ECOTOXICOLOGICAL IMPACTS OF LANDFILL

LEACHATE AND ITS TREATMENT USING GREEN

COAGULANTSAGAMUTHU PARIATAMBY, KEE YANG LING, NURUL ASYIKIN BT AHAZAR

CENTER FOR RESE ARC H IN WAS TE MAN AGEMEN T

I N S T I T U TE O F B I O L O GI C AL S C I E N C E S , U N I V E R S I T Y O F M AL AYA, 5 0 6 0 3 , K U AL A L U M P U R , M ALAY S I A

1

What Is A Landfill?

2

Landfill ImpactsA large number of impacts may occur from landfill operations. These impacts can include:

Injuries to wildlife

Infrastructure damage

Pollution of the local environment

Harbouring of disease vectors (such as rats/flies)

Methane is generated (by decaying organic wastes)

Fatal accidents (such as scavengers buried under waste piles)

3

Landfill Leachate During landfill site operation, a liquid known as leachate is produced. 3-4 million L/d in Malaysia.

It is a mixture of organic degradation products, liquid waste and rain water.

It has high organic carbon content and high concentrations of nitrogen

This liquid is highly toxic and can pollute the land, ground water and water ways

4

Landfill Toxins Many materials that end up as waste contain toxic substances.

Over time, these toxins leach into our soil and groundwater, and become environmental hazards for years.

Electronic waste is a good example.

Waste such as televisions, computers and other electronic appliances contain a long list of hazardous substances, including mercury, arsenic, cadmium, PVC, solvents, acids and lead.

5

Landfill Leachate Leachate contain compounds such as alkenes, ketones, esters, alcohols, polycyclic aromatic hydrocarbons (PAHs), phthalates, phenols, nitrogen compounds, carboxylic acids, amines, amides, aldehydes and carbohydrates (Dorian et al., 2013).

Persistent Organic Pollutants (POPs) are major concern in leachate due to their toxicity, persistence, long distance travel and bioaccumulation in animals.

More than 1000 chemicals were identified in contaminated groundwater at landfill site.

6

POPs Definition

POPs are organic compounds that resist chemical, biological and photolytic degradation due to their inherent characteristics.

7

Categories of POPs The intentionally produced POPs include: - pesticides and industrial chemicals that may be traded between countries.

The unintentionally produced POPs which are by-products of industrial or other processes involving combustion which are not products in commerce.

8

POPs Characteristics

Highly persistent

Long range transportability

Bio-accumulation

Highly toxic

(Source: Tang, 2013)

9

POPS cont’d

POPs are organic compounds with long half-lives that can persist for a very longtime in the environment (Revathi and Jennifer, 2006).

More than 800 compounds appear likely to meet the criteria for the classification asPOPs (Brown and Wania, 2008).

At least 120 of these chemicals are produced in high volumes (1000 tonnes per year)(Brown and Wania, 2008).

Stockholm Convention on POPs came into force in 2004 and aim to protect humansand environment from POPs (Xu et al., 2013).

10

POPs listed in Stockholm Convention amendment (Xu et al., 2013)

2001 amendment 2009 amendment 2011 amendment

Aldrin Chlordecone (Kepone) Endosulfan

Dieldrin Lindane

Endrin α- HCH

Chlordane Β- HCH

Heptachlor Hexabromobiphenyl

HCB Tetra-BDE and penta-BDE

Mirex Hexa-BDE and hepta-BDE

Toxaphene PFOs and its salts

PFOSF

DDT Pentachlorobenzene

PCBs

PCDDs and PCDFs

11

Pesticide

Industrial

By-product

Chemical Structures of POPs

12

Chemical Structures of POPs

13

POPs Status

Aldrin Registration expired in 1994

Chlordane Registration expired in 1997

Dieldrin Registration expired in 1994

DDT Registration expired in 1999

Endrin Never registered

Hexachlorobenzene Never registered

Mirex Never registered

Toxaphene Never registered

14

Status of POPs in Malaysia

(Source: Consumers’ Association of Penang, 2005; Revathi and Jennifer, 2006)

