Analytical methodsComposite samples

Analytical methods
Composite samples were obtained daily from the laboratory-scale treatment systems for analysis. The frequency at which the various analytical procedures were performed was as follows: TBOD5, (unfiltered) 4x/week; CBOD5 (unfiltered, nitrification inhibitor, Hach’s formula 2533, added), 2x/week; SBOD5 (filtered through a 1.5 μm filter), 2x/week; TSS (defined as that retained by a 1.5 μm), 4x/week; ammonia-N, 2x/week. Other analyses included DOC, nitrate-N of 1st and 2nd stage BAF effluent and 2-stage MBBR effluent, pH, dissolved oxygen and COD during the kinetic experiment.
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Influent wastewater and effluent from the MBBR and BAF were analyzed for total carbonaceous and soluble BOD5. Samples collected for BOD5 were analyzed within 24 hours of collection and kept in a 4oC refrigerator prior to analysis. Procedures recommended in Standard Methods (APHA, 1998) were used. Nitrification inhibitor (Hach’s formula 2533) was added to the CBOD5 samples (0.16 g per 300 ml of sample). Samples were filtered using a 55 mm diameter, 1.5μm-glass microfibre filter (Whatman Inc., USA) for soluble BOD determination. Estimation of sample dilutions for BOD analysis was accomplished by using a relationship established between DOC and TBOD5 and recommendations by Metcalf and Eddy, Inc. (1991) Each BODs (TBOD5, CBOD5, SBOD5) was performed in triplicate and the average is presented. Some results from the BOD test when final DO readings were below 1.0 mg O2/L were discarded as recommended in Standard Methods (APHA,1998). BOD test results with a DO change less than 2 mg O2/L but greater than 1.0 mg O2/L as a result of over dilution were used in data analysis. An oxygen probe (YSI Model 58, Yellow Spring Instrument Co.) was used to determine dissolved oxygen concentrations.Both influent wastewater and effluent samples contained sufficient bioparticles so that seeding was not necessary. However, BAF effluent samples had very low TSS; therefore, they were seeded with VT sewage (influent sample) to ensure that adequate microorganisms were present to degrade BOD in the sample. TSS and VSS, MLSS and MLVSS were determined using method 2540 D in APHA, 1999. A 1.5μm filter paper was used to filter the samples. Samples were oven dried at 105oC. VSS determination involved burning the weighed TSS sample in a muffle furnace at 500oC. Ammonia-N was determined by the titrimetric method (4500-NH3 C) as specified in Standard Methods (APHA, 1999). Nitrate-N concentration was determined by the ion chromatography method (4500 NO3-N C).

Kết quả (Việt) 1:

Phương pháp phân tíchMẫu tổng hợp được thu được hàng ngày từ hệ thống xử lý quy mô phòng thí nghiệm để phân tích. Tần số mà tại đó các thủ tục phân tích khác nhau đã được thực hiện là như sau: TBOD5, (unfiltered) 4 x / tuần; CBOD5 (unfiltered, nitrat hóa chất ức chế, công thức của Hach 2533, thêm), 2 x / tuần; SBOD5 (lọc thông qua một bộ lọc 1,5 μm), 2 x / tuần; TSS (xác định như vậy giữ lại bởi một 1,5 μm), 4 x / tuần; amoniac-N, 2 x / tuần. Phân tích khác bao gồm DOC, nitrat-N của giai đoạn 1 và 2 BAF nước thải và giai đoạn 2 MBBR nước thải, độ pH, giải thể oxy và COD trong thử nghiệm động lực.37Influent wastewater and effluent from the MBBR and BAF were analyzed for total carbonaceous and soluble BOD5. Samples collected for BOD5 were analyzed within 24 hours of collection and kept in a 4oC refrigerator prior to analysis. Procedures recommended in Standard Methods (APHA, 1998) were used. Nitrification inhibitor (Hach’s formula 2533) was added to the CBOD5 samples (0.16 g per 300 ml of sample). Samples were filtered using a 55 mm diameter, 1.5μm-glass microfibre filter (Whatman Inc., USA) for soluble BOD determination. Estimation of sample dilutions for BOD analysis was accomplished by using a relationship established between DOC and TBOD5 and recommendations by Metcalf and Eddy, Inc. (1991) Each BODs (TBOD5, CBOD5, SBOD5) was performed in triplicate and the average is presented. Some results from the BOD test when final DO readings were below 1.0 mg O2/L were discarded as recommended in Standard Methods (APHA,1998). BOD test results with a DO change less than 2 mg O2/L but greater than 1.0 mg O2/L as a result of over dilution were used in data analysis. An oxygen probe (YSI Model 58, Yellow Spring Instrument Co.) was used to determine dissolved oxygen concentrations.Both influent wastewater and effluent samples contained sufficient bioparticles so that seeding was not necessary. However, BAF effluent samples had very low TSS; therefore, they were seeded with VT sewage (influent sample) to ensure that adequate microorganisms were present to degrade BOD in the sample. TSS and VSS, MLSS and MLVSS were determined using method 2540 D in APHA, 1999. A 1.5μm filter paper was used to filter the samples. Samples were oven dried at 105oC. VSS determination involved burning the weighed TSS sample in a muffle furnace at 500oC. Ammonia-N was determined by the titrimetric method (4500-NH3 C) as specified in Standard Methods (APHA, 1999). Nitrate-N concentration was determined by the ion chromatography method (4500 NO3-N C).