水保所知识产出(1956---)知识库

为研究黄河水水肥气一体化灌溉时加气对灌溉水中黏性泥沙沉降能力的影响，配置 5 种浓度的高岭土悬浊液（1、
3、5、7 和 10 g/L）和 4 种肥料质量分数（0、0.2%、0.5%、1.0%）的硫酸钾肥、复合肥及尿素浑水，分析了加气前后的
相对含沙量、泥沙中值沉速和沉降泥沙中值粒径。结果表明：加气显著促进浓度为 3～10 g/L 黏性泥沙的絮凝沉降
（P<0.05），且促进作用随泥沙浓度的增加而增强。与未加气处理相比，冬、夏季加气处理后泥沙中值沉速分别提高
48.67%～70.98%和 33.04%～57.52%，沉降泥沙中值粒径增大 7.62%～13.95%和 6.83%～13.24%。加气促进黏性泥沙絮凝
沉降的作用与浑水中施加的肥料类型及浓度有关，促进作用随肥料浓度的增加而减小。对于肥料质量分数为 0.2%～1.0%
的硫酸钾肥、复合肥及尿素浑水，加气处理后泥沙中值沉速分别提高 20.00%～32.12%、18.71%～130.40%和 91.19%～
170.21%。施加硫酸钾肥加气后泥沙中值沉速最大，为 0.399～0.450 mm/s，施加复合肥加气后泥沙中值沉速最小，为 0.288～
0.330 mm/s。加气、肥料类型、肥料浓度分别单独或交互均极显著影响泥沙沉降（P<0.01）。研究结果对于明确水肥气一
体化灌溉管网系统泥沙淤积规律具有重要意义。

An integrated irrigation of water, fertilizer, and gas has been one of the most effective ways to alleviate the shortage
of water resources in the reaches of the Yellow River. However, high content of cohesive sediment in the Yellow River has
posed a great challenge on the water quality, as well as the flocculation and sedimentation of sediment resulting from the
fertilizer solution and bubbles. This study aims to explore the influence of aeration on the flocculation and settlement of
cohesive sediment during irrigation. A typical clay mineral of kaolin in the Yellow River was selected as the experimental
sediment, and tap water was used as the experimental water. A water quality test proved that there was a fewer content of iron
and other cations easy to form sediment flocculation. A Venturi circulation aeration device was used to fabricate the milky
uniform mixture of water and air. The diameter of bubbles produced by the device was generally 15 μm, and the average gas
holdup was 5.42%. The experiments were then carried out under various sediment concentrations (1, 3, 5, 7, and 10 g/L), the
different types of fertilizers (potassium sulfate fertilizer, compound fertilizer, and urea), and the mass fraction of fertilizer (0,
0.2%, 0.5%, and 1.0%). Some parameters were measured, including the relative concentration of sediment, the median settling
velocity of sediment, and the average particle size of the settling sediment before and after aeration. The results showed that
the 5-minute aeration in the Venturi circulation device significantly promoted the flocculation and sedimentation of cohesive
sediment with a concentration of 3-10 g/L (P<0.05). After the aeration, the median settling velocity of sediment increased by
48.67%-70.98% in winter, and 33.04%-57.52% in summer, while, the average particle size of settling sediment increased by
7.62%-13.95% in winter, and 6.83%-13.24% in summer, where the differences were significant (P<0.05). There was an
enhanced effect of the aeration on the sediment flocculation and settlement, with the increase of initial sediment concentration.
Subsequently, the promotion effect decreased with the increase of fertilizer concentration, closely relating to the type and
concentration of fertilizer applied in muddy water. When the potassium sulfate fertilizer, compound fertilizer, and urea
muddy water with the fertilizer mass fraction of 0.2%-1.0% were aerated, the median settling velocity of sediment increased by
20.00%-32.12%, 18.71%-130.40%, and 91.19%-170.21%, respectively, while the average particle size of settling sediment
increased by 2.47%-11.06%, 6.00%-12.87%, and 13.42%-16.89%, respectively. The aeration was greatly contributed to
promoting the sediment flocculation and settlement in the muddy water containing urea. The variance analysis indicated that
the aeration, fertilizer concentration, fertilizer type, and the interaction presented significant effects on the median settling
velocity of sediment (P<0.01). There was also an outstanding interaction among the aeration, fertilizer type, and fertilizer
concentration on the sediment deposition. Prior to the aeration, there was the largest value in the median settling velocity of the
sediment in the potassium sulfate fertilizer muddy water, whereas, the smallest in the compound fertilizer and urea muddy
water. After aeration, there was the largest value of 0.399-0.450 mm/s in the median settling velocity of the sediment in the
potassium sulfate fertilizer muddy water, whereas, the smallest of 0.288-0.330 mm/s in the compound fertilizer muddy water.
Consequently, the compound fertilizer with the appropriate concentration can be expected to be preferentially selected in the
integrated irrigation of water, fertilizer, and gas, further slowing down the sediment deposition in the irrigation pipe network
system. The findings are of great significance to clarify the sediment deposition of the water, fertilizer, and gas integrated
irrigation system. A sound theoretical basis can be also offered to take reasonable measures for the sediment deposition in the
pipe networks during irrigation.