07. Investigating the treatment of high dissolved organic water by using the combination of microorganisms - microalgae - biochar and Fe - Mn/AC nano material

Abstract

The technology of using microorganisms - microalgae biofilm in combination with nano-sized materials has been considered as an optimal technology for effective treatment of organically rich (polluted) water. This study isolated and cultured three strains of microalgae (Chlorella sp., Scenedesmus sp. and Spirulina sp.) and three strains of microorganisms (Bacillus sp., Aeromonas sp. and Pseudomonas sp.) which are capable in forming biofilms and treatment of high dissolved organic water. They were combined with the carrier as Fe - Mn/AC activated carbon nanomaterials to perform an experimental treatment model of water collected from the Bac Hung Hai irrigation system. The microalgae - microorganism mixture was enriched for 5 days and cultured in a medium containing the Fe - Mn/AC activated carbon nanomaterials for 3 days before using in the treatment model. After 6 days of experiment, formula CT4 with a mixture of wastewater, microalgae - microorganisms and Fe - Mn/AC activated carbon nanomaterials gave the highest treatment efficiency: BOD₅ decreased to 5.47 mg/L (42 %), total nitrogen and total phosphorus were 7.01 mg/L (75 % reduction) and 0.25 mg/L (63 % reduction), respectively. Treated water meets the national standards for water quality used for irrigation (QCVN 08-MT:2015/BTNMT - column B1). In addition to the high treatment efficiency, compared with the results of previous publications and in the optimal time (06 days), another advantage of this model is that there is no odor during the treatment process.