| Avermetin is a kind of efficient antibiotic medicament against insects and mites in a broad spectrum, which is the mixture developed by eight components from natural ferment of Afuman Streptomycete. For its good efficacy, selectivity and its wide application, Avermetin is widely used in the agricultural fields, what’s more, it has now become the largest variety of microbial pesticides.In the process of production of Avermetin, it produces a large number of smelly high concentration organic wastewater, whose main components lie in protein, sugar, volatile acid residue, mycelium and the fermentation process of metabolic product and the remnants of a small amount of AVM. Since its wastewater is a sort of organic pollution, with complicated composition, biological inhibitory substances, and the biochemical inhibitor, it is difficult to be degraded by creatures. To sum up, Avermetin wastewater is a kind of typical organic wastewater with the features of high pollution, high concentration and difficult refractory.This experiment adopts the combined process of the anaerobic-aerobic-Fenton oxidation to research the efficient treatment to Avermetin wastewater. With application of the main evaluation indexes such as COD, SS, it analyses and summarizes the running characteristics of the whole system, providing experimental reference for future research and practical engineering application. the results of experimental study show that:1. Making use of the vaccinated anaerobic granular sludge reactor to treat Avermetin wastewater. That is to treat Avermetin wastewater in a medium temperature (35plus or minus2℃) with anaerobic reactor, it shows that, when the reactor goes stable, the inlet COD concentration keeps about6000mg/L, the HRT increases from12h to48h, the volume load s about3.00kgCOD/(m3·d), and the degraded ratio of the system can be raised from28.6%to84.7%, the outlet COD is less than930mg/L, the rate of methane gas keeps steady at around0.4m3/kg COD, and the ratio of the biochemical (BOD5/COD) falls to0.34from0.48of raw water.2. Making use of anaerobic reactor of effluent biological contact oxidation treatment to treat Avermetin wastewater. This reactor applies good activated sludge inoculation hanging membrane, and it can meet the designed load in37days. It shows that, in a room temperature, the inlet COD concentration is about900mg/L, the pH7.5, the dissolved oxygen4.0mg/L, and the system can achieve the optimal treatment effect when the HRT is in10h, and the COD removal rate is52.5%, the outlet COD below430mg/L, and the ratio of the biochemical (BOD5/COD), by further, drops to0.16.3.Making use of Fenton oxidation/enhanced coagulation treatment contact oxidation to treat Avermetin wastewater. Through orthogonal and single factor experiment, it comes to the best processing conditions for Fenton oxidation:4.5pH,62.5mg/L FeSO4·7H2O dosing quantity,3ml/L H2O2(30%) dosing quantity, and the reaction time of90min. Under the previous condition, the COD removal rate is69.2%, the outlet COD is less than136mg/L. With Fenton reagent oxidation, pH is adjusted to about8.0,4.0mg/L polyacrylamide is added, then comes the process of strengthening coagulation, as a result, the outlet COD is less than105mg/L, and SS less than16mg/L. By this way, the ratio of the biochemical (BOD5/COD) goes down further from0.15to0.08of raw water and the outlet BOD5below10mg/L4. The total removal rate of the Combined process to COD and SS of Avermetin wastewater is respectively over98%and99%, and both of the outlet COD and SS are far above that required as the GB21903-2008"the Standard of Fermentation Pharmaceutical Industrial Water Pollutant Discharge "..5. The reagent cost of adopting the combined process of Avermetin wastewater5.80yuan/m3, and such a process enjoys a higher economic feasibility compared to other organic wastewater of high concentration but difficult refractory. |
PDF Full Text Request