Gravel Medium Research Articles

Fate and transport of fragmented and spherical microplastics in saturated gravel and quartz sand.

Microplastics in urban runoff undergo rapid fragmentation and accumulate in the soil, potentially endangering shallow groundwater. To improve the understanding of microplastic transport in groundwater, column experiments were performed to compare the transport behavior of fragmented microplastics (FMPs ∼1-µm diameter) and spherical microplastics (SMPs ∼1-, 10-, and 20-µm diameter) in natural gravel (medium and fine) and quartz sand (coarse and medium). Polystyrene microspheres were physically abraded with glass beads to mimic the rapid fragmentation process. The experiments were conducted at a constant flow rate of 1.50 m day-1 by injecting two pore volumes of SMPs and FMPs. Key findings indicate that SMPs showed higher breakthrough, compared to FMPs in natural gravel, possibly due to size exclusion of the larger SMPs. Interestingly, FMPs exhibited higher breakthrough in quartz sand, likely due to tumbling and their tendency to align with flow paths, while both sizes (larger and smaller relative to FMPs) of SMPs exhibited higher removal in quartz sand. Therefore, an effect due to shape and size was observed.

A Glance at a Sustainable Solution Using Vertical Constructed Wetland Based on Dewatered Drinking-Water Waste Augmented Nanoparticle Composite Substrate for Wastewater Treatment

The current investigation introduces and demonstrates a credible, economically sound system to remove agrochemical runoff using a vertical flow constructed wetland (VFCW). DuPont 1179 carbamate insecticide was applied as a simulating greenhouse crop production controller, which resulted in runoff loaded with DuPont 1179. A novel composite of constructed wetland from an alum sludge conjugate magnetite nanoparticle substrate was applied and supported with gravel as a filtration/adsorption bed in a vertical flow constructed wetland (VFCW) system. X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM) augmented with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) were employed to characterize the suggested composite substrate. The experimental data showed VFCW to be significant in eliminating DuPont 1179. The isotherm time was explored at 300 min, which corresponded to complete insecticide removal (100%). The operational parameters were located at the natural pH (6.9) of the solution and room temperature (25 °C). The VFCW column was also investigated at various substrate concentrations ranging from 100% to 40% of the composite material supported by a gravel medium, and the existence of composite at a 75% concentration showed the highest yield. The experimental data verified that the adsorption followed the pseudo second-order adsorption kinetic model. Furthermore, according to the isotherm model results, the scheme followed the Langmuir isotherm model. Thus, the presented study is a promising indicator of the possibility of using alum sludge conjugate nanoparticles for the elimination of agrochemicals from wastewater.

Radioactive parameter analysis in soil samples at the Cauvery river

Cauvery, one among the major rivers, passing through three states, namely Karnataka, Tamil Nadu and Kerala. This river is crucial for drinking water, irrigation and electricity. In India, river sand is a key component of building construction. Through a gamma ray spectrometer with a NaI doped with thallium detector, the natural radioactive elements such as uranium, thorium and potassium (238U, 232Th, 40K) are explored and analysed. This analysis was already published. As per the report of United States Department of Agriculture (USDA) sediment and sand grain size is divided into several types, which include gravel medium sand (250–500µm), fine sand (100–250 µm), very fine sand (50–100µm), silty sand (2–50µm) and clay (<2µm). The range of gravel medium sand to fine sand (>125 µm) and non-magnetic grains were separated with the help of American Society for Testing Materials standard sieve and strong electromagnet. Those two samples for each site were subjected to Gamma ray spectroscopy and analysed. Related parameters like Absorbed-Dose (Din & Dout), Annual effective dose equivalent (AEin & AEout) is computed and correlated. By comparing the results of this investigation to the global average, it can be seen that practically all radioactive parameters are under control. However, the Cauvery River, with the exception of site no 31, does not present a radioactive hazard.

Variation characteristics of water and sediment of managed aquifer recharge with the Yellow River water in the piedmont sand gravel channel in the North China Plain

Abstract A two-dimensional sand tank model was designed to investigate the water distribution and sediment clogging of the Yellow River water during the seepage recharge process of the piedmont sand gravel channel in the North China Plain. Due to the high permeability of the sand gravel medium, only infiltration deep runoff (IDR) and surface runoff (SR) occurred in the sand tank experiment. The increase in water released did not improve the effective recharge. The IDR accounted for 65–85% of the water released. After clogging appeared, the value decreased to 15–30%. More than 96% of suspended solids were deposited in the surface and upper areas of the sand tank, among which the sand gravel surface covered by the thin clay layer formed by suspended particles was the main cause of the change in the distribution of IDR and SR. A rubber dam can promote the conversion of high velocity SR to low velocity lateral shallow runoff (LSR) by 25–30% while increasing the deposition mass of suspended particles in the sand tank. The rationality of the sand tank model was verified by the numerical model, and the fitting degree between the simulated and the measured results was greater than 0.9.

