城市污泥作为边坡植物生长基质的效果分析

【目的】为了研究城市污泥用于边坡植物恢复的技术与效果。【方法】将城市污泥与建筑垃圾按体积比1∶1混配基质,覆盖于模拟的煤矸石边坡上,以田园土坡面为对照,种植臭椿,调查坡面植物生长情况,分析种植基质的理化性状、重金属含量、土壤酶活性等的变化。【结果】试验结果表明:植物生长季结束后,污泥混合基质坡面植物总盖度比对照坡面高30%,臭椿株高比对照高25%;含水量和电导率是对照的2倍和2.7倍,有机质含量是对照的3.6倍,全氮和碱解氮是对照的3.8倍和8倍,全磷和速效磷是对照的6.3倍和11.9倍,全钾和速效钾是对照的1.6倍和5.4倍。根际土壤脲酶、过氧化氢酶、蔗糖酶和碱性磷酸酶活性分别是对照的4.7倍、2倍、2.3倍和2.6倍。【结论】可见污泥混合基质保水性好,肥力高,能为植物生长提供充足的养分,而且重金属含量在安全使用范围内,并随着时间的推移呈下降趋势。因此,城市污泥用于边坡生态修复不仅效果良好,而且实现了污泥的资源化和无害化利用。

Analysis of the effectiveness of sewage sludge used as plant growth substrate for slope vegetation restoration

Objective]In order to explore the techniques for slope vegetation restoration using sewage sludge.Methods] the effect of sewage sludge substrate on the growth of vegetation was investigated.The simulated coal gangue slope was covered by the mixed substrate of sewage sludge and construction waste at volume ratio 1 ∶ 1,then Ailanthus altissima seeds were sowed,the growth of A.altissima and the herbs grown naturally were measured.The physical and chemical properties,heavy metal content,and soil enzyme activity of the substrate were analyzed.The garden soil was used as the control.Results]The results showed that,at the end of the growing season,the plant coverage on the treated slope was 30％ higher than that on the control slope.The height of A.altissima on the treated slope was 25％％ higher than on the control slope.And in rhizosphere soil on the treated slope,the water content,the conductivity,the organic matter content,the total nitrogen content,the available nitrogen content,the total phosphorus content,the available phosphorus content,the total potassium content,and the available potassium content were 2,2.7,3.6,3.8,8,6.3,11.9,1.6,5.4 times higher than on the control slope,respectively.The activities of urease,catalase,invertase,alkaline phosphatase in rhizosphere soil on the treated slope were 4.7,2,2.3,2.6 times higher than on the control slope,respectively.Conlusion]Thus the mixed substrate of sewage sludge and construction waste possessed high water holding capacity and fertility,and can provide sufficient water and nutrient for plants.Moreover,the contents of heavy metals were found to be in the safe range,which presented a decreased pattern along with time,Therefore,not only the slope vegetation restoration showed a good effect,but also the reclamation and harmless utilization of sewage sludge was realized.