底部微孔增氧管布设距离和增氧时间对刺参养殖池塘溶氧的影响

为明确刺参养殖池塘中微孔增氧的效果以及增氧管的布设间距、增氧时间对水体溶氧的影响,研究测定了在夏季刺参养殖池塘一个增氧周期内(每天23:00—7:00增氧8 h,7 d一个周期)水体中溶氧(DO)、亚硝酸盐氮(NO_2~--N)、COD的变化。结果显示:连续充气增氧的8 h内DO持续增加,增氧2 h上升速率缓慢,增氧2~6 h上升速率迅速提高,增氧6~8 h上升速率下降,连续充气8 h能够显著改变夜间溶氧降低现象;增氧7 d时间内,NO_2~--N和COD持续下降,分别由0.025 mg/L下降到0.014 mg/L、18.46 mg/L下降到14.15 mg/L。对充氧管道不同距离处DO的测定结果表明,距离增氧管1~2 m处DO较高,3~4 m处缓慢下降,与1~2 m处差异不显著(P0.05),DO保持在5.22 mg/L左右,距离5 m以上时DO下降速度较快,与1~2 m处差异显著(P0.05)。研究表明:微孔增氧可以明显增加水体DO,减少COD、NO_2~--N;微孔增氧机充氧时间6~8 h效果较好;微孔增氧管之间的布设距离在6~8 m可以实现高效增氧。

The influence of spacing and aerobic time on the dissolved oxygen levels by micropore tube aerator on the bottom of Apostichopus japonicus ponds

In order to clarify the effects of the dissolved oxygen levels and the influence of spacing and aerobic time on the dissolved oxygen level by micropore tube aerator on the bottom of Apostichopus japonicus ponds,the concentrations of DO,NO-2-N and COD were detected during one oxygen increasingcycle( A 7-day cycle,8h from 11:00 am to 7:00 am for oxygen increasing per day. ) in Sapostichopus japonicus ponds in summer. The results showed:the DO increased continuously during the 8-hour continuous period for oxygen increasing;The rising rate of DO was quiet low in the first 2 hours,increased rapidly during the middle 4 hours(2-6 h),slowly decreased during the last 2 hours ( 6-8 h ) . The oxygen increasing for 8 hours continuously could solve the problem of low dissolution of oxygen in nights. The COD and NO-2-N in the water reduced gradually after the 7 day-cycle of oxygen increasing. The concentration of NO-2-N decreased from 0. 025 mg/L to 0. 013 mg/L,and the concentration of COD decreased from 18. 46 mg/L to 14. 15 mg/L. The concentration of DO in the water decreased along with the distance from the pipe. The concentration of DO remained at a high level at the distance from 1-2 m. The concentration of DO at the distance from 3-4 m decreased slowly ( having no significant difference with the concentration at the distance from 1-2 m:P>0. 05) with the value remaining at 5. 22 mg/L,while it decreased dramatically at the distance far from 5 m ( having a significant difference with the concentration at the distance from 1-2 m:P<0. 05). All the results indicated that by micropore aerators, the concentrations of DO, NO-2-N and COD in the water increased efficiently;the proper time for oxygen increasing were 6-8 h and the suitable pipe spacing is 6-8 m.