奎河污灌区的氮、磷污染

Pollution of Nitrogen and Phosphorus in the Region of Wastewater Irrigation along Kui River.

田间污灌模拟实验及污灌区和非污灌区土壤、地下水中氮、磷含量的调查和对比分析表明，污水中含量高的氮、磷能显著提高土壤肥力，污灌区作物长势良好，但土壤中积累的氮和磷是污灌区地表水和地下水的潜在污染源．虽然土壤对ＮＨ＋４离子有很强的吸附、截留和转化作用，但含量高的ＮＨ＋４离子能缓慢下移，并在上层潜水中积累．污灌和降雨能淋溶土壤中经硝化作用产生的ＮＯ－２和ＮＯ－３离子，造成地下水的污染．饱和污灌３个月后，浅层地下水中的ＮＯ－２和ＮＯ－３离子仍严重超标．

Simulated test of wastewater irrigation in the field and chemical analysis of nitrogen and phosphorus in the soil and groundwater at wastewater irrigation area and control area showed that high contents of nitrogen and phosphorus in the wastewater had markedly improved soil fertility and the croup in irrigation area growed very well,but nitrogen and phosphorus which could pollute surface and ground water were accumulated in the soil. Ammonium ion was easily intercepted, sorbed and transformed by soil,but high concentration of ammonium ion could slowly transporte downward and accumulate in upper levels of phreatic water. Wastewater irrigation and rainfall drip can wash nitrite and nitrate ions produced by nitrification in the soil and pollute groundwater. The contents of nitrite and nitrate ions in shallow groundwater were still seriously beyond standard at condition of saturating irrigation after experience of three months.