Dual phytoremediation and biochar production by Eichhornia crassipes in hydroponic system receiving different 1,4-dioxane dosages.

This study focuses on applying phytoremediation as a low-effective and simple process to treat wastewater laden with 1,4 dioxane (DIOX). A floating macrophyte (Eichhornia crassipes) was cultivated under hydroponic conditions (relative humidity 50-67%, photoperiod cycle 18:6 h light/dark, and 28-33 °C) and subjected to different DIOX loads between 0.0 (control) and 11.5 mg/g fresh mass (FM). The aquatic plant achieved DIOX and chemical oxygen demand (COD) removal efficiencies of 76-96% and 67-94%, respectively, within 15 days. E. crassipes could tolerate elevated DIOX-associated stresses until a dose of 8.2 mg DIOX/g, which highly influenced the oxidative defense system. Malondialdehyde (MDA) content, hydrogen peroxide (H2O2), and total phenolic compounds (TPC) increased by 7.3, 8.4, and 4.5-times, respectively, in response to operating the phytoremediation unit at a DIOX load of 11.5 mg/g. The associated succulent value, proteins, chlorophyll-a, chlorophyll-b, and pigments dropped by 39.6%, 45.8%, 51.5%, 80.8%, and 55.5%, respectively. The suggested removal mechanism of DIOX by E. crassipes could be uptake followed by phytovolatilization, whereas direct photodegradation from sunlight contributed to about 19.36% of the total DIOX removal efficiencies. Recycling the exhausted E. crassipes for biochar production was a cost-efficient strategy, making the payback period of the phytoremediation project equals to 6.96 yr.

Eichhornia crassipes could be used in phytoremediation of 1,4 dioxane (DIOX)-laden water at DIOX load< 8.2 mg/g FM. E. crassipes removed 77­97% DIOX via uptake and phytovolatilization. Recycling exhausted-plant to produce biochar was cost-efficient with 7 yr-payback period.

Uptake of perfluoroalkyl substances PFOS and PFOA by free-floating hydrophytes Pistia stratiotes L. and Eichhornia crassipes (Mart.) Solms.

The phytoremediation potential of floating aquatic plants to accumulate and remove two common PFAS from contaminated water was investigated. Free-floating hydrophytes Eichhornia crassipes and Pistia stratiotes were grown in water spiked with 0.5, 1, or 2 ppm perfluorooctanoic acid (PFOA) or perfluorooctanesulfonic acid (PFOS) for seven days. Both species were able to accumulate PFOA and PFOS in this time frame, with translocation factors (TF) ranging from 0.13 to 0.57 for P. stratiotes and 0.18 to 0.45 for E. stratiotes, respectively. E. crassipes accumulated a greater amount of PFOA and PFOS than P. stratiotes, with 178.9 ug PFOA and 308.5 ug PFOS removed by E. crassipes and 98.9 ug PFOA and 137.8 ug PFOS removed by P. stratiotes at the highest concentrations. Root tissue contained a higher concentration of PFOA and PFOS than shoot tissue in both species, and the concentration of PFOS was generally significantly higher than PFOA in both E. crassipes and P. stratiotes, with concentrations of 15.39 and 27.32 ppb PFOA and 17.41 and 80.62 ppb PFOS in shoots and roots of P. stratiotes and 12.59 and 37.37 ppb PFOA and 39.92 and 83.40 ppb PFOS in shoots and roots of E. crassipes, respectively. Both species may be candidates for further phytoremediation studies in aquatic ecosystems.

This study investigates the feasibility of using wetland plants for the phytoremediation of PFAS. Prior published studies examine various plant interactions with PFAS but do not evaluate remediation potential of P. stratiotes.

The remediation of di-(2-ethylhexyl) phthalate-contaminated sediments by water hyacinth biochar activation of calcium peroxide and its effect on cytotoxicity.

