Vertical distribution of Fe and Mn and optimal pumping depth in a seasonal oxygen shortage reservoir
季节性缺氧水库铁、锰垂直分布规律及优化分层取水研究

Distribtuion of Fe and Mn along vertical profile in Aha Reservoir, a seasonal oxygen shortage water body with stratificated temperatures, was studied for evaluation of optimal pumping depth of a water supply plant. It was revealed that Fe and Mn distribution varies with different seasons and water states and show a typical vertical distribution. In summer and autumn, water of reservoir is stratificated. Upper stratum is in oxygen enriched status, at which Fe and Mn concentrations are less than 0.3mg/L and 0.1mg/L respectively. The effect of oxygen shortage in middle and lower states of the wather leads to release of Fe and Mn in deposit sediment to super jacentwater. The effects of bioturbation as well as changes of hydraulic factors lead to acceleration for release of interstitial water to reservoir water through resuspended the suspended particle in deposit sediment. As a consequence, high concentrations of Fe and Mn in middle and lower strata of water are emerged. The concentrations of Fe and Mn pumped by a water plant is high since the pumping inlet is set in lower stratum of reservoir and would be reduced by moving the inlet to optimal stratum.