WWF Better Sugar Business - London 23-24/6/05

Generation & management of effluents in cane sugar production

Generation & management of Generation & management of effluents in cane sugar productioneffluents in cane sugar production

Graham KingstonGraham Kingston11 & Samira Daroub& Samira Daroub22

1 1 BSES Limited, Bundaberg AUSTRALIABSES Limited, Bundaberg AUSTRALIA2 2 IFAS, University of Florida, USAIFAS, University of Florida, USA

WWF Better Sugar Business - London 23-24/6/05

OutlineOutline•• Which effluents?Which effluents?•• PerspectivePerspective•• Effluents from cane sugar industryEffluents from cane sugar industry

–– RunRun--offoff–– LeachingLeaching–– Atmospheric Atmospheric ““effluentseffluents””

•• Examples of progress to BMPExamples of progress to BMP•• ChallengesChallenges

WWF Better Sugar Business - London 23-24/6/05

Effluent streamsEffluent streams•• RunoffRunoff

–– Particles (eroded soil, organic matter, sorbed Particles (eroded soil, organic matter, sorbed nutrients & chemicals)nutrients & chemicals)

–– Soluble (nutrients, chemicals, salt, acid, Soluble (nutrients, chemicals, salt, acid, organic matter)organic matter)

•• LeachingLeaching–– Soluble (nutrients, chemicals, organics)Soluble (nutrients, chemicals, organics)

•• AtmosphericAtmospheric–– Particles (dust, smoke, ash)Particles (dust, smoke, ash)–– Gas (COGas (CO22, CO, CH, CO, CH44, NH, NH33, NO, NOxx, N, N22 ))

•• ByBy--productsproducts

WWF Better Sugar Business - London 23-24/6/05

Perspective on water based effluentsPerspective on water based effluents

•• Runoff & leaching with rainfall / irrigationRunoff & leaching with rainfall / irrigation•• Rainfall not manageableRainfall not manageable•• Risk managementRisk management

–– Assess field operations & rain riskAssess field operations & rain risk–– Manage irrigation, field operations & rain Manage irrigation, field operations & rain

riskrisk•• Scale of measurement for effluent reportScale of measurement for effluent report

–– Plot, field, farm, catchmentPlot, field, farm, catchment

WWF Better Sugar Business - London 23-24/6/05

RunRun--off (Erosion)off (Erosion)•• Tropics & subTropics & sub--tropicstropics

–– Risk periods & major eventsRisk periods & major events•• ScopeScope

–– 44--31 t/ha common; up to 500 t/ha31 t/ha common; up to 500 t/ha–– 10 t/ha ~ 1 mm depth10 t/ha ~ 1 mm depth–– Soil formed @ 25 mm / 300 Soil formed @ 25 mm / 300 –– 1000 yrs1000 yrs–– 50% of N & 80% of P lost in flood with 50% of N & 80% of P lost in flood with

particlesparticles•• SignificanceSignificance

–– OnOn--site site –– loss of soil, organic matter, loss of soil, organic matter, nutrients, water storagenutrients, water storage

–– OffOff--site site –– turbidity, eutrophicationturbidity, eutrophication•• ManagementManagement

–– Landscapes, field design, cover crops, Landscapes, field design, cover crops, residue retention, tail water dams, riparian residue retention, tail water dams, riparian zoneszones

WWF Better Sugar Business - London 23-24/6/05

Chemicals in effluentsChemicals in effluents•• Pesticides detectable in Pesticides detectable in

cane field effluentscane field effluents–– ““LowLow”” levels mostly at levels mostly at

catchment, higher at fieldcatchment, higher at field–– <1% atrazine & diuron <1% atrazine & diuron

exported Mauritius; ~6% exported Mauritius; ~6% atrazine in Louisianaatrazine in Louisiana

–– Low levels atrazine & Low levels atrazine & heptachlor Qld aquiferheptachlor Qld aquifer

–– PCDD concern Qld PCDD concern Qld geological not cane.geological not cane.

