Average Solids Concentration Research Articles

Impact of volatile solids destruction on the shear and solid-liquid separation behaviour of anaerobic digested sludge

Systematic and comprehensive characterisation of shear and solid-liquid separation properties of sludge across a wide range of solids concentration and volatile solids destruction (VSD) is critical for design and optimization of the anaerobic digestion process. In addition, there is a need for studies at the psychrophilic temperature range as many unheated anaerobic digestion processes are operated under ambient conditions with minimal self-heating. In this study, two digesters were operated at different combinations of operating temperature (15–25 °C) and hydraulic retention time (16–32 d) to ensure a wide range of VSD in the range of 0.42–0.7 was obtained. For shear rheology, the viscosity increased 1.3 to 3.3 times with the increase of VSD from 43 % to 70 %, while other parameters (temperature, VS fraction) having a negligible impact. Analysis of a hypothetical digester indicated that there is an optimum VSD range 65–80 % where increase in viscosity due to the higher VSD is balanced by the decrease in solids concentration. For solid-liquid separation, a thickener model and a filtration model were used. No significant impact of VSD on the solids flux, underflow solids concentrations or specific solids throughput was observed in the thickener and filtration model. However, there was an increase in average cake solids concentration from 21 % to 31 % with increase of VSD from 55 % to 76 %, indicating better dewatering behaviour.

Predicting pressure-drop for pseudo-homogeneous slurry flows using the mixture model at high solids concentrations

The main contribution of this paper is applying computational fluid dynamics (CFD) using the two-phase mixture model with algebraic slip, and turbulent dispersion to the slurry flow experiment of Kaushal et al. (2012). The results obtained were compared to the experimental results and numerical results reported by the same authors who used the mixture model as well as a more advanced Eulerian granular flow model. The authors reported that the mixture model predicted the pressure drops with very high errors, especially for the highest solids loading simulated with errors as high as 400% compared to their experimental data. They conclude that the mixture model cannot be used to predict the pressure drop of the slurry flow investigated at higher concentrations (30-50% solid fraction). In contrast to this, the pressure-drop predictions of the two-phase mixture model with algebraic slip and turbulent dispersion used in this study were in good agreement with the measured values. This calls the conclusion of Kaushal et al. (2012). to question, because they did not present any justification for 3-4 times higher pressure drop observed in their study using the mixture model in combination with the fact that no anomalies in particle concentration profiles were observed by them for the mixture model. A comparison between the two mixture models reveals that although they differ in some details, the basic structure of the models is the same. We conclude that the mixture model with algebraic slip, turbulent dispersion, and a suspension viscosity model can be used for pressure drop predictions for the slurry flow investigated even for high solids fraction. We also demonstrate that the laterally averaged solids concentration profiles are not predicted very accurately by the mixture model as well as the more complex granular model. The concentration profiles predicted by the mixture model is easily understood in contrast to the profiles predicted by the granular flow model. From an engineering viewpoint, preference should be given to a simpler model, as was used in this study which can predict pressure drop with similar accuracy compared to a more complex approach with a larger number of uncertainty parameters. Further research is necessary to correctly predict the solids concentration profile for slurry flow in pipelines.

Investigation of particle flow characteristics in a CFB recirculation system using electrical capacitance volume tomography

Gas-solid fluidized beds have complex flow characteristics and opacity, and the particle motion characteristics in the recirculation system of circulating fluidized bed (CFB) have not been studied thoroughly. In order to study the motion of gas-solid two-phase flow in a CFB recirculation system, a 32-electrode electrical capacitance volume tomography (ECVT) system was developed with an imaging speed of 120 frames per second. Under various working conditions, the experimental platform of CFB was also built to measure the particle flow in the CFB recirculation system with the 32-electrode ECVT system, including the solid concentration and the flow velocity of particles in the branch pipe. When the velocity of fluidized gas U f is adjusted from 2.73 m/s to 1.76 m/s, the average solid concentration in the riser is roughly distribution of upper dilute and lower concentrated along the axial direction. With the decrease of U f , the average solid concentration generally showed an increasing trend, and the difference of solid concentration between different planes in the branch pipe gradually decreased. The slug length in the imaging area decreases, and the rising velocity of the slug in the riser above the branch pipe decreases. ECVT continuous images (U f = 2.73 m/s). • The 3-D solid concentration distribution in the CFB recirculation system was investigated. • ECVT continuous images under three different working conditions are given. • Solid concentration in the CFB recirculation system was acquired from the ECVT images. • Solid velocity was gained by analyzing the time lag of the neighbour planes.

