赤峰地区污水厂污泥修复沙漠化土地的可行性研究

Feasibility Study of Remediation of Desertified Land by Sludge from Urban Sewage Treatment Plant in Chifeng Region

通过对赤峰地区6座污水厂污泥养分的调查,发现污泥有机质含量在24.93%~54.49%之间,总氮、总磷、总钾及钙含量分别为(19.18~39.68)、(14.75~22.61)、(6.65~8.36)与(13.9~16.49)g/kg。有机质与养分含量较高的分别是1~#、2~#与4~#污水厂的污泥。分析表明:赤峰地区经济较发达地区的城市污泥有机质、氮、磷、钾等养分含量普遍偏高,土地利用价值较大,经济欠发达地区则相反。在此基础上,对1~#、2~#与4~#污水厂污泥进行重金属监测,结果显示:1~#污水厂污泥中的各种重金属含量都不超标,用于沙漠化土地的改良是可行的;2~#污水厂的污泥重金属含量超标严重,不可用于改良沙漠化土地;4~#污水厂的污泥虽满足土地改良用泥质要求,但镍含量接近标准限值,施加时需谨慎。内蒙古赤峰地区是典型的干旱与半干旱地区,污泥用于沙漠化土地的生态修复将同时解决城市污水厂污泥的处理处置和土地沙漠化这两个广受关注的环境问题,具有一定的经济、社会、环境效益。

The sewage sludge from 6 sewage treatment plants was investigated in order to study whether the sludge is feasible for remediation of desertified land. The results were as follows: the content of organic matter was in the range of 24. 93% to 54. 49%,the contents of TN,TP,TK and Ca were19. 18 g / kg to 39. 68 g / kg,14. 75 g / kg to 22. 61 g / kg,6. 65 g / kg to 8. 36 g / kg and 13. 9 g / kg to16. 49 g / kg respectively. The sewage sludge from No. 1,No. 2 and No. 4 sewage treatment plants contained higher contents of nutrients. The analysis showed that the contents of organic matter,nitrogen,phosphorus and potassium were higher in developed areas with a high value of land use than those in underdeveloped areas in Chifeng Region. On the basis of this,the contents of heavy metals in sludge from the aforementioned plants were monitored. The results showed that the sewage sludge from No. 1 plant was feasible for remediation of desertified land due to its low content of heavy metals,the sewage sludge from No. 2 plant could not be used for remediation of desertified land due to its high content of heavy metals,and the sewage sludge from No. 4 plant needed to be treated carefully when applied due to the content of Ni near the upper limit although it met the other requirements for remediation of desertified land.As the Chifeng Region belongs to typical arid and semi-arid area,the application of sludge to ecological remediation of desertified land will solve the problems of disposal of sludge from sewage treatment plants and land desertification simultaneously,which has economic,social and environmental benefits.