宁夏灌溉回归水开发再利用的评价

宁夏灌溉回归水指灌溉农业土壤深层渗滤水、农田尾水、渠道渗漏水、退水及少量的工业废水和城镇生活污水,年排量３０～３５亿ｍ^３。对灌溉回归水２０种物质含量的评价表明,它属无毒有害型淡水。采取与渠水（来自黄河水）掺灌或轮灌对作物生长无不良影响,也不会引起土壤盐碱化,可大胆开发利用。

AN APPRAISAL OF THE DEVELOPMENT AND REUSE OF THERETURN WATER OF IRRIGATION IN NINGXIA

The return water of irrigation in Ningxia includes the deep seepage water in irrigation farming soil, the tail water of cultivated land,the seepage water of irrigation canals and part of industrial waste water and city sewage. The amount of return water per year is 3～3.5 billion m³ in Ningxia. The appraisal of 20 kinds of substances in the return water which has been heavily polluted and mineralized shows that it belongs to not poisonous but harmful fresh water. There will be no bad effects on crop growth and no threats of soil salinization and alkalization if the return water is mixed with canal water or rotation irrigation of the return water and canal water is adopted for arable land watering. Therefore, the return water should be developed and used with the least hesitation.