The Research Of Mechanism And Effect On Dredger Fill Improved By Industrial And Agricultural Waste

With the rapid development of economic and social, the contradiction between humanand land growing increase in tianjin region, large area of coastal reclamation epeirogenicarises at the historic moment. However, the quality of dredger fill in Tianjin Binhai area isill-structured, heavy, high salinity and poor permeability, it is difficult for landscaping. At thesame time, the regional environmental requirements become more and more strict, and thedisposal of solid waste has caused the attention of people. In order to solve these two aspectsof the problems, this article through the way of adding industrial and agricultural waste intothe dredger fill and adopts the physico-chemistry method to improve the dredger fill bydesalination content simulation experiments. According to the results of single factorexperiments by small soil columns to define the appropriate mix proportions, then the doublefactors mixed experiments by big soil columns was carried out for the study and analysis ofthe mechanism and effect. Combined with all the soil column experimental results,theyshowed that:1.The best volume ratio by adding chaff alone is between10%and20%, the physicalmethods improved the permeability of dredger fill significantly, increased the soil porosity,improved the penetration rate, at the end, the pH of leaching solution is up to9.0around, theconductivity drop rapidly in the first40h.2.The best mass ratio by adding desulfurization gypsum alone is between1%and2%,improved through chemical methods can change the physical and chemical properties of soil,reduce the salt ions in soil structure, and have a significant effect on inhibition of the soilsalinization. Eventually,the pH of leaching solution only up to7.8, the conductivity declinedrapidly in the first30h.3.The mixed adding of treatment3with (desulfurization gypsum1%+wheat20%) in soilcolumn experiment is the best, the improvement of the dredger fill accelerate the wetting peakdramatically,only use14hours can reach the bottom of40cm soil column, the infiltration rateof it is18times of control. The wet peak of control column is very slow, because theexpansive of soil results the stagnation of eluting.4.Analysis the conductivity and soluble of the leaching solution based on the mixedadding soil column experiment, the whole desalination process is characterized by threephases: rapid desalting, slow desalting and basically stable, the leaching efficiency in earlyphase is extremely high, so salt-leaching in early phase with high pressure water will have avery good effect. All the process, the pH of leaching solution in each treatments are abouteight, in treatment3, the linear fitting relationship between soluble y(g/L) and conductivityx(ms/cm) is: y=0.9212x-0.743(R=0.9984).5.At the end of the leaching, the leaching efficiency of total salt in the column soil is over 90%, the Na+and Cl-in the soil is as high as98%, CO32-,HCO3-,SO42-a slight increase, belowthe allowable range of the plant growth, the pH value of the soil in soil column was between7.5~7.7, it prevented the phenomenon of salinization effectively.6.The consumption of total water of treatment3is4460mL, the desalination process justused54h, soil and water ratio is1:1.42, the leaching solution volume in per unit time showeda trend of decreasing after first increase. Perennial ryegrass pot experiment on the improvedsoil, the growth condition is good, the improved soil can meet the basic needs of theherbaceous plant growth.