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Hazardous Waste Management Hierarchy A controlled site for disposal of wastes on land, run in accordance with safety and environmental requirements laid.

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Presentation on theme: "Hazardous Waste Management Hierarchy A controlled site for disposal of wastes on land, run in accordance with safety and environmental requirements laid."— Presentation transcript:

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2 Hazardous Waste Management Hierarchy

3 A controlled site for disposal of wastes on land, run in accordance with safety and environmental requirements laid down by a regulatory authority SECURED LANDFILL

4 WASTES ARE PLACED PERMANENTLY IN SECURED MANNER WASTE IS ENCAPSULATED FROM THE ENVIRONMENT BY IMPERMEABLE BARRIERS/ LINERS LEACHATE IS COLLECTED, REMOVED & TREATED THROUGHOUT ITS LIFE. A FACILITY WHERE

5  All hazardous waste treatment options result in residues and One of the safer methods for disposal of them  Best techno-economic option for some wastes. WHY LANDFILL ?

6 SECURED LANDFILL FACILITY Last Option Primarily Containment of contaminants

7 ATTENUATE & DISPERSE: Sites where leachate and waste is allowed to escape into the environment at a controlled rate. Pollution is reduced by degradation and attenuation within the landfills and by dilution of the leachate in the aquifer TYPES OF LANDFILL

8 Containment : Sites are aimed at isolating wastes and leachate from the surrounding environment for a considerable time. Archival : Sites are specifically engineered to contain wastes indefinitely, but also to permit later identification and retrieval.

9 METHODS OF LANDFILL Co-disposal : Disposal with M.S.W or similar wastes to take advantage of attenuation processes occuring in such wastes; Critical assessment for compatibility Mono-disposal: Disposal of wastes having same general physical and chemical form Multi-disposal: Disposal of chemically different wastes in the same site

10 Barrier No: 1 Degradation or fixation of pollutants in the waste prior to disposal Barrier No: 2 Suited location of the landfill site with regard to the geological/ hydro-geological situation of the area Barrier No: 3 Leachate collection and treatment system MULTI-BARRIER SYSTEM FOR SLF DESIGN

11 Barrier No: 4 : Bottom Liner System Interface between waste body & subsoil hinders leachate percolation. Barrier No: 5 Cover Liner System Avoids penetration of surface and rain water into waste body avoiding formation of leachate Barrier No: 6 Proper operation and maintenance of SLF Barrier No: 7 Post Closure measures & Repairability of barriers

12 BASIC COMPONENTS OF LANDFILL Impermeable Liner System on the base and side Top cover Leachate collection, removal and treatment scheme Surface Water Control Systems Other site infrastructure

13 Landfill

14 Why the Liner is required ? è Isolate the waste body from the environment è Contain the toxic leachate within landfill è Prevent contamination of Land and Groundwater è Avoid remediation in future

15 Which liner systems are available? Mineralic Geo-membrane Composite (Mineralic + Geo-membrane) Geo-synthetic Clay/ Bentonite Mats Bituminous Membrane Asphalt Concrete Liner

16 BOTTOM LINER Prevent migration of wastes or ‘by-products’ out of the landfill into subsoil, ground or surface water Should have chemical properties, sufficient strength and thickness to prevent failure due to : -Pressure gradients - Physical contact with the waste or leachate -Climatic conditions - Stress of installation and - Stress of daily operation

17 TYPICAL BOTTOM LINER COMBINATIONS  CLAY LINER ONLY  ASPHALTIC CONCRETE LINER  COMPOSITE LINERS  ONE CLAY LINER & ONE FLEXIBLE MEMBRANE LINER  ONE CLAY LINER & TWO FLEXIBLE MEMBRANE LINERS

18 Total Thickness # cm

19 DOUBLE COMPOSITE LINER (AS PER CPCB GUIDELINE)

20 ASPHALTIC CONCRETE LINER 2 BASE LAYERS 3 SEAL LAYERS FOUNDATION LAYER WASTE BODY

21 USEPA SPECIFICATION FOR BOTTOM LINERS Three type of liners are specified by USEPA Flexible Membrane Liners (FMLs) Compacted Clay Liners Composite Clay Liners (FML + Compacted Low permeability soil liners)

22 MATERIALS FOR FMLs Chlorosulfonated Polyethylene Linear LDPE / Very LDPE Polypropylene Ethylene Inter polymer alloy Neoprene Poly Vinyl Chloride Thermoplastic elastomers HDPE

23 Chemical compatability with waste leachate Ageing and durability Stress and strain characteristics Ease of installation Water permeation Key factors considered for selection of FML

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26 CLAY LINER –USEPA SPECIFICATION Thickness of compacted clay bottom liner = 3 feet Permeability of soil liners < 1 x cm/sec To achieve this, following characteristics of soil should be met. Soil should have at-least 20% fines i.e. fine silt and clay sized particles Plasticity Index (PI) > 1% (soils with PI higher than 30 to 40% are sticky and difficult to work within the field) Coarse fragments should be screened to no more than about 10% gravel size particle. No soil particles or chunks of rock larger than 1 – 2 inches in diameter.

