Biomineralization has become a research focus in wastewater treatment due to its much lower costs compared to traditional methods.However,the low sodium chloride(NaCl)-tolerance of bacteria limits applications to only...Biomineralization has become a research focus in wastewater treatment due to its much lower costs compared to traditional methods.However,the low sodium chloride(NaCl)-tolerance of bacteria limits applications to only water with low NaCl concentrations.Here,calcium ions in hypersaline wastewater(10%NaCl)were precipitated by free and immobilized Halovibrio mesolongii HMY2 bacteria and the differences between them were determined.The results show that calcium ions can be transformed into several types of calcium carbonate with a range of morphologies,abundant organic functional groups(C-H,C-O-C,C=O,etc),protein secondary structures(β-sheet,α-helix,3_(10)helix,andβ-turn),P=O and S-H indicated by P2p and S2p,and more negativeδ^(13)C_(PDB)(‰)values(-16.8‰to-18.4‰).The optimal conditions for the immobilized bacteria were determined by doing experiments with six factors and five levels and using response surface method.Under the action of two groups of immobilized bacteria prepared under the optimal conditions,by the 10^(th)day,Ca^(2+)ion precipitation ratios had increased to 79%-89%and 80%-88%with changes in magnesium ion cencentrations.Magnesium ions can significantly inhibit the calcium ion precipitation,and this inhibitory effect can be decreased under the action of immobilized bacteria.Minerals induced by immobilized bacteria always aggregated together,had higher contents of Mg,P,and S,lower stable carbon isotope values and less well-developed protein secondary structures.This study demonstrates an economic and eco-friendly method for recycling calcium ions in hypersaline wastewater,providing an easy step in the process of desalination.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41772095,42072136,41972108,42106144)the Natural Science Foundation of Shandong Province(Nos.ZR2019MD027,ZR2020QD089,ZR2021QE125)+4 种基金SDUST Research Fund(No.2015TDJH101)Scientific and Technological Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology(No.2016ASKJ13)Major Innovation Projects of Key R&D Program of Shandong Province(No.2019JZZY020808)the Foundation of SINOPEC(No.P20059-7)Innovation and Entrepreneurship Training program for College students(Nos.202110424157,202110424158)。
文摘Biomineralization has become a research focus in wastewater treatment due to its much lower costs compared to traditional methods.However,the low sodium chloride(NaCl)-tolerance of bacteria limits applications to only water with low NaCl concentrations.Here,calcium ions in hypersaline wastewater(10%NaCl)were precipitated by free and immobilized Halovibrio mesolongii HMY2 bacteria and the differences between them were determined.The results show that calcium ions can be transformed into several types of calcium carbonate with a range of morphologies,abundant organic functional groups(C-H,C-O-C,C=O,etc),protein secondary structures(β-sheet,α-helix,3_(10)helix,andβ-turn),P=O and S-H indicated by P2p and S2p,and more negativeδ^(13)C_(PDB)(‰)values(-16.8‰to-18.4‰).The optimal conditions for the immobilized bacteria were determined by doing experiments with six factors and five levels and using response surface method.Under the action of two groups of immobilized bacteria prepared under the optimal conditions,by the 10^(th)day,Ca^(2+)ion precipitation ratios had increased to 79%-89%and 80%-88%with changes in magnesium ion cencentrations.Magnesium ions can significantly inhibit the calcium ion precipitation,and this inhibitory effect can be decreased under the action of immobilized bacteria.Minerals induced by immobilized bacteria always aggregated together,had higher contents of Mg,P,and S,lower stable carbon isotope values and less well-developed protein secondary structures.This study demonstrates an economic and eco-friendly method for recycling calcium ions in hypersaline wastewater,providing an easy step in the process of desalination.
