The Research Of Heavy Metal Pollution On The Surrounding Environment Of Dabaoshan Polymetallic Sulfide Mining, North Guangdong Province

Guangdong Dabaoshan mine is one of large poly-metallic sulfide mines inchina. The mining area environment has been badly contaminated by heavy metalsfor a long time of exploitation. And affect the health of regional populations. In thispaper, the DaBaoshan Mine is as research objects. The present study carries fieldinvestigations and sampling around the mining area. Analysis of leachingexperiments and static immersion method were conducted to study the releaseproperties and transferring disciplinarian of heavy metals. And analysis the oxiderelease rule of heavy metal by oxidation kinetics experiment of mono-mineral. Andin this paper, the rice straw, the barnyard manure and the lime-stone complexes areas hybrid cladding, the techniques of handling for acid mine drainage by sulfatereducing bacteria was studied. The conclusions are as follows:（1）The leached amount of the heavy metals from soils was significantly smallerthan that from the mine tailings, but the leaching patterns were similar. At initial stage,the heavy metals leached out rapidly, but with the increasing time, the leached amountdecreased, and reached to a stable state at the time around100hours. The leachingrate of the heavy metals was in the order of Fe>Cu>Zn>Tl>Pb>Cd. The analysis ofannual leaching rates showed that under the action of natural precipitation, greatamount of heavy metals in the soils and mine tailings would leach to the local riversand underground water systems, and seriously endanger the local residents.（2）Depending on the static immersion test, we can get the following conclusions:The release of heavy metal ions in tailing is far more than the release of heavy metalions in soil. The release of heavy metal ions in solution which pH=2is far more thanthat in the other two solution. The releasing curves of heavy metal ions in twosamples are different. The heavy metal ions in soil release rapidly in the beginningand reach its maximum in ten days, then it gradually reduce. The concentration ofheavy metal ions in tailing increases gradually and remains stable finally. The stable release of toxic heavy metal TI is discovered both in soil and in tailing, and it can notbe effect virtually by acidic solution. And this fact needs special concern.（3）Pyrite, chalcopyrite and galena have happened kinetics of oxidation reactionin FeCl₃liquor under the condition of acid. The oxidation process of the three kindsof minerals is speeded up with increasing concentration of FeCl₃solution. Theoxidation rate of pyrite and chalcopyrite is increased with rising temperature ofreaction. But the oxidation rate of galena is constant almost with rising temperatureof reaction. The reaction rate from this study was conducted regression analysis bylog-log graph. Chalcopyrite oxidation rate was the fastest, and pyrite followed, andgalena was the slowest under the condition of the same oxidation reaction. And theoxidation of the three kings of minerals is controlled by surface reaction. Theoxidation of Fe（III） are much better than oxygen in the air for these single mineral.（4）There is a realistic low cost, low energy consumption in situ reactiveprocessing for the treatment of acid mine wastewater by sulfate reducing bacteria. Thelonger of hydraulic retention time, the higher of pH about waste water. It is declarethat HRT is good for the improvement of the acidic wastewater. The restore of SO₄^2-is the best effect when HRT is five days, and it is almost completely remove. And theheavy metal ion have different remove also, but the condition is complex. The removerate of Fe, Pb and Zn is better than Mn and Ni.