•• BMPBMP–– Soil, chemical, risk Soil, chemical, risk

periods, landscape periods, landscape location, watertablelocation, watertable

–– Tools & training Tools & training

WWF Better Sugar Business - London 23-24/6/05

Other soluble effluents in runOther soluble effluents in run--offoff

Soluble organics• Carbohydrates & alcohols in first run-off soon after

cane harvest– Potential for high BOD– BMP? Harvest scheduling, rain & irrigation in sensitive

zones

Acid export• Sulfuric acid from drained pyritic sediments

– Australia, Guyana, Indonesia; <3m above sea level• BMP strategies Australia

– Recognition & BMP– Drain & drainage management, liming– Successful self regulation linked to cane supply contract

WWF Better Sugar Business - London 23-24/6/05

Leached effluentsLeached effluentsIssues

– NO3, P, Chemicals, Salt, H+ ions

Impacts– Groundwater quality,

human health, biota, sub-soil acidity

Significance– Condition / site specific– FL 6-24% of N leached

• BMP – split applications– LA 3-8% of N leached,

15-60% as nitrate.

• BMP components– Rate of N applied– Placement

• Residue management– Products

• Slow release• N fixation in cane• Lime for acidity

– Split application– Risk periods– Extension & training

WWF Better Sugar Business - London 23-24/6/05

Effluents to atmosphere from the field Effluents to atmosphere from the field Pre / post harvest fires

• Reduction of non-commercial biomass

• Effluents– Smoke, ash– CO2, CO, NOx.

• Impacts– Greenhouse (mainly NOx)– Health / amenity

• BMP– Green cane system– Regulation– Codes of Practice

WWF Better Sugar Business - London 23-24/6/05

NitrogenNitrogen•• VolatilisationVolatilisation•• DenitrificationDenitrification•• SignificanceSignificance

–– Condition specificCondition specific–– Volatilisation 20Volatilisation 20--40% of N 40% of N

appliedapplied–– Denitrification 1Denitrification 1--20%, 2520%, 25--

60% of N applied60% of N applied

Management N gases–– Situation specific Situation specific

strategies are well knownstrategies are well known

Carbon dioxideCarbon dioxide–– Greenhouse neutral

Effluents to atmosphere from the fieldEffluents to atmosphere from the fieldGasesGases

Greenhouse neutral

WWF Better Sugar Business - London 23-24/6/05

Some examples of progress with BMPSome examples of progress with BMPAustraliaAustralia

–– Industry Envir. AuditIndustry Envir. Audit–– COMPASSCOMPASS–– Supply chain trainingSupply chain training

•• FERTCAREFERTCARE•• Grower coursesGrower courses•• Chemical accreditationChemical accreditation

–– Reef Water Quality PlanReef Water Quality Plan–– Self regulation ASS ManagSelf regulation ASS Manag’’tt

•• South AfricaSouth Africa–– Self assessment programSelf assessment program–– Short coursesShort courses

•• FloridaFlorida–– EAA BMPEAA BMP

WWF Better Sugar Business - London 23-24/6/05

Positive impact of BMP on P export in EAA Positive impact of BMP on P export in EAA --FloridaFlorida

•• BMP starts 1992BMP starts 1992--9393•• ComponentsComponents

–– Water managementWater management–– Nutrient managementNutrient management–– Particulates & sedimentsParticulates & sediments

•• Statutory requirementStatutory requirement•• VerificationVerification•• BMP point score linked to BMP point score linked to

farm tax.farm tax.•• Watertable & crop toleranceWatertable & crop tolerance

–– Cane better than vegetables & Cane better than vegetables & sodsod

Trends in P export from EAA with BMP

0

10

20

30

40

50

60

70

WY80-91

WY92-93

WY94 WY95 WY96 WY97 WY98 WY99 WY00 WY01 WY02 WY03 WY04

Water year

% P

load

redu

ctio

n

0

20

40

60

80

100

120

140

160

180

200

P co

nc. (

ppb)

% P load reduction_3yrP conc_ppb

Full BMP implementationPartial BMP

WWF Better Sugar Business - London 23-24/6/05

Challenges with effluent managementChallenges with effluent management

• Major climatic events• Global BMP

– Different environments, cultures, economies• Incentives for improved management

– Knowledge base on system buffering– End of pipe or system approach (time lines)

– Capital, economics, sugar price– Regulatory or voluntary BMP?– Organisation, resourcing, monitoring, R&D

WWF Better Sugar Business - London 23-24/6/05