Study On Treatment Efficiency Of Corridor-Type Microalgae Photobioreactor For Swine Wastewater Treatment

It is difficult to treat swine wastewater for the high concentration of nitrogen,phosphorus and organic pollutants in swine wastewater,which further led to large investment and high operating costs in the treatment of swine wastewater.Various types of photobioreactors developed by the purification capacity of microalgae can not only efficiently reduce the concentration of pollutants such as organic matter,nitrogen,and phosphorus in wastewater,but also produce a large amount of microalgal biomass,which can provide the recyclable possibility of biological energy and material.So it is undoubtedly a green,environmentally friendly and highly sustainable treatment technology with broad application prospects in the treatment of swine wastewater.However,the current research on the treatment of swine wastewater by microalgal photobioreactor is still short of study,and large-scale treatment engineering research is very poor.The thesis carried out actual investigation and monitoring of the operation effect of the corridor-type microalgae photobioreactor for the wastewater treatment of Xulun Farm in Yubei District,and analyzed its operating parameters and energy consumption.Through the pilot-scale reactor’s study further explored the treatment efficiency and main operating factors of the corridor-type microalgae photobioreactor,proposed corresponding operation optimization control schemes and parameters,and investigated the effect of the technology in practical engineering’s（Qian Farm）,which hope to provide corresponding theoretical basis and technical parameters for the engineering application of microalgae photobioreactor in the treatment of swine wastewater treatment.The research was supported by the following main conclusions:（1）Influent pollutant load has obvious influence on the treatment effect of corridor microalgae photobioreactor,under lower influent pollutant load（COD=483～493mg/L,NH4+-N=195～210mg/L,TP=19.9～21.4mg/L）,the time that the reactor from start to reach a stable operating state is shorter than the higher pollutant load（influent COD=1004～1086mg/L,NH4+-N=439～45mg/L,TP=30.5～31.8mg/L）,the microalgae biomass concentration in the reactor is also higher.Consistent with this,the reactor pollutant removal rate is also higher under low pollutant load.The actual engineering investigation shows that through strengthing the pretreatment or increasing the effluent backflow can control the microalgae photobioreactor’s influent pollution load;（2）Pushing flow velocity has an important effect on the growth of microalgae.When the flow velocity is between 0.125～0.15m/s,the growth of microalgae is poor,with an average biomass of 458 mg/L;When the flow velocity is 0.05～0.075m/s,the microalgae growth is better,the average biomass can reach 745mg/L,and the corresponding effect of the pollutant removal rate is also better.（3）The growth of microalgae and the removal of pollutants under the push-flow condition of only 12 hours during the day are better than the push-flow condition of 24hours,which is also more energy-saving and economical;（4）Practical engineering research shows that the corridor-type microalgae photobioreactor has a good treatment effect on large-scale swine wastewater.When the flow rate is 40m³/d,HRT=15d,the effective water depth is 0.35m,the influent CODcr=634～713mg/L,NH₄⁺-N=233～307mg/L,TP=25.4～28.7mg/L,and the push flow velocity is controlled in 0.05m/s～0.075m/s,the effluent indicators are better than Discharge Standard of Pollutants for Livestock and Poultry Industry（GB18596-2001）,And the effluent’s CODcr and NH₄⁺-N can reach the first grade criteria of Integrated wastewater Discharge Standard（GB8978-1996）.The removal rates of CODcr,NH₄⁺-N and TP can respectively reach 94%～99%,97%～100%and 82%～95%;（5）Practical engineering research shows that under the operating conditions of controlled push flow rate and intermittent push flow of 12h during the day,the operating cost of the technology is only 2.00 yuan/ton,which compared with traditional wastewater treatment technology for swine wastewater,such as activated sludge and so on,has a good advantage in operating costs.