Preliminary Research On The Technology Of Composting Green Waste As The Substrate Of Green Roof

At present, based on scientific research which vegetation can absorb the particle in the air and reduce the heat island effect. However modern cities have so many skyscrapers that have no more ground to plant vegetation. The best plan which not only improving the rate of afforestation but also no occupying any land is green roof.One of the key conditions about green roof is culture substrate. The problems lie on domestic substrate are lack of categories、high cost、exploiting the poor、unstable property、unrenewable resource and so on. According to above defects,this experiment screened the organic waste from industrial and agricultural,and investigated composting plant located in hangzhou jinxiu scenic spots 、sewage treatment plant in zutuan town、pig farm in xiaoshan, then determining the proper waste. By adjusting the parameters of high temperature aerobic compost, makingthe compost experiences three periods: warming、hyperthermy、maturity. ultimately the compost turn into horticultural production. Mixing the horticultural production with perlite、coal cinder、plant ash in different proportions, the different mixing regards as the substrate of green roof.In order to assess the affects of the substrate,utilizing spss software to figure out the results. Then obtaining the best substrate. The experiment gets the main achievements as follows:(1)Due to the different volume of compost and material, leading to different parameter scope. In this experiment, getting the parameter: the volume of compost= 100L、C/N=25、water=60%、air quantity=200~300L/H、the time of aeration=10min(on) 50min(off) circulation、the grain of compost<1cm2,after 40 days, the compost is mature.(2)Mixing the garden waste、tea slag、pig manure as the ratio 4:3:6 in 28 days.After the compost is mature,comparing the effect of compost、turf、soil that regard as substrate.Comparing the growth of green vegetable seeds for the two weeks,The results show that the compost is better than turf as green roof substrate.(3)Mixing the garden waste、sludge as the ratio 6:5 in 41 days.Then mixing the mature compost、perlite、coal cinder、plant ash in different proportion so that can get different substrates for sedum lineare. Finally comparing the effect of all substrates. The result is that mature compost: perlite=5:1 is best. The indicator including the length of leaf and branch、the width of leaf、net weight is better than others obviously.To industrialize the green roof,the cost control is one of the most significant conditions. Utilizing the organic waste as the substrate of green roof has two meanings: First, making full use of organic waste can obtain the low cost and stable substrate. Second, disposing the organic waste and reducing the use of unrenewable resource, protecting the ecosystem. The social and economy benefit can not be ignored.