直接驯化嗜盐菌处理高盐废水的研究

Acclimatization of halophilic bacteria for biology treatment of high-salt wastewater

从大连旅顺盐场底泥中筛选出适合高盐度的嗜盐菌,在序批式间歇反应器(SBR)中对其进行3.5%(质量分数)盐度的驯化,污泥混合液悬浮固体(MLSS)平均质量浓度达600mg/L。污泥比耗氧速率(SOUR)测量结果显示,内源呼吸阶段污泥SOUR为10.36mg/(g.h),外源呼吸阶段污泥SOUR达到29.09mg/(g.h),表明所筛选的嗜盐菌培养的污泥具有较高活性。利用培养的污泥进行高盐模拟废水处理试验,结果表明,对盐度为3.5%、COD为240～340mg/L的高盐废水,在每周期12h、曝气量0.6L/min、污泥MLSS为600mg/L、污泥龄为18d条件下,COD去除率达95%以上,NH4+-N去除率达61%,TP去除率达55%。改变进水有机负荷对出水COD去除影响不大,该系统耐有机负荷冲击能力较强;盐度负荷的改变对COD的去除影响不大,而NH4+-N去除率有明显变化,在3.5%和5.0%的盐度下,NH4+-N去除率分别为61%和31%。

The halophilic bacteria adapted to high salinities were isolated from the substrate sludge of Dalian Lvshun Salt Field in China. These bacteria were acclimated in the sequencing batch reactors （SBR） with salinity was 3.5 %, and sludge with average concentration of 600 mg/L was obtained. The specific oxygen uptake rate （SOUR） was measured, and the results showed that the endogenous and exogenous respiration of oxygen uptake rate were reached 10.36 mg O2/（gVSS · h） and 29.09 mg O2/（gVSS· h） respectively. This indicated that the sludge cultivated from the halophilic bacteria had high activity. A system that employing this sludge was built for the treatment of high-salt wastewater, with the operating conditions of salinity of 3.50%, COD of 240-340 mg/L, an operating period of 12 h, aeration rate of 0.6 L/min and sludge retention time of 18 d, the system achieved the COD, NH4＋--N and TP removal efficiency of 95 %, 61% and 55 % respectively. The organic loading had little effect on COD removal, which means the resistance capability of this system against organic loading was high. NH＋-N removal efficiency of the system was highly correlated with salinity loading, when the salinity loading was 3.5 % and 5 %, the removal efficiency of NH/-N were 61% and 31% respectively.