One-Dimensional Experimental Investigation of Polyethylene Microplastic Transport in a Homogeneous Saturated Medium

Plastics are widely used in every part of life. Microplastics (MPs) are classified as emerging contaminants in nature. Yet, microplastic transportation parameters in groundwater are not characterized well. In this study, microplastic transport in saturated homogeneous media was investigated. For this purpose, one-dimensional column tests were performed using the fluorescent and microplastic tracers to figure out the hydrodynamic conditions for the microplastic transport. Large silica, small silica, sand, and coarse gravel were the tested media. The hydrodynamic transport parameters were calculated by inverse solution methodology using the experimental and the analytical solution results. Only the coarse gravel medium with a minimum 1 mm and maximum 20 mm (5 mm of median) pore sizes and kinematic porosity 40.2% were found to be suitable for the transport of the used polyethylene (PE) whose particle size was between 200 and 500 µm. It is not possible to transport PE particles of selected size from fine-grained media. Transportation occurred in coarse-grained media such as coarse gravel. The calculated dispersivity values for the coarse gravel were 2.58 and 3.02 cm by using fluorescent and PE tracers, respectively. The experiments showed that the used PE particles cannot be transported if the mean flow velocity is lower than 2.02 cm/min in the coarse gravel medium. The microplastic accumulation might be an issue for an actual aquifer rather than the transportation of it considering the actual groundwater flow velocity is generally much lower.

Hardened Edges Effects on Wear Characteristics of Cultivator Sweeps Using Circular Soil Bin Test

Abstract Tillage tools are subject to friction and low-stress abrasive wear processes with the potential deterioration of the desired soil quality, loss of mechanical weed efficacy, and downtime for replacing worn tools. Limited experimental methods exist to quantify investigate the effect of wear-resistant coatings on shape parameters of soil-engaging tools. ASTM standard sand/rubber wheel abrasion and pin-on-disk tests are not able to simulate wear characteristics of the complex shape of the tillage tools. Even though the tribology of tillage tools can be realistic from field tests, tillage wear tests under field conditions are expensive and often challenging to generate repeatable engineering data due to variable soil conditions in the field. A technique that simulated tillage wear of cultivator sweep in a circular soil bin filled with abrasive gravel medium and moisture condition was developed and applied to quantify the wear characteristics of cultivator sweeps with and without hardfaced edges. The hardfaced cultivator sweep had a cemented carbide chip applied to the bottom cutting edge and front tip sections of a standard cultivator sweep according to a proprietary CADEN Edge welding process. The CADEN Edge hardfaced sweeps showed improved wear performance 1.7 times and 3.5 times on mass and shape (sweep length and sweep wing cutting width) dimensions, respectively, compared with the un-hardened standard sweep. The results implied hardfaced cultivator sweep with cemented carbide chips provide potential in maintaining tillage productivity and the desired soil quality for seed-bed preparation.

Nonlinear acoustic landmine detection experiment: Cylindrical drumlike landmine simulant buried in wetted or unwetted pea gravel

