Small knowledge of sedimentation tank dredging 1. What should I pay attention to when dredging?

For the newly opened fish pond, green manure can be put into the pond, and sludge can be made as soon as possible by composting, so that humus in the sludge can be embedded in soil gaps and covered on the soil, so that it can be basically isolated from the original soil, and play the role of fertilizer supply, fertilizer preservation and fertilizer adjustment.

After one year in pond culture, a lot of silt was deposited at the bottom (generally about 10 cm per year). Therefore, after fishing in the dry pond, the mud around the bottom of the pond should be dug out and placed on the dike and the dike slope. When it is slightly dry, it should be stuck on the embankment slope and patted tightly, and then ryegrass or vegetables should be transplanted immediately as green feed for fish.

This can not only improve the pond conditions, increase the water storage capacity, but also provide high-quality fertilizer for the cultivation of green fodder, and also reduce the collapse of pond slopes and dikes due to the mud-fixing and slope protection function of grass roots. After the whole pond, wash the pond with medicine.

2. How to dredge the pond?

The so-called pond dredging is to remove too much silt.

Under normal circumstances, the pond is maintained at 10? 20 cm silt is beneficial to aquaculture production: exceeding the limit will not only reduce the water body, but also increase the oxygen consumption of pool water, which will easily lead to flooding accidents and fish diseases. Therefore, removing excessive silt is a very important technical link.

However, due to the large and heavy dredging labor, many production units often do not deal with it. Over time, the sludge in the pond is getting thicker and thicker, which makes the production capacity decrease obviously and is not conducive to aquaculture and water body operation. This situation mostly occurs in farms that have been raising fish for more than 10 years without dredging, and the situation in some old ponds is even more serious.

In order to restore the productivity of the pond, it is necessary to dredge the pond. The easiest way to dredge the pond is to drain the water in the pond, dry the silt, and then dig it manually to pick out the excess silt.

However, this method is too labor-intensive, inefficient and slow, and people are reluctant to adopt it in the future. In some places, the method of fish-rice, fish-barnyard grass and fish-melon rotation is adopted. One is to plant rice in pond sludge to harvest rice, and melons or barnyard grass are used as green feed for herbivorous fish, or part of them are used as natural bait for cultivating fish species, silver carp and bighead carp.

When the pond mud is dry, use machinery (bulldozers, excavators, etc.) for centralized operation. ), the dredging is closely combined with pond maintenance and slope protection. Of course, this method is very effective, but it needs certain investment conditions to put it into practice.

When the service life of the pond is short, the bank is relatively complete, or the slope of the pond is hardened and does not need a lot of maintenance, you can use the dredger modified by turbidity current to carry out the dredging operation with water, and a part of the sludge with water will be transported to the waiting place of the pond every year or every other year (a small embankment is built on the bank to retain the mud) as green manure, or transported to other low-lying shallow ponds and wasteland, or most of the pond water will be discharged at the end of the non-production season. At present, several types of dredging machinery, such as mud pumps and winches, have been used in some areas.

In a word, it is difficult to dredge ponds, and the ways and methods of efficient mechanical dredging need further study.