The Effects Of Aged Refuse On The Growth And Development Of Barley Seedlings And Zebrafish Embryos

With the rapid economic development of China’s economy and people’s living standards,the amount of municipal solid waste were quickly increased.In 2014,the urban garbage transport volume in China reached 1.786×108 t.Currently,there are three main ways in garbage treatment,including incineration,composting and sanitary landfill.Sanitary landfill are listed as the main approach in the world.Because the current suburban landfill capacity is saturated and the selection of new waste treatment plant site is more and more difficult,applications of waste landfill have been extremely limited.Therefore,sustainable landfill is the best way to solve those urgent problems and the utilization of aged refuse is the key method.The aged refuse is a type of waste which can be exploited.It refers to a class of stabilized soil material fresh garbage in the landfill after a long process of physical,chemical and biological effect.The utilization of aged refuse can increase existing landfill capacity and is benefit for achieving sustained dynamic landfill.It is mainly based on its good porous structure,huge specific surface area and relatively rich volume in microorganisms and nutrient content of N,P and K.However,due to the special procession of the aged refuse and mechanism of formation,it is inevitably for the aged refuse to contain some hazardous heavy metals and organic compounds.When utilizing the aged refuse,toxic and hazardous substances which are on its surface may enter the environment and do harmful to ecological environment and human health.Nowadays,there are few reports about the influence which utilizing the aged refuse to environment.In this study,we set Taiyuan Dongshan Xingou Sanitary Landfill mineralized refuse as the research object.Based on the analysis of its physical and chemical properties,we will inspect the effects of different particle size of the mineralized garbage and toxic make to the growth of barley and development in zebrafish embryos.Research findings indicates that:The particle size of aged refuse is uneven.In which,the larger particle size(diameter greater is larger than 150 p.m)of the aged refuse make a large amount,while the percentage of a smaller particle size(particle size is less than 105 μm)is less.The pH value decreased with the decrease of particle-size of the aged refuse,while electrical conductivity,CODCr,total salt amount and total nitrogen showed negative correlation with the particle-size.Through the aged refuse leachate contamination found on barley seedlings,the aged refuse inhibit the growth of barley seedlings.And it is also relevant to the particle size distribution.As the particle size decreases,the leachate of aged refuse on seed germination,seedling root length,shoot length,fresh weight and dry weight inhibitory effect is more obvious.Then,the 0 hpf and 24 hpf zebrafish embryos were exposed to aged refuse leachate,respectively,and we found that different size garbage can significantly inhibited the hatching and development of zebrafish embryos.At the same time,aged refuse lachate induced embryonic pericardial edema and spinal deformity with decreasing particle size and increasing toxicity.The results of 0 hpf and 24 hpf zebrafish embryos exposure experiments showed that,the aged refuse make strong toxic effects to embryos.In summary,we observed the significant variations in barley seedlings and zebrafish embryos in response to different sizes of the aged refuse leachate,including barley germination rate,root length,shoot length,fresh weight,dry weight and zebrafish embryos’ condensation rate,hatching rate,abnormality rate and changes in blood circulation.In this case,we explore the toxic effects of different particle sizes of the aged refuse and provide a theoretical basis for the utilization of the aged refuse.