规模化猪场粪污废水生物聚沉氧化新工艺及其生产性实验效果研究

针对我国猪场粪污废水现行厌氧-好氧活性污泥法处理模式达标难度大、运行成本高的问题，研发出生物聚沉氧化新工艺（bio-coagulation dewatering followed by bio-oxidation, BDBO)。在广东惠州某5万头猪场构筑了采用该工艺的实际工程，通过现场采样，详细分析新工艺各个单元的污染物，包括化学需氧量（COD）、氨氮、总氮（TN）和总磷（TP）的变化情况，研究了新工艺对猪场粪污废水的处理效果及机制。结果表明，在水力停留时间（HRT）仅为2.5 d的新工艺系统中，猪场粪污原水（进水）的COD、氨氮和TP分别为（11 697±1 484）、（837±25）、（532±97）mg·L-1，处理出水水质分别为（273±58）、（44±9）、（4.5±1.0）mg·L-1，总去除率分别达到了97.7%、94.7%、99.2%，出水远优于广东省地方畜禽养殖业污染物排放标准（DB 44/613-2009）。运行成本大约6元·t-1，比原常规处理系统（采用生化处理+物化处理组合工艺）出水水质更好，成本约为原处理系统的1/2~1/3，并同步解决了污泥的深度脱水问题。研究发现新工艺可相对快速处理达标并且成本相对较低，其机制在于废水进入常规生化系统（A2/O）之前，高效去除了悬浮颗粒物（SS），使得以SS形式存在的COD、P和部分N被大幅度削减。新工艺解决了目前猪场废水处理时间长、难达标（尤其是氨氮）、运行成本高的难题。

A case study on effectiveness of a novel treatment process for purifying swine wastewater from large-scale piggery by using bio-coagulation dewatering followed by bio-oxidation

In view of difficulty and high cost of conventional anaerobic-aerobic activated sludge technique to successfully treat swine wastewater for meeting effluent discharge standard, a novel approach called as bio-coagulation dewatering followed by bio-oxidation (BDBO) is developed. BDBO technique was applied in a piggery with 50 000 pigs located in Huizhou city, Guangdong province. The water quality indexes (COD, NH3-N, TN and TP) of the effluent at different treatment stages in this project were investigated and determined for successive 4 months. The results showed that, in this BDBO process with only 2.5 d hydraulic retention time (HRT), the concentration of COD, NH3-N, and TP of final effluent were decreased to (273±58), (44±9) and (4.5±1.0) mg·L-1 from initial (11 697±1 484), (837±25) and (532±97) mg·L-1 in influent with removal efficiencies of 97.7%, 94.7% and 99.2%, respectively. Obviously, the effluent quality was much superior to the relative discharge standard by Guangdong province (DB 44/613-2009). Moreover, its operating cost was only about 6 yuan·t-1, which was about 1/2 to 1/3 of the costs with conventional anaerobic-aerobic activated sludge system. In addition, BDBO process also improved efficiently advanced dewatering of sewage sludge. The above-mentioned merits exhibited by BDBO process were found to be mainly attributed to absolutely removal of SS prior to A2/O stages. As a result, most of COD, P and partial N in the form of SS in the influent could be greatly reduced before the influent was treated with anaerobic-aerobic activated sludge technique. This already-pretreated influent only containing soluble COD, N and P due to completely removing SS was much easier for water purification through consequent A2/O processes. The novel BDBO process is of a great application prospect in the field of animal wastewater treatment because of a short HRT, meeting easily discharged standard (especially for NH3-N), and efficient operating cost.