为了解草鱼养殖池塘水体中悬浮颗粒物(SS)的组成结构及其变化特征,采用静沉降方式对草鱼养殖水体沉降处理,运用激光粒度分析仪探究养殖水体沉降前后悬浮颗粒物的粒径分布(PSD)变化情况、测定沉降前后水质指标变化情况及分析悬浮颗粒物沉降特性.结果显示:草鱼池塘养殖水体中产生的SS随时间延长逐渐减低,30 min后水体中SS显著降低(P<0.05),150 min后上层水体中SS可降低 60%以上;静置 30 min后,上下水体中SS的PSD呈现显著性差异(P<0.05),粒径大于 100 μm的SS沉积于底部,上层水体中的SS整体趋于小粒径分布;随着沉降时间延长,水体中SS的比表面积逐渐增加,颗粒无机物(PIM)较颗粒有机物(POM)沉降速度快,150 min后,水体SS的主要成分为POM;SS对水质有影响作用,水体中的TN、TP的质量浓度随沉降时间延长而降低(P<0.05),在 120 min后趋于稳定.研究结果进一步了解草鱼养殖池塘养殖水体悬浮颗粒物沉降特性,为调控草鱼养殖池塘水体中的悬浮颗粒物提供一定的理论依据.
In order to understand the composition and structure of suspended solids(SS)in the water of grass carp ponds and its changing characteristics,a static sedimentation method was adopted for the sedimentation treatment of grass carp aquaculture water,and a laser particle size analyzer was used to investigate the changes in the particle size distribution(PSD)of SS before and after the sedimentation of aquaculture water,to determine the changes in the water quality indexes before and after the sedimentation,and to analyze the characteristics of the sedimentation of the suspended particulate matter.The results showed that the SS produced in the aquaculture water of grass carp ponds gradually decreased with time,the concentration of SS in the water decreased significantly(P<0.05)after 30 min,and the SS in the upper water could be reduced by more than 60%after 150 min;After 30 min of standing,the PSD of SS in the upper and lower water bodies showed significant differences(P<0.05),SS with particle sizes larger than 100 μm were deposited at the bottom,and SS in the upper water body tended to be distributed in small particle sizes as a whole;with the prolongation of the settling time,the specific surface area of the SS in the water body increased gradually,particulate inorganic matter(PIM)had a faster settling rate than particulate organic matter(POM),and after 150 min After 150 min,the main component of SS in the water body was POM;SS had an influential effect on the water quality,TN and TP mass concentration in the water body decreased with the prolongation of settling time(P<0.05)and stabilized after 120 min.The results of the study further understand the settling characteristics of SS in the aquaculture water body of grass carp aquaculture ponds,and provide a certain theoretical basis for the regulation of SS in the aquaculture water body of grass carp aquaculture ponds.