Co-immobilization ofPseudomonas stutzeriYHA-13 andAlcaligenessp. ZGED-12 with polyvinyl alcohol–alginate for removal of nitrogen and phosphorus from synthetic wastewater

Abstract

Nitrogen (N) and phosphorus (P) are the two main factors causing water eutrophication. Immobilized micro-organisms have been widely studied in N and P removal. However, the effects of various immobilizing conditions on the removal efficiency of N and P using immobilized micro-organism beads (IMOBs) remain unclear. Polyvinyl alcohol (PVA) and alginate, as the two frequently immobilizing-used matrixes, were used for co-immobilizing Pseudomonas stutzeri YHA-13 and Alcaligenes sp. ZGED-12. PVA, alginate and CaCl₂contents, immobilization time and different wet biomass ratios of P. stutzeri to Alcaligenes sp. were conducted to elucidate their roles in and influences on the removal efficiency of N and P from synthetic wastewater. The application potential of IMOBs was estimated as well. Results showed that IMOBs prepared by cross-link of 4% PVA and 2-3% alginate with 5% CaCl₂and saturated boric acid solution for 10-15 min are the best ones in removal of N and P. Though IMOBs containing P. stutzeri and/or Alcaligenes sp. were capable of removal of the two nutrients, the highest removal efficiency was observed when the wet biomass ratio of P. stutzeri to Alcaligenes sp. was adjusted to 2:2. In addition, the IMOBs were of good ability to remove chemical oxygen demand (COD), NO(3)(-), NO(2)(-), NH(4)(+)- N, total nitrogen (TN) and total phosphorus (TP) from artificial wastewater. Of which, micro-organisms immobilized in matrixes were mainly responsible for NO(3)(-) and TP removal. Therefore, P. stutzeri YHA-13 and Alcaligenes sp. ZGED-12 are reliable bioresources to remove N and P from wastewater.

Enrichment of Denitrifying Bacterial Community Using Nitrite as an Electron Acceptor for Nitrogen Removal from Wastewater

“…In addition, the predominant genus, Pseudomonas, increased to 56.13%, and Dechloromonas was present at a ratio of 5.19% after enrichment of the denitrifying bacterial community using nitrite as an electron acceptor. These bacteria were proved to be associated with the process of denitrifying phosphorus removal [45][46][47]. Previous studies reported that short-chain fatty acids (SCFAs) play an important role in biological phosphorus removal [48,49].…”

Characterization of Aerobic Denitrifying Bacterium Pseudomonas mendocina Strain GL6 and Its Potential Application in Wastewater Treatment Plant Effluent

“…If the carbon source is insufficient, its nitrogen removal efficiency will decrease. To date, there have been many aerobic denitrifying bacteria isolated from the ecosystems, such as Pseudomonas stutzeri strain T1 [9], Vibrio diabolicus SF16 [10], Pseudomonas stutzeri YHA-13 [11], and Enterobacter cloacae strain HNR [12]. However, the literature describing the isolation of aerobic denitrifiers from constructed wetlands is quite limited.…”

Efficient phosphate accumulation in the newly isolated Acinetobacter junii strain LH4

“…Phosphorus (P) is an abundant element in the lithosphere and is essential for all living organisms (Liu et al 2016). In aquatic systems, however, excessive P input can result in eutrophication, leading to harmful algal blooms that impact fish growth and animal and human health (Ascott et al 2016;Han et al 2014). P-induced eutrophication has been frequently reported and has attracted widespread concern.…”

“…P-induced eutrophication has been frequently reported and has attracted widespread concern. When the P concentration exceeds 0.1 mg L −1 and the total P (TP) content is much lower than that of total nitrogen (TN), indicating P limitation (i.e., TN:TP > 15:1), eutrophication occurs (Han et al 2014). In addition to eutrophicationtriggered deterioration of water quality, phosphate (PO 4 3− ) deposition is prevented by eutrophication, thereby reducing fertilizer production and global food security (Pantano et al 2017).…”

“…To enhance its effectiveness for Nand P-removal, denitrifying and PO 4 3− -accumulating organisms (PAOs) are often applied in the floating-bed system (Li et al 2011). To date, several bacteria capable of efficient P accumulation have been reported, such as Accumulibacter (Acevedo et al 2012;Tu and Schuler 2013), Acinetobacter (Hrenovic et al 2010), Alcaligenes (Han et al 2014;Joo et al 2006), Alphaproteobacteria (Nguyen et al 2012), Dechloromonas (Tu and Schuler 2013), Defluviicoccus (Tu and Schuler 2013), and Tetrasphaera (Tu and Schuler 2013). Because PAOs can accumulate abundant PO 4 3− under aerobic conditions and transfer poly-PO 4 3− to ATP under anaerobic conditions to assist in the synthesis of polyhydroxyalkanoates, a growing number of studies have tried to use these bacteria to promote simultaneous removal of volatile fatty acids and P from wastewater (Yu and Li 2015).…”