Evaluating the performance of conventional DAF and PosiDAF processes for cyanobacteria separation at a pilot plant scale

Abstract In this work, a commercially available water treatment polymer poly(N,N-diallyl-N,N-dimethylammonium chloride) (PDADMAC) and a hydrophobically modified polymer (HMP) designed to adhere to bubble surfaces were applied for the first time in the novel Posi-dissolved air flotation process (PosiDAF) that uses polymer-modified bubbles, at pilot-scale for the treatment of waste stabilisation pond samples rich in algae. It was found that PDADMAC in PosiDAF gave comparable removal to that achieved using conventional DAF at >95% cell separation. Furthermore, the float layer was more uniform and thicker with up to 8% solid contents compared to conventional DAF, which comprised discrete floc clusters with an average solid concentration of ∼4.1%. In contrast to the use of PDADMAC, the application of the HMP did not achieve similarly good separation at pilot scale. It was hypothesised that this may be due to the micellisation of the HMP on the bubble surface, creating unstable bubbles that coalesced and prevented polymer–bubble–cell interactions, which are crucial for effective cell separation. On comparison of the costs of PosiDAF and conventional DAF, it was found that PosiDAF resulted in cost-savings of up to 74% due to low chemical consumption. In summary, PosiDAF reduced chemical cost and increased solid contents in the metal-free float.

Anaerobic Dynamic Membrane Bioreactor Development to Facilitate Organic Waste Conversion to Medium-Chain Carboxylic Acids and Their Downstream Recovery

Platform chemicals such as medium-chain carboxylic acids (MCCAs) can be produced from organic waste streams via chain elongation in anaerobic mixed-culture bioreactors. A product recovery system is needed to collect MCCAs from the bioreactor effluent. Membrane-based liquid–liquid extraction, the most commonly used product recovery approach, requires suspended solids removal from the bioreactor effluent to avoid membrane fouling. An anaerobic dynamic membrane bioreactor (AnDMBR) was developed to evaluate MCCA production from brewery and prefermented food waste and to produce a permeate with low suspended solids to facilitate downstream product recovery. The AnDMBR employed an inexpensive stainless-steel mesh as the support material for the development of a biofilm or dynamic membrane, which was responsible for solids–liquid separation. The AnDMBR produced a permeate quality with an average total suspended solids (TSS) concentration of 0.12 g L–1, while the average bioreactor TSS concentration was two orders of magnitude higher (21.6 g L–1). A maximum solids removal efficiency of ≥99% was achieved and good permeate quality was sustained for over 200 days without fouling control or cleaning the support material. In addition to solids–liquid separation, the dynamic membrane was responsible for a substantial fraction of the biological activity of the AnDMBR. The relative activity of Clostridiales, as determined by 16S rRNA sequencing, correlated with MCCA production and was higher in the dynamic membrane (20.0 ± 4.9%) than in the suspended biomass (5.2 ± 2.7%) in the bioreactor. This observation was consistent with MCCA production data as the permeate MCCA concentrations were significantly (p = 8.2 × 10–5) higher than that in the bioreactor, suggesting that the dynamic membrane biofilm contributed to chain elongation.

Rheological characterisation of synthetic and fresh faeces to inform on solids management strategies for non-sewered sanitation systems

In order to obviate the economic issues associated with pit latrine emptying and transport such as high water additions and rheologically difficult sludge properties, the implications of prompt solid/liquid separation were investigated. This was achieved through rheological characterisation of fresh human faeces and synthetic faeces, and comparison with aged faecal sludges. Shear yield stress, thixotropy and post-shear structural recovery were characterised for a total solids (TS) concentration range of 5–35% total solids (TS) and stickiness yield stress was determined for concentrations up to 100% TS. Fresh faeces rheology proved to be favourable when compared to aged matrices, evidenced by a lower shear yield stress and higher gel point solids concentration, suggesting that aging could alter the physico-chemical properties of faecal sludge. Fresh and synthetic faeces exhibited similar shear thinning, thixotropic behaviour with the majority of structural breakdown occurring at a low shear rate of 10 s−1, and the extent increasing with higher solids concentrations. At 32% TS, fresh faeces shear yield stress was permanently reduced by 80%, suggesting that low shear pumping could reduce the energy demand required for faeces transport. The sticky phase, which represents the region to avoid faecal transport and mechanical drying processes, was identified to range from 30 to 50% TS, with 25% TS as ideal to commence dewatering processes. This also coincides with the average solids concentration of faeces, which is achievable by source separation. This study has identified that handling of fresh faeces as opposed to aged faecal sludges would result in economic and environmental benefits, with energy, water and labour savings.

