摘要
为了有效提高污泥水解效率、缩短厌氧消化时间,以K2FeO4为氧化剂破解剩余污泥,考察K2FeO4投加量(50~500 g/kg,以干质量计)对污泥破解率的影响,分析水解液各项特征指标并对其可生化性能进行预测,探究该方法作为污泥厌氧预处理的可行性.结果表明:污泥水解效率随着K2FeO4投加量的增加而升高,当搅拌速率为500 r/min、反应时间为2 h、K2FeO4投加量为500 g/kg的条件下,可实现最高的污泥破解率(34.6%).污泥水解液中有机物以多糖、蛋白质为主,并有少量挥发性有机酸;污泥破解过程也伴随着P和NH4^+-N的释放,上清液中ρ(TP)最高可达496 mg/L,且以正磷酸盐为主(约310 mg/L),可对其进行回收.采用三维荧光体积积分的方法对污泥水解液的可生化性能进行预测,发现污泥经K2FeO4预处理后,水解液中RB(易降解有机质)和PB(难降解有机质)荧光强度均明显增加,当K2FeO4投加量为50 g/kg时,F digestion(生物可降解性指数)达到最大值(4.75),预测此时污泥的可生化性能最佳.以K2FeO4为氧化剂预处理污泥可有效提升污泥水解效率,但若作为厌氧消化预处理,应综合考虑污泥破解率和可生化性能.研究显示,搅拌速率为500 r/min、反应时间为2 h、K2FeO4投加量为50 g/kg预处理条件下污泥的可生化性能最佳.
In order to improve the hydrolysis of sludge and shorten the retention time of anaerobic digestion,the feasibility of using K2FeO4 as oxidant to disintegrate waste activated sludge was studied in this research.The effect of K2FeO4 dosage(based on dry weight,50-500 g/kg)on the degree of sludge disintegration was investigated,and the characteristics of hydrolysate were measured to predict its biodegradability.The results showed that the sludge hydrolysis efficiency increased with the dosage of potassium ferrate.The maximum sludge disintegration rate of 34.6%was obtained at the K2FeO4 dosage of 500 g kg when the stirring rate was 500 r/min and the reaction time was 2 h.The organic matters in the sludge hydrolysate were mainly composed of polysaccharides and proteins,as well as some low concentrations of volatile organic acids.In addition,the disintegration was accompanied by the release of phosphorus and ammonia.The concentration of total phosphorus in the hydrolysate was up to 496 mg/L and orthophosphate was the main species(about 310 mg/L)that can be considered for recycling.The biodegradability of sludge supernatant was predicted by the three-dimensional fluorescence volume integration method.It was found that the fluorescence intensity of the easily degraded organic matter(RB)and refractory organic matter(PB)increased significantly after K2FeO4 pretreatment,nevertheless the maximum value(4.75)of the biodegradable index(Fdigestion)was found at the dosage of 50 g/kg,which indicated the best biodegradability.The results indicated that K2FeO4 pretreatment could effectively improve the hydrolysis efficiency of waste activated sludge.However,both the degree of sludge disintegration and the biodegradability of the pretreated sludge should be considered when K2FeO4 oxidation is used as the pretreatment before anaerobic digestion.Overall,the study shows that the best biodegradability of sludge can be obtained at the K2FeO4 dosage of 50 g/kg when the stirring rate is 500 r/min and the reaction time is 2 h.
作者
张皖秋
徐苏云
孙洋洋
张雨辰
ZHANG Wanqiu;XU Suyun;SUN Yangyang;ZHANG Yuchen(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China)
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2020年第4期1045-1051,共7页
Research of Environmental Sciences
基金
国家自然科学基金项目(No.51308337)
上海理工大学科技发展项目(No.2018KJFZ111)。
关键词
剩余污泥
水解液
总磷
三维荧光
可生化性
waste activated sludge
hydrolysate
total phosphorous
3D fluorescence
biodegradability
