenic for warm-blooded animals and human.