Carbon source addition project of a sewage treatment plant in Tianjin

    A treatment plant in Tianjin mainly treats residential sewage, the current inflow of about 9000m3/d, using the improved A2O+ advanced treatment process, the effluent quality has reached the Tianjin Municipal Municipal Sewage Treatment Plant water pollutant discharge standard (DB12599-2015) A standard.

    At present, the influent COD of wastewater treatment plant is low, and additional carbon source is needed to ensure the total nitrogen of effluent reaches the standard. The original carbon source is liquid composite carbon source, COD equivalent is 330,000 mg/l, and the dosage is 1.5t per day. To reduce the amount and cost of carbon sources. The production test was carried out from October 17 to October 27, 2019, and the comparison test was carried out with the addition of primary carbon source from October 5 to October 16. Factory test results are as follows:

The amount of BioC-1M carbon source is reduced to 29.7% of the carbon source in the plant, and the operating cost is reduced.

FIG. 1 Comparative analysis of TN of system effluent after adding BioC-1M carbon source

    As can be seen from Figure 1, the influent TN of the sewage plant varies greatly, and the effluent TN can basically be stabilized below 10mg/l to meet the standard. After the replacement of carbon source, the amount of carbon source added is 29.7% of the original carbon source when the treated water is larger and the effluent quality is better than that of the original carbon source added. According to the plant test results, the cost of BioC-1M carbon source per ton of water can be saved about 5.3% compared with the original carbon source when the treated water quantity and effluent quality are the same.

    At present, BioC-1M carbon source is added to Tianjin Ninghe First sewage treatment plant, and the dosage is about 450kg/d, and the effluent is stable and up to standard.