Evaluation of lemna minor and cyanobacteria effect in aerated and non-aerated conditions on biological oxygen demand (BOD),dissolved chemical oxygen (COD),total coliform and faecal coliform of municipal and industrial wastewater

ABSTRACT

Water scarcity and its growing demand, especially in arid and semi-arid countries, put a lot of pressure on water resources and with the increasing limitation of water resources, the use of wastewater is considered as an unconventional water source and the only sustainable source of water for irrigation of agricultural products. In this study, the performance of Lemna minor and filamentous cyanobacteria in the treatment of two types of industrial and municipal effluents were investigated separately. The experiment was performed as a factorial experiment in a randomised complete block design with three replications. The experiment was performed as a factorial experiment in a randomised complete block design with three replications. The highest reduction for BOD and COD factors was observed in the presence of lemna minor, and cyanobacteria showed a more favourable effect on total coliform factor, while both treatments could not reduce the total coliforms to the desired level and it seems that they need time or complementary methods for optimal treatment and reuse in nature. It is worth noting that the lemna minor was very successful in reducing faecal coliform and reduced it to 100% in the first five days. In general, lemna minor was more successful than cyanobacteria. It seems that cyanobacteria need more time for optimal results because the best results of cyanobacteria occurred in a period of 10 to 15 days.

KEYWORDS:

• BOD
• COD
• cyanobacteria
• lemna minor
• wastewater

Disclosure statement

No potential conflict of interest was reported by the author(s).