| 英文摘要 |
Nitrogen-containing chemicals used in chemical and petrochemical industries significantly increase the discharging levels of ammonia nitrogen in many industrial wastewaters in Taiwan. Since the TW EPA has struck wastewater discharge standards for ammonia, many TW domestic industries are looking for more effective treatment methods for decontaminating nitrogen-containing wastewater. Conventional treatment of ammonia adopts biological method for low-concentration nitrogen-containing wastewater, while high-concentration nitrogen-containing wastewater is treated by stripping. However, these methods suffer several downsides, including time-consuming, energy-intensive, and additional need for secondary liquid-waste treatment. A more practical and effective alternative method is urgently needed to overcome the current shortcomings of poor ammonia removal in TW wastewater treatments.
This project proposes three green wastewater treatment technologies to remove ammonia and nitrate from industrial wastewaters: (1) gas stripping combined with catalytic oxidative activated carbon (COAC) for treating medium-concentration NH3-N wastewater; (2) denitrification catalyst (DNC) for treating medium and high concentration of nitrate wastewater; and (3) polyvinyl alcohol (PVA) Bioball for treating medium and low concentration nitrate wastewater. For the treatment of medium-concentration (200–5,000 mg/L) NH3-N wastewater, an air stripping followed by COAC oxidation strategy was examined in a pilot scale. The result showed that the removal rate of NH3-N reached higher than 94% for the metal surface treatment industry. Denitrification catalyst (DNC) coupled with reducing agents (such as waste ammonia and sodium acetate) was used to treat medium and high concentrations (500-5,000 mg/L) of nitrate wastewater. The result of pilot test (nitrate: 200–400 mg/L) showed excellent nitrate removal, reaching the discharge standard under optimal conditions. PVA bioball was applied for the treatment of medium and low concentration (< 500 mg/L) nitrate wastewater. At the volume load of 2.5 kg NO3-N/m3-d, the nitrate concentration in the effluent water achieved < 30 mg /L. The pilot test (nitrate: 100-150 mg/L) results confirmed that bioball could effectively remove nitrate to meet the discharge standard. An expert consultation meeting has been held. On-site interviews with six manufacturers were conducted. The feasibility of integrated packaged wastewater treatment plants was assessed. In order to increase the exposure of the three major green processing technologies developed in this project, a seminar was held in the field. In addition, 3 DMs were made as technical textbooks, the contents of this project were filmed, and the results of this project were published in domestic journals and seminars.
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