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Oczyszczanie ścieków mleczarskich w bioreaktorach typu SBR na przykładzie PHU „Zarębski" w Ksawerowie

Liwarska-Bizukojć E., Majerowska A.

Technologia Wody

2014

Nr 4 (36)

34--37

Celem pracy była charakterystyka składu ścieków mleczarskich oraz właściwości osadu czynnego pochodzącego z sekwencyjnego bioreaktora porcjowego (SBR), w którym te ścieki były oczyszczane. Skład surowych ścieków mleczarskich był zróżnicowany pod względem zawartości związków węgla, azotu i fosforu. ChZT ogólne wahało się od 3961 do 12 215 mg 021, a zawartość związków azotu i fosforu wynosiła odpowiednio od 18,5 do 101,7 mg N l oraz od 13,7 do 115 mg P 1_1. Pomimo wysokiego stężenia związków biogennych, a zwłaszcza fosforu, poziom ich usunięcia ze ścieków był wysoki i wynosił średnio 96,5, 88,1 i 97,7% kolejno dla ChZT, azotu ogólnego i fosforu fosforanowego. Zarówno stężenie biomasy osadu czynnego w bioreaktorze SBR, jak i jej aktywność oddechowa były wysokie. Kłaczki osadu były małe lub średnie, o zwartej strukturze i niewielkiej liczbie bakterii nitkowatych. Osad miał dobre właściwości sedymentacyjne (indeks Mohlmana od 36 do 71 ml gZog,_1).

The aim of this work was to describe the composition of the influent and effluent of the SBR system treating dairy wastewater and characterize the activated sludge coming from this system. The composition of the influent differed with respect to the content of carbon, nitrogen and phosphorus. The total COD varied from 3961 to 12 215 mg 021-1, while total nitrogen and phosphorus contents varied from 18,5 to 101,7 mg N l1 and from 13,7 do 115 mg P I-1, respectively. Despite high concentration of nutrients, particularly phosphorus, the level of their removal from wastewater was high and on average equal to 96,5, 88,1 and 97,7% subsequently for COD, Ntot and phosphates. Activated sludge biomass concentration and its respiration activity were high as well. Small and medium size floes of compact structure dominated. The number of filamentous bacteria was very low and it was correlated with good settling properties of sludge (Mohlman sludge index from 36 to 71 ml g TSS _1).

Wpływ procesu filtracji na relację między ilością substancji organicznych i związków biogennych w ściekach mleczarskich

Ostrowska K., Janczukowicz W., Rodziewicz J., Mielcarek A.

Rocznik Ochrona Środowiska

2013

Tom 15, cz. 2

1411--1425

Nowadays, high effective carbon, nitrogen and phosphorus removal based on activated sludge is the most popular method of dairy wastewater treatment. In activated sludge systems efficient nutrient compounds removal is determined by the quantity and quality of easily available forms of organic carbon. For both biological phosphorus removal and biological nitrogen removal to occur, an easily biodegradable carbon source must be present in the treating wastewater. The organic compounds used in the processes of denitrification and enhanced biological phosphorus removal (EBPR) usually are presented in treating wastewater, what is called an internal source of carbon. However, many industrial wastewater, including dairy wastewater, very often do not have sufficient amounts of carbon, in relation to the concentration of nitrate and phosphates, to ensure efficient both denitrification and biological dephosphatation processes. When biological nitrogen and phosphorus removal is limited by the availability of easily biodegradable forms of organic carbon a supplemental carbon source must be add to the wastewater, hence so-called external source of carbon should be applied to provide energy necessary for the nutrient removing bacteria to grow and perform their work. One of the most popular sources of organic carbon is acetic acid, which is one of the best available forms of carbon by denitrifying bacteria and those accumulating polyphosphates (PAO). Apart from acetic acid and acetates use is made of a number of the volatile fatty acids (VFA), including propionic acid, butyric acid, valeric acid, and such substrates as: glucose, methanol or ethanol. Since the use of chemical compounds in the form of technical products (e.g. acetic acid, citric acid) is generally expensive, cost-saving solutions are sought. According to literature data, wastewater with high COD/(N + P) ratio after acidogenic fermentation can be used as an external source of VFA in wastewater with low concentrations of easily available organic compounds treatment. The aim of this study was to determine the influence of the filtration process on the content of organic compounds (measured as COD) in relation to the concentration of nutrients (measured as the sum of TKN and TP) in process dairy wastewater, in terms of the possibility of effective VFA production. It was observed, that filtration process ensures improvement of the COD/(N + P) ratio only in wastewater from the selected sections of dairy production. The best result, if percentage increase of the COD/(N + P) ratio is considered, was obtained for the wastewater from butter production. Densification of wastewater from butter production resulted in 95% increase of the COD/(N + P) ratio without a significant increased nutrient concentration. Filtration process provided the highest COD/(N + P) ratio (219,18 mg O2/(mg N + mg P)) and reduced both nitrogen and phosphorus concentrations in the permeate from the apparatus room. The results obtained suggest, that acidogenic fermentation of wastewater from the apparatus room and butter production with high COD/(N + P) ratio can serve as an external source of VFA in biological wastewater treatment process of wastewater with low concentrations of easily available organic compounds, which ensures effective nitrogen and phosphorus removal.