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

Abstract

In order to solve the problem of pollution of acid mine drainage (AMD), such as low pH value and being rich in SO42−, Fe and Mn pollution ions, etc., immobilized particles were prepared by using sugar cane-refining waste (bagasse), a natural composite mineral (called medical stone in China) and sulfate-reducing bacteria (SRB) as substrate materials, based on microbial immobilization technology. Medical stone is a kind of composite mineral with absorbability, non-toxicity and biological activity. The adsorption capacity of medical stone is different according to its geographic origins. Two dynamic columns were constructed with Column 1 filled by Fuxin’s medical stone-enhanced SRB immobilized particles, and Column 2 filled by Dengfeng’s medical stone-enhanced SRB immobilized particles as fillers. The treatment effect on AMD with SRB-immobilized particles enhanced by medical stone from different areas was compared. Results showed that Column 2 had better treatment effect on AMD. The average effluent pH value of Column 2 was 6.98, the average oxidation reduction potential (ORP) value was −70.17 mV, the average removal percentages of SO42−, Fe2+ and Mn2+ were 70.13%, 83.82% and 59.43%, respectively, and the average chemical oxygen demand (COD) emission was 555.48 mg/L.

Study on the Effectiveness of Sulfate-Reducing Bacteria Combined with Coal Gangue in Repairing Acid Mine Drainage Containing Fe and Mn

“…SRB: in order to improve the repair effect of SRB-combined coal gangue, wet mud at the foot of gangue piles of Haizhou open-pit mine in Fuxin City was taken as seed mud. According to the enrichment and culture method of SRB, the seed mud was inoculated into the sterilized Starkey medium for anaerobic culture [25]. When H 2 S and black precipitate appear, SRB is cultured [26].…”

“…Then the SRB with strong activity was enriched. Among them, the main components of the Starkey medium are: 0.5 g Na 2 SO 4 , 1.0 g NH 4 Cl, 0.5 g K 2 HPO 4 , 0.1 g CaCl 2 •H 2 O, 2.0 g MgSO 4 •7H 2 O, 1.2 g (NH 4 ) 2 Fe(SO 4 ) 2 •6H 2 O, 0.1 g ascorbic acid, 4.0 mL sodium lactate solution, 1.0 g yeast extract, 1 L distilled water, pH = 7.0, sterilized at 121 • C for 30 min [25].…”

Applications of Electrokinetic Remediation inEnvironmental Restoration

“…AMD bacteria can be cost effective alternative to chemical compounds, which can be used to lower pH of the ferric phosphorus sludge to recover iron and phosphorus. The effluent, in case of addition of chemical compounds, contains high concentration of undesirable by-products that would complicate and interfere with the subsequence processes [20,21]. Moreover, the high cost of the traditional chemical compounds makes the whole process uneconomical.…”

“…In this technique optimum sulfur reducing bacteria (SRB) should be used coupled with electrokinetics to recover phosphorous, iron, and sulphur. Iron will be transported by electromigration and accumulated at the cathode, while sulfur will be recovered from the anode compartment [19,20,21]. Figure 4 shows electrokinetic voltage controller (EKVC) device, which was designed and manufactured to switch the electric potential between the two electric circuits such that at any given time there is only one electric current running through either electric circuit in the electrokinetic cell.…”

Loading Performance of a Novel Shearer Drum Applied to Thin Coal Seams

“…Coal is an important, globally relevant energy source to support industrial production and development and mining it safely and efficiently has been studied extensively [1,2]. As the key equipment in the longwall mining coalface, the shearer's cutting and traction performance has been investigated [3,4].…”