Nutrient Remediation Efﬁciency of the Sedge Plant ( Cyperus alopecuroides Rottb.) to Restore Eutrophic Freshwater Ecosystems

: The current study investigated the nutrients removal efﬁciency of the sedge macrophyte Cyperus alopecuroides to treat water eutrophication, besides evaluating the recycling possibility of the harvested material. Samples of sediment, water, and plant tissues were taken seasonally from six polluted and three unpolluted locations for this investigation. The growth properties of C. alopecuroides showed remarkable seasonal differences in plant density and biomass, with the maximum values (7.1 individual/m 2 and 889.6 g/m 2 , respectively) obtained during summer and the minimum (4.1 individual/m 2 and 547.2 g/m 2 , respectively) in winter. In polluted locations, the above-ground tissues had an efﬁciency to remove more contents of N and P (11.9 and 3.8 g/m 2 , respectively) than in unpolluted ones (7.1 and 3.4 g/m 2 , respectively). The high-nutrient standing stock of C. alopecuroides supports its potential use for nutrient removal from eutrophic wetlands. The tissues of C. alopecuroides had the maximum nutrients removal efﬁciency to remediate great amounts of Na, K, and N in summer, and Ca, P, and Mg in spring. Above- and below-ground parts of C. alopecuroides from unpolluted locations can be considered as a rough forage for beef cattle, dairy cattle, goats, and sheep. The present study indicated the potential of C. alopecuroides in restoring eutrophic freshwater ecosystems, and, thus, it can be used in similar habitats worldwide.


Introduction
Nutrient pollution of water bodies is today among the most serious environmental issues, owing mostly to the uptake of N and P compounds because of anthropogenic and agricultural drainages, which causes eutrophication [1,2]. This sort of pollution can cause color, taste, and odor alterations, besides oxygen depletion and biodiversity loss in water resources [3]. Several nutrient sources, including agricultural drainage, sewage, and anthropogenic wastes, have been identified as increasing load of nutrients in aquatic ecosystems [4,5]. Excess nutrients in aquatic water bodies are a global challenge due to the repercussions of eutrophication [6], a widespread water pollution issue that causes excessive growth of aquatic plants [7]. Furthermore, excessive fertilizers frequently exceed crop requirements, releasing nutrients, particularly P and N, from agricultural lands into bodies of water [8,9]. Excess nutrients tend to concentrate in wetland sediments and can be returned to the above-water layer (i.e., internal nutrient loading), sustaining eutrophication hazards [10,11]. Accelerated eutrophication can reduce water quality and availability [12]. each site was sampled instantly across 5 quadrats (0.5 × 0.5 m) reflecting the C. alopecuroides population (n = 120 in polluted locations and n = 30 in unpolluted locations). All plant shoots were collected at the soil surface in each quadrat, and the total number of shoots was tallied to determine the shoot density (shoot/m 2 ). The plants were then transported to the laboratory in polyethylene bags and rinsed twice with tap water to remove dirt and then rinsed once with de-ionized water. Following that, five individuals were chosen at random from each quadrat to measure stem length, diameter, and leaf area using the following equation [31]: Leaf area (cm 2 /leaf) = 0.905 × length of the leaf (cm) × breadth at a midway point along the length (cm) (1) 31.13757 E), which receive industrial, agricultural, and sewage wastes from neighboring areas, to assess the study plant's capability for nutrient remediation (Figure 1). Three unpolluted locations along the Nile (29.81908 N, 31.29253 E), Egypt's principal drinking water source, were chosen for comparison in spring and autumn (2017). During each sampling season, each site was sampled instantly across 5 quadrats (0.5 × 0.5 m) reflecting the C. alopecuroides population (n = 120 in polluted locations and n = 30 in unpolluted locations). All plant shoots were collected at the soil surface in each quadrat, and the total number of shoots was tallied to determine the shoot density (shoot/m 2 ). The plants were then transported to the laboratory in polyethylene bags and rinsed twice with tap water to remove dirt and then rinsed once with de-ionized water. Following that, five individuals were chosen at random from each quadrat to measure stem length, diameter, and leaf area using the following equation [31]: Leaf area (cm 2 /leaf) = 0.905 × length of the leaf (cm) × breadth at a midway point along the length (cm) The above-ground components were weighed and dried in the oven at 65 °C until constant weight, yielding dry weight values per shoot. The fresh (g FW/m 2 ) and dry (g DW/m 2 ) biomass were then estimated by multiplying the average fresh and dry weight (g/shoot) by the shoot density (shoots/m 2 ).  The above-ground components were weighed and dried in the oven at 65 • C until constant weight, yielding dry weight values per shoot. The fresh (g FW/m 2 ) and dry (g DW/m 2 ) biomass were then estimated by multiplying the average fresh and dry weight (g/shoot) by the shoot density (shoots/m 2 ). Three composite samples of C. alopecuroides plants' above-ground shoots (stem and leaves), as well as below-ground rhizomes and roots, were collected seasonally from each location for plant analysis. Oven-dried samples were homogenized in a metal-free plastic mill (Philips HR2221/01, Shanghai, China) and then passed through a 2 mm mesh sieve. A one-gram powdered sample was digested in a 20-mL tri-acid combination of HNO 3 :HClO 4 :HF (1:1:2, v:v:v). A microwave gadget was utilized for digesting (Perkin Elmer Titan MPS, PerkinElmer Inc., Waltham, MA, USA). Total N was calculated using the Kjeldahl method; P was calculated using a spectrophotometer (CECIL CE 1021, Cecil Instruments Limited, Milton, Cambridge, UK); Ca, Na, and K were calculated using a flame photometer (CORNING M410, Sherwood Scientific Limited, Cambridge, UK); and Mg was calculated using an atomic absorption photometer (Shimadzu AA-6300, Shimadzu Co. Ltd., Kyoto, Japan). Allen [32] discussed all these plant analysis methods. Furthermore, the nutritional contents (g DM/m 2 ) of the above-and below-ground portions were calculated by multiplying the nutrient concentrations by the biomass of the appropriate organ.

