Phytoremediation of Landfill Leachate. Paige Griffin

Transcription

1 Phytremediatin f Landfill Leachate Paige Griffin

2 Landfill facts and figures Americans generate apprximately 250 millin tns f trash annually, and apprximately 57% f the waste is landfilled 1 Over 2,500 landfills are currently in peratin in the United States EPA estimates 10,000 ld and abandned municipal landfills exist

3 What is landfill leachate? Liquid that mves thrugh r drains frm a landfill Generated by Excess rainwater perclatin thrugh waste 2 Inherent water cntent f wastes 3

4 Physical, chemical, and micrbial prcesses ccurring in the waste release pllutants frm the waste int perclating water 4 4 majr grups f pllutants 2 : Leachate cmpsitin Disslved rganic matter (e.g., COD, TOC) Inrganic macr cmpnents (e.g., calcium, sdium, chlride, irn) Heavy metals (e.g., cadmium, cpper, zinc, chrmium) Xenbitic cmpunds (e.g., pesticides, armatic hydrcarbns)

5 Leachate cmpsitin 5

6 Leachate has the ptential t cntaminate grundwater Histrically, landfills were built withut engineered liners Recently, a study estimated that 82% f landfill cells had leaks in the liners 6 Leachate run-ff may pllute surface water The prblem Surface water pllutin less cmmn than grundwater pllutin Landfills may generate leachate fr hundreds f years after clsure

7 Questin 1 Name ne envirnmental issue assciated with landfill leachate.

8 Cnventinal leachate treatments Leachate transfer 3 Recycling Cmbined treatment with dmestic sewage Bidegradatin Aerbic prcesses (lagns, activated sludge) Anaerbic prcesses (anaerbic digestin) Chemical and physical methds 1 Chemical xidatin Chemical precipitatin Cagulatin/flcculatin Sedimentatin prb_slutins/msw_lenchate.html prb_slutins/msw_lenchate.html

9 Phytremediatin f leachate Jnes et al, 2006

10 Gal Case study 1: Intrductin 7 Cmplete rehabilitatin f municipal slid waste landfill site Design Leachate treated by cnstructed wetlands and then pumped back t irrigate vegetated landfill cver Plants Phragmites australis (wetlands) willw and grasses (sil cver)

11 Case study 1: CW results Average 60% remval f majr pllutants achieved desired efficiency as leachate pretreatment

12 Case study 1: Plant cver results Beneficial effect f leachate applicatin n landfill vegetatin was bserved Trees started t leaf earlier cmpared t surrunding vegetatin Vegetatin indices were higher thrughut whle vegetatin seasn Cmparisn f irrigated vs. nn-irrigated plants In irrigated plants, nitrgen, sdium, and cadmium levels were higher in plant leaves Nitrgen, sdium, cadmium, zinc, and manganese levels were higher in plant wd

13 Case study 1: Cnclusins Irrigatin did nt shw excess accumulatin f salts, heavy metals, r nutrients that culd negatively affect sil prperties and plant grwth Further mnitring is required t determine lng-term effects f irrigatin Under cntrlled cnditins, leachate acts as gd fertilizer T achieve higher nutrient remval, tree species with higher bimass prductin shuld be used

14 Additinal literature and findings Irrigated trees n landfill caps prmted favrable envirnment fr methane xidizing bacterial ppulatins 8 Spray irrigatin f leachate resulted in the death f native trees and shrubs in Australia, with n regrwth 9 Pplars and willws have been shwn t have high evaptranspiratin rates when irrigated with leachate

15 Questin 2 Name ne plant previusly mentined that culd be used t remediate landfill leachate

16 Human health cnsideratins Received little attentin Few quantitative reprts n micrbilgical cmpsitin f leachate 10 General perceptin: Due t high temperatures during waste decmpsitin, lw ph, and antibitic characteristics, it is generally thught that mst bacterial, prtzal, and viral ppulatins are deactivated11, 12, 13 If pathgens d persist, they are unlikely t survive fr lng perids 14,15

17 References Cver slide pht: (1) US EPA, Methane Emissins frm Landfills. < (2) Kjeldsen et al., Present and Lng-Term Cmpsitin f MSW Landfill Leachate: A Review. Critical Reviews in Envirnmental Science and Technlgy. Pp (3) Renu et al., Landfill leachate treatment: Review and pprtunity. Jurnal f Hazardus Materials. Pp (4) Christensen and Kjeldsen, Basic bichemical prcesses in landfills. Sanitary Landfilling: Prcess, Technlgy and Envirnmental Impact. (5) Jnes et al., Phytremediatin f landfill leachate. Waste Management. Pp (6) Zer Waste America. LANDFILLS: Hazardus t the Envirnment. < (7) Justin and Zupancic, Cmbined purificatin and reuse f landfill leachate by cnstructed wetland and irrigatin f grass and willws. Desalinatin 246, pp (8) Maurice and Lagerkvist, LFG emissin measurements in cld climatic cnditins: seasnal variatins and methane emissins mitigatin. Cld Regins Science and Technlgy 36, pp (9) Chan, Changes t a sil n irrigatin with a sanitary landfill leachate. Water, Air, and Sil Pllutin 17, pp

18 (10) Andrettla and Cannes, Chemical and bilgical characteristics f landfill leachate. In: Landfilling f Waste: Leachate. Pp (11) Engelbrecht and Amirhr, Inactivatin f enteric bacteria and viruses in sanitary landfill leachate. Federal Cmmunicatins Cmmissin, NTIS/PB 234. (12) Dnnelly et al., Recvery f faecal indicatr and pathgenic micrbes frm landfill leachate. Land dispsal: municipal slid waste, EPA. (13) Pahren, Micr-rganisms in municipal slid waste and public health implicatins. CRC Critical Reviews in Envirnmental Cntrl 17, pp (14) Cker, Bilgical aspects f the dispsal utilizatin f sewage sludge n land. Advances in Applied Bilgy 9, pp (15) Menzies, Pathgen cnsideratins fr land applicatin f human and dmestic animal wastes. In: Sils fr Management f Organic Wastes and Waste Waters. American Sciety f Agrnmy Crp Science Sciety f America-Sil Science Sciety f America. Pp

19 Answers t quiz questins 1. Cntaminatin f grundwater r surface water 2. Reeds, willw, pplar, grasses, shrubs