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

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

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。

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, NH_3-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, NH_3-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 about1/2 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 A^2/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 A^2/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.