Sediments and Water Analysis
Sediment samples (three composite) were obtained from each location using a stainless steel crab. They were dried before being sieved using a 2 mm sieve. A portable calibrated salinity multi-parameter instrument (Hanna HI 9811-5, Hanna Instruments Italia Srl, Villafranca Padovana, Italy) was used to determine sediment pH and electrical conductivity (EC) from 1:5 (w/v) sediment-water extracts [32]. The dissolved nutrients were calculated using established procedures of Allen [32]. Total N was determined using the Kjeldahl method; P was determined using the molybdenum blue method and a CECIL CE 1021, Cecil Instruments Limited, Milton, Cambridge, UK spectrophotometer; and Na and K were measured using a CORNING M410, Sherwood Scientific Limited, Cambridge, UK flame photometer. Direct titration against AgNO 3 solution with 5 percent potassium chromate indicator for chlorides determination. Titration against 0.01 N HCl was used to determine carbonates and bicarbonates, and a spectrophotometer was used to estimate sulphates at 500 nm (CECIL CE 1021, Cecil Instruments Limited, Milton, Cambridge, UK) as barium sulphate. Three composite samples (1 L each) of surface water from polluted and unpolluted water bodies were obtained from each location for water analysis. The same sediment analytical procedures were used to assess water pH, EC, CO 3 , HCO 3 , SO 4 , Cl, N, P, K, and Na [32].

Data Analysis
A paired-sample t-test was used to compare the differences in sediment variables between contaminated and unpolluted sites. Prior to doing an analysis of variance (ANOVA), the Shapiro-Wilk and Levene tests were used to assess the presence of a normal distribution and variance homogeneity in the data set, respectively. When log transformation was required, it was utilized. One-way ANOVA was used in SPSS software to examine the significance of seasonal changes in nutrients across the several organs of C. alopecuroides plants [39]. At p < 0.05, Tukey's HSD test revealed significant differences between means.

Sediment and Water Properties
The descriptive statistics of the paired sample t-test indicated significant differences in all investigated sediment variables between the unpolluted and polluted locations (Table 1). It was found that the nutrient contents of the polluted locations were higher than those of the unpolluted ones. Likewise, the sediment of the polluted locations was more saline (476.4 µS/cm) than that of the unpolluted one (372.7 µS/cm) in contrast with the pH value (5.4 for polluted and 7.3 for unpolluted sediments). Moreover, the nutrient contents of the sediments fell in the order: Na > N > K > P in the unpolluted sediments, and N > K > Na > P in the polluted sediments. The water chemical study, on the other hand, revealed substantial changes in pH, EC, SO 4 , N, P, Na, and Cl between contaminated and unpolluted locations. Except for P, K, CO 3 , and HCO 3 , most of the variables studied were collected in the sediment more than in the water. The nutritional elements were found in the following sequence in polluted and unpolluted areas: P > K > Na > N.

