基础工程废弃泥浆环境化学效应的实验研究

STUDY ON ENVIRONMENTAL CHENICAL EFFECTS OF WASTE DRILLING SLURRY IN FOUNDATION ENGINEERING

基础工程施工过程中会产生大量废弃泥浆,对水源、土壤和生物等造成了较大的危害。为定量评价废弃泥浆的环境化学效应,本文综合运用理论研究和实验分析等方法获取了废弃泥浆的基本性能、矿物组成和粒径级配;比较不同浓度废弃泥浆对土壤渗透性、保水性、理化性质等参数的影响;通过对废弃泥浆上清液浊度、重金属离子浓度、总盐度等参数进行测试,从电化学、浊度、离子成分等角度分析其对环境的影响,评价其环境化学危害性。结果表明:废弃泥浆会使土壤塑限减小,这一影响随时间推移而增大;当废弃泥浆浓度超过40%时,土壤的电导率、TDS、盐度和pH值均已不适于植物生长。而废弃泥浆上清液的重金属浓度、TDS和浊度均超环境容许排放上限,其中As浓度超出国标标准值18倍、Cd浓度超出20倍、Se浓度超出208倍,对生态环境污染风险较高。

A large amount of waste slurry will be produced during the construction of foundation works,which will cause great harm to water sources,soil and plants.In order to quantitatively evaluate the environmental effects of waste slurry,the basic properties,mineral composition and particle size grading of waste slurry are obtained by comprehensive experimental analysis and theoretical research;The effects of different concentrations of waste slurry on soil permeability,water retention,physical and chemical properties were compared;By testing the turbidity,heavy metal ion concentration,total salinity and other parameters of the waste slurry supernatant,the impact of the waste slurry supernatant on the environment is analyzed from the perspective of electrochemistry,turbidity,ion composition,etc.,and its environmental hazards are evaluated.The experimental results show that waste slurry will reduce the plastic limit of soil,which will increase with time.When the concentration of waste slurry exceeds 40%,the conductivity,TDS,salinity and pH of soil are not suitable for the growth of plants.However,the concentration of heavy metals,TDS and turbidity of the supernatant of the waste slurry exceed the upper limit of the allowable discharge of the environment.Among them,the concentration of As exceeds the national standard value by 18 times,the concentration of Cd exceeds 20 times,and the concentration of Se exceeds 208 times.Therefore,the risk of ecological environment pollution is high.