Maximum concentration limit in Class IIA standard for pesticide levels in Malaysian river water suitable as water supply

Pesticides

Maximum pesticide

concentration limit

Lindane 2 µgl-1

Heptachlor 50 ngl-1

Endosulfan 10 µgl-1

Total DDTs 100 ngl-1

Dieldrin 20 ngl-1

15

(Source: Leong et al., 2007)

Overview of POPs dispersion in the environment of air, water and biosphere

16

(Source: Langenbach, 2013)

Mechanism of POPs Degradation

17

Mechanism of POPs Degradation

Example:

Chemical stability: DDT degrades to DDE

DDE is less toxic than DDT but more resilient in the environment

18

Sources of POPsSources of POPs

Agricultural area

Rice Paddy

Vegetable farm

Landfill

Consumer products

Process

Industrial

Chemical

Thermal

19

Effects of POPs on wildlife/ humans

Cancers

Birth defect

Dysfunctional immune, development and reproductive systems

Fertility problems

Disease susceptibility

Diminished intelligence

20

Challenges in POPs ManagementOver the last decades, organochlorine pesticides were found extensively in used

(Sani, 2007).

About 253,989 kg of DDT had been applied as insecticide residual spray between

1991 to 1998 in Malaysia (Sani, 2007).

The total volume of leachate generated from landfills in Malaysia is estimated at

approximately 3.0 million liters per day (Agamuthu,2001).

In Malaysia, non-pesticide source of POPs are not well monitored (Roland et al.,

2011).

Methods such as coagulation, precipitation, and reverse osmosis have been

found to be limited for POPs removal (Rashed, 2013).

21

Challenges in POPs ManagementVery slow progress with the destruction of POPs pesticides and polychlorinated biphenyl (PCB) stockpiles

Exports of POPs in waste and products from industrial countries

Most ‘remediation’ undertaken to date involves containment rather than the ‘destruction or irreversible transformation’

Leaves pollutants for future generations to manage and is not consistent with sustainable development

Continued use of POPs such as DDT can therefore be of lowest financial cost to the original consumer

22

Characteristics of Leachate Samples from Selected Landfills in Malaysia

23

JSL- Jeram Sanitary

Landfill

PBSL- Pulau Burung

Sanitary Landfill

BTSL- Bukit Tagar

Sanitary Landfill

Leachate Treatment Methods

• Aerobic Treatment

• Anaerobic Treatment

Biological Treatment

• Floatation

• Coagulation

• Adsorption

• Membrane Filtration

Physical/Chemical Treatment

24

Aerobic Treatment Suspended Growth Systems

Lagoons

Activated Sludge Processes

Sequencing Batch Reactors

Attached Growth Systems

Trickling Filters

Moving Bed Biofilm Reactors

25

Anaerobic TreatmentSuspended Growth Systems Attached Growth Systems

Digesters (UASB, EGSB,DSF) Anaerobic Filter

Hybrid Bed Filter

26

Floatation

27

CoagulationAdvantages

Aluminum sulfate, Ferrous sulfate, Ferric chloride and Ferric chloro-sulfate are commonly used coagulants.

Effective for organic compounds and heavy metals.

Disadvantages

Consistent sludge volume is produces

Increase in concentration of Aluminum or Iron, in the liquid phase, ,may be observed

High pH has to be maintained

28

AdsorptionAdvantages

Design and operating adsorption columns are easy

Availability materials which can be used as adsorbents(coconut shells, charcoal, zeolite, incinerator ash)

High removal efficiency of > 90% COD

Disadvantages

Constant regeneration of activated carbon

Disposal of used carbon

Cost of GAC & PAC

29

Membrane Filtration

30

Disadvantages in using Alum

Aluminium sulphate (alum) is a commonly used inorganic salt for treating wastewater.

