Impacts of applying treated wastewater from olive

mills on soil and plant growth

Regional Conference on "Sustainable Integrated Wastewater Treatment and Reuse" Sharm El Shaikh, Egypt

Dec 1-2, 2014

Munir J. M. Rusan Jordan University of Science and Technology Irbid - JORDAN

Goal & Objectives of MEDOLICO – The goal of MEDOLICO is to Prevent /reduce the environmental

risk presented by OMW on the Mediterranean Sea Basin

– The specific objectives of MEDOLICO are to:

1. Evaluate advanced techniques of OMW treatment

2. Valorize the by-products recovered from the OMW

3. Evaluate the phytotoxicity of the treated and untreated OMW

This is the objective of this study

This study is part of the activities of the EU funded project “MEDOLICO” MEDOLICO = Mediterranean Cooperation in the Treatment and Valorization of Olive Mill Wastewater (OMW)

• According to the ENPI CBC Mediterranean Sea Basin Program 2007-2013,

– 60% of urban wastewater still flows untreated into the Mediterranean,

– 48% of major coastal cities have no sewerage works and

– 50% of liquid industrial waste is not treated

– 30 MCM of OMW generated annually in the Mediterranean region. It is

evaporated as basic treatment method or just disposed in the areas surrounding

the olive Mills

Potential for contamination is real

Wastewater management is crucial for sustainability of MED environment

OMW:

• Is a liquid industrial ww from olive

oil extraction process

• Composed of large amounts organic

load that is mainly non-

biodegradable and has phytotoxic

properties due to their containing

polyphenols

• Imposes a great deal of impact on

environment & public health

• Polluting power=150 times MWW

OMW in Jordan Currently there are 130 olive mills

under operation

Generate 200,000 m3/year of OMW

It is prohibited to discharge OMW to

the sewage system or MWW trt plant

OMW is disposed to dumping sites or

illegally to the surrounding areas

without treatment, imposing real

threat to environ. & public health.

Challenges of OMW treatment Can not be treated in municipal ww treatment plants

Complexity & costs of treatment options are limiting factors

The majority of OMW treatment options are not commercially used

The most common and cheapest treatment option is lagooning (natural

evaporation), widely used in most Mediterranean countries. However, this is not

friendly to the environment .. Health… odor, gas emission … etc

Objective: The Objective of this study was to determine the phytotoxicity of untreated and

treated OMW by various technologies on plant growth and soil properties.

These technologies has been developed and evaluated within EU MEDOLICO

project

Photo-oxidation

JACTO Bioreactor

F

Microfiltration with RO or NF MF+NF MF+RO Photo

Oxidation JACTO

Bioreactor

OMW samples treated by different techniques

RAW 100% OMW

Treatments Code

Tap water Control

Tap water + Fertilizer W+F

Aerobic Biological Oxidation via JACTO Reactor JR

Solar Fenton Oxidation SFO

Microfiltration Nanofiltration MF+NF

Microfiltration Reverse Osmosis MF+RO

Undiluted Untreated Supernatant OMW 100%OMW

Greenhouse pot experiment was conducted to evaluate the following

treatments:

Major characteristics untreated and treated OMW

MF= Microfiltration; RO= Reverse osmosis; NF= Nano filtration; SF= Solar Fenton oxidation; JR= Jacto Reactor; EC= Electrical conductivity; TP= Total polyphenols; COD = Chemical oxygen demand; TSS = Total suspended solids; VSS = Volatilized suspended solids; BOD = Biological oxygen demand; DOC = Dissolve organic carbon; 1 dS/m = 1 mS/cm = 1000 µS/cm

Parameters Units W W+F* 100% OMW

JR SFO MF+NF MF+RO

pH initial - 7.80 7.80 4.7 6.19 2.02 1.8 4.50

pH adj - 7.80 7.80 6.0 6.00 6.00 6.0 6.00

EC dS m-1 0.56 0.56 7.6 5.30 1.50 11.4 0.12

TSS mg L-1 10 10 1236 362 310 378 12.0

TP mg L-1 0.98 0.98 1666 573 6 343 0.98

COD g L-1 ND ND 118.8 12.10 0.83 10.87 0.50

N mg L-1 11.7 11.7 96.8 68.6 10.0 33.6 4.4

P2O5 mg L-1 34.3 34.3 369.5 300.8 31.0 152 31.8

K2O mg l-1 11 11 2441 343 45 164 8

MF +RO

MF +NF

SFO JR 100% OMW

Greenhouse Pot experiment was conducted:

