ADSORPTION OF FECAL ADSORPTION OF FECAL COLIFORMS, COLIFORMS, ESCHERICHIA ESCHERICHIA

COLICOLI IN DIFFERENT SOILS IN IN DIFFERENT SOILS IN

SARAWAKSARAWAK

Ling Teck Yee, Goh Soon Hian and Ling Teck Yee, Goh Soon Hian and Kasing ApunKasing Apun

Faculty of Resource Science & Faculty of Resource Science & TechnologyTechnology

University Malaysia SarawakUniversity Malaysia Sarawak94300 Kota Samarahan94300 Kota Samarahan

INTRODUCTION INTRODUCTION

• animal waste is a potential source of animal waste is a potential source of bacteria pathogensbacteria pathogens

• microbial contamination occurs microbial contamination occurs through animal wastewater discharge through animal wastewater discharge & lagoon effluent& lagoon effluent

• adsorption of adsorption of E. coliE. coli in soil depends in soil depends on organism surface, soil particles & on organism surface, soil particles & medium medium

• microbial adsorption in soil increased microbial adsorption in soil increased with clay content & organic matterwith clay content & organic matter

INTRODUCTION INTRODUCTION

• microbial adsorption in soil increased microbial adsorption in soil increased with clay content with clay content (Ling et al., 2002; (Ling et al., 2002; Weaver et al., 1978) &Weaver et al., 1978) & organic matter organic matter (Marshall, 1971)(Marshall, 1971)

• Both solid waste and lagoon effluent Both solid waste and lagoon effluent application on land are viable options application on land are viable options for animal waste management for animal waste management

• soils that are not capable of soils that are not capable of adsorbing fecal bacteria can be adsorbing fecal bacteria can be avoided as waste disposal sitesavoided as waste disposal sites

OBJECTIVES OBJECTIVES

• to determine the adsorption kinetics to determine the adsorption kinetics of of E. coliE. coli in a soil‑water system in a soil‑water system

• to compare the adsorption of to compare the adsorption of E. coliE. coli in three different types of soilsin three different types of soils

MATERIALS & METHODSMATERIALS & METHODSSoils Collection & AnalysisSoils Collection & Analysis• 3 different soils collected around 3 different soils collected around

KuchingKuching• particle size analysis by Pipette method, particle size analysis by Pipette method,

Soil pH by pH meter, total organic Soil pH by pH meter, total organic matter by Loss-on-ignition method matter by Loss-on-ignition method

Bacteria Isolation & IdentificationBacteria Isolation & Identification• E. coliE. coli isolated from fresh farm isolated from fresh farm

wastewater wastewater • Gram test & API 20E diagnostic kitGram test & API 20E diagnostic kit

MATERIALS & METHODSMATERIALS & METHODSAdsorption KineticsAdsorption Kinetics• 6 ml of adjusted initial bacteria 6 ml of adjusted initial bacteria

concentration (10concentration (1066 cfu/ml) was added cfu/ml) was added to 6 g of soilto 6 g of soil

• sampling at 0, 5, 15, 30, 60 & 120 sampling at 0, 5, 15, 30, 60 & 120 minutesminutes

Batch AdsorptionBatch Adsorption• using different initial bacteria using different initial bacteria

concentrations from 10concentrations from 1022 to 10 to 101111 cfu/mlcfu/ml

Table 1. Physical & chemical characteristics of the 3 different soils

used in the study

Soil Clay

(%)

Fine Silt

(%)

Med. Silt

(%)

Coarse Silt

(%)

Sand

(%)

Organic Matter (%)

pH

Clay Loam

35.2 10.2 17.6 8.4 28.6 15.5 4.5

Silt Loam

18.6 8.3 47.7 13.0 12.4 13.3 5.7

Sandy Loam

6.8 3.6 19.1 11.5 59.0 7.3 3.8

RESULTS & DISCUSSIONRESULTS & DISCUSSION• sorption equilibrium of sorption equilibrium of E. coliE. coli

between water & soil achieved between water & soil achieved immediately in 2 stepsimmediately in 2 steps

• percent sorption increased with percent sorption increased with initial bacteria concentrations at initial bacteria concentrations at low bacteria concentrations low bacteria concentrations

• bacteria uptake over 99% at high bacteria uptake over 99% at high bacteria concentrationsbacteria concentrations

• soils with higher clay & organic soils with higher clay & organic matter has significantly higher matter has significantly higher adsorption capacityadsorption capacity

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

0 20 40 60 80 100 120

Time (Min)

Co

nc

en

tra

tio

n in

su

sp

en

sio

n

(cfu

/ml)

Clay Loam Silt Loam Sandy Loam

Figure 1. E. coli depletion from 3 soils for 120 mins, initial bacteria

concentrations of 4.50 x 106cfu/ml

0

20

40

60

80

100

120

0 2 4 6 8 10 12 14Initial Concentration (log cfu/ml)

Perc

ent A

dsor

bed

(%)

Clay Loam Silt loam Sandy loam

Figure 2. Percent of E. coli adsorbed with different initial concentrations in

the 3 soils

RESULTS & DISCUSSIONRESULTS & DISCUSSION• significantly higher bacterial significantly higher bacterial

adsorption than Commerce clay loam adsorption than Commerce clay loam & San Angelo sandy clay loam & San Angelo sandy clay loam (Ling (Ling et al., 2002; Weaver et al., 1978) et al., 2002; Weaver et al., 1978)

• Daniels (1980),Daniels (1980), optimum adsorption optimum adsorption of bacterial to soil particles of bacterial to soil particles generally occurs in low pH generally occurs in low pH conditionsconditions

• Hattori (1970),Hattori (1970), bacteria-clay bacteria-clay complex is more stable in acidic complex is more stable in acidic conditionsconditions

CONCLUSION CONCLUSION

• sorption equilibrium of sorption equilibrium of E. coli E. coli was was immediateimmediate

• high high E. coliE. coli removal in soil systems removal in soil systems• effectiveness of bacteria removal is effectiveness of bacteria removal is

dependent on bacteria concentration dependent on bacteria concentration • soil with higher clay & organic matter soil with higher clay & organic matter

content has higher capacity for content has higher capacity for adsorbing adsorbing E. coliE. coli

ACKNOWLEDGEMENTACKNOWLEDGEMENT

The authors are grateful to The authors are grateful to University Malaysia Sarawak University Malaysia Sarawak for providing the research for providing the research

grant (No.249/01)grant (No.249/01)