Growth Properties
C. alopecuroides growth measurements revealed significant seasonal fluctuation in plant density, leaf area, and biomass ( Figure 2). Summer had the highest plant density and biomass (7.1 individual/m 2 and 889.6 g/m 2 , respectively), whereas spring had the maximum leaf area (119.1 cm 2 ). Winter, however, had the lowest plant density, leaf area, and biomass (4.1 individual/m 2 , 52.1 cm 2 , and 547.2 g/m 2 , respectively). It is worth mentioning that the plant density and leaf area in the unpolluted areas (7.8 individual/m 2 and 114.0 cm 2 , respectively) were comparable to those reported in the spring, summer, and autumn, but markedly different from those recorded in the polluted water bodies during winter. In contrast, the biomass of C. alopecuroides obtained from unpolluted regions (796.8 g/m 2 ) differed significantly from that observed in spring, summer, and winter but Sustainability 2022, 14, 2823 6 of 16 was equivalent to that found in contaminated locations during autumn. The paired sample t-test revealed significant differences in plant density, leaf area, and biomass between contaminated and unpolluted areas.

Inorganic Nutrient Concentrations
The statistical analysis (one-way ANOVA) confirmed the significant seasonal fluctuation in the investigated inorganic nutrients rather than Mg and Na in the above-and below-ground tissues of C. alopecuroides, while the paired sample t-test revealed significant differences in all nutrients (except N, P, and Mg in the below-ground parts and Na and Mg in the above-ground tissues) between polluted and unpolluted locations ( Figure 3). During the summer, the below-ground components from polluted areas supplied the highest Na and K concentrations (173.5 and 207.9 mg/kg, respectively), but the lowest P and Mg concentrations (3.6 and 2.3 mg/kg, respectively). They also found the highest N and P concentrations (12.2 and 5.3 mg/kg, respectively) and the lowest Na, K, and Ca concentrations (161.2, 173.9, and 10.4 mg/kg, respectively) during the winter. It is worth mentioning that the concentrations of the examined elements (save N and Mg) in the unpolluted belowground areas were higher than those in the polluted areas. The concentration of nutritional elements in the below-ground portions was as follows: K > Na > N > Ca > P > Mg. On the other hand, above-ground sections of C. alopecuroides gathered from contaminated areas had the highest K and P (185.9 and 4.4 mg/kg, respectively) during spring, N (12.0 mg/kg) during summer, Ca (11.9 mg/kg) during autumn, and Na and Mg (166.3 and 2.5 mg/kg, respectively) during winter ( Figure 3). Furthermore, the concentrations of Na, K, and P in the unpolluted shoots were higher, while those of N, Ca, and Mg were lower than in the polluted areas. The plant branches accumulated nutrients in the following order: K > Na > Ca > N > P > Mg. > Mg. On the other hand, above-ground sections of C. alopecuroides gathered from contaminated areas had the highest K and P (185.9 and 4.4 mg/kg, respectively) during spring, N (12.0 mg/kg) during summer, Ca (11.9 mg/kg) during autumn, and Na and Mg (166.3 and 2.5 mg/kg, respectively) during winter ( Figure 3). Furthermore, the concentrations of Na, K, and P in the unpolluted shoots were higher, while those of N, Ca, and Mg were lower than in the polluted areas. The plant branches accumulated nutrients in the following order: K > Na > Ca > N > P > Mg.

Nutrient's Removal Efficiency
The statistical study (one-way ANOVA) indicated that the inorganic nutrient levels of K, N, and Ca in C. alopecuroides above-ground tissues differed considerably across seasons ( Figure 4). The paired sample t-test also found significant differences in Ca, N, P, and

Nutrient's Removal Efficiency
The statistical study (one-way ANOVA) indicated that the inorganic nutrient levels of K, N, and Ca in C. alopecuroides above-ground tissues differed considerably across seasons ( Figure 4). The paired sample t-test also found significant differences in Ca, N, P, and K between polluted and unpolluted sites. C. alopecuroides tissues accumulated the most Na, K, and N (0.16, 0.18, and 11.9 g/m 2 , respectively) during summer and the least Ca, P, and Mg (9.1, 3.8, and 2.1 g/m 2 , respectively) during spring. Winter, on the other hand, has the lowest nutritional level of all tested seasons. It is worth noting that plant issues gathered larger Na, K, P, and Mg concentrations, but lower N and Ca contents, from unpolluted rather than polluted sites. The annual average of the nutrient contents accumulated per unit area of C. alopecuroides' above-ground tissues was as follows: Ca > N > P > Mg > K > Na.