The presence of di-(2-ethylhexyl) phthalate (DEHP) in the aquatic systems, specifically marine sediments has attracted considerable attention worldwide, as it enters the food chain and adversely affects the aquatic environment and subsequently human health. This study reports an efficient carbocatalytic activation of calcium peroxide (CP) using water hyacinth biochar (WHBC) toward the efficient remediation of DEHP-contaminated sediments and offer insights into biochar-mediated cellular cytotoxicity, using a combination of chemical and bioanalytical methods. The pyrolysis temperature (300-900 °C) for WHBC preparation significantly controlled catalytic capacity. Under the experimental conditions studied, the carbocatalyst exhibited 94% of DEHP removal. Singlet oxygen (1O2), the major active species in the WHBC/CP system and electron-rich carbonyl functional groups of carbocatalyst, played crucial roles in the non-radical activation of CP. Furthermore, cellular toxicity evaluation indicated lower cytotoxicity in hepatocarcinoma cells (HepG2) after exposure to WHBC (25-1000 µg mL-1) for 24 h and that WHBC induced cell cycle arrest at the G2/M phase. Findings clearly indicated the feasibility of the WHBC/CP process for the restoration of contaminated sediment and contributing to understanding the mechanisms of cytotoxic effects and apoptotic of carbocatalyst on HepG2.

Evaluation of water hyacinth utility through geospatial mapping and in situ biomass estimation approach: a case study of Deepor beel (wetland), Assam, India.

As an invasive species, water hyacinths (Eichhornia crassipes) are known to progressively proliferate and cause the ecological invasions of the aquatic environment. The incursions of the water hyacinths not only cause the disappearance of native species but gradually degrade the natural habitats of freshwater regimes. The control and management of these species are laborious task; however, transforming weed into wealth can substantially serve a sustainable approach to reduce the efforts. Therefore, the present study intends to utilize the application of geospatial techniques for mapping the water hyacinths growth in the Deepor beel (wetland) of Assam, India. Sentinel based image analysis has shown that pre-monsoon seasons has encountered massive productivity and area coverage of water hyacinth, whereas in post-monsoon seasons, productivity of water hyacinths reduces to half. Furthermore, in situ biomass estimation of the water hyacinth samples, same around the productive season has been collected and was analyzed as 6 kg (green biomass) and 1 kg (dry biomass after sun-dried). Finally, this hybrid approach evaluated the production and revenue generation from Moorhen yoga mat (handicraft item) made from the dried water hyacinths. After assuming the actual availability of 50% of total mass yield of water hyacinths, around ~ 0.8 million (8.8 lakhs) yoga mats can be commercially produced within the most productive seasons. The revenue generation from the yoga mat in the domestic and international markets evaluated around US $12.79 million (Rs. 105.85 crore) and US $15.99 million (Rs. 132.31 crore), respectively, from a single productive season. Thus, applicative intent of this study can boost potential market in Assam, renovate the weed waste of water hyacinth into wealth generation, and sustainably support the livelihoods of the local communities.

Enhanced removal of antibiotics using Eichhornia crassipes root biomass in an aerobic hollow-fiber membrane bioreactor.

The impact of water hyacinth (Eichhornia crassipes) root biomass (WHRB) on pharmaceutical wastewater treatment with an aerobic hollow-fiber membrane bioreactor (HF-MBR) was investigated. The performance of the bioreactor was assessed in terms of COD (Chemical Oxygen Demand) and antibiotic removal and membrane biofouling rate. For deeper insight, microbial communities in sludge and biofilm layers were analyzed through Illumina sequencing. The addition of WHRB into the HF-MBR increased the COD (by 6%), as well as antibiotics and transformation products removal efficiency. Removal efficiencies of 97%, 98% and 84% were obtained for removal of erythromycin, sulfamethoxazole, and tetracycline. Furthermore, WHRB modified the biodegradation network, increased the relative abundances of Chloroflexi, Proteobacteria and Nitrospirae and decreased Firmicutes, compared with the control with antibiotics. The addition of WHRB also enriched Actinobacteria and Bacteroidetes while decreasing the phylla Chloroflexi and Saccharibacteria in the biofilm.

Accumulation, distribution and removal of triazine pesticides by Eichhornia crassipes in water-sediment microcosm.

After application, pesticides remained in the field may contaminate water resources through surface runoff and leaching, posing a threat to aquatic ecosystem. In the current study, the accumulation, translocation, distribution and removal of four triazine pesticides (simazine, atrazine, terbuthylazine and metribuzin) by free floating aquatic plant Eichhornia crassipes (E. crassipes) in water-sediment microcosm were investigated and the removal mechanisms were explored. E. crassipes was exposed to an initial concentration of 50 µg·L-1 and the pesticide levels in water, sediment, roots and shoots of E. crassipes were monitored during 30 days. The results demonstrated that E. crassipes was capable of accumulating triazine pesticides with the bio-concentration factor (BCF) ranging from 0.8 to 18.4. Triazine pesticides were mainly stored in roots, and root accumulation and translocation amount depend on the hydrophobicity of the pesticides. The removal of the pesticides in water were significantly accelerated by the presence of E. crassipes, with the removal efficiency ranging from 66% to 79% after 30 days of treatment. Though phytoaccumulation only constituted 2-18% of the total spiked pesticides in the microcosm, E. crassipes played a vital role in removing simazine, atrazine and metribuzin. However, microbial degradation in sediment was the main pathway for the removal of terbuthylazine in the microcosm. This study demonstrated the potential application of E. crassipes to accelerate removal of contaminants from aquatic environment.

