Microbial flocculant produced by a novel Paenibacillus sp., strain A9, using food processing wastewater to replace fermentation medium and its application for the removal of Pb(II) from aqueous solution

Abstract

Due to high production costs, the popularization and application of microbial flocculants in the field of water treatment have been limited. In this study, the capture of lead ions by the fermentation broth of a novel Paenibacillus sp. strain A9 and cultured with food wastewater was further investigated. The results revealed that the production of MBFA9 could be increased significantly by adding a small amount of carbon and nitrogen to food wastewater. Under the best experimental conditions (pH 8.5, culture temperature 30°C, 150 r/min), adding 1% (m/v) carbon and 0.1% (m/v) nitrogen to 1% (v/v) wastewater resulted in a yield of MBFA9 of 6.29 g/l. At a temperature of 30°C, pH of 5, contact time of 35 min, and FBA9 dosage of 5%, the removal rate and removal capacity of Pb(II) reached the highest values of 95.1% and 317 mg/g, respectively. Field emission scanning electron microscopy analysis indicated that bacterial cells, metabolite small molecule acids, and MBFA9 in FBA9 all contributed to the removal of Pb(II). Fourier-transform infrared spectrometry analysis indicated that functional groups such as –OH, –COOH, –CO, and –NH2 existed in MBFA9 and on the cell surface. Various mechanisms involved in Pb(II) removal can occur simultaneously, including cell surface adsorption, microcrystallization, and biological flocculation.

Bio-mediated detoxification of heavy metal contaminated soil and phytotoxicity reduction using novel strain of Brevundimonas vancanneytii SMA3

“…To mitigate charging effects, observations were conducted at an exceedingly low kV, assisted by a charge compensator. When utilizing EDX, samples were immediately checked with a FESEM and a 20.00 kV EHT accelerating voltage for the presence or absence of elements [ 44 ].…”

Raoultella ornithinolytica as a Potential Candidate for Bioremediation of Heavy Metal from Contaminated Environments

“…Subsequently, the dried samples were sputter-coated with gold for 120 s at 22 kV [ 35 ]. Samples were then scanned by FE-SEM and EDS, with the accelerating voltage applied at 15 kV for FE-SEM and 20 kV for EDS images [ 36 ].…”

Preparation, Performances, and Mechanisms of Microbial Flocculants for Wastewater Treatment

“…The use of yeast extract, glucose, and so on in the process of laboratory culture is too large and the cost is too high, which is not conducive to mass production and application. Wastewater, food wastewater, and other wastewater are complex components, which can provide energy for microorganisms while reducing the content of organic matter and nitrogen in wastewater [57,161], given the difference of the contents of the different wastewaters. The reasonable ratio of different wastewater can effectively reduce the external energy, and in the process of building a cheap medium, the water purification effect can be better [162].…”