A laboratory experiment for studying acoustic landmine detection involves an 8 in. diameter, 4 in. tall drumlike landmine simulant buried two inches beneath the surface of a pea gravel medium in a cylindrical tank (9 in. O.D., 2 in. thick, 24 in. tall). The cylindrical column of gravel is supported on the sides by the concrete wall, and underneath by the thin circular acrylic top plate of the simulant (which has a thick aluminum bottom plate). Above the surface, a fine spraying mister is controlled to wet the gravel at regular intervals. A porous system near the bottom of the tank drains off excess water. For airborne acoustic excitation two loud speakers are driven by an amplified swept tone (50–850 Hz). A laser Doppler vibrometer connected to a spectrum analyzer measures the particle velocity response across the surface. Nonlinear tuning curve responses were measured on the surface to compare the characteristic frequency shift of the resonant peak with amplitude for nonwetted or wetted gravel. Then, at fixed drive amplitude, the tuning curve response was measured at discrete scan locations across the gravel. Therefore, at any specific resonant frequency, the mode shape response of the coupled simulant-gravel system can be measured.A laboratory experiment for studying acoustic landmine detection involves an 8 in. diameter, 4 in. tall drumlike landmine simulant buried two inches beneath the surface of a pea gravel medium in a cylindrical tank (9 in. O.D., 2 in. thick, 24 in. tall). The cylindrical column of gravel is supported on the sides by the concrete wall, and underneath by the thin circular acrylic top plate of the simulant (which has a thick aluminum bottom plate). Above the surface, a fine spraying mister is controlled to wet the gravel at regular intervals. A porous system near the bottom of the tank drains off excess water. For airborne acoustic excitation two loud speakers are driven by an amplified swept tone (50–850 Hz). A laser Doppler vibrometer connected to a spectrum analyzer measures the particle velocity response across the surface. Nonlinear tuning curve responses were measured on the surface to compare the characteristic frequency shift of the resonant peak with amplitude for nonwetted or wetted gravel. Then, at ...

Using gravel for environmental enrichment in salmonid hatcheries: The effect of gravel size during egg incubation, endogenous and first feeding in rainbow trout

Environmental enrichment aims for a deliberate increase in structural complexity in otherwise plain rearing units, helping to reduce aberrant traits and promote welfare of fish kept in captivity. Before putting enrichment protocols into practice, however, practitioners like hatchery managers need clear guidelines on enrichment measures and on the substrates used. In the present study, we used rainbow trout as a model species for salmonid rearing and investigated the use of a single layer of three different gravel types, i.e., small (4–8 mm), medium (8–16 mm) and large (16–32 mm), for environmental enrichment during egg incubation, endogenous and first feeding of rainbow trout and compared this to a barren control. From the egg stage onwards, we determined mortality, fungal prevalence as well as growth of larvae and fingerlings. We found that gravel size significantly affected mortality and fungal prevalence with the smallest gravel size and the control showing the lowest incidents. Growth of larvae and fingerlings was not affected by gravel, both when compared between gravel types and to the barren control. When using gravel for environmental enrichment in salmonid hatcheries, a small gravel size should be used. Small gravel provides the fish with a more natural environment without compromising practical feasibility of enrichment in hatcheries, still allowing for easy visual inspection and manual control of the reared fish.

Balancing competing life‐stage requirements in salmon habitat rehabilitation: between a rock and a hard place

Gravel augmentation is often applied to rivers and streams to rehabilitate salmonid spawning and incubation habitat. However, the effect of gravel size on salmon spawning utilization and embryo survival during incubation is not well understood. We conducted an experiment on a regulated and previously mined Northern California salmonid‐bearing stream in which different sized gravel (small, medium, and large) patches were placed into the stream's degraded spawning reach. We documented Oncorhynchus tshawytscha (Chinook salmon) spawning activity within the three gravel sizes for two seasons. In addition, we deployed Chinook salmon embryos into each gravel size patch and allowed them to incubate until estimated emergence time. Although all experimental gravel sizes were predicted to be within the spawning population's mobilization capabilities, model results indicated the probability of salmon building redds decreased as substrate size increased. Conversely, embryo survival increased as gravel size increased. A possible mechanism of disparate Chinook salmon embryo survival is provided by an observed decrease in embryo survival correlating with greater presence of embryo predators (leeches), which are associated with smaller gravel. Our results indicate a parent‐offspring conflict in optimal spawning gravel size for Chinook salmon, and suggest that an intermediate gravel size would maximize overall reproductive success across both spawning and incubation life stages.

Restoring hardwood trees to lake riparian areas using three planting treatments

AbstractLake riparian areas provide wildlife habitat for a wide variety of species. Residential development throughout such lakeshore areas of the United States has increased exponentially in recent decades. Awareness of the vulnerability and importance of lakeshore ecosystems has increased concurrently. Lakeshore habitat restoration projects have been implemented to mitigate some of the negative impacts of human shoreline development, and containerized (CT) trees are frequently one of the highest costs associated with such restoration projects. As an alternative, we tested the effectiveness of using dormant bare‐root (BR) trees in restoration projects along two lakeshores in northern Wisconsin, U.S.A. In addition, we experimented using BR stock that was incorporated into gravel medium at a local nursery and planted later in the summer months. We monitored growth and survival of four native tree species in these three planting treatments over a 3–4‐year period. CT red maple (Acer rubra), paper birch (Betula paperifera), and northern red oak (Quercus rubra) increased in size significantly faster than BR and/or gravel culture (GC) counterparts, whereas CT showy mountain ash (Sorbus decora) growth rates were similar to those of BR and GC stock. Mortality was generally low, but for those species/planting treatments with higher mortality (paper birch and red oak), CT trees were more likely to survive than BR or GC trees. Our results show that the success of deciduous BR and/or GC tree stock relative to CT trees is species dependent, and for some species, CT trees' higher growth rates and survivorship could offset their higher costs.