1. Crop = Corn

2. Five Kgs soil

3. Periodic irrigation up to the field capacity

4. After harvest plant growth parameters

and soil and plant samples were analyzed

physical and chemical properties

6. Soil characterized by being basic, alkaline

low in OM, N, P and micronutrients Soil Characteristics

pH 8.18

ECe (dS m-1) 0.61

CEC (cmol kg-1) 34.32

O.M (%) 0.72

N (%) 0.01

P (mg kg-1) 7.10

K (mg kg-1) 452

CaCO3 (%) 13.38

Fe (mg kg-1) 3.56

Mn (mg kg-1) 5.58

Zn (mg kg-1) 1.88

Cu (mg kg-1) 1.22

Bulk density (g cm3) 1.38

Texture Class Silty clay loam

Results

100

133

21

72

43 46

74

0

20

40

60

80

100

120

140

W W+F UOMW SFO JR MF+NF MF+RO

Re

lati

v to

co

ntr

ol,

%

Treatments

Dry weight, g pl-1

Relative to control (W) %

100 114

61

92

74

41

90

0

20

40

60

80

100

120

W W+F UOMW SFO JR MF+NF MF+RO

Re

lati

v to

co

ntr

ol,

%

Treatments

Plant hight, cm

Relative to control (W)%

b a c c d d e

b a b b d c c

Trts N P K

g plant-1 g plant-1 g plant-1

W 0.99 b 0.09 b 1.38 b

W+F 1.63 a 0.20 a 2.28 a

UOMW 0.24 c 0.03 d 0.32 e

SFO 0.76 bc 0.07 b 1.00 c

JR 0.39 bc 0.04 c 0.60 d

MF+NF 0.49 bc 0.06 c 0.65 d

MF+RO 0.72 bc 0.04 c 1.03 c

LSD0.05* 0.62 0.02 0.24

Nutrient uptake, g plant-1

Low nutrient uptake with OMW may lead to accumulation in the soil

Trts Fe Mn Zn Cu Cd Pb

mg pl-1 mg pl-1 mg pl-1 mg pl-1 mg pl-1 mg pl-1

W 3.68 a 1.86 0.39 0.02 0.06 0.18

W+F 4.12 a 1.96 0.74 0.16 0.03 0.15

UOMW 1.74 b 1.44 0.27 0.03 0.03 0.08

SFO 1.58 b 1.81 0.36 0.03 0.04 0.08

JR 1.44 b 1.62 0.21 0.03 0.03 0.12

MF+NF 1.92 b 1.91 0.44 0.02 0.03 0.09

MF+RO 1.09 b 1.83 0.25 0.02 0.03 0.17

LSD0.05 0.76 NS NS NS NS NS

Micronutrients and heavy metals uptake, mg plant-1

Bio MF+NF W+F MF+RO SFO

Treatments pH EC dS m-1

TP %

O.M %

Bulk density g cm-3

W 7.86 0.98 0.12 0.71 1.27 W+F 7.85 0.87 0.14 0.65 1.23 UOMW 7.70 5.88 16.55 2.10 1.07 SFO 7.73 2.51 0.07 0.79 1.27 JR 7.72 6.20 12.07 1.26 1.10

MF+NF 7.73 5.73 1.41 0.62 1.21 MF+RO 7.72 0.45 0.10 0.67 1.25

LSD0.05 0.12 0.81 2.08 0.23 0.13

Soil properties

Treatments N Olsen-P Exch- K

% mg kg-1 mg kg-1

W 0.09 8.83 e 631 d

W+F 0.09 34.63 c 624 d

UOMW 0.12 82.50 a 2926 a

SFO 0.10 18.80 de 582 d

JR 0.13 44.27 bc 2613 b

MF+NF 0.13 29.60 d 1548 c

MF+RO 0.11 12.83 e 588 d

LSD0.5 NS 14.14 315

Trts

DTPA- Zn

DTPA- Cu

DTPA- Fe

DTPA- Mn

DTPA- Cd

DTPA- Pb

mg kg-1

mg kg-1

mg kg-1

mg kg-1

mg kg-1

mg kg-1

W 1.88 1.49 1.50 c 1.10 c 0.11 0.40

W+F 1.84 1.32 1.56 c 1.30 c 0.08 0.51

ROMW 1.45 1.30 3.12 a 3.40 a 0.10 0.31

SFO 1.82 1.64 1.20 c 2.13 b 0.09 0.39

JR 1.43 1.47 2.94 a 2.73 b 0.12 0.38

MF+NF 1.66 1.44 2.07 b 2.57 b 0.11 0.29

MF+RO 1.77 1.52 1.28 c 2.21 b 0.09 0.30

LSD0.5 NS NS 0.60 0.71 NS NS

Infiltration Rate – at the beginning of the study

Infiltration Rate – at the end of the study

Conclusions:

Raw OMW did not prohibit plant growth but significantly reduced it Unlike in

germination test inn an earlier study),

OMW treated by MF-RO, MF-NF, SF, or JR resulted in good plant growth and

significantly reduced the phytotoxicity effect, thus can be used as a source of IW.

However, fertilizer should be added as a supplement as the effect on plant growth

was less than fertilized treatments and special management is required

Infiltration rate is much lower for untreated OMW, indicating negative impact on soil

structure, therefore, soils should be tilled properly to improve water infiltration and

permeability

OMW tend to increase the levels of salts, P, TP and OM, therefore, soil and plant

quality parameters should be evaluated periodically