Evaluation of the aerobic degradation of suspended organic matter derived from the local topography in a natural river

通过野外观测，估算了天然河流(包括急流、平缓小溪、水塘和河流交界处)悬浮物的质量平衡。在与堰相邻的回水池中，估算了回水对河床的沉降和好氧降解，评价了回水对河水有机污染的影响，在正常排放条件下，流入回水的悬浮物重量约45%落在河床上，其余部分向下游流动而不下沉。沉积物由重量为26%的有机颗粒和其他无机物组成。不同河流流量不同，有机颗粒对溶解有机碳的降解率为30%~100%。NAT…沙坝下溶解性有机碳好氧降解的估算对天然河流中的沙洲改善受污染河流水质的能力进行了评估。艾奥伊河是尼约多河的一条支流，BOD浓度较高，泥浆悬浮物浓度较高，与干流汇合，有机负荷和浊度增加是河流环境保护面临的严重问题。目前已形成了一些涉及流域内污水处理厂的方案，同时沙丘的自然净化功能变得重要，在进入干流之前降低了有机负荷。为了弄清与沙丘地表径流和地下水流动的有机污染有关的指标的纵向变化，进行了详细的观测。由于流速较低，沙丘表面流中可观察到悬浮有机物的沉降和好氧降解。另一方面，地表水流入沙丘以下地下水的量微乎其微，预计溶质通量也很小。这是由于纸浆污泥堆积在砂孔中造成的。如果减少悬浮污泥，去除沙面上的悬浮污泥，利用沙丘辅助其他设施改善河流水质似乎是可能的。较少

Mass Balance Estimation of Suspended Organic Matter Flowing into the Backwater Pool of a WeirMass balance of suspended organic particles was estimated along a natural river including rapid streams, gentle streams, pools and river junctions was estimated by field observations. In the backwater pool adjacent to a weir, the settlement and aerobic degradation on the riverbed were estimated and the effects of the backwater on the organic pollution of the river water were assessed.Under ordinary discharge conditions, about 45% in weight of suspended materials flowing into the backwater settles upon the riverbed, where the remained fraction flows downstream without sinking. The sediments consist of the organic particulates, 26% in weight, and other inorganic materials. The degradation rate of organic particles to dissolved ones varies 30% to 100% of the settling rate of them according to the river discharge.Estimation of Aerobic Degradation of Dissolved Organic Carbon below Sand Bars in a Nat … More ural RiverThe ability of sand bars in a natural river to improve the water quality of polluted river was assessed. Aioi River, one of the branches of Niyodo River, which has relatively high BOD concentration with suspended pulp sludge, joins the main stream and the organic load and the turbidity increase are the serious matter of concern from the stand point of the river environment conservation. Some schemes involving waste water treatment plants within the river basin are now formed and at the same time, the natural purification functions of sand dunes become important which decrease the organic load just prior to inflowing the mains stream.Detailed observations were conducted in order to clarify the longitudinal change of indices relating to the organic pollution of the surface flow and the groundwater flow of the sand dunes. Settlement and aerobic degradation of suspended organic matter were observed in the surface flow on the sand dunes because of the relatively low velocity. On the other hand, the influxes of surface water into groundwater below the dunes were negligibly small and the little amount of dissolved matter flux was expected. This is due to the pulp sludge packing of the sand pore. If the suspended sludge is decreased and that on the sand surface removed, it is seemed to be possible to apply the sand dunes to improve the river water quality with the aid of other facility. Less