Lab Scale Design and Performance Study of Filter Media: A Potential Application in Irrigation Run off

Presence of nutrients such as nitrogen (N), phosphorous (P), potassium (K) in water bodies majorly contributed by irrigation run off resulting in the prolific growth of aquatic weeds that cause undesirable effects including water flow obstruction, damage of river banks, decrease in the quality of agricultural field and loss of aquatic life. Therefore, it is vital to device novel methods for the removal of N, P, K in irrigation run offs. We established a novel filter media named Multi Filter Media (MFM) using the natural waste material like coconut fifer and paddy husk with course sand of size 4.75 mm to 2 mm and supported by gravel medium. Extensive Experiment prove that 85% to 90% of potassium and phosphorous were successfully removed. Further, 50% of annual maintenance cost of the selected study area of the drainage carrier drain will be reduced, while adopting this method of Multi filter media made up of concrete in the irrigation field.

Designing and construction of simulated constructed wetland for treatment of sewage containing metals

ABSTRACTA simulated horizontal flow constructed wetland (CW) has been designed with gravel medium and aquatic plants Typha latifolia and Polygonum hydropiper to assess its performance efficiency for sewage treatment. Monitoring of fully developed CW revealed a high removal of nutrients and metals from sewage after treatment at varying retention times. The percent (%) removal of biological oxygen demand, total dissolved solids, total suspended solids, PO4-P and total nitrogen in CW planted with T. latifolia were 88.20, 61.9, 72.12, 74.23 and 66.78%; however, with P. hydropiper, reductions were 79.47, 53.47, 55.46, 60.40 and 52.87%, respectively, at 8 d retention time. In addition, T. latifolia and P. hydropiper accumulated substantial amount of metals in their tissues particularly in roots. T. latifolia root accumulated maximum amount of Zn (40.44 µg/g dw) followed by Cu (39.24 µg/g dw), Pb (37.78 µg/g dw) and Cr (19.95 µg/g dw) as compared to P. hydropiper, which was 17.85, 33.43, 36.19 and 9.67 µg/g dw, respectively. Further, plant-specific high translocation factor (>1) of metals were observed at different retention times. Results suggest that simulated CW may be applied as an ecofriendly and low-cost tool to treat sewage before discharge into a fresh water body.

Conifer restoration on lakeshores using 3 planting techniques

Interest in lakeshore habitat restoration has increased concomitant with growing awareness of the importance of these areas for maintaining water quality and for providing terrestrial and aquatic wildlife habitat. Lakeshore restoration efforts are often limited by the high cost of suitable plant material. We compare the effectiveness of containerized and more cost-effective bareroot and innovative gravel-culture planting techniques for 5 conifer species: balsam fir ( Abies balsamea (L.) Mill. [Pinaceae]), white spruce ( Picea glauca (Moench) Voss [Pinaceae]), red pine ( Pinus resinosa Aiton [Pinaceae]), eastern white pine ( Pinus strobus L. [Pinaceae]), and northern white cedar ( Thuja occidentalis L. [Cupressaceae]). Plantings were monitored for 4 growing seasons (year of planting and 3 subsequent). Annual growth rates for 4 of the 5 species did not differ significantly among planting techniques. The exception was containerized balsam fir, which experienced a greater height growth rate than did bareroot and gravel-culture stock. Survival of gravel-culture stock was greater than that of bareroot stock and similar to that of containerized stock for all of the conifers examined, except for red pine. Red pine gravel-culture stock had the lowest survival of any species or treatment (29%), suggesting that this technique is poorly suited for this species. We conclude that the time frame for bareroot native conifer planting may be extended for most of the species examined through the midsummer months by growing bareroot stock in irrigated gravel medium until lifting and planting. For some species, however, neither bareroot planting technique is likely to equal or exceed the growth and survival of containerized stock in lakeshore restoration. Haskell DE, Bales AL, Webster CR, Flaspohler DJ, Meyer MW. 2017. Conifer restoration on lakeshores using 3 planting techniques. Native Plants Journal 18(3):235–244.

