Plants used in Phytoremediation

PLANTS USED FOR PHYTOREMEDIATION Rashad Reed and Kenong ZhangBZ 572 Fall 2010November 18, 2010

Plant ClassificationOrnamental PlantsPot marigold (Calendula officinalis)Common hollyhock (Althaea rosea) Chinese brake fern (Pteris vittata )Aquatic PlantsWater Hyacinth (Eichhornia crassipes )Eurasian Watermilfoil (Myriophyllum spicatum)Fool's Watercress (Apium nodiflorum)Duckweed (Lemna trisulca L.)Pot Marigold and Common Hollyhock

Features of Ornamental PhytoremediationEmploys phytostabilization of pollutantsFound to phytoremediate heavy metals, i.e. Cd, PbOrganic phyoremediation of petroleum (TPH) Cultural background and influence (marketing, aesthetics)Profitability to existing nursery, fertilizer, and gardening industriesPublic acceptanceAdvantages: Can be used in urban environments without changing existing landscape.Relatively low costsNon-food chain plants that can be periodically phytoextracted for pollutants.Can be genetically modified to not produce pollen or set seed with minimal effect to ecologyOrnamental Phyto Case StudyLiu et. Al tested 3 ornamentals, Impatiens Balsamina, Althaea rosea and Candulata officinalis for ability to tolerate and accumulate Cd and Pb.Soil and hydro conditions testedCd levels ranged from 0, 10, 30, 50, 100 mg/Kg-1 Pb was added to Cd in the following concentrations: 0 + 0 (control), 1 + 50, 3 + 50, 5 + 50, 10 + 50, 1 + 100, 3 + 100, 5 + 100 and 10 + 100 mg L-1Pb(NO3)2 form of bioavailable leadCdCl22.5H2O form of bioavailable cadmiumOrnamental Phyto Case StudySoilImpatiens balsamina had leaves turn brown under >50 mg/KgC. officinalis height increased as Cd levels increasedA. rosea height slightly decreased for levels above 50 mg/Kg (insignificant)C. officinalis and I. balsamina accumulates more Cd in roots than the shoot at every Cd levelA. rosea accumulates more Cd in shoots for 10, 30, and 50 mg/Kg, but more Cd in the roots under 100 mg/Kg CdCl22.5H2O

Ornamental Phyto Case Study

Ornamental Phyto Case StudyA. rosea had the highest ability to accumulate Pb, the maximal Pb concentration in the shoots and roots was 24 and 640 mg kg1Phytotoxicity shown (Cd and Pb = 10 + 50 and 10 + 100 mg L1)C. officinalis had the highest ability to accumulate Cd, the Cd concentration in the shoots and roots reached 825 and 1585 mg kg1 in TP4 treatment, 700 and 1492 mg kg1 in TP8 treatment, respectivelyAll three plants had a lower general affinity for PbOrnamental Phyto Case StudyCase study conclusionsC. offinalis is tolerant to Cd levels, but is not a hyperaccumulator since more Cd was found in the roots than in the shoots. PhytostabilizationA. rosea, tolerant to heavy metals and is a hyperaccumulater of Cd when conc. < 100 mg kg-1Efficacy of ornamentals was examined and has potential for use in urban environments with moderate to high Cd/Pb contamination levels

Fern PhytoremediationClassification: Marattiales, Ophioglossales, and leptosporangiate ferns Best used in areas of high humidityAbility to uptake high levels of arsenicIndustrial applications in phytoremediationHumidity requirements reduces water necessityFast growing species and varieties available (increased biomass) Ornamental use: Japanese painted fern