Variations of arsenic forms and the role of arsenate reductase in three hydrophytes exposed to different arsenic species.

In order to understand the mechanisms of arsenic (As) accumulation and detoxification in aquatic plants exposed to different As species, a hydroponic experiment was conducted and the three aquatic plants (Hydrilla verticillata, Pistia stratiotes and Eichhornia crassipes) were exposed to different concentrations of As(III), As(V) and dimethylarsinate (DMA) for 10 days. The biomass, the surface As adsorption and total As adsorption of three plants were determined. Furthermore, As speciation in the culture solution and plant body, as well as the arsenate reductase (AR) activities of roots and shoots, were also analyzed. The results showed that the surface As adsorption of plants was far less than total As absorption. Compared to As(V), the plants showed a lower DMA accumulation. P. stratiotes showed the highest accumulation of inorganic arsenic but E. crassipes showed the lowest at the same As treatment. E. crassipes showed a strong ability to accumulate DMA. Results from As speciation analysis in culture solution showed that As(III) was transformed to As(V) in all As(III) treatments, and the oxidation rates followed as the sequence of H. verticillata>P. stratiotes>E. crassipes>no plant. As(III) was the predominant species in both roots (39.4-88.3%) and shoots (39-86%) of As(III)-exposed plants. As(V) and As(III) were the predominant species in roots (37-94%) and shoots (31.1-85.6%) in As(V)-exposed plants, respectively. DMA was the predominant species in both roots (23.46-100%) and shoots (72.6-100%) in DMA-exposed plants. The As(III) contents and AR activities in the roots of P. stratiotes and in the shoots of H. verticillata were significantly increased when exposed to 1 mg·L-1 or 3 mg·L-1 As(V). Therefore, As accumulation mainly occurred via biological uptake rather than physicochemical adsorption, and AR played an important role in As detoxification in aquatic plants. In the case of As(V)-exposed plants, their As tolerance was attributed to the increase of AR activities.

Dynamics of Metal Pollution in Sediment and Macrophytes of Varthur Lake, Bangalore.

Eutrophication and metal contamination are the principal pollution problem for almost all inland lakes in world. Phytoremediation is one of the viable solutions for this concern. The present study analysed the concentration and distribution of six metals (cadmium, chromium, copper, nickel, lead and zinc) in sediment and macrophyte samples of Varthur Lake, Bangalore. Higher concentrations of studied metals in sediment were observed at the inlet and north shoreline regions of the lake. Alternanthera philoxeroides and Eichhornia crassipes accumulated higher concentration of metals than other species. Accumulation of metals in the sediment were Cu > Zn > Cr > Ni > Pb > Cd, whereas the order in macrophyte samples was Cu > Zn > Cr > Pb > Ni > Cd. Bioconcentration factor (BCF) and translocation factor (TF) of metals in macrophytes revealed metal pollution could be remediated through phytoextraction and phytostabilization.

Sensitivity of the macrophytes Pistia stratiotes and Eichhornia crassipes to hexazinone and dissipation of this pesticide in aquatic ecosystems.

Herbicide wastes from agriculture areas can contaminate water resources and affect non-target organisms. Since herbicides reach groundwater and rivers, these residues can damage the aquatic ecosystem. Hexazinone is an herbicide widely used in sugarcane cultivation and has a potential to contaminate water resources. Therefore, studies are necessary to know the possible damages of this herbicide on aquatic organisms, as well as the behavior of this pesticide in those systems. In this study, our objective was to evaluate the sensitivity of the macrophytes Pistia stratiotes and Eichhornia crassipes to hexazinone, as well as the dissipation of these pesticides. The variables intoxication, fresh matter accumulation, and leaf anatomy were used to evaluate the sensitivity of the macrophytes to hexazinone. The hexazinone concentration in water was performed by HPLC-MS. Hexazinone concentrations equivalent to 111 and 333 µg L-1 were toxic to the macrophytes. Pistia stratiotes produced less fresh matter production than Eichhornia crassipes when exposed to the hexazinone. The hexazinone application did not change the adaxial epidermic (EAD), abaxial epidermic (EAB), palisade parenchyma (PP), aerenchyma (AER) and leaf blade (LAF) of Pistia stratiotes at any concentration tested. Concentrations equivalent to 333 µg L-1 changed the PP and LAF of Eichhornia crassipes. The presence of this herbicide in water negatively affects the fresh matter accumulation and leaf structure of the Pistia stratiotes and Eichhornia crassipes, respectively. The presence of these macrophytes delayed the dissipation of hexazinone due to them impair other pathways of degradation of this herbicide in aquatic environments. The presence of this herbicide in water negatively affects the growth and development of the Pistia stratiotes and Eichhornia crassipes.

