味精废水短程硝化工艺的运行性能

Monosodium glutamate wastewater treatment with a full-scale SHARON reactor

通过现场试验研究了工程规模的短程硝化反应器处理实际味精废水的运行性能.结果表明,短程硝化工艺（Single Reactor High Activity Ammonia Removal Over Nitrite,SHARON）适合处理低浓度味精废水（pH值为9.36-10.49;NH4^＋-N浓度为239.70-341.23mg·mL^-1;COD为1000-1500mg·mL^-1）.短程硝化反应器的硝化性能良好,短程硝化效率（Partial Nitrification Efficiency,PNE）高达94.56%±4.30%;在反应器内pH值为9.25-9.80、游离氨（Free Ammonia,FA）浓度为20-70mg·mL^-1的工况下,短程硝化反应器运行性能稳定,PNE达96.64%±4.73%,出水中（NO2^--N）/（NH4^＋-N）为0.70-1.35,出水pH值稳定在6.50-7.00,适用于后续厌氧氨氧化工艺（Anaerobic Ammonium Oxidation,ANAMMOX）处理.进水FA浓度不宜过低,若反应液中的FA浓度低于20mg·mL^-1,可导致NO3^--N浓度升高,不利于NO2^--N积累.采取一次性投加石灰的方式调节废水碱度,只适用于进水NH4^＋-N浓度较低的情况;若进水NH4^＋-N浓度较高,则会导致进水pH过高而抑制亚硝酸菌生长,宜采用多次投加或分段投加石灰的方式来调节废水碱度.

The performance of a full-scale SHARON（Single Reactor High Activity Ammonia Removal Over Nitrite）reactor was investigated for treatment of monosodium glutamate wastewater.Results showed that the SHARON process was suitable for treatment of monosodium glutamate wastewater with NH＋4-N concentration of 239.70-341.23 mg·L^-1 and COD of 1000-1500 mg·L^-1.When the pH of the wastewater was 9.36-10.49,the partial nitrification efficiency（PNE）was higher than 94.56%±4.30%.Reactor performance was even stable when the pH values（9.25-9.80）and free ammonia（FA）concentrations（20-70 mg·L^-1）in the reactor were higher than the threshold inhibition values.Under these conditions,the effluent pH of the SHARON reactor were around 6.50-7.00 and（NO-2-N）/（NH^4＋-N）ratios were maintained at 0.70-1.35 with PNE as high as 96.64%±4.73%,which were quite suitable for the subsequent ANAMMOX（Anaerobic Ammonium Oxidation）process.It was also demonstrated that the NO-3-N concentration would increase with low NO-2-N accumulation if the FA concentration was lower than 20 mg·L^-1.It is proposed that adjustment of alkalinity by adding lime all at once is suitable for low ammonium-containing wastewater.However,for high ammonium-content wastewater it is recommended that lime should be added several times or in several sections.Otherwise,ammonia-oxidizer may be inhibited by the high pH and FA concentration.