Chinese brake fern and Japanese painted fern

Arsenic accumulation in fernsMa et al. (2001) reported the first known arsenic hyperaccumulator Chinese brake fern (Pteris vittata L.).Tu et al. 2002 found that P. vittata grown in an As-contaminated soil accumulated total dry biomass of 18 g plant-1 after 18 weeks of growthChinese brake fern tolerant of high concentrations of arsenic, up to 1,500 mg As kg-1 soilFerns operate by phytoextracting Arsenic, As(V) or As(III), storing As in the frondsFerns hyperaccumulate As through phosphate transporters and do not have phosphate deficiency symptoms at high levels of AsFern phytoremediation (mechanism)Contains arsenate reductase (AR) genes to reduce arsenate to arseniteAR was not detectable in the fronds, suggests that arsenate reduction, occurs in rootsArsenite is then transported to shoots, where it may be stored in the vacuoles (Lombi et al., 2002)75-95% As in the fronds is present in the form of arsenite (Ma et al. 2001, Zhang et al. 2002). Fern Phytoremediation in Practice10 g As/L-1 is the limit set by US EPAOver 29 million people in Bangladesh may be exposed to over 50 g/L As.Bangladesh, India, and Pakistan have problems with ground water contamination from AsUp to 7500 mg As/kg on a contaminated site without showing toxicity symptoms. (Ma et al, 2001)Contamination comes from industrial and chemical plants, dumping effluent into groundwaters (lack of regulation)

Scope of Arsenic contaminaton

Practical Urban PhytoremediationHyde Park neighborhood: Augusta, GA

Phyoremediation in practiceLow-lying geographic area containing approximately 200 houses and surrounded by industry, abandoned industry, railroad lines and large highways.Problems of high poverty levels (>70%) Abandoned houses, overgrowth of weeds, snakes, etc.Illegal dumping and drain contaminationLack of community cohesiveness and/or solid leadershipPhytoremedation can be used as a part of a larger objective in urban environmental renewal Hyde Park Pictures

Bob Safay. ATSDR Regional Representative. U.S. EPA, Region IV released a report in 1994.The most serious contamination found near the Goldberg site.From ditch sediments: Highest lead detected was 1800 mg/kg, and the highest level of PCBs was 13.2 mg/kgFrom soil samples: lead (1100 mg/kg), arsenic (59 mg/kg), and dioxin/furans (0.0001 mg/kg

Agency for Toxic Substances and Disease Registry report, APPENDIX 3 - MARCH 1994 HEALTH CONSULTATION

Phytoremediation plan

Perennials Alpine Pennygrass, Thlaspi caerulescens Hairy Goldenrod, Solidago hispida Yellow Tuft, Alyssum lesbiacum Bladder Campion, Silene vulgaris Horse bean, Vicia faba Trees and ShrubsAspen, Populus tremula Shrub violet, Hybanthus floribundus Grasses Indian grass, Sorghastrum nutans Kleingrass, Panicum coloratum Little bluestem, Schizachyrium scoparius Bent grass, Agrostis castellana Aquatic plantsAquatic plants are those plants living in and adapted to aquatic environments, which can only grow in water or permanently saturated soil.Bodies of aquatic plants can be either floating or submerged.Aquatic plants are often viewed as indicators of aquatic environment pollution.

Living environment of aquatic plants

RiversLakesConstructed WetlandsHydroponic systems

Where do they live?Mechanisms of aquatic plants phytoremediation Inorganic pollutantsRhizofiltration Phytostabilization Phytoextraction Organic pollutantsPhytodegradation Phytovolatilization Rhizodegradation

Constructed WetlandsHigh substrate heterogeneity Wide application for pollutants removal and phytoremediationAct as a cover above contaminated areasRhizofiltration techniques are the most commonly usedPollutant removal efficiencies are significantly related to plant species present

Pollutant Removal Efficiencies of Constructed Wetlands(Otte and Jacob, 2006)Benefits and drawback of constructed wetlandBenefits:Aesthetical functionsProvide habitat for wildlife animal speciesEducational resourcesLittle maintenance requiredIncreased Cost-efficiency