Assessment of the Cu(II) and Pb(II) removal efficiency of aqueous solutions by the dry biomass Aguapé: kinetics of adsorption.

Plant-based materials are promising adsorbents for treating liquid effluents. This study describes the kinetic and equilibrium parameters that best represent the copper(II) and lead(II) removal process by Eichhornia crassipes (Aguapé) dry biomass from aqueous solution, using a batch adsorption system. The plants were washed, dried, and reduced to small particles. The adsorption kinetics were assessed by varying the metal concentrations in 5, 10, and 20 mg L-1 and a control treatment (without metals) with a mixture contact time of between 5 and 720 min. Equilibrium data were fitted to the Langmuir and Freundlich models. Kinetic assay revealed fast adsorption: kinetic equilibrium was attained within 2 h with a removal efficiency of ~ 60%. The results demonstrated a fast recovery cycle of metals using the biosorbent. The biomass of E. crassipes is low cost with potential for use as a biosorbent to remove metals from solutions.

Effects and Removal of the Antibiotic Sulfadiazine by Eichhornia crassipes: Potential Use for Phytoremediation.

The antibiotic sulfadiazine (SDZ) is a challenging threat to the health of aquatic organisms, as it frequently occurs in aquatic ecosystems. Tolerance mechanisms and accumulation of SDZ in a floating macrophyte (Eichhornia crassipes) under hydroponic conditions were investigated in this study to provide more insight into the SDZ removal process. Results show that the presence of 1 mg L-1 SDZ decreased the quickest and ranged from 669.45 to 165.34 µg L-1 from days 5 to 25. Exposing E. crassipes to SDZ ( < 1 mg L-1) maintained stable leaf photosynthetic efficiency. The overall increase in superoxide dismutase and peroxidase activities with SDZ treatments indicated that leaves were resistant. SDZ was absorbed by E. crassipes, following the sequence of root > aerial parts under all treatments. These findings suggest that E. crassipes has the ability to phytoremediation SDZ contaminated water.

Phytoremediation of industrial mines wastewater using water hyacinth.

The wastewater at Sukinda chromite mines (SCM) area of Orissa (India) showed high levels of toxic hexavalent chromium (Cr VI). Wastewater from chromium-contaminated mines exhibit potential threats for biotic community in the vicinity. The aim of the present investigation is to develop a suitable phytoremediation technology for the effective removal of toxic hexavalent chromium from mines wastewater. A water hyacinth species Eichhornia crassipes was chosen to remediate the problem of Cr (VI) pollution from wastewater. It has been observed that this plant was able to remove 99.5% Cr (VI) of the processed water of SCM in 15 days. This aquatic plant not only removed hexavalent Cr, but is also capable of reducing total dissolved solids (TDS), biological oxygen demand (BOD), chemical oxygen demand (COD), and other elements of water also. Large-scale experiment was also performed using 100 L of water from SCM and the same removal efficiency was achieved.

Biosorption of Pb(II) by Bacillus badius AK strain originating from rotary drum compost of water hyacinth.

The presence of heavy metals in the environment due to industrial activities is of serious concern because of their toxic behaviour towards humans and other forms of life. Biosorption of Pb(II) using dry bacterial biomass of Bacillus badius AK, previously isolated from water hyacinth compost, has been undertaken in batch system. The optimum conditions of biosorption were determined by investigating the initial pH, contact time, initial biomass dosage at constant temperature of 40 °C, initial metal concentration of 100 mg/L and rotational speed of 150 rpm. The optimum pH was found to be 5 and equilibrium contact time was 2.5 h. The maximum biosorption capacity of Pb(II) on Bacillus badius AK was 138.8 mg/g at an initial concentration of 100 mg/L. A kinetics study revealed that the adsorption process followed pseudo second order rate kinetics. The experimental data were fitted to the Langmuir isotherm. Characterization of the biomass indicated the presence of several functional groups. The results indicated that the bacterium Bacillus badius AK is efficient for the removal of Pb(II).

