Research On The Utilization Of Sintered Ceramsite For Algal Mud And Silt Resources

River and lake desilting project produced a large number of silt and blue algae mud has become the municipal departments need to solve the problem at the same time,desilting silt because of its own special mineral composition,can be used for resource utilization of sintered ceramsite cyanobacteria mud,on the other hand,due to its contain lots of organic components,as additive in the heart of the ceramsite mixture could replace the traditional inorganic hole agents,improves the performance of the haydite expansion This paper in view of the taihu lake cyanobacteria dredging silt and clay,system understanding of their physical and chemical properties,on the effective dehydration processing,adding correction components(calcium oxide kaolin and fly ash)to explore the best scheme for sintering ceramsite,while fully evaluating the environmental risks of sintering ceramsite.(1)The basic physical and chemical properties of the sludge and algal mud This work first carried out a detailed investigation on the water distribution of the sludge and algal mud.Among them,the free water interstitial water and the bound water in the sludge were about50%,and the free water interstitial water and the bound water in the 20%and 26%algal mud were about 27%,respectively.20%and 45%indicated that the dewatering difficulty of the sludge was significantly lower than that of algal mud.On the other hand,the composition of sludge and algal sludge was analyzed,especially the content of heavy metal elements and algal toxin in the sludge was investigated.The results showed that there were a lot of heavy metals of Cu,Zn,Cr and Pb in the sludge,and the leaching concentration had exceeded the national standard for heavy metal leaching of solid waste.In addition,the concentrations of Rr Yr and Lr in algal sludge were 4.92ug/kg 10.68ug/kg and 3.99ug/kg,respectively.(2)the silt mud efficient dehydration This work of silt and mud dehydration conditioner preprocessing,and then USES the plate and frame filter further removal water dewatering conditioner including the kinds of inorganic salts dewatering conditioner(aluminium chloride ferric sulfate polyaluminium chloride,etc.)and organic polymer dewatering conditioner(polyacrylamide gender carboxymethyl starch,etc.)The results showed that amphoteric carboxymethyl starch had the best dewatering effect,which could dehydrate about 45%and 38%of the sludge and algal sludge.At the same time,the water distribution of dehydrated sludge and algal sludge was investigated in detail.The results showed that amphoteric carboxymethyl starch could not only remove the free water of sludge and algal sludge to the greatest extent,but also promote the conversion of interstitial water and bound water into free water to be removed.(3)Sintered ceramsite This work uses dehydrated silt and algal mud,by adding correction components to sintered ceramsite by investigating the cylinder compressive strength of sintered ceramsite 24 h water absorption rate,total porosity and bulk density,etc.,to select the best scheme of ceramsite sintering at the same time to the best scheme of sintered ceramsite for environmental risk assessment.The results show that in the optimal sintering scheme,the addition amount of silt is 60%,the content of algal mud is 20%,and the addition amount of correction component is 20%(kaolin:fly ash:calcium oxide=2:2:1).The optimal compressive strength of the ceramsite was 2.85 MPa,the water absorption rate was 17.4%,and the bulk density was 352 kg/m~3.The quality of the ceramsite reached the standard of heavy metal leaching test stipulated by GB T 17431.1-2010 and the results of algal toxin leaching showed that the quality of the ceramsite met the national standard.To sum up,to remove silt and algae mud as the main raw materials,reasonable dehydration of building materials production of building ceramsite,has good social and economic benefits,which will greatly promote the rational use of resources,reduce the consumption of mineral resources hope that this paper on the production of ceramsite to provide new ideas.