Drawbacks: Limited by plant tolerance and pollutant bioavailabilityLimited plant life expectancy Susceptible to climate change, pollution, and diseaseHeavy MetalHeavy metal ions of Cd2+, Hg2+, and Pb2+ are nonessential and toxic to plants Cu2+, Zn2+, Mn2+, Fe2+, Ni2+, and Co2+ are essential micronutrients for plants, but toxic when present in high concentrationHyperaccumulators: plant species tolerate, uptake, and translocate high levels of certain heavy metals that is toxic to other species.Contain >100 mg/kg of Cd, >1000 mg/kg of Cu, or >10,000 mg/kg of Zn and Mn(dry weight in leaves)

Heavy Metal ToxicityMercury toxicity symptomsconcentration deficits Impaired motor functionLead toxicity symptoms Learning disabilityMental retardation Chromium toxicity symptomsDamage DNADamage kidney

PbHgTypical Species for Heavy Metal RemovalEurasian Watermilfoil (Myriophyllum spicatum)Water Hyacinth (Eichhornia crassipes )Duckweed (Lemna trisulca L.)

Fool's Watercress (Apium nodiflorum)

Water HyacinthFloating plant with broad ,thick, and glossy leaves that the plant body can grow as much as 1m high.Able to phytoaccumulate metal pollutants contain Ag, Pb, Cd and Zn in municipal and agricultural wastewater.Known as one of the plants with fastest growth rate that can double population in 2 weeks.High invasive potential.

Case Study: Removal of Cadmium and Zinc by Water HyacinthThe stock solution was prepared in distilled water with analytical grade CdCl2. 2 H2O and ZnSO4.7H2O which was later diluted as required. The plants were maintained in tap water with concentrations of 0.5, 1, 2, 4 mg/L of Cd and 5, 10, 20, 40 mg/L of Zn.The test durations were 0 (two hours), 4, 8 and 12 days.Relative growth, metal accumulation, and bioconcentration factor (BCF) are evaluated.

Relative growth (above) and BCF (below)

Relative plant growthMetal AccumulationZnCdCdZnBCFCd

Zn(Lu et al., 2004)Eurasian watermilfoilSubmerged aquatic perennial plant which grows in still or slow-moving water. Slender stems up to 3 m long with numerous leaflets thread-like, 4-13mm long. Introduced to North America between the 1950s and 1980s where it has become invasive species.Able to uptake and remove lead, zinc, and copper from wastewater.

Plant tissue was washed with 3% HCl solution previously.Metal source were provided by CuSO4, ZnSO4, and Pb(NO3)2 to prepare the stock solutions with concentration of 2, 4, 8, 16, 32 and 64 mg/L (doubling). Standard curves were made.Absorption tests were conducted in 250 ml conical flasks placed on orbital shaker and contact for 2 hours.Filtrate was analyzed by atomic absorption spectrophotometer (AAS) to determine sample metal concentrations.

Case Study: Removal of Lead, Zinc, and Copper by Eurasian watermilfoil (Keskinkan et al., 2003)

According to figure 1 (left), equilibrium were reached after about 20 mins after beginning; after that the data was adhered well to the Langmuir equation (see below) which means that absorption was as a monolayer.The value of metal concentration of solution on time t over the beginning concentration Ct/C0 is shown below:Compare of the metal uptake capacities (qmax, mg/g) of Myriophyllum spicatum to other plant species:(Keskinkan et al., 2003)Fool's WatercressHollow stems rooting at base and finely grooved. About 0.3-1m high.Simply pinnate leaves in shiny bright green in color with 2-4 pairs of lobes.Usually find in grown ditches, shallow ponds or very damp places.Capable to uptake and remove various heavy metals such as Hg, Cr, Pb, Cu, and Zn.

