Ecology, Environment and Conservation Paper

ECOLOGICAL RISK ASSESSMENT TO OLIVE OIL MILL WASTEWATER (OMW) WITH BIOASSAY ON PLANT SPECIES

Mohammad Reza Massoudinejad1, Kamyar Arman and Ehsan Aghayani

Abstract

Phytotoxicity can be determined as seed germination, root elongation, and seedling growth. Olive oil mill wastewater (OMW) is one of the most polluted food industrial wastewaters. Results of this study showed that load pollution of OMW with reference to COD (36240 mg/L) is 70 times and phenolic compounds concentration (299 mg/L) is 1000 times more than municipal wastewaters. The aim of this study is to assess the effects of OMW application as irrigation water on in vitro germination. The germination assay was conducted with a radish, cress and tomato seeds. Germination of all seeds was obtained for a dilution of Control=0%, T1=0.1%, T2=1%, T3=10%, T4=25%, T5=50%, T6=100% OMW. Non-diluted sample of OMW completely blocked the germination of almost all seeds (radishes, cress and tomato seeds). The addition of raw OMW at high concentrations (over 25% OMW) blocked in vitro seed germination and with increasing concentrations of 0.1% to 25% OMW, vitro seed germination reduced strongly. The great toxicity of the OMW observed in an in vitro experiment. According to results of wastewater toxicity assessment in OMW, risks of untreated wastewater discharge to ecosystems and its toxicity effects on different plant species were confirmed.