以典型石灰铁盐法处理二种含砷废水产生的污泥(污酸渣和砷酸钙渣)为研究对象,采用ICP-AES、SEM-EDS、XRD、XPS和化学物相分析等检测手段对其化学组成、形貌特征、物相结构及砷的赋存状态进行研究,采用毒性浸出实验和BCR三步连续提取法考察污泥中砷的浸出行为.研究结果表明,污酸渣和砷酸钙渣中砷的含量分别为2.5%和21.2%,主要组成物相为砷酸盐及砷氧化物,均以无定型的颗粒均匀分散或团聚在污泥中.砷的浸出毒性超出TCLP标准规定限值的119和1063倍,浸出率分别为47.66%和50.15%.砷以酸可提取态和可还原态为主,两者共占90%左右,而稳定的残渣态含量相对较低,这是含砷石灰铁盐渣浸出毒性大、环境活性高的直接原因.本研究为含砷石灰铁盐渣无害化处理技术提供了大量有用的基本数据.
Physicochemical properties and leaching behaviors of two typical arsenic-bearing lime?ferrate sludges (ABLFS), waste acid residue (WAR) and calcium arsenate residue (CAR), are comprehensively described. The chemical composition, morphological features, phase composition and arsenic occurrence state of WAR and CAR are analyzed by ICP?AES, SEM?EDS, XRD, XPS and chemical phase analysis. The toxicity leaching test and three-stage BCR sequential extraction procedure are utilized to investigate arsenic leaching behaviors. The results show that the contents of arsenic in WAR and CAR are 2.5% and 21.2% and mainly present in the phases of arsenate and arsenic oxides dispersed uniformly or agglomerated in amorphous particles. The leaching concentrations of arsenic excess 119 and 1063 times of TCLP standard regulatory level with leaching rates of 47.66% and 50.15% for WAR and CAR, respectively. About 90% of extracted arsenic is in the form of acid soluble and reducible, which is the reason of high arsenic leaching toxicity and environmental activity of ABLFS. This research provides comprehensive information on harmless disposal of ABLFS from industrial wastewater treatment of lime?ferrate process.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%