Page 18 - Volume 3, Issue 1, January 2010

1

Laboratory of Pesticides Toxicology, Department of

Pesticides Control & Phytopharmacy, Benaki Phy-

topathological Institute, 7 Ekalis Str., GR-145 61 Kifis-

sia (Athens), Greece

2

Department of Pharmacognosy and Natural Products

Chemistry, Faculty of Pharmacy, University of Athens,

Panepistimiopolis of Zografou, GR-157 71 Zografou

(Athens), Greece

Corresponding author:

k.machera@bpi.gr

Hellenic Plant Protection Journal

3:

17-24, 2010

Acute toxicity of Olive Mill Wastewater on rats,

Vibrio fischeri

and

Artemia fransiscana

A. Charistou

1

, K. Kyriakopoulou

1

, P. Anastasiadou

1

, N. Fokialakis

2

, A.L. Skaltsounis

2

and K. Machera

1

Summary

Although the annual quantity of wastewater generated by olive oil mills in the Mediterra-

nean basin is 10-12x10

6

m

3

, it is only recently that solutions for proper management of Olive Mill Waste-

water (OMW) are under serious consideration. The common practice for handling such liquid by-prod-

ucts has been the deposition in oxidation tanks/ponds. No special attention is paid to the polluting po-

tential of OMW or the intrinsic toxicity of the mixture to aquatic organisms. The acute toxicity of OMW

produced in a three-phase olive mill on the island of Crete, Greece, was tested on Wistar rats and on

two marine species, the photobacterium

Vibrio fischeri

(Microtox® assay) and the crustacean

Artemia

fransiscana

. The acute toxicity to the aquatic organisms was also determined for the treated OMW (fol-

lowing a pilot scale treatment system developed in the frames of the EU LIFE-Environment program

MINOS) and the isolated polyphenol mixtures. The untreated OMW exhibited low acute oral toxici-

ty on rats but high toxicity on the photobacterium

V. fischeri

and the crustacean

A. fransiscanα

. Treat-

ment of OMW led to the production of wastewater of lower toxicity to the photobacterium

V. fischeri

(eight-fold reduction following one-cycle treatment and about twenty-fold reduction following two-

cycle treatment). On the contrary, the above mentioned treatment of OMW had no effect on the ex-

hibited toxicity against the crustacean

A. fransiscana

. The polyphenolic fraction isolated from OMW, on

the other hand, exhibited high toxicity on the photobacterium

V. fischeri

but low toxicity on the crus-

tacean

A. fransiscanα.

Therefore, further study is needed on the OMW management before its deposi-

tion into the environmental system.

Additional Keywords:

aquatic organisms, environment, Microtox

®

, pollution, polyphenols

result, the annual yield of Olive Mill Waste-

water (OMW) in the Mediterranean basin is

about 10-12x10

6

m

3

, withmore than 2x10

6

m

3

of this quantity being produced in Greece.

For the management of OMW the common

practice is its deposition in oxidation tanks/

ponds, regardless of the fact that OMW con-

tains macromolecules, such as polysaccha-

rides, lipids, proteins as well as a number

of aromatic molecules referred to as phe-

nolic compounds. The polluting potential

of OMW is 100-fold greater than that asso-

ciated with urban wastes attributable to its

high organic load and its extremely high

volume (20). Additionally, the organic con-

tent of OMW, mainly due to the presence of

polyphenolic compounds, has a great anti-

microbial and phytotoxic effect, which sup-

press the activity of the microorganisms in-

volved in the biodegradation. Therefore,

Introduction

The annual world production of olive oil is

more than 2 million tones, and more than

80% of this quantity is produced in Spain, It-

aly and Greece. In Greece, olive cultivation

is placed among the major crops and olive

groves cover an area of about 7,371 km

2

(13).

In most cases the production of olive oil is

made by the centrifugation method, which

results in the generation of 5 m

3

wastewa-

ter per tone of olive oil produced (4, 8). As a