Dynamic experiments of acid mine drainage with Rhodopseudomonas spheroides activated lignite immobilized sulfate-reducing bacteria particles treatment

Abstract

Aiming at the problem that the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB) biological method is susceptible to pH, metal ions, sulfate and carbon source. Lignite immobilized SRB particles (SRB-LP) and Rhodopseudomonas spheroides (R. spheroides) activated lignite immobilized SRB particles (R-SRB-LP) were prepared using microbial immobilization technology with SRB, R. spheroides and lignite as the main substrates. The dynamic experimental columns 1# and 2# were constructed with SRB-LP and R-SRB-LP as fillers, respectively, to investigate the dynamic repair effect of SRB-LP and R-SRB-LP on AMD. The mechanism of AMD treated with R-L-SRB particles was analyzed by scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectrometer and low-temperature nitrogen adsorption. The result showed that the combination of R. spheroides and lignite could continuously provide carbon source for SRB, so that the highest removal rates of SO42−, Cu2+ and Zn2+ in AMD by R-SRB-LP were 93.97%, 98.52% and 94.42%, respectively, and the highest pH value was 7.60. The dynamic repair effect of R-SRB-LP on AMD was significantly better than that of SRB-LP. The characterization results indicated that after R-SRB-LP reaction, the functional groups of −OH and large benzene ring structure in lignite were broken, the lignite structure was destroyed, and the specific surface area was 1.58 times larger than before reaction. It illustrated that R. spheroides provided carbon source for SRB by degrading lignite. The strong SRB activity in R-SRB-LP, SRB can co-treat AMD with lignite, so that the dynamic treatment effect of R-SRB-LP on AMD is significantly better than that of SRB-LP.

Composition of the microbial community in surface flow-constructed wetlands for wastewater treatment

“…As indicated in Table 2 , a pH decrease was noted at the start of the experiment, particularly in CW2. Throughout the experiment, the continuous pH decrease in CW2 is linked to the presence of lignite, known for its pH-lowering effect due to its limited negative charge, reducing the removal action of H+ ions ( Di et al, 2022 ). The pH value from CW3 provides additional evidence supporting the pH decline observed in CW1 and CW2, attributed to the presence of lignite.…”

Remediation of Acid Mine Drainage in the Haizhou Open-Pit Mine through Coal-Gangue-Loaded SRB Experiments

“…A completely randomized design was used to explore the influence of five factors, namely, the type of coal gangue (1-4# CG), the dosage of coal gangue (20, 30, 40, 50 and .36 E) was taken as the seed mud, and the SRB was anaerobically cultured using Starkey medium [25,28]. SRB, after separation and purification, was used in this study.…”

“…Xianjun Wang et al [27] showed that SRB can effectively remove SO 4 2− in AMD and improve the pH value of AMD. Junzhen Di et al [28] showed that SRB can efficiently repair AMD pollution and metabolize SO 4 2− to form metal sulfide precipitation. However, SRB is sensitive to the environmental pH value and concentration of heavy metal ions [29].…”

“…(b) Cultured SRB samples. SRB: The wet mud from the lower part of the coal gangue hill in the Haizhou openpit mine (42 • 0 9.90 N, 121 • 41 12.36 E) was taken as the seed mud, and the SRB was anaerobically cultured using Starkey medium[25,28]. SRB, after separation and purification, was used in this study.…”