| The utilization of solid waste resources has important significance to reduce environmental pollution.The development of scale and industrialization of the aquaculture industry has increased the production of eggshells and livestock manure,However,the environmental burden become heavier due to the difficulty in disposal of eggshells and livestock manure.Cr,Cu,Zn,As and other heavy metal residue problems have become the key problems of restricting the use of pig manure in China.China has the enormous output of eggs and pig manure production in the world,how to make full use of these two kinds of resources is of great significance for our environmental protection career.In this paper,we discussed with the two kinds of waste resource characteristics and combined them together and utilized.The pig manure is used as an example to achieve the effect of waste management waste.The main research contents and results are as follows:1.To study the processing technology,we choose to use 900?calcined eggshells as adsorbent.When the usage was 2.5%,the removal rate of the four kinds of heavy metals in the solution are at least90%,the removal rate is higher than zeolite,bentonite,kaolin and other adsorbents,in order to expanded production mode,we choose to use the kiln to calcining the eggshell,the removal effect of heavy metal is the same as the calcined eggshell in laboratory.It was found that add 2.5%calcined eggshell has good effect in removal heavy metal in piggery wastewater.The eggshell structure and morphology were characterized using SEM,TG-DSC,XRD,FT-IR,the results indicated that the calcination can increase the eggshell porosity and surface area,after calcined the composition of eggshell was found to be mainly CaO and CaCO3.The mechanism of adsorption of eggshell is mainly due to its high calcium carbonate composition and multilayer microporous structure.2.The study on the digestion effect of different digestion systems on pig manure.We choose the HNO3-HCl-HF as the digestion system.The recovery rate of Cr,Cu,Zn,As was 102.4%,103.7%,102.1%,101.6%.The detection limits of Cr,Cu,Zn,As by ICP-OES were respectively 1.3?g/g,0.5?g/g,2.6?g/g and 7.8?g/g with a precision of between 2.2%-3.2%.The recovery rate of Cr,Cu,Zn,As was between 91.7%-108.9%.However,ICP-MS has a lower detection,the detection limits of Cr,Cu,Zn,As by ICP-MS were respectively 0.19?g/g,0.07?g/g,0.37?g/g,0.09?g/g with a precision of between2.0%-10.6%.The recovery rate of Cr,Cu,Zn,As was between 95.0%-112.5%.Results of recovery experiment showed that the method is suitable for the detection of Cr,Cu,Zn,As in pig manure by using ICP-OES and ICP-MS.3.The study on the passivation effect of eggshell on heavy metal,the passivation effect of 5%on Cr,Cu,Zn and As was the best.The correlation analysis of the physical and chemical properties of compost was carried out,and it was found that adding processing eggshell had no obvious effect on the root of pig manure.During the composting process,the total heavy metal was increased,when the addition amount of 2.5%and 5%,Cu and Zn content compared with contrast blank treatment with significant difference?P<0.05?,therefore,add the processing eggshell have certain influence to changes over the total heavy metal processing,but different elements performance is not the same.Distribute the Cr,Cu,Zn,and As characteristic of heavy metal species,the inactivating of Cr,Cu,Zn,and As could be enhanced by adding processing of eggshell.Add processing eggshell can be reduced to its biological availability,When the usage amount of processing of the eggshell was 5%,the study showed that the processing of eggshell shape variation of heavy metals in the composting process has a significant difference?P<0.05?.Acid extractable and reducible are theaffluent to be used part of heavy metal fraction.To sum the distribution ratio of the two forms was decreased by 7.7%,46.7%,53.0%and 13.5%.The analysis of shows that add5%?w/w?processing eggshell the effect of Cr,Cu,Zn,As passivation is the better. |
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