Alum is chosen for treating POPs due to

- Low cost

- Easily available (Renault et al., 2009)

However, alum is not environmental friendly as it produces large amount of sludge and possible to be toxic.

The effectiveness of alum is highly dependent on pH and the flocs are not very mechanically resistant when formed in cold water (Renault et al., 2009).

31

What is Green Coagulant? Green coagulant is natural coagulant that is commonly used in water treatment due to its relatively cost-effective compared to chemical coagulants, can be easily processed in usable form and biodegradable.

32

Example of Green Coagulants Source

Guar gum Seed of the guar plant (Cyamopsis

tetragonoloba).

Xanthan gum Strain of bacteria used during the

fermentation process, Xanthomonas

campestris

Locust bean gum Seed of the carob tree

Role of Green Technology

Natural coagulants are better options as compared to chemical coagulants in treating POPs due to

- Minimal coagulant dosage requirement

- Efficiency at low temperature

- Produce small volume of sludge

Chemical coagulants are generally more expensive, toxic and with low biodegradability (Verma et al, 2012).

33

Role of Green TechnologyPOPs Removal Using Guar gum

34

(Source: Kee et al., 2015)

35

Results and DiscussionPercentage of POPs removal in leachate using Guar Gum and Alum, at pH12 at

various dosage.

To remove more than 80% of

POPs in leachate, 4.0 mg/L of

Guar gum or 0.5g/L of alum is

used.

This indicated that 125 times

much higher concentration of

alum is needed as compared

to Guar gum to effectively

remove POPs in leachate.

36

Results and DiscussionResponse surface plot for pyridine,3-(1-methyl-2-pyrrolidinyl) and

bis(2-ethylhexyl) phthalate removal by Guar Gum addition

Design-Expert® Software

Pyridine,3-(1-methyl-2-pyrrolidinyl) removal99

47

X1 = A: pHX2 = B: Guar Gum Dose

Actual FactorC: Mixing speed = 200.00

4

6

8

10

12

3.00

3.50

4.00

4.50

5.00

47

59

71

83

95

P

yri

din

e,3

-(1

-me

thyl-

2-p

yrr

olid

inyl)

re

mo

va

l

A: pH B: Guar Gum Dose

Design-Expert® Software

Bis(2-ethylhexyl) phthalate removal99

31

X1 = A: pHX2 = B: Guar Gum Dose

Actual FactorC: Mixing speed = 200.00

4

6

8

10

12

3.00

3.50

4.00

4.50

5.00

31

44.25

57.5

70.75

84

B

is(2

-eth

ylh

exyl)

ph

tha

late

re

mo

va

l

A: pH B: Guar Gum Dose

When the Guar gum is added in low concentration, it attached to the colloidal particles by

forming bridge which enable the removal of POPS in leachate

When Guar gum was added in excess, there is insufficient particles surface for the biopolymer

attachment (Tripathy & De, 2006)

37

Results and DiscussionSEM and FTIR Analysis

Guar gum flocs had porous,

cross linkage and amorphous

surface structure as compared

to alum

The free reactive hydroxyl

groups in the Guar gum

backbone was substituted by

different functional groups

which enable the removal of

POPs

POPs Removal Using Xanthan Gum

38

2.5 mg/l of Xanthan Gum3.0 mg/l of Xanthan Gum4.0 mg/l of Xanthan Gum5.0 mg/l of Xanthan Gum

Role of Green Technology

Recent studies found that 85.91% and 94.08% of bis(2-ethylhexyl) phthalate were effectively removed from leachate using Guar gum and Xanthan gum, respectively at pH12.

Polymer bridging by green coagulant was responsible for POPs removal

Removal of POPs by alum was less efficient as compared to green coagulant.

39

ConclusionThere is a growing concern on ecotoxicological impacts of landfill leachate and its treatment .

POPs which are commonly found in landfill leachate are potentially hazardous to living organism because of their higher degree of halogenations, inclination to bioaccumulate in the lipid component and their resistance to natural degradation.