Experimental investigation on solid particle distribution in dense solid–liquid stirred tank

As an important indicator to evaluate the suspension effect, the uniformity of solid particle distribution is directly related to mass transfer and reaction efficiency. Therefore, it is necessary to investigate the solid particle distribution in viscous system. The particle distribution of a dense solid–liquid system composed of glass beads-malt syrup stirred by the propeller is investigated experimentally by optical probe method, and the effects of impeller speed, number of baffles, particle size, average solid concentration and liquid viscosity on the solid particle distribution are discussed. The results show that, compared with the radial direction, the axial concentration distribution in the stirred tank is more uneven, and the axial mixing index is about 2–5 times the radial one. With the increasing stirring speed, the axial mixing index decreases slowly at first, then sharply decreases after reaching the just off-bottom suspension speed, and finally tends to be stable. The uniformity varies inversely with particle size and average solid concentration and directly with liquid viscosity. When the same effect is achieved, less energy is required without baffles.

Runoff‐generated debris flows: Observation of initiation conditions and erosion–deposition dynamics along the channel at Cancia (eastern Italian Alps)

AbstractIn the Dolomitic region, abundant coarse hillslope sediment is commonly found at the toe of rocky cliffs. Ephemeral channels originate where lower permeability bedrock surfaces concentrate surface runoff. Debris flows initiate along such channels following intense rainfall and determine the progressive erosion and deepening of the channels. Sediment recharge mechanisms include rock fall, dry ravel processes and channel‐bank failures. Here we document debris flow activity that took place in an active debris flow basin during the year 2015. The Cancia basin is located on the southwestern slope of Mount Antelao (3264 m a.s.l.) in the dolomitic region of the eastern Italian Alps. The 2.5 km2 basin is incised in dolomitic limestone rocks. The data consist of repeated topographic surveys, distributed rainfall measurements, time‐lapse (2 s) videos of two events and pore pressure measurements in the channel bed. During July and August 2015, two debris flow events occurred, following similarly intense rainstorms. We compared rainfall data to existing rainfall triggering thresholds and simulated the hydrological response of the headwater catchment with a distributed model in order to estimate the total and peak water discharge. Our data clearly illustrate how debris entrainment along the channel is the main contributor to the overall mobilized volume and that erosion is dominant when the channel slope exceeds 16°. Further downstream, sediment accumulation and depletion occurred alternately for the two successive events, indicating that sediment availability along the channel also influences the flow behaviour along the prevailing‐transport reach. The comparison between monitoring data, topographical analysis and hydrological simulation allows the estimation of the average solid concentration of the two events and suggests that debris availability has a significant influence on the debris flow volume. © 2020 John Wiley & Sons, Ltd.

Exogenous Gibberellic Acid Advances Reproductive Phenology and Increases Early-Season Yield in Subtropical Blackberry Production

Inadequate winter chill causes poor and erratic budbreak in blackberry (Rubus L. subgenus Rubus Watson), limiting the commercial production in subtropical climates. We examined the effects of exogenous gibberellic acid (GA3) on the reproductive phenology, fruit number, yield, and fruit quality of three blackberry cultivars (‘Natchez’, ‘Navaho’, and ‘Ouachita’) grown under subtropical climatic conditions in two consecutive growing seasons. A single spray application of GA3 at 0 or 49 g·ha−1 was performed when plants were dormant in late December to late January. Exogenous GA3 advanced the onset of budbreak by 12 to 82 days, flowering by four to 20 days, and fruit ripening by 0 to 15 days. When pooling across the cultivars, it also increased early-season yield by 83% to 276% in two consecutive growing seasons and total-season yield by 60% in the second growing season. Among the cultivars, the yield responses to GA3 were most consistent in ‘Ouachita’, with early-season yield increasing by up to 499%. The average berry weight and soluble solids concentration were slightly reduced by GA3, but these reductions were not consistent in the two growing seasons and the impact on overall fruit marketability was small. These results suggest that exogenous GA3 is an effective bud dormancy breaking compound for blackberry, and it could be an important adaptation tool for subtropical blackberry production.

