摘要
粤北大宝山铁铜多金属矿床的尾矿富含硫化物矿物,在化学和生物氧化作用下,产生pH<5的酸性矿山废水(AMD).本文对大宝山槽对坑、铁龙AMD的10个采样点的表层沉积物进行物相和微观形貌分析,测定水样和表层沉积物中Pb、Cu、Mn、Cr等重金属离子的含量,讨论pH与次生矿物对重金属元素在水-表层沉积物分布差异的影响.结果表明:AMD的表层沉积物的次生矿物主要由铁、锰的氢氧化物、铁矾类矿物、羟氧硫铅矿和偏砷酸氢铁矿组成,其中含铁次生矿物具有一定的空间演化特征.水-表层沉积物的重金属浓度空间分布差异主要受pH和次生矿物组合控制.水的重金属含量总体是随着pH的降低而增大,且Pb、Cu、Mn具有显著相关性.羟氧硫铅矿是Pb的主要沉淀方式;水钠锰矿的析出沉淀影响Mn、Pb、Cu的沉降率;水铁矿、针铁矿、施威特曼石控制低pH环境中Cu的沉降行为;针铁矿、黄钾铁矾、施威特曼石是水溶液中Cr的强力清除剂.
The chemical and biological oxidations of tailings,which are rich of sulfide minerals,at Dabaoshan iron-copper polymetallic deposit produced acid mine drainages（AMD） with pH5.Microscopic morphologies of the surface sediments collected from 10 sampling sites were investigated,and concentrations of heavy metals such as Pb,Cu,Mn,Cr in the water and sediment samples were determined.The effects of pH and secondary minerals on the distribution of heavy metals in the water-surface sediment were then discussed.The results show that the dominant secondary minerals in the AMD surface sediments were iron-manganese hydroxides,iron sulfates,sidpietersite and kaatialite.The iron-bearing secondary minerals were characterized by a spatial evolution.The spatial distribution of heavy metal in water-surface sediments was mainly influenced by pH and secondary mineral assemblages.The concentrations of heavy metals in water increased with the decrease of pH.Pb,Cu and Mn in water had significant correlation with each other.The main precipitation form of Pb was sidpietersite.The deposition of Mn,Pb and Cu was influenced by the formation of binessite.The sedimentation behavior of Cu in low-pH environment was controlled by ferrihydrite,goethite and schwertmannite.Goethite,jarosite,and schwertmannite were powerful scavengers of Cr in aqueous solutions.
出处
《环境科学学报》
CAS
CSCD
北大核心
2018年第1期133-141,共9页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.41373079)~~
关键词
酸性矿山废水
沉积物
重金属
次生矿物
acid mine drainage
sediment
heavy metals
secondary mineral
