| Heparin sodium is glucosamine sulfate’s sodium salt extracted from porcine or bovine intestinal mucosa. As the most medicine for anti-coagulation, anti-blood lipid, protecting endothelial cell and anti-inflammatory, heparin sodium’s market demand has been relatively strong. China has rich heparin raw materials and is the main country in producing and reporting crude heparin sodium.As heparin extraction process is relatively limited,"three high" wastewater which has high concentration of salt, organic matter, ammonia nitrogen generated in the manufacture process of heparin sodium. If discharged into the river directly will lead to water corruption and deterioration, causing great harm to the water environment. Treating such wastewater by general physical and chemical methods is not only high cost, low efficiency, but also may bring secondary pollution.Biological methods make up these disadvantages, become a hot research spot in high salt wastewater treatment.Based on the successfully acclimation of high salt tolerance activated sludge, this paper mainly discussed the optimum operating conditions (aeration time, pH, temperature) of SBR process in heparin sodium production wastewater treatment, and also the anti-load-shock(organic load, ammonia load, salinity load) capacity under the best operating conditions. In addition, considering the microbial inhibition toxic effects of high salt (Na+), the paper also studied the effects of metal ions (K+, Ca2+, Mg2+) on activated sludge performance based on antagonistic effects in such wastewater treatment, as a reference to alleviate salt toxicity.The results showed that:1. After seeding a certain salt tolerance of activated sludge in the SBR reactor, acclimating a higher salt tolerance of sludge through gradually increasing the salt concentration and organic loading has a good feasibility. Acclimation was divided into nine stages, for which the influent COD concentration from1000mg/L gradually increased to2000mg/L, influent NaCl concentration from15500mg/L gradually increased to32000mg/L, sludge load from0.067kgCOD/(m3·d) gradually to1.176kgCOD/(m3·d). After49days of acclimation, sludge become khaki, settling performance was better, COD removal rate was 90.5%.2. Aeration time, pH and temperature have varying degrees of impact on the system performance. By contrast testing, the optimum operating conditions were:2cycles per day,12hours per cycle,10hours for aeration time;7.5for pH and26-29℃for temperature. Under the optimum operating conditions, COD and NH3-N removal rate remained at90%, purification works best.3. Under the premise of parameter optimization and stable operation, the SBR reactor has good resistance capacity on organic load, ammonia loading and salinity load. Different loads affected the system differently:organic load affected less, COD removal rate remained at90%or more; addition of ammonia load showed a greater impact on the system than reduction, NH3-N removal rate to more than90%required continuous run for2-3cycles when ammonia load was300-500mg/L; the impact of salinity load was small, COD and NH3-N removal rate to more than90%required continuous run for2cycles when salinity load was40000-65000mg/L.4. Different types and concentrations of metal ions showed different effects on COD and NH3-N removal rate, sludge concentration and sedimentation rate.The effects on sludge performance may be related with the operating cycle and the add way of metal ions.40mg/L potassium ion was most conducive to the removal of COD,100mg/L was most conducive to the removal of NH3-N, increased by respectively2.8%and39.8%compared with the blank group, the addition of potassium ions will reduce the sludge sedimentation rate;50mg/L calcium ion was most conducive to the removal of COD,200mg/L was most conducive to the removal of NH3-N, increased by respectively8.0%and9.9%compared with the blank group, and sludge growed faster when calcium ion was30mg/L and200mg/L;150mg/L magnesium ion was most conducive to the removal of COD,20mg/L was most conducive to the removal of NH3-N, increased by respectively3.8%and28.4%compared with the blank group, and magnesium ion can effectively improve the sludge sedimentation rate. |
PDF Full Text Request