Systematic Study On The Rainwater Purification Effect Of Permeable Brick Paving

As a typical Low Impact Development?LID?technology,permeable brick pavement systems play an important role in both regulating runoff and reducing pollution.important role,has been more widely used.However,compared to other low-impact development techniques such as bioretention ponds and grassed trenches,permeable brick pavement decontamination is more difficult due to the lack of plant synergy.The performance is relatively poor,making the system practicality is reduced.In view of this,in order to further improve the permeable brick pavement decontamination effect,improve the practicality of the permeable brick pavement,the development of permeable brick pavement system on the A systematic study of the effects of stormwater runoff purification is necessary.First,static adsorption experiments with three permeable brick materials were conducted to investigate the adsorption of contaminants by the brick particle material,and then the Permeable brick dynamic pollutant abatement effect experiments to study the filtering effect of permeable bricks on pollutants,combined with static brick particle materials.Adsorption effect to investigate the decontamination mechanism of water-permeable brick.The results show that the permeable brick particle materials have different degrees of adsorption effect on TP,Cu,Zn,Pb;permeable brick materials will be The release of NH₄⁺-N,TN and COD?except for steel slag permeable brick?occurs to varying degrees.The physical retention of permeable brick plays a key role in the SS filtration process.Removal by filtration of SS.Permeable bricks do not filter as well as SS,TP and heavy metals for dissolved pollutants such as COD,NH₄⁺-N and TN.This is mainly due to two reasons:?1?soluble substances are difficult to be adsorbed and trapped by the brick;?2?there is also a release of contaminants from the brick material itself.Secondly,the external factors influencing the decontamination effect of permeable brick pavement were investigated to further explore the decontamination endowment and cleaning characteristics of permeable brick.The results show that the pollutant concentration has little effect on the removal effect of SS,TP,COD,Cu,Zn,Pb;and the effect on the The pollutants NH₄⁺-N and TN,which have a lower removal rate,have a greater influence.Rainfall intensity had little effect on the removal rates of SS,TP,Cu,Zn and Pb,while NH₄⁺-N,TN and COD had a greater effect on the removal rates of NH₄⁺-N,TN and COD.The removal rate decreases significantly with the increase in rainfall intensity.For permeable brick easy to remove the pollutants?SS,TP,Cu,Zn,Pb?in the cleaning process is not easily washed out,difficult to The removed contaminants?COD,TN,NH₄⁺-N?are easily flushed out during the cleaning process.Thirdly,in view of the relatively poor decontamination effect of permeable brick pavement grassroots,a new type of frame grassroots permeable brick pavement was introduced,and Assessment of the feasibility of the frame subgrade as a permeable brick pavement base.The results show that the 3-5 mm crushed stone frame substrate is slightly inferior to the permeable concrete block substrate in terms of contaminant removal,but has a lower water discharge than the cement concrete block substrate.The lower the pH value,the lower the surface water quality standard can be met.The better the removal of contaminants,the more effective the 3-15 mm graded gravel and the 3-5 mm grained small gravel are at cleaning.Replacement of zeolite,volcanic rock and iron filings has the potential to further improve the quality of the effluent.Frame substrates are easy to apply and have the advantage of reducing the alkaline environment of the effluent by reducing the particle size of the filler or replacing it with a functional filler.To further improve the quality of the water,Therefore,the"well"frame structure is feasible as the permeable brick paving base.Fourthly,by changing the type of filler in the frame substrate,the role and mechanism of different fillers in the removal of contaminants will be revealed,and the fillers will be determined.Decontamination efficiency is enhanced to further clarify the feasibility of framing substrates.The results show that the permeable brick pavement with different filler frames has higher removal rates of SS and TP,and.The chemisorption of rich in Ca²⁺,Mg²⁺,Al³⁺,Fe²⁺and Fe³⁺fillers is also an effective way to remove phosphorus,and zeolite is more effective for NH₄⁺-N.rich in Fe₂O₃ of volcanic rocks and cinder have a good effect on COD,and the iron chips can effectively reduce NO₃^--N.The adsorption effect,different filler grass-roots permeable brick pavement on the runoff of heavy metals Cu,Zn,Pb has a better removal effect,but Overall removal effect is good.During the 120min simulated initial rainwater filtration process,the potential of the system to degrade dissolved pollution decreased slightly.The overall operation of the filler layer was stable and pollution control and improvement was obvious.In the later stage,the system could be maintained and maintained by replacing the internal filler.Finally,for permeable tile pavement surface permeable tiles easily clogged,as well as the lack of targeted restoration measures to ceramic permeable tiles for The object of study is to investigate the clogging law and mechanism of permeable brick in the process of rainwater infiltration,and to explore the different recovery methods on its water permeability.Effect.The results show that the permeability coefficient of permeable bricks shows an exponential decay trend with the increase in the volume of clogging solution;clogging mainly occurs in the permeable bricks'Within the upper layer?1.0 cm?,where the 0.5-1.0 mm pore size is most affected by the clogging process;the permeable brick has the greatest impact on the large and small The diameter of the particles are all trapped to some extent.High-pressure washing as the main one or a combination of cleaning processes to recover better;high-pressure washing operating conditions show that the wet condition or Washing after the rain recovery effect is better;in the case of clogging is not serious,increase the frequency of cleaning,a reasonable increase in the length of cleaning can achieve better The recovery effect.The study can provide effective technical support for the application and maintenance of permeable brick paving...