Batch Sorption Experimental Study for Phosphorus Removal Mechanisms Using Wetland Gravel Medium

Sorption experiments conducted for estimation of the phosphorus sorption capacity for the local gravel. The tests performed for two different concentrations of the influent phosphorus solution i.e. 4mg/L and 8 mg/L. Experimental results were then modeled using Langmuir and Freundlich equation. Batch isotherm studies show that the P sorption study follows the Freundlich isotherm rather than the Langmuir isotherm. Additionally, ultimate sorption capacities were calculated, and observed that the gravel medium has a sorption capacity in the range of 17mg/kg ~ 22 mg/kg of the gravel. The ultimate quantity estimated was more by using the Freundlich isotherm as compared to the Langmuir isotherm. Also, the sorption capacity was more in the case for the higher concentration effluent (8mg/L) than, the lower one (4mg/L). During the design phase of the wetland system, batch isotherm studies represent a useful criterion for practical considerations of the application of the media. Therefore, the information will enable to short-list materials for wetland or filter design.

Assessment of Density‐Induced Tracer Movement in Groundwater Velocity Measurements with Point Velocity Probes (PVPs)

AbstractThe concept of equivalent freshwater head was adapted to predict the conditions under which density‐driven flow would adversely impact measured groundwater velocities using point velocity probes (PVPs). Theoretically, vertical flow will result from any density contrast between the PVP tracer and the groundwater. However, laboratory testing of tracers with salinities ranging from 0 to 2000 mg NaCl/L showed that horizontal velocities could be determined with good accuracy with up to 60% of the total flow being vertical due to density effects in a gravel medium. The available data suggest that density effects are less likely to be pronounced in sandy sediments. The relative amount of vertical flow due to tracer density can be estimated from vertical and horizontal velocities measured with PVPs, or from the ratio of vertical to horizontal hydraulic gradients. The equivalent freshwater gradient produced from a given tracer salinity at 10 °C (a typical groundwater temperature at moderate latitudes) can be estimated from 7.80 × 10−7 × (MNaCl), where MNaCl is the mass of NaCl added, in mg, to 1 L of site groundwater in the mixing of the tracer. Equations for other temperatures were also determined.

Enhanced phosphorus removal from sewage in mesocosm-scale constructed wetland using zeolite as medium and artificial aeration

Phosphorus (P) contained in sewage maybe removed by mesocosm-scale constructed wetlands (MCW), although removal efficiency is only between 20% and 60%. P removal can be enhanced by increasing wetland adsorption capacity using special media, like natural zeolite, operating under aerobic conditions (oxidation-reduction potential (ORP) above+300 mV). The objective of this study was to evaluate P removal in sewage treated by MCW with artificial aeration and natural zeolite as support medium for the plants. The study compared two parallel lines of MCW: gravel and zeolite. Each line consisted in two MCW in series, where the first MCW of each line has artificial aeration. Additionally, four aeration strategies were evaluated. During the operation, the following parameters were measured in each MCW: pH, temperature, dissolved oxygen and ORP. Phosphate () and chemical oxygen demand (COD), five-day biological oxygen demand (BOD5), total suspended solids (TSS) and ammonium. (NH 4+−N ) were evaluated in influents and effluents. Plant growth (biomass) and proximate analysis for P content into Schoenoplectus californicus were also performed. The results showed that removal efficiency was 70% in the zeolite medium, presenting significant differences (p<.05) with the results obtained by the gravel medium. Additionally, aeration was found to have a significant effect (p<.05) only in the gravel medium with an increase in up to 30% for removal. Thus, S. californicus contributed to 10–20% of P removal efficiency.

Phosphorus removal by blast furnace slag and cement clinker – flow cell studies for estimation of sorptive capacity for use with constructed treatment wetlands

Blast furnace slag and cement clinker were explored in long-term flow cell experiments for estimation of their phosphorus (P) removal efficiencies. A local gravel, typically used in constructed treatment wetlands, was used as a control medium. The experiments examined the removal of phosphorus from a solution initially containing 4 mg P/L. The slag and clinker were nearly 100% efficient due to very high sorptive capacities. The control gravel medium removed 50% of the influent phosphorus. Results from this study indicate that the use of blast furnace slag in constructed wetlands or filter beds is a promising solution for P removal via sorption mechanisms.