Organic Nutrient Content
The organic nutrient analysis of C. alopecuroides above-and below-ground tissues revealed significant seasonal fluctuation in the elements studied (Table 2). Below-ground tissues accumulated higher levels of all organic elements than above-ground tissues, contributing to the highest levels of crude fibers (CF) and carbohydrates (NFE) (7.9% and 73.1%, respectively) during summer, ether extract (EE: 1.1%) during spring, ash content (11.3%) during autumn, and total protein (TP: 8.8%) during winter. During the winter, the above-ground parts had the lowest values of CF, TP, and NFE (55.4%, 5.4%, and 28.9%, respectively). Significant differences in estimated organic nutrients were found between unpolluted and polluted water bodies, except for EE and ash content (in below-ground tissues) and EE, ash content, and TP (in above-ground tissues) ( Table 3). Below-ground tissues in polluted areas showed a significant decrease from 34.3% to 20.0% for CF, but an increase from 4.2% to 7.7% for TP and from 50.2% to 61.6% for NFE. However, the above-ground tissues showed a significant decrease in NFE from 42.1% to 37.6%, but a remarkable increase in CF from 40.5% to 46.9%. Na, K, and N (0.16, 0.18, and 11.9 g/m 2 , respectively) during summer and the least Ca, P, and Mg (9.1, 3.8, and 2.1 g/m 2 , respectively) during spring. Winter, on the other hand, has the lowest nutritional level of all tested seasons. It is worth noting that plant issues gathered larger Na, K, P, and Mg concentrations, but lower N and Ca contents, from unpolluted rather than polluted sites. The annual average of the nutrient contents accumulated per unit area of C. alopecuroides' above-ground tissues was as follows: Ca > N > P > Mg > K > Na.

Organic Nutrient Content
The organic nutrient analysis of C. alopecuroides above-and below-ground tissues revealed significant seasonal fluctuation in the elements studied (Table 2). Below-ground tissues accumulated higher levels of all organic elements than above-ground tissues, contributing to the highest levels of crude fibers (CF) and carbohydrates (NFE) (7.9% and 73.1%, respectively) during summer, ether extract (EE: 1.1%) during spring, ash content (11.3%) during autumn, and total protein (TP: 8.8%) during winter. During the winter, the above-ground parts had the lowest values of CF, TP, and NFE (55.4%, 5.4%, and 28.9%, respectively). Significant differences in estimated organic nutrients were found between unpolluted and polluted water bodies, except for EE and ash content (in below-ground tissues) and EE, ash content, and TP (in above-ground tissues) ( Table 3). Below-ground tissues in polluted areas showed a significant decrease from 34.3% to 20.0% for CF, but an increase from 4.2% to 7.7% for TP and from 50.2% to 61.6% for NFE. However, the aboveground tissues showed a significant decrease in NFE from 42.1% to 37.6%, but a remarkable increase in CF from 40.5% to 46.9%.

Forage Quality
The forage quality of C. alopecuroides plants was evaluated, and all the analyzed nutritional characteristics showed considerable seasonal change (Table 4). During the summer, below-ground tissues had its maximum DE, ME, and NE (3.3, 2.7, and 1.3 Mcal/kg, respectively), but the lowest GE (379.1 Mcal/kg). Furthermore, they had the most DCP (4.7%) but the lowest TDN (56.3%) throughout the winter. During winter, above-ground tissues showed the lowest levels of DCP (1.5%), DE, ME, and NE (1.9, 1.6, and 0.8 Mcal/kg, respectively), and the greatest levels of TDN (59.2%) and GE (420.0 Mcal/kg). There were no significant variations in plant forage quality characteristics (save DCP, ME, and NE in below-ground tissues and DCP in above-ground tissues) between polluted and unpolluted areas on an annual basis (Table 5). Under pollution conditions, DCP, ME, and NE levels in C. alopecuroides below-ground tissues increased significantly (0.4-3.7%, 1.9-2.3 Mcal/kg, and 0.9-1.2 Mcal/kg, respectively). In polluted areas, however, the DCP decreased significantly from 2.6 to 1.9% in above-ground tissues. F-values represent one-way ANOVA; means in the same column followed by different letters are significantly different at p < 0.05 according to Tukey's HSD test; *: p < 0.05; **: p < 0.01; R: root system; S: shoot system.

