氨吹脱与酸吸收一体酒糟沼液处理试验装置研究

Ammonia Stripping and Acid Absorption Integrated Test Device for Vinasse Slurry Treatment

针对酒糟沼液氨氮浓度高,采用氨吹脱技术回收氮养分存在碱剂利用率低、气液接触效果差和氨吸收率低等问题。为提高酒糟沼液氨回收效率和工艺经济性,对酒糟沼液氨吹脱工艺进行了条件优化,探索了不同温度、Ca(OH)_(2)投加量和填料种类对氨吹脱与酸吸收一体试验装置运行效果的影响,并进行了酒糟沼液氨吹脱工艺经济性评价。结果表明,经正交试验得到影响因素重要性由强到弱依次为:Ca(OH)_(2)投加量、气流量、温度,较优工艺参数组合为Ca(OH)_(2)投加量6.6 g/L、气流量6 L/min和温度52℃,相应的氨氮去除率为99.0%;Ca(OH)_(2)对SCOD和TP有较好的去除效果,Ca(OH)_(2)投加量6.6 g/L条件下对应的SCOD和TP去除率分别为32.5%和65.7%。氨氮吹脱与酸吸收一体试验中,相对于不投碱情景,投加Ca(OH)_(2)大幅提高了吹脱过程中氨氮、TN、EC、SCOD和TP去除率,分别达97.4%~97.7%、79.8%~84.2%、68.3%~77.4%、36.8%~45.3%和77.1%~91.0%。对比不同温度、填料种类和Ca(OH)_(2)投加量条件下,获得较适宜氨吹脱参数为多面空心球填料、温度37℃、两次(吹脱8 h投9.9 g/L和30 h投7.4 g/L)投加Ca(OH)_(2),其氨氮去除率达到了97.4%,出水氨氮质量浓度低(100 mg/L左右),氨回收量达1.22 kg/m^(3)。对氨吹脱与酸吸收一体试验装置处理酒糟沼液工艺运行进行比较,相比于不投碱和一次投碱情景,两次投碱方案达到97%氨氮去除率需要的工艺运行时间短,处理成本为9.75元/m^(3),具有较好的经济性。因此,氨吹脱对于高氨氮浓度的酒糟沼液处理体现出较好的适宜性,通过氨吹脱高效回收氮养分可缓解沼液农田利用压力,对沼液资源化利用具有重要意义。

The ammonia nitrogen concentration in vinasse slurry is high,and the use of ammonia stripping technology to recover nitrogen nutrients has problems such as low utilization rate of alkali agent,poor gas-liquid contact effect and low ammonia absorption effect.In order to improve the ammonia recovery efficiency and process economy of vinasse slurry,the conditions of the vinasse slurry ammonia stripping process were optimized,and the effects of different temperatures,Ca(OH)_(2)dosage and filler types on ammonia stripping and acid absorption were explored.The influence of the operation effect of the integrated test device was evaluated,and the economical evaluation of the ammonia stripping process from the vinasse slurry was carried out.The results showed that the order of importance of influencing factors was obtained by orthogonal test was alkali dosage,air flow and temperature.The optimal process parameter combination was Ca(OH)_(2)dosage of 6.6 g/L,gas flow of 6 L/min and at a temperature of 52℃,the corresponding ammonia nitrogen removal rate was 99.0%;Ca(OH)_(2)had a good removal effect on SCOD and TP,and the corresponding SCOD and TP removal rates were 32.5%and 65.7%under the condition of 6.6 g/L alkali dosage.The addition of Ca(OH)_(2)compared with the plan without alkali significantly improved the removal rates of ammonia nitrogen,TN,EC,SCOD and TP in the stripping process,reaching 97.4%~97.7%,79.8%~84.2%,68.3%~77.4%,36.8%~45.3%and 77.1%~91.0%,respectively.The suitable anmonia stripping parameters are hacketten filler 37℃and twice adding Ca(OH)_(2).The ammonia nitrogen removal rate reaches 97.4%,the effluent ammonia nitrogen concentration is as low as about 100 mg/L,and the ammonia recovery amount reaches 1.22 kg/m^(3).Compared with the scenario of no alkali addition and one-time alkali addition,the ammonia nitrogen removal rate can exceed 97%in the two-time alkali addition process scenario.The effluent ammonia nitrogen concentration was low(about 100 mg/L),and the treatment cost was 9.75 yuan/m^(3),which had a relatively good economy.Therefore,ammonia stripping had good suitability for the treatment of scenario with high ammonia nitrogen concentration.The efficient recovery of nitrogen nutrients through ammonia stripping can relieve the pressure of biogas slurry farmland utilization,which was of great significance for the resource utilization of biogas slurry.