Application of bioflocculant-producing bacteria, heterotrophic nitrogen-removal bacteria, poly-phosphate bacteria and water-hyacinth (Eichhornia crassipes) for wastewater treatment of MyTho rice-noodle factories, Tien Giang province, Vietnam

Abstract

Rice-noodle wastewater represents a serious problem regarding environmental degradation and human health protection. The aim of the study was to create the application of bioflocculant-producing bacteria, heterotrophic nitrogen-removal bacteria, poly-phosphate bacteria and water hyacinth (Eichhornia crassipes) for wastewater treatment of My Tho rice noodle factories, Tien Giang province, Vietnam in order to get an insight into number of entities that discharge polluted water into environment. An experiment was carried out with containers havingdifferentcapacitiesfrom 100-mL, 1-L, 10-L, 100-L and 1000-L and 3 replications to select best strains of bioflocculant-producing bacteria, heterotrophic nitrogen bacteria, poly-P bacteria and water-hyacinth for removing toxic element to wastewater before releasing to river/canal. Application of two bioflocculant-producing bacterial strains PO.01.C and PRO.03.B (protein and polysaccharide) into rice-noodle wastewater, aeration in 3 hours, held on 21 hours, supernatant moved to other container, adding heterotrophic nitrogen removal bacterial strain and poly-P. strain 064.B, aeration 8 hr/24hr during 7 days and wastewaters were transferred other containers containing water-hyacinth (Eichhornia crassipes) in 2 days, the results recorded that pH of wastewater increased from 4.68 to 6.13, TSS and BOD5 concentration of wastewater reduced from 369 and 1200 mg/L to 17 and 23 mg/L, respectively. TKN and TP decreased from 45 and 6.3 mg/L to 7.57 and 4.56 mg/L, respectively. All targets reached to 40/2011 standard / Ministry of Natural Resource and Environment of Viet nam.