【作者】 杨杰；

【导师】 姚宏；

【作者基本信息】 北京交通大学 ， 市政工程， 2010， 硕士

【摘要】 我国总体水资源不足,导致农业缺水日趋严重,尤其是北方干旱缺水地区,农业上不得不用大量的污水灌溉农田。污水中含有大量N、P、K等营养元素,其中,磷是庄稼生长必需的重要营养元素之一。本研究针对农田土壤中的磷素,采取污灌农田土壤磷素调查分析与室内土柱试验模拟相结合进行了以下两方面的研究：一方面对污水渠两侧农田土壤磷素及常规理化性质进行调查分析,研究污水灌溉农田土壤磷素的空间分布及形态组成；另一方面进行室内土柱试验,分析研究不同浓度含磷污水淋溶条件下,磷在土壤中的变化规律。结论如下：1、大规模采样研究发现,土壤全磷含量大多集中在300-700mg/kg之间,均值为451.42mg/kg,整体来看属于缺乏水平,其中有两个全磷含量较高的区域,出现在孔家乡和钱家乡附近,这与当地的土质成分以及多年采用污水灌溉等因素有关。2、有多年污灌历史的剖面相比常年采用地下水灌溉的剖面,土层全磷变化趋势相似,只是污灌区域剖面全磷含量峰值较清灌区域具有一定距离的下移,但峰值大小没有明显差距,且峰值较低,均在500mg/kg以下。结合当地长期施肥以及多年污水灌溉的历史可以推断,污水灌溉对当地土壤磷素的积累和迁移影响并不显著。3、孔家乡土壤磷素的空间变异特征研究表明,孔家乡全磷、有效磷、NaOH-Pi和Ca-P具有相似的空间分布特征,整体来看,北部污灌区域含量较高,南部清灌区域较低,特别是有效磷含量,污灌区域比清灌区域高66.49%。4、室内土柱试验研究表明,土壤具有较好的固磷作用,含磷污水进入土壤,可以通过吸附和沉淀反应截留在土壤中。试验灌以三年灌溉水量24L,地下60cm以上磷素含量变化显著,60cm以下变化不大,说明磷素随水分向下迁移的速率较小,这与磷在土壤中主要以吸附态和沉淀态存在有关。有效磷的迁移累积速率与淋溶液的浓度有关,浓度越大,速率越快。以当地污水处理厂出水灌溉农田,对土壤磷素的迁移转化影响甚微。如果提高淋溶液的磷浓度,则可以有效提高表层土壤中的有效磷含量,因此,从污水灌溉角度出发,用于农田灌溉的污水可以适当放宽对磷的要求。更多还原

【Abstract】 The lack of overall water resources of our country leads to increasingly serious water shortage; especially in arid areas in northern China, Agriculture had to use a large number of sewage irrigating. Sewage contains large amounts of N, P, K and other nutrients, such as phosphorus is necessary for crops to grow as one of the important nutrients.This issue aims at researching phosphorus in the agricultural soil, combining soil phosphorus to wastewater irrigation Investigation and simulation of laboratory soil column experiment getting the following two studies:1、investigate on both sides of the sewers from agricultural soils and the conventional physical and chemical properties and analyze of wastewater irrigation and the spatial distribution of soil phosphorus in the form; 2、do the laboratory soil column experiment; analyze the phosphorus in the soil variation at different concentrations of phosphorus-containing waste water leaching conditions.That is the conclusion:1、Most of the soil total phosphorus concentration among 300～700mg/kg and the Average value is 451.42mg/kg, as a whole belong to low standards.There have two areas with higher phosphorus content, and appear near the kongjiaxiang and qianjiaxiang, which related to the local soil composition and irrigation with sewage so many years.2、With many years of history of sewage irrigation the 7th hole and the 8th hole compared to the 9th hole with year-round using of groundwater for irrigation, soil phosphorus has the similar changes, only phosphorus content of the 7th hole and the 8th hole have a certain distance down than the 9th hole, but no significant difference between the peak size, and the peak was both less than 500mg/kg. With local long-term fertilization and irrigation water for many years of history can be inferred, sewage irrigation on local soil phosphorus accumulation and migration is not significant.3、Spatial variability of soil phosphorus studies of kongjiaxiang have shown that in kongjiaxiang total phosphorus, effective phosphorus, NaOH-Pi and Ca-P have similar spatial distributions, all in all, higher in northern and southern lower. Especially effective phosphorus, sewage irrigation area is 66.49% higher than groundwater irrigated area. 4、Soil column experiments showed that the soil has good stabilizing phosphorus function, when phosphorus-containing waste water into the soil, adsorption and precipitation reactions can trapped phosphorus in the soil. If we irrigate three-year irrigation water volume (24L), the phosphorus content of more than 60cm underground changed significantly, above 60cm little changed, which indicated that phosphorus with water down the rate of migration is lower, this is mainly related to phosphorus as adsorbed state and precipitated state exists in the soil and sediment. Cumulative rate of migration of phosphorus changes along with the concentration of leaching solution, the greater the concentration, the faster rate. Using local sewage treatment plant effluent irrigating soils have little effect on migration and transformation of soil phosphorus. If you increase the concentration of phosphorus leaching solution, you can effectively improve the surface soil effective phosphorus content; therefore, just considering from the perspective of phosphorus, agricultural irrigation water can be appropriately broadened the requirements of phosphorus.更多还原