(Vlyssides et al., 2005)A mathematical model was established to evaluate the inherent capacity of watercress to uptake heavy metals.Plant uptake rate follows the first order kinetic model depending on the heavy metal concentration in the plant biomass.This model allowed to evaluate the specific uptake rate and the maximum content within plant biomass. The relationship between metal concentration in solution Es (mg/L) and plant biomass Ep (mg/g) is:

Case Study: Removal of Copper, Lead etc. by Fools Watercress

(Vlyssides et al., 2005)

Change of heavy metal concentrations in solution and plant biomass(Vlyssides et al., 2005)

The estimated absorption kinetic parameters for various heavy metals, by Apium Nodiflorum using the data acquiredE = the saturation heavy metal concentrations in the plant biomasskm = maximum uptake rate of metal KS = saturation constant(Vlyssides et al., 2005)DuckweedHas a very simple structure that lacks obvious stems or leaves, with small plate-shaped structure floating on water surface.Reproduction is mainly rely on asexual budding.High pollutant removal potential due to small size, fast growth, and easy to cluture.

(Kara and Kara, 2004)The duckweed obtained from natural lake was acclimatized to laboratory conditions for one week before starting research.Solution of Cadmium was prepared using Cd(NO3)2 and contact with plant sample for different length.After absorption, water samples were analyzed by AAS at 228.8nm. Case Study: Removal of Cadmium by Duckweed

Cd removal efficiencies(Kara and Kara, 2004)

Aquatic Plants VS. Terrestrial Plants in PhytoremediationAdvantages of aquatic plantsFaster growth and larger biomass production rateRelative higher capability of pollutant uptakeBetter water purification effects due to direct contact

GO AQUATIC!Aquatic Plants VS. Terrestrial Plants in PhytoremediationAdvantages of terrestrial plantsMore plant-soil microbe interactions to enhance pollutant uptakeHigher tolerance against severe weather and temperature change More sophisticated root system

GO TERRESTRIAL!ConclusionsOrnamental phytoremediation is beautiful, profitable and effective: utilizing phytoextraction and phytostabilizationFerns hyperaccumulate As which can be useful in contaminated groundwater regions, such as BangladeshHyde Park, Augusta GA has a current and ongoing contamination problem that ornamentals may help to alleviate without affecting food chain or food supply

ConclusionsMost of the aquatic plants showed high heavy metal phytoremediation potential are usually considered as invasive species, which indicates that there are numerous positive aspects of those species that is able to take advantage ofTo achieve better remediate effects, more effort is required to accelerate the pace of phytoremediation techniques from laboratory experiment to practical use.