Bioremediation of arsenic from water with citric acid cross-linked water hyacinth (E. crassipes) root powder.

A green and novel approach was demonstrated for successful remediation of arsenic from contaminated water by citric acid (CA) cross-linked water hyacinth root powder (RP). Different analytical techniques were used to investigate the binding and structural properties of prepared materials. Titanium dioxide played a significant role in the cross-linking process. Incorporation of CA into RP enhanced its integrity, and thus removal efficiency remained unaffected after several cyclic runs. Also the turbidity which formed due to treatment with uncross-linked RP was reduced to below the permissible limit. Effect of the amount of CA, material dose, treatment time, initial ion concentration, and pH were investigated. Use of 10% (w/w) CA was found to be sufficient to bring down the turbidity of the treated water below 2.5 nephelometric turbidity unit (NTU) without hampering the removal capacity/rate. A material dose of 5 g/L removed successfully total inorganic arsenic concentration to below 10 µg/L. The sorption process could be reasonably explained by Langmuir isotherm, and the maximum adsorption capacity was found to be 28 µg of arsenic/g. The material was found to be more efficient at acidic pH (pHZPC = 6.72). The sorption process was governed by a pseudo-second-order kinetic model.

Expression of Echmr gene from Eichhornia offers multiple stress tolerance to Cd sensitive Escherichia coli Δgsh mutants.

The detoxification of heavy metals frequently involves conjugation to glutathione prior to compartmentalization and eflux in higher plants. We have expressed a heavy metal stress responsive (Echmr) gene from water hyacinth, which conferred tolerance to Cd sensitive Escherichia coli Δgsh mutants against heavy metals and abiotic stresses. The recombinant E. coli Δgsh mutant cells showed better growth recovery and survival than control cells under Cd (200 µM), Pb(200 µM), heat shock (50 °C), cold stress at 4 °C for 4 h, and UV-B (20 min) exposure. The enhanced expression of Echmr gene revealed by northern analysis during above stresses further advocates its role in multi-stress tolerance. Heterologous expression of EcHMR from Eichhornia rescued Cd(2+) sensitive E. coli mutants from Cd(2+) toxicity and induced better recovery post abiotic stresses. This may suggests a possible role of Echmr in Cd(II) and desiccation tolerance in plants for enhanced stress response.

Waterscape determinants of net mercury methylation in a tropical wetland.

The periphyton associated with freshwater macrophyte roots is the main site of Hg methylation in different wetland environments in the world. The aim of this study was to test the use of connectivity metrics of water bodies, in the context of patches, in a tropical waterscape wetland (Guapore River, Amazonia, Brazil) as a predictor of potential net methylmercury (MeHg) production by periphyton communities. We sampled 15 lakes with different patterns of lateral connectivity with the main river channel, performing net mercury methylation potential tests in incubations with local water and Eichhornia crassipes root-periphyton samples, using (203)HgCl2 as a tracer. Physico-chemical variables, landscape data (morphological characteristics, land use, and lateral connection type of water bodies) using GIS resources and field data were analyzed with Generalized Additive Models (GAM). The net Me(203)Hg production (as % of total added (203)Hg) was expressive (6.2-25.6%) showing that periphyton is an important matrix in MeHg production. The model that best explained the variation in the net Me(203)Hg production (76%) was built by the variables: connection type, total phosphorus and dissolved organic carbon (DOC) in water (AICc=48.324, p=0.001). Connection type factor was the best factor to model fit (r(2)=0.32; p=0.008) and temporarily connected lakes had higher rates of net mercury methylation. Both DOC and total phosphorus showed positive significant covariation with the net methylation rates (r(2)=0.26; p=0.008 and r(2)=0.21; p=0.012 respectively). Our study suggests a strong relationship between rates of net MeHg production in this tropical area and the type of water body and its hydrological connectivity within the waterscape.

Arsenic and other heavy metal accumulation in plants and algae growing naturally in contaminated area of West Bengal, India.

