摘要
研究了柠檬酸、草酸和乙酸溶液对污泥中重金属(Cd、Pb、Cu和Zn)的去除效果,以及处理前后析出液和污泥中硝态氮和铵态氮的浓度变化.结果表明,0.8mol.L-1柠檬酸溶液可去除污泥中76.0%的Pb和92.5%的Zn,是较好的重金属去除剂.污泥经有机酸处理后,有大量的硝态氮和铵态氮溶解于析出液中,与加入蒸馏水的对照处理相比,有机酸可大幅度增加析出液中铵态氮的含量,减少硝态氮含量.由于污泥处理过程中有其他形态的氮的转化,处理后污泥中仍含有较高浓度的硝态氮和铵态氮.0.5mol.L-1草酸处理的析出液中硝态氮和铵态氮浓度分别为2.8和888.1mg.L-1,且重金属含量不高,可作为较好的液体肥料进行回收利用.
This paper studied the removal effect of citric acid, oxalic acid and acetic acid on cadmium （Cd） , lead （Pb） , copper （Cu） and zinc （Zn） in sewage sludge, and the changes of NO3^ - -N and NH4 ^＋-N concentrations in extracted liquid and sludge before and after treated. The results showed that 0. 8 mol · L^-1 of citric acid had better effect, which could remove 76. 0% of Pb and 92.5% of Zn in the sludge. After treated with test organic acids for 24 hours, large amounts of NO3^ --N and NH4^＋-N dissolved in extracted liquid. Compared with the control （distilled water）, organic acids greatly increased the NH4 ^＋ -N, but decreased the NO3 ^--N in extracted liquid. Because of the transformation of other forms nitrogen in the process of acid treatment, the NO3 ^- -N and NH4^ ＋-N concentrations in the treated sludge were still high. The extracted liquid after the sludge was treated with 0. 5 mol · L^-1 of oxalic acid contained 2.8 mg · L^-1 of NO3^ --N and 888. 1 mg · L^-1 of NH4^＋-N but a few of heavy metals, which was able to be reused as a liquid fertilizer.
出处
《应用生态学报》
CAS
CSCD
北大核心
2007年第9期2085-2090,共6页
Chinese Journal of Applied Ecology
基金
国家重点基础研究发展规划项目(2004CB418503)
中-俄国际合作资助项目(20611120015).
关键词
污泥处理
有机酸
重金属
硝态氮
铵态氮
disposal of sewage sludge
organic acid
heavy metal
NO3^ - -N
NH4^＋ -N.