Study on the length of pipe inlet section of pulp fluid based on CFD

In the paper industry, to determine the installation positions of concentration sensor and flow sensor of pulp pipe transportation system, the length of pipe inlet section of pulp fluid must be determined. In order to solve the problem that it is difficult to determine the length of pipe inlet section of pulp fluid, the paper presents a method to determine the length of pipe inlet section of pulp fluid, and the relationship between the length of inlet section and pulp fluid parameters is studied by this method. Firstly, CFD (Computational Fluid Dynamics) method is applied to obtain flow velocity and solid phase concentration distribution data of pulp fluid at different axial positions in the pipe. Then, Pearson correlation coefficient method is applied to analyze these data. Finally, the length of pipe inlet section of pulp fluid is determined according to the obtained correlation coefficient, and the relationship between the length of pipe inlet section of pulp fluid and initial average flow velocity and solid phase concentration is obtained. The conclusion shows that the method can well obtain the length of pipe inlet section of pulp fluid, which provide some theoretical basis for the design of pulp pipe transportation system.

Numerical simulation of secondary sedimentation tank based on population balance model

A technical method of grid flocculation wells is proposed to control the effects of heterogeneous flow on the flow regime and the removal efficiency of suspended solids in the secondary sedimentation tank. The flocculation and sedimentation of activated sludge in sedimentation tanks were simulated by a combination of population balance model (PBM) and computational fluid dynamics. Compared with the prototype of the flocculation well, the grid split the vortex under inertia and the turbulence of the grid, which increased water viscosity, improved the energy dissipation of the flocculation well by more than 40%. The energy consumed by the viscous action provided the power for flocculation of the activated sludge, and reduced the volume fraction of particles with a particle size of less than 98μm by over 50%. After the addition of No. 2.5 (grid interval is 25 mm) and No. 3.5 (grid interval is 35 mm) grids, the concentration of effluent suspended solids was reduced by 29.3% and 69.4% respectively, compared with the prototype. The average suspended solids concentration of the No. 3.5 model of the actual optimization was 9.2 mg L-1, which was similar to the simulation results, indicating the effectiveness of the optimization method.

Recovery of calcium phosphate granules from black water using a hybrid upflow anaerobic sludge bed and gas-lift reactor

Adding calcium during anaerobic digestion of vacuum collected black water (BW) in an up-flow anaerobic sludge bed (UASB) reactor increased the retention of total phosphorus (P) in the reactor from 51% to 87%. However, the insufficient mixing in the reactor caused cementation and relatively high content of organics in the recovered calcium phosphate (CaP) granules, limiting the P recovery. In this study, the UASB reactor was mixed with an internal gas-lift (UASB-GL) to prevent cementation and to enhance the P content in CaP granules. The novel UASB-GL reactor operated for 300 days, treating concentrated BW. At steady state, the removal of total COD and P was 92% and 90%, respectively. The gas injection created a sludge bed with an average total suspended solids concentration of 73 ± 16 g/L at the bottom and 31 ± 5 g/L at the top of the reactor. The concentration of solid P at the bottom of the reactor was 4.58 ± 1.34 gP/L, while at the top a much lower concentration was obtained (0.75 ± 0.32 gP/L). 89% of the CaP granules was found at the bottom of the reactor. The harvested CaP granules (>0.4 mm diameter) contained on average 7.8 ± 0.6 wt% of P. A potential recovery of 57% of P in BW as CaP granules was calculated, considering actual application of the UASB-GL reactor in source separated sanitation.

Tribo-erosion performance of few HVOF coated micron layers subjected to equi-sized slurry particles

A comparative study on characteristic and erosion behavior of the 4 different high velocity oxy-fuel sprayed WC-10Co-4Cr, Colmonoy-88, Stellite-6 and Ni-Cr coatings on pump impeller stainless steel (SS 410) has been evaluated in the current investigation. First, the various micron layers were characterized by using energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), scanning electron microscopy (SEM), micro hardness and micro roughness, and after that were subjected to erosion wear testing. Ducom slurry pot test rig with fly ash as erodent was used for erosion wear experiments, and the impact of four process parameters, namely, rotational speed, average particle size, solid concentration and time duration on slurry erosion of SS 410 were investigated. From erosion wear experimentation, it was concluded that the erosion wear highly depends upon the effecting parameters. The erosion resistance of coatings is found to be in following order WC-10Co-4Cr > Colmonoy-88 > Stellite-6 > Ni-Cr. It might be because of the higher hardness of WC-10Co-4Cr coating as compared to other coatings. Further the results show that the erosion wear of WC-10Co-4Cr, Colmonoy-88, Stellite-6 and Ni-Cr coatings was observed maximum at impact angle of 30°, 45°, 60° and 90° respectively.

