不同比例湿解产物在土壤中的物质变化及腐熟度

Substance changes and maturity of different concentration of hydrothermal treated wastes in soil

将经湿解工艺处理后的园林废物与土壤按1∶3、1∶5和1∶10(湿质量)3种比例均匀混合作为实验物料,同时以自然土壤作为参照,研究了在田间条件下,不同浓度的湿解产物在土壤中的物质变化以及腐熟度。结果表明:在培养期间,3种比例混合物料的温度均接近于土壤对照样的温度,稍低于环境温度;pH值均略呈碱性,并随土壤浓度的增加而接近土壤对照样的pH值;w(C)/w(N)比、w(水溶性有机碳WSC)/w(有机态氮Norg)和w(NH4+-N)/w(NO3--N)均随培养时间的增加而下降,而阳离子交换量(CEC)和CEC/w(全C)恰好相反,并随湿解产物浓度的增加而增加,14d后,这些指标均接近土壤对照样的参数,实验结束时,均达腐熟。3种比例混合物料的种子发芽系数均大于80%,湿解产物浓度对种子发芽系数无明显抑制作用,湿解后的产物可直接安全应用于土壤中。

Three different ratios of hydrothermal-treatment garden wastes and soil （1 ： 3, 1 ： 5, 1 ： 10, wet weight） were incubated for 63 days in soil to determine hydrothermal-treatment products substance changes and maturity. Compared with the incubated natural soil, the results show that the temperatures of the three incubated materials approached the temperature of the natural soil, and were slightly lower than environmental temperature. During the incubation, the fluctuation of pH of all incubated materials was not significant （but 1 ： 3〈1 ： 5〈1 ： 10〈soil）. ω（C）/ω（N）, ω（water soluble organic-C： WSC）/ω（Norg） and ω（NH4^＋-N）/ω（NO3^--N） of all materials significantly decreased, on the contrary, cation exchange capacity （CEC） and CEC/ω（Total-C） slowly increased with the increase of hydrothermal-treatment products＇ concentration. After 14 days, all measured parameters approached those of the natural soil. When the incubation was finished, the three incubated materials reached maturity. The germination indices of all incubated materials were greater than 80%, and the concentration of the hydrothermal treated wastes hadn＇t remarkable effect on the seed germination index. The hydrothermal treated products can be directly applied to soil as a soil amendment.