كاهش بارآلودگي رواناب هاي شهري با استفاده ار بتن متخلخل جاذب

چكيده انگليسي :

Abstract Impermeable urban passages have led to many problems that leads to flooded street during rainfall and this can make traffic more difficult for pedestrians and cars Hence in order to do better management of surface runoff in cities various ways are used to make pavement surface of streets permeable Since surface runoff can be used to recharge groundwater and maintain the ecological balance in urban areas nowadays application of porous pavement technique in urban passages attraks much attentions in many countries This method is effective in removing a fraction of pollutant from runoff and consequently leads to water quality improvement which will percolate in the lower soil layers In addition due to the fact that urban runoff pollution enters a significant volume of contamination into water resources a number of studies have been done in this field The use of different absorbent and also porous pavement concrete have considerable contribution in urban runoff pollution reduction The purpose of this research is to study the effect of cheap and available porous concrete and absorbent urban runoff pollution reduction Therefore zeolite adsorbent and slag are used in under study concrete samples Firstly porous concrete samples control concrete and porous concrete containing slag and zeolite adsorbent were made Metal and glass column were constructed in the dimension of 152 152 700 mm Within each column filled with layers of sand filters aggregation and each of the three types of porous concrete Experiments were performed in five separated series Water quality parameters such as electrical conductivity EC turbidity lead heavy metal chemical oxygen demand COD and total suspended solid TSS were examined In each case the solution enters from the top of the column and the output sample collected from the bottom of the column in 2 steps concrete concrete and filter and were taken to the laboratory for analysis The results showed none of the 3 types of porous concrete control zeolite slag can reduce the electrical conductivity of saline water and the percent of removal of this case are not considerable However the concrete showed significant influence in reduction of four other parameters So that on average turbidity of runoff in the sample input reached from the 64 NTU to 23 NTU in the output water from the porous concrete containing adsorbent and 5 NTU in both of the absorbing concrete and filter that its removal efficiency was over 90 Heavy metal concentration reduction showed desirable performance so that initial concentration 2 mg L in input water samples was reached to about 0 2 mg L in output water samples In other words the removal efficiency was 90 Better result and the high efficiency 96 was observed in use of filters Lead concentration varied from 2 to 5 The highest removal is related to porous concrete containing zeolite and filter In this term the concentration of 5 mg L in input water sample was reached to 0 125 mg L in output water samples that was equal to 97 5 Use of porous concrete containing zeolite was also effective in runoff chemical oxygen demand COD reduction and have 60 89 removal efficiency that in the case of application of filter its efficiency has been increased to 74 The use of concrete as well as filter to reduce total suspended solid TSS has desired efficiency about 70 Keywords Urban runoff Porous concrete Treatment Pollution Zeolite PDF created with pdfFactory trial version www pdffactory com

سقائيان نژاد، سهيلا

كاهش بارآلودگي رواناب هاي شهري با استفاده ار بتن متخلخل جاذب

تصفيه آلودگي , زئوليت