Mountain cheese factory wastewater treatment with the use of a hybrid constructed wetland

This paper describes the activity period of an experimental hybrid wetland system placed in a cold climate region. The aim is to determine the efficiency of the system in reducing TSS, BOD 5, COD and other pollutants. The constructed wetland consists of a fat-removal unit and a basin for the storage and the distribution of the wastewater which precedes three phytoremediation beds: the first two are parallel and they work as submerged vertical flow wetland with gravel medium for an area of 180 m 2; the last is a submerged horizontal flow wetland with sand medium and an area of 360 m 2. The CW was designed to process a total estimated BOD 5 loading rate of about 24 g m −2 d −1, which was less than half of the average actual loading rate. The wastewater treatment did not meet the required Italian law outflow limits, most likely due to BOD 5 overloading.

Treatment of high-strength wastewater in tropical vertical flow constructed wetlands planted with Typha angustifolia and Cyperus involucratus

The ability of vertical flow (VF) constructed wetland systems to treat high-strength ( ca. 300 mg L −1 of COD and ca. 300 mg L −1 total-nitrogen) wastewater under tropical climatic conditions was studied during a 5-month period. Nine 0.8-m diameter experimental VF units (depth 0.6 m) were used: three units were planted with Typha angustifolia L., another three units were planted with Cyperus involucratus Rottb and three units were unplanted. Each set of units were operated at hydraulic loading rates (HLRs) of 20, 50 and 80 mm d −1. Cyperus produced more shoots and biomass than the Typha, which was probably stressed because of lack of water. The high evapotranspirative water loss from the Cyperus systems resulted in higher effluent concentrations of COD and total-P, but the mass removal of COD did not differ significantly between planted and unplanted systems. Average mass removal rates of COD, TKN and total-P at a HLR of 80 mm d −1 were 17.8, 15.4 and 0.69 g m −2 d −1. The first-order removal rate constants at a HLR of 80 mm d −1 for COD, TKN and total-P were 49.8, 30.1 and 13.5 m year −1, respectively, which is in the higher range of k-values reported in the literature. The oxygen transfer rates were ca. 80 g m −2 d −1 in the planted systems as opposed to ca. 60 g m −2 d −1 in the unplanted systems. The number of Nitrosomonas was two to three orders of magnitude higher in the planted systems compared to the unplanted systems. Planted systems thus had significantly higher removal rates of nitrogen and phosphorus, higher oxygen transfer rates, and higher quantities of ammonia-oxidizing bacteria. None of the systems did, however, fully nitrify the wastewater, even at low loading rates. The vertical filters did not provide sufficient contact time between the wastewater and the biofilm on the gravel medium of the filters probably because of the shallow bed depth (0.6 m) and the coarse texture of the gravel. It is concluded that vertical flow constructed wetland systems have a high capacity to treat high-strength wastewater in tropical climates. The gravel and sand matrix of the vertical filter must, however, be designed in a way so that the pulse-loaded wastewater can pass through the filter medium at a speed that will allow the water to drain before the next dose arrives whilst at the same time holding the water back long enough to allow sufficient contact with the biofilm on the filter medium.

Morphology, ecology, and contaminant removal efficiency of eight wetland plants with differing root systems

The objective of this study was to test the hypothesis that fibrous-root plants and rhizomatic-root plants are characterized by different root morphologies, root growth and distribution, and contaminant removal capabilities. Four fibrous-root and four rhizomatic-root wetland plants were studied in mono-cultured microcosms which received wastewater. Fibrous-root plants had significantly greater (P < 0.05) small-size root (diameter ≤ 1 mm) biomass and a larger (P < 0.05) root surface area per plant than the rhizomatic-root plants and exhibited accelerated growth in both shoots and roots compared to the rhizomatic-root plants. Fibrous-root plants developed the majority of their root biomass increment within a shallower gravel medium than the rhizomatic-root plants. All plants demonstrated fast root biomass growth from July to September. The wetland microcosms planted with fibrous-root plants showed significantly higher (P < 0.05) ammonium-nitrogen (NH4-N) and nitrate-nitrogen (NO3-N) removal rates from July to December than those planted with the rhizomatic-root plants. These results suggest that root characteristics of wetland plants, which are related to their shoot and root growth, root distribution, and decontamination ability, can be used in the selection of wetland plants with a higher contaminant removal capacity and in the construction of a multi-species wetland plant community.