On the hydrodynamics of a pseudo two-dimensional two-zone gas-solid fluidized bed

The hydrodynamics of a pseudo 2-dimensional two-zone fluidized bed reactor has been studied using both experimental and numerical techniques. In the experimental section a coupled Particle Image Velocimetry (PIV) and Digital Image Analysis (DIA) technique was employed to obtain the averaged particle circulation pattern, bubble dynamics, bed surface fluctuations and the average bubble induced void fraction. To obtain more insight about the hydrodynamics of these fluidized bed types the Eulerian-Eulerian approach was adapted in the numerical section. The results show an alternative reciprocating trend in the bed surface in the left and right sides of the fluidized bed. It was shown that this reciprocating trend originates from two main reasons: the presence of the cavities (small bubbles) below the nozzle tips and the gas hydrodynamics inside the T-shape nozzle. Finally, the average particles circulation patterns, average solid concentration and the granular temperature variation were studied.

Transesterification of Waste Activated Sludge for Biosolids Reduction and Biodiesel Production

Transesterification of waste activated sludge (WAS) was evaluated as a cost-effective technique to reduce excess biosolids and recover biodiesel feedstock from activated sludge treatment processes. A laboratory-scale sequencing batch reactor (SBR) was operated with recycling transesterification-treated WAS back to the aeration basin. Seventy percent recycling of WAS resulted in a 48% reduction of excess biosolids in comparison with a conventional SBR, which was operated in parallel as the control SBR. Biodiesel recovery of 8.0% (dried weight basis) was achieved at an optimum transesterification condition using acidic methanol and xylene as cosolvent. Average effluent soluble chemical oxygen demand (COD) and total suspended solids (TSS) concentrations from the test SBR and control SBR were comparable, indicating that the recycling of transesterification-treated WAS did not have detrimental effect on the effluent quality. This study demonstrated that transesterification and recycling of WAS may be a feasible technique for reducing excess biosolids, while producing valuable biodiesel feedstock from the activated sludge process.

The ultimate mineral processing challenge: Recovery of rare earths, phosphorus and uranium from Florida phosphatic clay

Phosphate beneficiation in Florida generates more than one tonne of phosphatic clay, or slime, per tonne of phosphate rock produced. Since the start of the practice of large-scale washing and desliming for phosphate beneficiation, more than 2 Gt of slime has accumulated, containing approximately 600 Mt of phosphate rock, 600 kt of rare earth elements (REEs) and 80 million kilograms of uranium. The recovery of these valuable elements from the phosphatic clay is one of the most challenging endeavors in mineral processing, because the clay is extremely dilute, with an average solids concentration of 3 percent, and fine in size, with more than 50 percent having particle size smaller than 2 µm, and it contains nearly 50 percent clay minerals as well as large amounts of magnesium, iron and aluminum. With industry support and under funding from the Critical Materials Institute, the Florida Industrial and Phosphate Research Institute in conjunction with the Oak Ridge National Laboratory undertook the task to recover phosphorus, rare earths and uranium from Florida phosphatic clay. This paper presents the results from the preliminary testing of two approaches. The first approach involves three-stage cycloning using cyclones with diameters of 12.4 cm (5 in.), 5.08 cm (2 in.) and 2.54 cm (1 in.), respectively, to remove clay minerals followed by flotation and leaching. The second approach is a two-step leaching process. In the first step, selective leaching was conducted to remove magnesium, thus allowing the production of phosphoric acid suitable for the manufacture of diammonium phosphate (DAP) in the second leaching step. The results showed that multistage cycloning with small cyclones is necessary to remove clay minerals. Selective leaching at about pH 3.2 using sulfuric acid was found to be effective for removing more than 80 percent of magnesium from the feed with minimal loss of phosphorus.

Municipal wastewater sludge as a sustainable bioresource in the United States

Within the United States and Puerto Rico, publicly owned treatment works (POTWs) process 130.5 Gl/d (34.5 Bgal/d) of wastewater, producing sludge as a waste product. Emerging technologies offer novel waste-to-energy pathways through whole sludge conversion into biofuels. Assessing the feasibility, scalability and tradeoffs of various energy conversion pathways is difficult in the absence of highly spatially resolved estimates of sludge production. In this study, average wastewater solids concentrations and removal rates, and site specific daily average influent flow are used to estimate site specific annual sludge production on a dry weight basis for >15,000 POTWs. Current beneficial uses, regional production hotspots and feedstock aggregation potential are also assessed. Analyses indicate 1) POTWs capture 12.56 Tg/y (13.84 MT/y) of dry solids; 2) 50% are not beneficially utilized, and 3) POTWs can support seven regions that aggregate >910 Mg/d (1000 T/d) of sludge within a travel distance of 100 km.

