Study On The Runoff Pollution Control By Waste Bricks

Bricks constitute a significant part of construction and demolition wastes.These bulky materials,if not reused or recycled,are mostly landfilled for disposal.The purpose of this study is to investigate the removal efficiency of waste bricks towards runoff pollutants in order to apply them as the filler layer in the sponge city infiltration facility,providing a new direction for recycling of the waste bricks and reducing the cost of the construction of sponge city.In this study,four typical architectural waste bricks were selected as adsorbents to examine their removal on pollutants normally appeared in runoff（i.e.,heavy metals and polycyclic hydrocarbons,pharmaceuticals and personal care product）.The adsorption behavior of four kinds of waste bricks and these pollutants was systematically studied.Then,one waste brick column experiment was carried out to investigate the hydraulic performance and pollutant removal effect.The main aspects which studied through the static experiments in this research were shows as following:（1）The adsorption behavior of heavy metal Zn on four different types of waste bricks were studied,respectively,and the results showed that the adsorption capacity was decreased as follows:cinder bricks>lime sand bricks>gray clay bricks>red bricks.And the adsorption kinetics and the adsorption isotherms of the Zn and on four waste brick materials were well fitted by pseudo-second-order model and Langmuir model,respectively.（2）The adsorption efficiency of four kinds of waste bricks on PPCPs and PAHs.A typical PPCP three chloronet,two typical PPCPs phenanthrene and pyrene were selected as target pollutants.The experimental results show that the adsorption of PPCPs and PAHs by four kinds of sorbents was different from that of heavy metals.The adsorption capacity was decreased as follows:red clay bricks>cinder bricks>lime sand bricks>gray clay bricks.And the adsorption kinetics and the adsorption isotherms of the Organic compound and on four waste brick materials were also well fitted by pseudo-second-order model and Langmuir model,respectively.Through the dynamic column experiment,we have mainly studied two aspects:（1）the hydraulic performance of red brick.The experimental results show that the permeability of red brick was good,and the permeability coefficient is about2.55×10^-3 m/s.If it is applied to sponge city infiltration facilities,it could meet the design target of total runoff and peak flow volume reduction.After the rainwater flows through the red brick filling layer,the pH slightly rises,and the effluent pH is relatively stable.This characteristic makes the red brick more suitable for the area with acid rain.（2）The pollution control effect of waste red clay bricks.It was found that in dynamic situations,red brick has better removal effect on Cu,Pb and Zn in heavy metals,while Cr removal is relatively weak.In addition,red brick has good removal effect on TN and TP.The commonly used bricks in the architecture tend to diversify.So the building waste bricks will be more diverse now and in the future.Therefore,the study on the adsorption of various kinds of architectural waste bricks to many kinds of pollutants will help to provide theoretical support for the practical application of waste bricks.