background and purpose:moving bed biofilm reactor is an aerobic attached growth with better biofilm thickness control, lack of plugging and lower head loss. consequently, this system is greatly used by different wastewater treatment plants. high tds wastewater produced petrochemical, leather tanning, sea food processing, cannery, pickling and dairy industries. the aim of this study was to evalu...

[1] A mechanistic model is derived for the rate of fluvial erosion into bedrock by abrasion from uniform size particles that impact the bed during transport in both bed and suspended load. The erosion rate is equated to the product of the impact rate, the mass loss per particle impact, and a bed coverage term. Unlike previous models that consider only bed load, the impact rate is not assumed to...

Representative bed material samples were taken from the two gauging sites on rivers omi for sieve analysis to obtain the grain size distribution of its bed materials. The analyses of the grain size distribution showed that the bed load accounted for 9% of the total estimated suspended sediment load of 1,703, 548.113 kg/annum in river omi. River omi bed material had a geometric mean particle siz...

Gravel bed channels have a much greater capacity than sand bed channels to regulate the mobility of the bed surface through the formation of a surface layer of bed particles that is coarser than the particles supplied as load. The coarse surface layer affects bed mobility in two important ways. First, it reduces differences in mobility between coarser and finer particles on the bed surface by m...

The development of particle-enriched regions (bed-load) at the base of particle-laden gravity currents has been widely observed, yet the controls and relative partitioning of material into the bed-load is poorly understood. We examine particle-laden gravity currents whose initial mixture (particle and fluid) density is greater than the ambient fluid, but whose interstitial fluid density is less...

[1] A variety of formulae has been developed to predict bed load transport in gravel bed rivers, ranging from simple regressions to complex multiparameter formulations. The ability to test these formulae across numerous field sites has, until recently, been hampered by a paucity of bed load transport data for gravel bed rivers. We use 2104 bed load transport observations in 24 gravel bed rivers...