Spatio-temporal variation of septage characteristics of a semi-arid metropolitan city in a developing country.

Septage is the solid sludge that accumulates in septic tanks over a period of time. Many of the developing countries in the world face the challenging task of septage management. Due to the high variability in the nature of septage, there is a need to study its physical and chemical characteristics in order to suggest a sustainable treatment methodology. The present study deals with the characterization of septage collected from different locations of Chennai city in India, in two different seasons (summer and winter). The characterization includes parameters such as solids, organics, inorganics, nutrients and heavy metals. Septage showed significant difference in concentrations of pollutants from one season to the other (p>0.05). The average total solids concentration is found to be 1.6 times higher during winter season than compared to summer season. Average concentrations of solids were 2185±1070 and 3555±2935mg/L during summer and winter, respectively. Liquid characterization of septage showed total chemical oxygen demands (COD) of 905±603mg/L (summer) and 1460±1295mg/L (winter). Similarly, average soluble biochemical oxygen demand (sBOD) was found to be 117±54mg/L during summer and 211±220mg/L during winter season. Studies also showed that septage was rich in nutrients such as total nitrogen (4-500mg/L), ammoniacal nitrogen (2-129mg/L), total phosphate (5-236mg/L) and heavy metals such as copper, zinc, lead and manganese. Overall characterization indicates that the collected septage samples are highly variable in nature with respect to sources, season and locations of collection. As the septage is rich in organic matter and nutrients, it can be used as a resource like soil conditioner or as a substitute for chemical fertilizer in agriculture, after proper treatment, leading to a new evolution in sanitation.

Increasing efficiency of thickener operation in concentrate plant of iron ore mine using coagulation-flocculation

Thickener is a main and fundamental step in modern mining separation processes. In this research, the effectof flocculant consumption rate and feed solid concentration of settling rate of layers was studied with differentconcentrations in iron ore mine of Jalalabad, Zarand, Kerman, Iran. The experiments were performed in two1000 ml graduated cylinders (61 and 62 mm diagonal and heights of 339 and 349 mm) while the average offeed solid concentration was 12 percent. Additional tests were performed with feed solid concentration of 8,10, 12, 14, and 16 percent solid weight and dosage rate of flocculant was 10, 14, 18, 22, and 26 g/trespectively. Results depicted that with increasing the flocculant dosage to 22 g/ton, settling rate increasedfrom 0.3 to 0.9 cm/s reaching maximum, and with increasing from 22 to 26 g/ton, settling rate was decreaseslowly and reached from 0.9 to 0.7 cm/s.

A Runoff and Sediment Routing Model for Open Lot Beef Feeding Facilities

Abstract. Feedlot runoff is a potential environmental contaminant and requires proper management to minimize impact on water quality. In designing runoff management systems, accurately assessing the amount of runoff that will be generated is of foremost importance. Along with overall quantity of runoff, the temporal pattern, both throughout the year and within an individual storm event, can have important implications for sizing control system components, in determining the performance the control system achieves, and in the overall pollution potential of the feedlot. This review summarizes the hydraulic properties of the feedlot surface, specifically focusing on variables that impact the total volume of effluent generated and the resulting amount of sediment transported. The work cumulates in development of a feedlot runoff routing model, presented as a series of equations that are implemented within the updated Iowa State University-Vegetative Treatment Area model, with a sediment transport/erosion component. Overall, the results indicated that a curve number of 91 was best for estimating runoff volumes, but substantial variation about this value could occur. The calibrated model was able to accurately estimate average total solids concentrations of lots of different size, shape, and surface condition under different hydraulic situations (R 2 = 0.92 for calibration and the slope of the measured vs. modeled data was not different than one during model validation). Most calibration and validation feedlots were earthen, had the majority of runoff from rainfall events, had mounds within the pen, and were scraped only once or twice per production cycle; thus model performance may be limited for other situations. The feedlot runoff and sediment routing components were used to assess the impact of various feedlot design characteristics, including feedlot area, aspect ratio, and slope, on solids transport from the feedlot surface. This model can be used to evaluate the risk that feedlot runoff poses to water quality for prioritizing feedlots that are in need of enhanced runoff control systems, and to evaluate the hydraulic and sediment loadings that a runoff control system is required to handle.