27 On-site soils can be blended with imported clay minerals. (e.g on-site sandy soils + imported sodium bentonite) Calcium bentonite, lime, cement, clay soil from nearby or other areas,etc are also used. Clay soil is likely to form chunks and difficult and hence easier to blend on-site sandy soils with dry bentonite powder. BLENDED SOILS –USEPA SPECIFICATION

28 COVER LINER (AS PERCPCB GUIDELINE)

29 HDPE Liner Gravels Section AA Cover Liner Soil Bund Storm Water Drain Channel 375 m 2 m 0.7 m 0.5m 2:1 Slope 3%

30 USEPA GUIDELINES FOR TOP LINER FLEXIBLE MEMBRANE LINER (MIN. 20 MILS ) COMPACTED SOIL – MIN. 60 CM THK SOIL DRAINAGE LAYER – MIN. 30 CM THK VEGETATIVE COVER – MIN. 60 CM THK (UPPER SLOPE : 2 TO 5 % WASTE BODY

31 TOP LINER – NPC DESIGN TOP LINER – NPC DESIGN 3 MM THK POLYESTER BASED MODIFIED BITUMINOUS FELT 25 CM THK COMPACTED SOIL 2 X 25 CM THK WELL COMPACTED SOIL 2 X 25 CM THK MODERATELY COMPACTED SOIL VEGETATION WASTE BODY

32 COMPACTED SUBBASE 75 MM THK P.C.C 1:3:6 MASTIC ASPHALT LAYER 2CM THK 3 MM THK POLYESTER BASED MODIFIED BITUMINOUS FELT WASTE BODY SIDE LINER – NPC DESIGN

33 LEACHATE COLLECTION & REMOVAL Drainage Layer Granular (Sand or gravel, no fine, 2-5 cm dia particle, min.30 cm thk, min K=1 cm/s ) Synthetic (nets, mats, geo-textiles) Pipes and Appurtenances Cushions LEACHATE TREATMENT LEACHATE STORAGE & TRANSFER Epoxy coated RCC Sump with level control submersible pump

34 SURFACE WATER CONTROL SYSTEMS RUN-OFF  Collect and control run-off from active and inactive portions of the landfill from 24 hour – 25 year storm  Collect and contain leachate contaminated storm water that accumulates in active fill area  Protect integrity and effectiveness of landfill cover system RUN-ON  Intercept and divert run-on away from active and closed land fill cells from peak discharge of 25 year storm  Minimise site erosion

35 GROUND WATER MONITORING  Designed to detect contaminant leakage shortly after its occurrence and before significant contamination of ground water  Hydraulically up-gradient and down-gradient wells  Placed around perimeter of fill area within several hundred feet of SLF  No. of wells- Site specific, depends on Size of SLF, Hydro-geology  Minimum Requirements  1 well in up-gradient (Background)  3 wells in down-gradient

36 IDENTIFICATION OF WASTES THAT CAN BE LANDFILLED 1.Wastes that will definitely need to be landfilled as no other options are practicable e.g. Asbestos 2. Wastes that could be safely landfilled without prior treatment e.g. Bio-degradable wastes – technically possible; Better options often exist.

37 3.Wastes which could be landfilled after pre-treatment e.g., Liquid wastes; heavy metal salts.Pre- treatment options can include detoxification, precipitation, solidification as appropriate 4. Wastes that should not be landfilled e.g., Explosives, Compressed toxic gases, Liquid PCBs for technical reasons

38 CRITERIA FOR DISPOSAL OF H.W IN SLF To be dewatered up to the level of 60 – 70% solids Following are not be allowed to dispose of directly in SLF if waste - Is a fluid, slurry or paste - Is delivered under pressure or under vacuum - Has an obnoxious odour - Reacts with moisture to generate high heat or gases - Is highly inflammable (flash point < 40 o C) - Contains very strong oxidising agents - Contains volatile substances of significant toxicity

39 CRITERIA FOR DISPOSAL OF H.W IN SLF - Contains > 10 mg/Kg Cyanide in the original sample - Contains > 10 mg/kg Chromate in the original sample - Contains > 0.5% (Wt.) Mercury - Falls below a pH value of 2, if eluated 1/10 - Contains > 10 mg/1 of water soluble Arsenic in a 1/10 eluate - Contains > 10 mg/1 of water soluble Mercury in a 1/10 eluate - Contains > 3% solvents free from Halogen - Contains more than 0.5% Halogenated solvents - Contains > 0.1% poly-halogenated substances of Significant toxicity (PCBs)

40 Criteria for Hazardous Waste Landfilling in Germany due to “Technical Instructions for HWM” 1991

41 PARAMETERVALUE pH4 – 13 Conductivity<100,000 S/cm Total Organic Carbon<200 mg/1 Phenols<100 mg/1 Arsenic<1 mg/1 Lead<2 mg/1 Cadmium<0.5 mg/1 Chromium VI<0.5 mg/1 Copper<10 mg/1 Nickel<2 mg/1 Mercury<0.1 mg/1 Zinc<10 mg/1 Fluoride<50 mg/1 Ammonia<1,000 mg/1 ELUATE QUALITY

