A study on the purification of wastewater with sprinkling management to suburban forest

在城郊次生林中进行了喷灌管理对污水净化效果的研究。本研究项目得到的结果如下：分别以D2 O和15 HN 4Cl作为水分和营养元素的示踪剂，研究了次生林土壤水分和表土主要离子的垂直运动。用氯乙烯管柱采集不同林分的原状土柱。用人工降雨装置分两次将雨水溶液均匀滴在柱上。连续10 h，降雨强度为4 mm/hr，第二次降雨时，用D_2O和~（15）NH_4Cl标记的示踪剂溶液淋洒在棕壤柱上，Cl ~-、Mg ~（2+）和Ca ~（2+）浓度随D_2O的释放而增加，只有少量~（15）NH_4 ~+-N迁移到棕壤柱的下层。D_2O标记水的下降速度与Mg ~（2+）和Ca ~（2+）的下降速度基本一致。而在林下清除站收集的15 NH ~（4+）-N则随D_2O标记水排放到土柱上，在重水排放口，由于阴离子吸附作用，土壤柱中Cl ~-浓度没有明显增加。

The purfication of wastewater with sprinkling management was studied in suburban secondary forest. The result that we could got with this research project is the following.The vertical movement of soil water and major ions in topsoil of secondary forests were investgated by using D2O and 15HN4Cl as tracers of water and nutrient elements, respectively. Undisturbed soil columns were collected with cylinders made of vinyl chloride pipe in different stands. The rain soluion was dropped uniformly on the column by using the artificial rainfall equipment in twice. The artificial rainfall was continued for 10 hours at constant intensity of 4mm/hr. At the second time of rainfall, the tracer solution labeled with D2O and 15NH4Cl applied on the column.The concentrations of Cl-, Mg2+, and Ca2+ increased with the D2O discharge and only small quantity of 15NH4+-N moved to the lower horizon on the Brown forest soil columns. The downward velocity of the D2O-tagged water agrred approximately with that of Mg2+ and Ca2+. But large amount of the 15NH4+-N was discharged with the D2O-tagged water on the column that was collected in the forest floor removal stand. In spit of heavy water dischraging, the concentration of Cl- in dischraged soil solution did not increase obviously in Andosol column because of the effect of anion absorption into the soil.