垃圾填埋场隔离墙浆材防渗作用的研究

Research of impervious effect on isolation wall slurry for landfill site

为研制出一种低渗透系数并对垃圾填埋场渗滤液等污染物有一定吸附阻滞作用的浆材,用于垃圾场隔离墙防渗工程。通过正交试验优选出了以膨润土为主的浆材配合比:钙质膨润土20%～30%、水泥16%～28%、粉煤灰18%～24%、纯碱1.1%～1.5%、稀释剂FCLS加量0.30%～0.72%,余之为水。该浆材结石率>99.5%,固结体28 d渗透系数<0.96×10-7cm/s,无侧限抗压强度<2.1 MPa,浆材固结体对CODCr、BOD5、铵态氮和磷的吸附阻滞率达到了85%以上,对Hg、Pb等重金属离子阻滞率在99%以上。黏土基浆材通过渗滤沉积作用和吸附滞留作用,实现了对垃圾填埋场渗滤液中污染物阻滞能力的提高。

In order to develop one kind of slurry with low permeability coefficient and certain adsorption and block to pollutants in leachate,it was used in anti-seepage engineering of leachate for landfill site.Through the orthogonal experiment,the selected optimal formula of the slurry with a bentonite base were： bentonite 20%-30%, cement 16%-28%, fly ash 18%-24% ,Na2CO3 1.1%-1.5%, diluent FCLS 0.30%-0.72% ,and etcaeteras was water.This slurry had a concretion stone ratio of greater than 99.5% ,concretion body 28 day coefficient of permeability of less than 0.96 × 10^-7 cm/s, compressive strength of less than 2.1 MPa.The slurry concretion body＇s hindered CODc, BOD5,NH4-N and phosphorus adsorption block rates reached upper 85%, block rate reached upper 99% to Hg, Pb and other heavy metal ions.Through the infiltration sedimentation and adsorption fixation of clay base slurry material, the retardation capability of it was improved for pollutants of landfill site leachate.