The present study was conducted to quantify the arsenic (As) and other heavy metal concentrations in the plants and algae growing naturally in As contaminated blocks of North-24-Pargana and Nandia district, West Bengal, India to assess their bioaccumulation potential. The plant species included five macrophytes and five algae were collected from the nine selected sites for estimation of As and other heavy metals accumulated therein by using Inductively Coupled Plasma Mass Spectrophotometer (ICP-MS). Results revealed that maximum As concentration (117mgkg(-1)) was recorded in the agricultural soil at the Barasat followed by Beliaghat (111mgkg(-1)) sites of North-24-Pargana. Similarly, concentration of selenium (Si, 249mgkg(-1)), lead (Pb, 79.4mgkg(-1)), chromium (Cr, 138mgkg(-1)) was also found maximum in the soil at Barasat and cadmium (Cd, 163mgkg(-1)) nickel (Ni, 36.5mgkg(-1)) at Vijaynagar site. Among the macrophytes, Eichhornia crassipes found more dominating species in As contaminated area and accumulate As (597mgkg(-1)) in the shoot at kanchrapara site. The Lemna minor found to accumulate maximum As (735mgkg(-1)) in the leaves at Sonadanga and Pistia stratiotes accumulated minimum As (24.5mgkg(-1)) in the fronds from Ranaghat site. In case of diatoms, maximum As (760mgkg(-1)) was accumulated at Kanchrapara site followed by Hydrodictiyon reticulatum (403mgkg(-1)) at the Ranaghat site. High concentration of As and other heavy metal in soil indicates long term effects of irrigation with contaminated ground water, however, high concentration of heavy metals in naturally growing plants and algae revealed their mobilization through leaching and possible food chain contamination. Therefore, efficient heavy metal accumulator macrophytes Eichhornia crassipes, Lemna minor, Spirodela polyrhiza may be exploited in removing metals from contaminated water by developing a plant based treatment system. However, As accumulator algal species may be used as a bioresource for understanding algae mediated As detoxification and bioindication studies.

Phytoextraction of trace elements by water hyacinth in contaminated area of gold mine tailing.

The ability of water hyacinth (Eichhornia crassipes) to uptake Ag, Ba, Cd, Mo, and Pb from waters in gold mine tailing area was studied. All experiments were carried out in the field conditions without using of model system. Bioconcentration (BCF) and translocation factors (TF) as well as elements accumulation by plant in different points of tailings-impacted area were evaluated. It has been shown that water hyacinth demonstrates high ability to accumulate Mo, Pb, and Ba with BCF values 24,360 ± 3600, 18,800 ± 2800 and 10,040 ± 1400, respectively and is efficient in translocation of Mo and Cd. The general trend of the plant accumulation ability in relation to the studied elements corresponds to their concentration in the medium. As the distance from tailings increases, concentration of Ag, Ba and Pb in plant decreases more clearly than that of Cd, while the amount of Mo accumulated by plant doesn't drop significantly in accordance with its concentration in water. Under the conditions of the confluence of river Ur and drainage stream Ba and Ag can be considered as potential candidates for phytomining.

Phytoremediation efficiency of Eichhornia crassipes in fly ash pond.

The present study was focused on field research to examine the phytoremediation potential of naturally grown Eichhornia crassipes in fly ash (FA) pond. Field results indicate the efficiency of E. crassipes for remediation of heavy metals from FA pond. The bioconcentration factor trend was Cr (3.75) > Cu (2.62) > Cd (1.05), and Cu (1.35) in root and stem, respectively. The survival and abundance growth of E. crassipes in the circumstance of heavy metal enriched FA pond is another highlight of the present research that reveals its toxitolerant characteristics. Thus, this lesson on phytoremediation proved that E. crassipes is a potential accumulator of Cu, Cr, and Cd from FA ponds and is a promising species for FA pond's remediation globally.

The efficient role of aquatic plant (water hyacinth) in treating domestic wastewater in continuous system.

In this study, water hyacinth (Eichhornia crassipes) was used to treat domestic wastewater. Ten organic and inorganic parameters were monitored in three weeks for water purification. The six chemical, biological and physical parameters included Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Ammoniacal Nitrogen (NH3-N), Total Suspended Solids (TSS), and pH were compared with the Interim National Water Quality Standards, Malaysia River classification (INWQS) and Water Quality Index (WQI). Between 38% to 96% of reduction was observed and water quality has been improved from class III and IV to class II. Analyses for Electricity Conductivity (EC), Salinity, Total Dissolved Solids (TDS) and Ammonium (NH4) were also investigated. In all parameters, removal efficiency was in range of 13-17th day (optimum 14th day) which was higher than 3 weeks except DO. It reveals the optimum growth rate of water hyacinth has great effect on waste water purification efficiency in continuous system and nutrient removal was successfully achieved.