Manure processing to reusable water using constructed wetlands Meers E., Michels E., March 8, 2011.

Manure processing to reusable water using constructed wetlands

Meers E., Michels E., March 8, 2011

Presentation outline

I. General introductionmanure excesses & manure treatment

II. Treatment to dischargeable water using constructed wetlands as a tertiairy step

II. Project overviewre-use of treated effluents as secondary water resource

I. General Introduction

Exceedance over EU Nitrate directive% in 2003-2004% in 2004-2005% in 2005-2006

Manure excess on soil balance

The Flanders situation

Intensive industrial farmingresults in localized nutrient (N,P)excesses at a regional level.

Similar situations in US (NC),France (Bretagne), Netherlands,Germany (Nord Westfalen), Italy,

Animal manure

Solid fraction

Liquid fraction

Physical separation Composting

Soil enhancer

Nutrient reduction by biological treatment

Manure processing

Fertilizer

Spreading over land

Animal manure

Solid fraction

Liquid fraction

Physical separation Composting

Soil enhancer

Nutrient reduction by biological treatment

Dischargeablewater

Constructed wetlands

Manure processing

Fertilizer

Spreading over land

Cascade of plant- & microbial based processes

Constructed wetlands

Rich diversity of plant species and substrates

Constructed wetlands

Constructed wetlands

“Intelligent design”: control in function of crucial monitoring parameters, feed forward & feedback loops

Cost per m3

‣Constructed wetlands were designed as an alternative for spreading manure

‧Surface: – In general: 1 m² / 1 m³ manure per year (~ 1 ha for 10.000 pigs)

– In practice: > 1 m² / 1 m³ manure

‧Cost (current systems): – 3,5-4,5 €/m³ (incl. operational and investment cost, period 10 year)

– After depreciation (10 years): 2,5-3,0 €/m³

‧Various additional break-throughs pending with impact on :

capacity (m3/m2.j) and hence cost per m3

II. Treatment to dischargeable water

Constructed wetlands

< 15 mg/l total nitrogen

< 2 mg/l totaal phosphor

< 125 mg/l COD

300 mg/l total nitrogen

250 mg/l total phosphor

3000 mg/l COD

Liquid fraction after biology Effluent Constructed Wetlands

Constructed wetlands

VLAREM standard

N content

environmental quality standard

III. Project overview: water re-use

Animal manure

Liquid fraction

Physical separation

Nutrient reduction by biological treatment

Dischargeablewater

Constructed wetlands

Water scarcity & water re-use

‣sufficient water supply is one of the most important environmental and economical challenges in agriculture in the near future

‣use of purified water on the farm is scarce

‣is reuse of end effluent of constructed wetlands an option?

Project

5 different CW locations, monthly sampling

physico-chemical parameters (non-limitative list)SS EC pH Ptot ortho-P NTU hardnessNtot NO2 NO3 NH4 BOD COD CaMg K Na F Cl SO4 AlCd Cu Fe Mn Ni Pb ZnCo Cr

bacteriological parametersC. perfringens Enterococci total Coliforms Salmonella E. coli colony count

(37°C)colony count (22°C) spores sulfite red. Clostridia

reuse options (high & low grade)drinking water live stock cleaning waterirrigation cooling water

ICH – 0,5 ha

PI – 1 ha

LA – 0,5 ha

GI – 3 ha

WVL– 3 ha

Wetland areaPrim. & Sec. Manure treatment

Pig farm

Results- compared to pig drinking water

Overall excellent results

Problem parameters

Location

Ex. Other spore elements: mainly below DL

Total nitrogen

VLAREM (15 mg/l)

No criteria for drinking or irrigation water

Nto

t m

g/l

Location

NitrateN

tot

mg

/l

Location

NO

3 m

g/l

Drinking water (taste)

pig: 100 mg/l

≠appl. Irrigation, process-, cooling- & cleaning water : -

algal bloom, leaching

Total phosphorus

VLAREM (2 mg/l)

No criterium for drinking water

essential element, non toxic, eutrofication pipes

Intensive agri- & horticulture: 15 mg/l

algal bloom storage

Process-, cooling- & cleaning water: -

eutroficationLocation

P (

mg

/l)

Total colony count (37°C)

Time

Cfu

/ml

Criterium drinking waterpig: 100.000 cfu/ml

Hardness

Location

Ha

rdn

ess

(D

°H)

Drinking water

pig: 20 D°H

≠appl. irrigation

21,5 D°H

Risk clogging

Cool- & cleaning water

salt deposit upon heating, ex. cooling greenhouse

Iron content

Variability in location

Drinking water pig: 0,5 mg/l

taste, smell, clogging

Irrigation: 0,5-15 mg/l

+: grassland, vegetables, green house farming, cultivation trees

-: open-air culture, intensive agri- & horticulture, substrate culture

Rust deposit

Ground water in Western Flanders: up to 4 mg/l

Iron removal necessary

-:

Location

Fe

(m

g/l)

Spores sulfite reducing Clostridia

Time

Cfu

/ 1

00

ml

Criterium drinking waterpig: 0 cfu/ 100 ml

Conclusions

‣preliminary results indicate that effluent quality scores better than initially anticipated, both for the bacteriological as well as the physicochemical parameters.

‣even for high grade applications constraints for reuse were limited to parameters which are easy to address using simple polishing steps.

‣we expect that reuse of constructed wetland effluent in various applications will have important economical and environmental benefits.

On site polishing

Future perspectives

Biodiversity

Biomass for energy

Algae production

Aquaculture

Contact

‣even for high grade applications constraints for reuse were limited to parameters which are easy to address using simple polishing steps.

‣we expect that reuse of constructed wetland effluent in various applications will have important economical and environmental benefits.

Prof. dr. ir. Erik Meers

(e-mail): [email protected]

dr. ir. Evi Michels

(e-mail): [email protected]