42 PARAMETERVALUE Chloride<10,000 mg/1 Cyanide<1 mg/1 Sulphate<5,000 mg/1 Nitrite<30 mg/1 AOX<3 mg/1 Water sol. Content<10% STRENGTH Transversal Strength (Vane Testing) >25 kN/m 2 Unconfined Compression Test>50 kN/ m 2 Axial Deformation>20% DEGREE OF MINERALISATION OR CONTENT OF ORGANIC MATERIALS Annealing loss of the dry residue at 550 o C <10 W.% ELUATE QUALITY

43 CPCB CRITERIA FOR NON- ACCEPTANCE OF WASTE IN SLF  Bulk or non-containerized liquid hazardous waste  Slurry type hazardous waste containing free liquid or waste sludge  Incinerable / compostable waste or any other type of waste from which energy recovery is feasible  In-compatible wastes not to be placed in same landfills

44 CPCB CRITERIA FOR NON-ACCEPTANCE OF WASTE IN SLF  Wastes in-compatible with liner material without containerisation  Extreme hazardous waste (e.g radioactive waste)  Non-hazardous waste (e.g MSW) not to deposited in HW Landfills

45 1Oxidising mineral acids1 2CausticsH2 3Aromatic hydrocarbonsH,F 3 4Halogenated organics H,F, GT H, GF 4 5Metals GF, H,F H,F5 6Toxic metalsSS6 7Sat. Aliphatic HydrocarbonsH,F7 8Phenols and cresolsH,F8 9Strong oxidising agentsHH,F H9 10Strong reducing agents H,F GT H, GT GF, H H,F E Water and mixtures containing water HH,ES GF, GT 11 12Water reactive substancesExtremely reactive: do not mix with any chemical or waste material12 E ExPLOSIVE F FIRE GF FLAMMABLE GAS GT TOXIC GAS H HEAT GENERATION S SOLUBILISATION OF TOXINS LIST OF INCOMPATIBLE WASTES

46 CPCB SPECIFIED DESIGN REQUIREMENTS FOR LINERS  Stability at base of landfill (in soft soil) & in sides  Strength to withstand construction loads/ vehicle loads  Permeability and material properties as specified in guidelines  Compatibility with leachate & waste  Transition filters bt. Waste & leachate collection layer to prevent clogging of leachate collection layer

47 CRITERIA FOR HAZ. WASTE LANDFILLS  CONSTRUCTION & OPERATION CRITERIA  INSPECTION, MONITORING & RECORD KEEPING CRITERIA  POST-CLOSURE CRITERIA  FINANCIAL ASSURANCE CRITERIA  CONTIGENCY PLAN FOR EMERGENCIES

48 CRITERIA FOR HAZ. WASTE LANDFILLS  LOCATIONAL CRITERIA  SITE SELECTION  SITE INVESTIGATION CRITERIA  PLANNING & DESIGN CRITERIA  WASTE ACCEPTANCE CRITERIA  LANDFILL LINER CRITERIA & COVER CRITERIA

49 CPCB SPECIFIED DESIGN REQUIREMENTS FOR LINERS  Protection layer / transition layer between each component of liner system may be provided  Between Leachate collection layer & HDPE  With Silt / local earth (15 cm thk) / Geo-textile  Adequate clay additive in amended soils

50 ASPECTS CONSIDERED IN THE DESIGN OF SLF  Selection of appropriate liner system for SLF  Desired design period of the SLF in years  Type of landfill desired  Pit (cell wise development) / continuous  Depth of hard stratum from G.L.  Total lay out size & total area of the SLF

51  Nearest G.W.T. reported in monsoon season  Depth of landfill below ground level  Height of stock pile above ground level  Inner side, bottom – longitudinal & transverse slopes  Provision and layout of roads, storm water drain, green belt, office, security, lab, weigh bridge, Vehicle washing area, leachate sumps, etc around the SLF

52 BROAD DESIGN BASIS FOR SECURED LANDFILL FACILITY Quantity of sludge generated  Evolving specific sludge generation factor (I.e. ton of sludge / ton of product)  Sludge generation for envisaged production in future Characteristics of sludge generated  Specific gravity of dry solids in sludge  Bulk density of raw sludge

53  Sludge treatment requirements  Moisture content of sludge  Results of Eluation tests  Chemical composition of sludge  Moisture content, density & other characteristics of sludge after treatment SITE CRITERIA Topography of the site area Geological / Hydro-geological situation of the site (characteristics of the subsoil, presence of aquifers layers, ground water table etc.) Rainfall situation in the region of the site area

54 AREA REQUIREMENT FOR SLF Height of Landfill = m Infrastructure, support facilities & green belt = % of landfill Landfill size classification Small : < 5 hectares Medium : hectares Large : > 20 hectares

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