Experiment on the treatment of acid mine drainage with optimized biomedical stone particles by response surface methodology

Abstract

The immobilized particles were used to treat acid mine drainage (AMD) in the study, which owns the characteristics of serious pollution and high managing cost. The immobilized particles were prepared with sulfate reducing bacteria (SRB) and medical stones. In order to investigate the interactive influence of medical stones on the particle properties, the salt modification condition, content, and size of the medical stone were taken as the influential factors. At the same time, the removal rate of SO and Mn, the release of total irons (TFe) and chemical oxygen demand (COD) and pH value were taken as the response values in the experiment. On the basis of the orthogonal experimental research, a response surface model was established. The experimental analysis showed that the particles can get the best treatment effect, when using the salt-modified medical stone with the content of 15% and particle size of 200~300 mesh. At this time, the removal rates of Mn and SO in wastewater were 83.10 and 96.22%, respectively. The release contents of TFe and COD were 2.99 mg L and 1828.54 mg L, respectively, and the pH value was 7.05. Then, biological medical stone particles were prepared according to the optimal ratio in the response surface experiment. The adaptability of biomedical stone particles was studied at different concentrations of SO, Mn and pH value. The results showed that the high concentration of SO inhibited the metabolism of SRB, while Mn had a less effect. The biomedical stone particles could regulate pH value very well.

Study on treatment of acid mine drainage by nano zero-valent iron synergistic with SRB immobilized particles

“…It has been reported that SRB can convert sulfate into sulfide using organic matter under anaerobic conditions [35]. The results of previous studies [36] showed that in the immobilized particles filled with corn cob, SRB and salt-modified Wheat meal stone, the hydrolyzed products of corn cob could be used for SRB growth. When the removal area of SO 4 2is stable, the removal rate of the three kinds of particles has a small difference.…”

Experimental study on the treatment of AMD by SRB immobilized particles containing “active iron” system

“…According to the previous research method of Di Junzhen's research group [35][36][37], highactivity SRB immobilized particles were prepared. The production steps of highly active SRB immobilized particles were as follows.…”

Dynamic Experimental Study on Treatment of Acid Mine Drainage by Bacteria Supported in Natural Minerals

“…At the same time, the effluent ORP values of both Column 1 and Column 2 showed a trend of decreasing first and then increasing, and the average ORP values were −63.74 mV and −70.17 mV, respectively. On 1-7 days, the pH value increased rapidly, mainly due to the pH adjustment ability of medical stone [18] and the tight binding of ligands on the surface of bagasse to H 3 O + [11]. The rapid decrease of effluent ORP value at this stage was due to the reaction between AMD and SRB in the particles.…”

“…It has large surface area, more pores and strong cation exchange capacity, and has been widely used in wastewater treatment [15,16]. In addition, medical stone has a good bidirectional adjustment ability to the pH value in the aqueous solution, and it is capable of adsorbing and fixing metal ions [17,18]. Therefore, if medical stone is used as the filler of microbial immobilized particles, not only the activity of acid pH to SRB can be reduced, but also the metal ions in AMD can be removed by adsorption.…”