References:1. Otte, ML and Jacob, DL (2006) Constructed Wetlands for Phytoremediation. Phytoremediation Rhizoremediation 57-67.2. Kamal, M, Ghaly, AE, Mahmoud, N, Ct, R (2004) Phytoaccumulation of heavy metals by aquatic plants. Environment International 29: 1029-1039.3. Skinner, K, Wright, N, Porter-Goff, E (2007) Mercury uptake and accumulation by four species of aquatic plants. Environmental Pollution 145: 234-237.4. Titus JE and Urban RA (2009) Aquatic Plants: A General Introduction. Encyclopedia of Inland Waters 43-51.5. Keskinkan O, Goksu MZL, Yuceer A, Basibuyuk M, Forster CF (2003) Heavy metal adsorption characteristics of a submerged aquatic plant (Myriophyllum spicatum). Process Biochemistry 39(2): 179-183.6. Vlyssides A, Barampouti EM, Mai S (2005) Heavy Communications in Soil Science and Plant Analysis metal removal from water resources using the aquatic plant Apium nodiflorum. 36: 1075-1081.7. Lu X, Kruatrachue M, Pokethitiyook P, Homyok K (2004) Removal of Cadmium and Zinc by Water Hyacinth, Eichhornia crassipes. Science Asia 30: 93-103.8. Kara Y, Kara I (2004) Removal of Cadmium from water using Duckweed (Lemna trisulca L.). International Journal of Agriculture & Biology 7: 660-662.9. Duan G, Zhu Y, Tong Y, Cai C, Kneer R (2005) Characterization of arsenate reductase in the extract of roots andfronds of Chinese brake fern, an arsenic hyperaccumulator. Plant Physiology 138, 461-46910. Ma, L.Q., K.M. Komar, C. Tu, W. Zhang,and Y Cai. 2001. A fern that hyperaccumulates arsenic. Nature. 409:579.11. Internet source, Banglopedia.org http://www.banglapedia.org/httpdocs/HT/A_0308.HTM12.Internet source, Slide 15. http://www.hamitekllc.com/sites/mountainmovers.org/files/img/arsenic-poisoning.gifReferences:13. Tu, C., L.Q. Ma, A.O. Fayiga and EJ Zillioux. (2004) Phytoremediation of Arsenic-Contaminated Groundwater bythe Arsenic Hyperaccumulating Fern Pteris vittata L . International Journal of Phytoremediation, 6(1):3547.14. Internet source, Slide 3(b). http://www.types-of-flowers.org/pictures/alcea_rosea.jpg15. Internet source, Slide 3(a). http://pics.davesgarden.com/pics/2009/03/02/purplesun/ed602b.jpg16. Hyde Park Charettte Report. October 2008. The University of Georgia College of Environment and Design Center for Community Design and Preservation. www.ced.uga.edu/charrettes.html17. Rathinasabapathi, Bali, L.Q. Ma and M Srivastava. (2006) Floriculture, Ornamental and Plant Biotechnology Volume III. Global Science Books, UK.18. Tu C, Ma LQ (2005) Effects of arsenic on concentration and distribution of nutrients in the fronds of the arsenic hyperaccumulator Pteris vittata L. Environmental Pollution. 135, 333-340.19. Internet source, slide 11(b). http://www.shadesofgreenusa.com/Priclist_files/painted_fern1.jpg20. J. Liu, Q. Zhou, T. Sun, L.Q. Ma and S. Wang. (2008) Identification and Chemical Enhancement of Two Ornamental Plants for Phytoremediation. Bull Environ Contam Toxicol 80:260265.21. J. Liu, Q. Zhou, T. Sun, L.Q. Ma and S. Wang. (2008) Journal of Hazardous Materials 151:261267.22. Fiegl, J., Bryan P. McDonnell, Jill A. Kostel, Mary E. Finster, and Dr. Kimberly Gray "A Resource Guide: The Phytoremediation of Lead to Urban, Residential Soils". http://www.civil.northwestern.edu/EHE/HTML_KAG/Kimweb/MEOP/INDEX.HTM

References:23. Lombi E., F. Zhao, M. Furhrmann, S.Q. Ma and S. McGrath. (2002) Arsenic distribution and speciation in the fronds of the hyperaccumulator Pteris vittata. New Phytologist. 156: 195203.24. Zhang WH, Cai Y, Tu C, Ma LQ. (2002) Arsenic speciation and distribution in an arsenic hyper accumulating plant. Sci Total Environ.; 300(1-3):167177. 25. Zhao FJ, Dunham SJ, McGrath SP. Arsenic hyper accumulation by different fern species. New Phytologist. 2002;156(1):2731.26. I. Alkorta, J. Hernndez-Allica, and C. Garbisu (2004) Environment International. 30: 7, 949-951. 27. Safey, Bob. Agency for Toxic Substances and Disease Registry. (1994)Appendix 3 March 1994 Health Consultation. http://www.atsdr.cdc.gov/HAC/pha/pha.asp?docid=1029&pg=6

Suggested reading material

Checker, Mellissa. (2005) From Friend to Foe and Back Again: Industry and environmental action in the urban south http://www.augustaneeds.com/files/ASU_HydePark_MelissaChecker_2005.pdf

Checker, Mesllisa (2005) Polluted Promises: Environmental Racism and the Search for Justice in a Southern Town. NYU Press, NewYork, NY.