Discussion
The water body's sediment and water chemistry indicate the type and intensity of point-source contamination [29]. It was discovered that nutrient concentrations were higher in polluted areas than in unpolluted areas, and higher in sediments than in water. These findings are consistent with those of Ghazi et al. [31] and Galal et al. [40], who found that sediment from polluted water bodies contained more nutrients and heavy metals than sediment from the unpolluted River Nile. Agricultural drainage, as well as home and industrial effluents from anthropogenic activities, are the primary causes of pollution in eutrophic water bodies, according to Galal et al. [41]. In the same vein, polluted areas in the current study are surrounded by huge amounts of agricultural fields, which could dramatically raise the levels of water nutrients, particularly N and P, and, hence, enhance eutrophication [42,43].
C. alopecuroides plant density and biomass showed substantial seasonal variation, with the highest values recorded during the summer and the lowest values acquired during the winter. Many water macrophytes, such as Phragmites australis [29], Cyperus articulatus [40], Vossia cuspidata [41], Ludwigia stolonifera [43,44], Arundo donax [45], and Typha domingensis [46] have shown similar results. C. alopecuroides had the highest biomass of 0.9 kg/m 2 , which is higher than the same species' 0.1 kg/m 2 [24] and 0.6 kg/m 2 [47], but lower than the 1.7 kg/m 2 [40] and 5.0 kg/m 2 [48] for C. articulatus. Low biomass through winter may be due to low temperature, eco-physiological behavior, and water body monitoring systems [24], in addition to the short growing season, water eutrophication intensity, and severe conditions such as competition [43]. Furthermore, Eid et al. [29] linked this decline to the winter season's glucose transfer from below-ground to above-ground tissues. Furthermore, the average biomass in polluted areas was much lower than in unpolluted areas, which could be related to high heavy metal content, which inhibit plant development [31].
According to Manolaki et al. [18], there is a significant fluctuation in the absorption potential of aquatic macrophytes dependent on sediment and water chemistry, where these plants demonstrate seasonal development fluctuates depending on their nutrient requirements. There is a large seasonal fluctuation in the inorganic nutrients among C. alopecuroides tissues and between unpolluted and polluted regions. This finding is consistent with Klaus et al. [49] and Galal et al. [41], who determined that plant size and growing season are the primary causes of nutritional variance. The below-ground regions of polluted water bodies contributed the most Na and K concentrations during the summer, and the least N and P concentrations during the winter. However, the above-ground shoot had the greatest K and P levels in the spring, the highest N levels in the summer, the highest Ca levels in the autumn, and the highest Na and Mg levels in the winter. According to Vymazal [16], plant tissues gathered most nutrients at the start of the growth season, and the least at maturity and senescence. Furthermore, according to Vymazal and Richardson [50], increased sediment or water nutrient contents may not enhance nutrient concentrations in plant tissues but may increase above-ground biomass.
The plant nutrient content (storage capacity or nutrient standing stock) is calculated by multiplying an organ's biomass by its element concentration. The aquatic plant biomass is regarded as the most important component in determining the nutrient standing stock [16]. The tissues of C. alopecuroides exhibited the maximum nutrient standing stock (g/m 2 ) of Na, K, and N throughout the summer, while the highest Ca, P, and Mg were obtained during the spring. Above-ground tissues in polluted areas acquired higher levels of N and P (11.9 and 3.8 g/m 2 , respectively) than in unpolluted areas (7.1 and 3.4 g/m 2 , respectively). These values are lower than those reported by Zhao et al. [51] on P. australis throughout the summer (74.5 and 7.3 g/m 2 , respectively). Furthermore, Vymazal et al. [52] showed that tall macrophytes such as P. australis and Phalaris arundinacea can remove 30.0 and 80.0 g N/m 2 , respectively, as well as 2.0 and 6.0 g P/m 2 , and that these values can surpass 150.0 g N/m 2 and 15.0 g P/m 2 in high biomass stands. Furthermore, C. alopecuroides' nutritional content supports its possible use for nutrient remediation from eutrophic water bodies by above-ground biomass harvesting.
