| Wastewater has become one of the worsening environmental problems, with the continuing development of human society. Accordingly, the treatment of wastewater, especially domestic wastewater, has been one of the major research topics in contemporary world. Since 1999, domestic wastewater has surpassed industrial wastewater to become the NO.l pollution source, contaminating seriously drink water and underground water and resulting in adverse impacts on people's production and life. With regard to methods of wastewater treatment, centralized wastewater treatment plants can only be established and run in large and medium-sized cities where both technology and wealth are sufficient. People in small-sized cities, towns and vast rural areas have no choice but explore other types of wastewater treatment. One of the alternative methods is the use of biogas purified set, which has been deployed to treat domestic wastewater in cities and town for over 20 years. With the development of anaerobic digestion technology, the use of biogas purified set has become the major method of domestic wastewater treatment in small cities and towns in China, and as a supplementary measure, it is applicable to cities, towns and rural areas where the drainpipe systems are not well established.It has become one of the key tasks in contemporary China to research on wastewater treatment techniques with higher efficiency, lower investment, less power-wasting, less space demand and fewer running expenses, and the research shall take into consideration of China's reality and the nature and potential use of the wastewater. The followings are described in this thesis:(1) domestication of anaerobic active sludge and aerobic active sludge;(2)devising and making of anaerobic reactor; (3)running of anaerobic reactor; (4)devising and making of aerobic reactor;(5)running of aerobic reactor combined with latest chemical additives;(6)optimization of the parameters. In the study of anaerobic reactor, we also studied the anaerobic reactors currently used to simplyfy the reactor configuration according to water power principle. In the study of aerobic reactor, we make and improve reactor in which wastewater can flow and mix with airs without power-drive. In the digestion study of black water, we improve indexes of out-let wastewater by changing HRT, in-let wastewater, techniques and experiment set. The results of experiments are as follows. Firstly, when anaerobic HRT is 15 days and aerobic HRT is 6.5 days, indexes of out-let wastewater cannot reach Integrated Pollutant Discharge Standard The Second Level Standard as COD, NH4+-N, TP, SS, colour, respectively, 204.9mg/L, 66.3mg/L, 3.8 mg/L, 59.7 mg/L, 200. However, when chemical additives was put in, the indexes of out-let wastewater would be higher than Integrated Pollutant Discharge Standard The Second Level Standard as COD, NH4+-N, TP, colour, respectively, 86.2mg/L,13.4mg/L, 0.7 mg/L, 60. Secondly, when anaerobic HRT is 24 days and aerobic HRT is 10.2 days, indexes of out-let wastewater come close to or surpass Integrated Pollutant Discharge Standard The Second Level Standard as COD, NH4+-N, TP, SS, colour, respectively, 144.6mg/L, 41.3mg/L, 2.5 mg/L, 41.2 mg/L, 160. Thirdly, when anaerobic HRT is 30 days and aerobic HRT is 12.7 days, indexes of out-let wastewater can come close to or surpass Integrated Pollutant Discharge Standard The Second Level Standard as COD, NH4+-N, TP, SS, colour,respectively, 97.6mg/L, 32.5mg/L, 1.4 mg/L, 36.9 mg/L, 100. Forthly, when anaerobic HRT is 36 days and aerobic HRT is 15.2 days, indexes of out-let wastewater can overcome Integrated Pollutant Discharge Standard The Second Level Standard as COD, TP, SS, colour, respectively, 85.3mg/L, 0.9 mg/L, 35.2 mg/L, 90 and NH4+-N come close to Integrated Pollutant Discharge Standard The Second Level Standard as 26.9 mg/L.The results attained in this thesis are encouraging, and show promising application. |
PDF Full Text Request