Characteristics of the main polluting trace elements in the water environment of mining subsidence p

Available online at www.sciencedirect.comJOURNAL OF CHINAUNVERSITYOFScienceDirectMINING &TECHNOLOGYELSEVIERJ China Univ Mining & Technol 18 (2008) 0362 0367www.elsevier.com/locate/jcumtCharacteristics of the main polluting trace elements in thewater environment of mining subsidence poolsYAO En-qin', GUI He-rong'2'Department of Resources and Engineering. Anhui University of Science and Technology, Huainan, Anhui 23200, China2Suzhou College, Suzhou, Anhui 234000, ChinaAbstract: Mining subsidence pools are water bodies formed by soil subsidence near mines. We studied the impact the surroundingcoal production activities and power plants have on these waters by measuring the concentrations of harmful trace elements in thesewaters. The concentration of the four clements F, Hg, Se and As increased by 0.92%, 0.78%, 0.70% and 0.81%, respectively, in theDatong mining subsidence pool from November 2004 to November 2006. The four clements increased by 1.58%， 1.23%, 1.08%and 0.92%, respectively, in the Xie' er mining subsidence pool and 1.16%， 1.06%， 1 .02% and 1.01%, respectively, in the Pansanmining subsidence poolver the same tume Pperiod. The absolute levels of F, Hg, Se and As in the pool are related to the backgroundlevels of the elements. A close relationship between nearby coal mines and power plants and increasing levels of the measuredelements is noted.Key words: mining subsidence pool; trace elements; coal mine; water environment1 Introductioncoal mining subsidence pools was based on theserviceable life of the coal mines located next to theSubsidence pools from coal mining are commonpools. The Datong mine was founded in 1921 andenvironmental hazards, which can destroy vegetationabandoned in 1980. The Datong mining subsidenceand human structures. The pools also can influencepool, located to the east of Huainan near the Datongsurface or ground water. The result is a seriouslymine, has a history of around 60 years. Since coaldegraded environment in the area of the mines.mining has ceased the subsidence pool has beenMining subsidence generally occurs in low-lyingstable and it is no longer sinking. It is isolated waterareas that have relative high groundwater levels. Theunconnected to surface flows. The flooded area is 2.4subsidence area may be in the form of basin seepers,hm' with a maximum depth of 8-10 m. The Xie'erwhich ,generally are permanent pools, or seasonalmining subsidence pool, with a history more than 30pools'". The recent, growing concemn for environ-years long, lies to the west of the Xie er mine. Themental protection has resulted in initial restorationXie'er subsidence pool began its collapse in the lateprojects that address subsidence basins and have met1960's. Now it has formed a pool with an area of 14with some success. By study of the water collcted inhm' and a maximum depth of 7 m. Because of watersubsidence zones some idea of the local air pollutantsrecharging from the Huaihe River the subsidencemay be obtained. So, by analyzing trace elements inareas are continuing their subsidence now. Athe pool water we may infer the effect local miningperennial coal gangue hill, with an area of 500 m',and power plant operations have on the environment.lies to the north of the Xie' er subsidence pool.The Pansan mine subsidence pool lies to the north2 An overview of mining subsidence poolsof Huainan city near the Pansan coal mine and thePansan coal preparation plant. With a total area ofand their surroundings1000 hm', it is 100 m wide and 200 m long. TheHuainan is a center for coal extraction as well as adepth is 2-3 m. The subsidence area of the Pansancenter for thermal power generation. The selection ofpool is verv laree. Since the Nihe River forms the中国煤化工Received 10 August 2007; accepted 05 January 2008Projects 070414168 supported by the Provincial University National Natural Science FYHCN M H Go Koy NaouscsnFoundation of Anhui ProvinceCorresponding author. Tel: +86 S54-13155402501; E-mail adress: pfyiao@ 163.comYAO En-qin ctalCharacteristics of the main polluting trace elements in the363northem border of the pool, pool conditions arecity: The Luohe power plant, the Tjia' an power plantgreatly affected by the water level of the Nihe. Theand the Pingwei power plant. The Luohe power plantsubsidence is recent; Trees and telephone poles caris to the east of Huainan, the Tianjia' an power plant isstill be seen in the pool. The pool is mostlyto the central east of Huainan and the Pingwei powersurrounded by farmlands although there are severalplant is to the north (These Huainan coal mines,residential buildings nearby, within 1000 m of thepower plants and subsidence pools are shown in Fig.pool. There are three large power plants in Huainan).务|angermineSA N Pansan minin. Pansubsidencc poolPansan mir; Pingweipower plamyssower planty