In English

Study of the Bioaugmentation of Grease Separators Using the GOR BioSystem™

Aline De Santa Izabel Alves
Göteborg : Chalmers tekniska högskola, 2014. 84 s.
[Examensarbete på avancerad nivå]

Grease separators (GS) are the first preventive strategy to reduce the entry of fats, oils and grease (FOG) into the sewage system. Since its patent in 1883, very little has been developed in order to improve the function and maintenance of these devices. One of the strategies to upgrade the GS performance is through the use of bioaugmentative systems. However,limited scientific-based knowledge of the performance and bioaugmentation of GS is available to promote sound regulations regarding the use, maintenance and improvement of GSs in Sweden. Thus, an important consideration of this study was to evaluate the function of accepted GSs and the effects of bioaugmentative systems in its performance. Grease separators from three different food-producing establishments (FSEs) (one restaurant from an elementary school and two full service restaurants) located in Danderyd and Stockholm municipalities were evaluated. The GS of one of the full service restaurants was treated with a bioaugmentative system (GOR BioSystem™) and monitored for changes in the effluent quality and FOG accumulation compared to an untreated control period. This evaluation consisted of two cycles, lasting approximately one month (five weeks) each, which was in accordance to the regulation for the intervals between the pump outs in the Stockholm region. The GS from an elementary school in Danderyd municipality was treated and monitored for ten weeks with the same bioaugmentative system (GOR BioSystem™) while one untreated standard GS from a full service restaurant in Stockholm was monitored for five weeks as a control. Regular analysis including FOG (either ether soluble, emulsified and separable fat), biochemical oxygen demand, chemical oxygen demand, total suspended solids, pH,temperature, conductivity, grease cap thickness and bottom solids accumulation and odor was performed. In general, the chemical and physical parameters were similar in both treated and untreated cycles in the full service restaurant analyzed with and without the treatment with GOR BioSystemTM. However, lower levels of grease cap development and solids accumulation and odor were achieved in the treated cycle. No grease accumulation was detected in the GS bioaugmented for ten weeks while a considerable amount of both grease and solids accumulated in the control untreated GS after 25 activity days. There were no indications that the bioaugmentation promoted by GOR BioSystem™ led to a deterioration of the effluent quality or released additional amounts of oil and greases in the collection system. Furthermore, it is expected that the use of GOR BioSystem™ can improve the rationalization of the handling of organic waste with the reduction of waste transports.

Nyckelord: bioaugmentation, Bacillus sp>., grease separators, wastewater treatment

Publikationen registrerades 2015-03-02. Den ändrades senast 2015-03-02

CPL ID: 213282

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