Increased nutrient content in aquatic habitats because of industrialization, urbanization, and enhanced anthropogenic activities could lead to eutrophication and degradation of these ecosystems [42]. To help restore these ecosystems, aquatic plants should be harvested during the growing season, when the biomass and nutritional contents of the plant tissues are at their peak [14,29]. Our research found that summer is the best time to harvest C. alopecuroides for greatest removal of Na, K, and N, while spring is best for removal of Ca, P, and Mg from eutrophic water bodies. This conclusion is consistent with the findings of Galal et al. [41,43], who attributed it to the greatest nutrient accumulation (particularly N and P) linked with maximal plant biomass throughout the summer. Furthermore, Eid et al. [29] identified spring as the best period to harvest P. australis with the maximum nutrient content and biomass to address Lake Burullus eutrophication in Egypt. According to Kasak et al. [53], removing nutrients through biomass collection is effective for rebuilding nutrient-depleted aquatic habitats. The biggest issue in eutrophic water bodies about leaving aquatic biomass unharvested throughout the growing season is the excessive nutrient re-adsorption from aquatic plants to the environment rather than absorbing them during senescence [14]. Furthermore, harvesting aquatic plants must consider that these plants inhibit the formation of algal blooms in eutrophic water bodies by mitigating light and nutrients [54], and, thus, harvesting large stands of aquatic biomass will accelerate algal growth, leading to phytoplankton dominance [7].
According to Geurts et al. [14], plants should be collected at the highest protein content for high forage quality, and C. alopecuroides should be harvested during winter to be used as fodder, where its below-ground parts have the highest protein content (8.8%), and the above-ground shoots can produce fiber-rich fodder (CF = 55.4%). The crude fiber value of Egyptian clover (Trifolium alexandrinum), a typical grazing herb, exceeded 21.5% [55]. According to El-Kady [56], the lowest protein content needed for animal feed was 6-12%. The above-and below-ground sections of C. alopecuroides meet the criterion for animal maintenance based on the values observed in the current study (5.5-8.8%). Furthermore, the measured values are consistent with the protein level (2.7-13.4%) of some tough feed [57]. The great protein content of C. alopecuroides tissues may boost bovine meat and milk supply, which can be limited by low protein forages. The ether extract (crude fats) concentration is comparable to that of some tough fodder (0.5-3.1% [57]). Furthermore, the various tissues of C. alopecuroides were fiber-rich fodder, outperforming the Egyptian clover (21.5% [55]).
TDN is an adequate measure for the animals' feed energy, according to El-Beheiry [58]. The TDN of the above-and below-ground sections of C. alopecuroides in the current study exceeded 57.0%, which meets the diet requirements (50.0%) of breeding cattle [37]. Furthermore, the mean DE (up to 2.9 Mcal/kg) saved the amount (2.7 Mcal/kg) required by sheep [59], and the ME (1.7-2.3 Mcal/kg) approximated the breeding cattle and sheep requirements [37,59]. It is worth mentioning that the forage value of C. alopecuroides above-and below-ground portions from contaminated or unpolluted areas meets the forage scales of beef cattle [37], dairy cattle [60], goat [61], and sheep [62]. It is also vital to examine this species' ability to accumulate heavy metal contaminants in its tissues [24]. As a result, while harvesting C. alopecuroides plants from polluted water bodies for use as animal fodder, caution should be exercised [63,64].

Conclusions
The above-ground biomass and plant density of C. alopecuroides were at their highest during the summer and at their lowest during the winter. The below-ground parts from polluted areas accumulated the highest Na and K concentrations during summer, and N and P concentrations during winter, whereas the above-ground shoot accumulated the highest K and P concentrations during spring, N during summer, Ca during autumn, and Na and Mg concentrations during winter. The plant gathered most of the nutrients studied in the belowground rather than the above-ground sections. C. alopecuroides' high nutrient standing stock (g/m 2 ) supports its potential use for nutrient removal from eutrophic wetlands by biomass harvesting. C. alopecuroides tissues had the maximum nutrient removal efficiency, remediating considerable amounts of Na, K, and N in the summer and Ca, P, and Mg in the spring. Harvested plants from contaminated water bodies could be converted to ash and packed in a safe place to recover the accumulated heavy metals for economic purposes. Furthermore, the above-and below-ground sections of C. alopecuroides from unpolluted areas can be harvested to be used as rough feed for beef cattle, dairy cattle, goats, and sheep to recycle the collected materials. The present study indicated the potential of C. alopecuroides in restoring eutrophic freshwater ecosystems, and, thus, it can be used in similar habitats worldwide.