摘要
针对国内粉煤灰产量大、贮存污泥量大的现状,开展了利用改性粉煤灰固定贮存污泥中主要重金属的研究。采用"微波-碱"方法对粉煤灰进行改性,利用扫描电镜、红外光谱、X射线衍射、X射线荧光光谱和比表面积测定等手段,对粉煤灰改性前后的物化性质进行分析,并考察其改性后对贮存污泥中Cu和Zn的钝化效果。结果表明,在微波功率为400 W、辐照10 min、NaOH浓度为6 mol/L、浸渍时间为3 h、碱灰比为5:1的条件下,获得的粉煤灰具有最大比表面积,并生成了新的矿物质Ca_2SiO_4,增加了新的表面基团。该改性粉煤灰有利于贮存污泥中的重金属Cu和Zn向稳定态转化,钝化效果优于未改性粉煤灰;当改性粉煤灰的添加量为40%时(扣除干释作用),钝化7 d,污泥中Cu和Zn的各种形态已达到稳定化,且所占比例不随时间的推移而改变。
Aimed at the large production of fly ash and a large amount of storage sludge in China, a study was carried out on passivation of main heavy metals stored in sludge by modified fly ash. The mi- crowave/alkali methods were used to modify fly ash, the chemical and physical properties of fly ash be- fore and after modification were analyzed by scanning electron microscope, infrared spectroscopy, X-ray diffraction, X-ray fluorescence spectroscopy and specific surface area measurement, and the passivation performance of Cu and Zn stored in sludge by the modified fly ash was investigated. The results showed that under the conditions of microwave power of 400 W, irradiation of 10 min, NaOH concentration of 6 tool/L, immersion time of 3 h and alkali/fly ash ratio of 5 ： 1, the modified fly ash had the maximum specific surface area, and a new mineral （Ca2 SiO4 ） was generated during passivation, which added new group on the surface of fly ash. The modified fly ash was conducive for stable transition of Cu and Zn, and the passivation performance was better than the unmodified fly ash, especially when the addition ratio of the modified fly ash was 40% （deducting dry release effect） and passivation lasted for 7 d, different forms of Cu and Zn in sludge could reach a stabilized state, and the proportion of each form did not change with time.
出处
《中国给水排水》
CAS
CSCD
北大核心
2016年第13期91-95,共5页
China Water & Wastewater
基金
国家水体污染控制与治理科技重大专项(2014ZX07202-011)
关键词
粉煤灰
微波-碱改性
污泥
重金属
钝化
fly ash
microwave/alkali modification
sludge
heavy metal
passivation
作者简介
边靖（1977-），科，高级工程师，设计工作。女，天津人，大学本主要从事市政给排水的E-mail：bianjing99@cemi．com．cn
通信作者：赫俊国E-mail：junguohe@263．net