To address the threat posed by widespread POPs contamination, remediation technologies continue to be developed to treat these pollutants.

Natural coagulant such as Guar gum and Xanthan gum were very effective in treating POPs and are highly recommended as an option for treating POPs because it is a biodegradable biopolymer, non-toxic, involved low treatment cost, easily available and is produced in abundance.

40

Acknowledgement• Ministry of Higher Education (MOHE) for providing the Fundamental Research Grant

Scheme (FRGS) (Project No: FP052-2013B)

• University of Malaya, Kuala Lumpur for Postgraduate Research Fund (PPP) (Project No: PO008-2014A)

41

Thank you

42

References-1

Agamuthu, P. (2001). Solid waste: principles and management with Malaysian case studies. KualaLumpur, Malaysia: University of Malaya Press.

Brown, T. N., & Wania, F. (2008). Screening chemicals for the potential to be persistent organicpollutants: a case study of Arctic contaminants. Environ Sci Technol, 42(14), 5202-5209.

Kee, Y. L., Mukherjee, S., & Pariatamby, A. (2015). Effective remediation of phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate in farm effluent using Guar gum – A plant basedbiopolymer. Chemosphere, 136, 111-117.

Megharaj, M., Ramakrishnan, B., Venkateswarlu, K., Sethunathan, N., & Naidu, R. (2011).Bioremediation approaches for organic pollutants: A critical perspective. Environment International,37(8), 1362-1375.

Mukherjee, S., Pariatamby, A., Sahu, J. N., & Sen Gupta, B. (2013). Clarification of rubber millwastewater by a plant based biopolymer – comparison with common inorganic coagulants. Journal ofChemical Technology & Biotechnology, 88(10), 1864-1873. doi: 10.1002/jctb.4041

43

References-2Rashed, M. N. (Ed.). (2013). Adsorption technique for the removal of organic pollutants from water andwastewater. doi: 10.5772/54048

Revathi, R. & Jennifer, M. (2006). Overview of the POPs pesticide situation in Malaysia. International POPsElimination Project, Penang, Malaysia.

Renault, F., Sancey, B., Badot, P.-M., & Crini, G. (2009). Chitosan for coagulation/flocculation processes–aneco-friendly approach. European Polymer Journal, 45(5), 1337-1348.

Roland, W., Alan, W., Martin, F., & Fardin, O. (2011). Persistent organic pollutants and landfills – a review ofpast experiences and future challenges. Waste Management and Research, 29(1), 107-121.

Rui, L. M., Daud, Z., & Latif, A. A. A. (2012). Treatment of Leachate by Coagulation-Flocculation usingdifferent Coagulants and Polymer: A Review. International Journal on Advanced Science, Engineering andInformation Technology, 2(2), 1-4.

44

References-3Sani, I. Md. (2007). Persistent Organic Pollutants in Malaysia. ln A. Li, S. Tanabe, G. Jiang, J. P. Giesy, & P.K. S. Lam (Eds.), Development in environmental science (pp.629-655). Netherland: Elsevier.

Sen Gupta, B., & Ako, J. (2005). Application of guar gum as a flocculant aid in food processing and potablewater treatment. European Food Research and Technology, 221(6), 746-751. doi: 10.1007/s00217-005-0056-4

Tang, Hubert Po-on. (2013). Recent development in analysis of persistent organic pollutants under theStockholm Convention. TrAC Trends in Analytical Chemistry, 45(0), 48-66. doi:http://dx.doi.org/10.1016/j.trac.2013.01.005

Verma, A. K., Dash, R. R., & Bhunia, P. (2012). A review on chemical coagulation/flocculation technologies forremoval of colour from textile wastewaters. Journal of Environmental Management, 93(1), 154-168.

Xu, W., Wang, X., & Cai, Z. (2013). Analytical chemistry of the persistent organic pollutants identified in theStockholm Convention: A review. Analytica Chimica Acta, 790, 1-13.

45