Study On The Reutilization Of River Sediment-New Type Ceramisite Filter Media Development And Application

The dissertation can be divided into five parts: characteristics of river sediment, technique and mechanism of producing ceramisite filter media from river sediment, characters and structure of the production, transactions and characters of heavy metals during the sintering process and in the products, application study in wastewater treatment.Chemical contents, particle distribution, mineral contents and heavy metals in the river sediment from Shanghai Longhua Gang and Pengyuepu are determined. Results show that the chemical contents and particle distribution are like clay minerals, which provide possibility of reutilization. Heavy metals content in the river sediment and concentration in the leachate are very high but not reaching the level of hazard waste.Sewage sludge, Guangxi Baini and water glass are chosen to be the additives. Orthorhombic experiment to produce river sediment ceramisite is carried out to determine the technique conditions. Effect of sintering point, sewage sludge content and adherent content to the characters of ceramisite made from river sediment are found through experiment, which are specific surface area, bulk density, porosity, specific water absorption and particle density. Function of primary chemical contents in the sintering process, porosity formation mechanism and solid phase reaction are also analyzed.Performance of the ceramisite made from river sediment is tested and analyzed, which emphases on the measurement of specific surface area, crystallized materials, adsorption capacity, configuration of the porosity and leaching behavior of heavy metals in river sediment ceramisite. Results show that river sediment ceramisite can be fit for the requirements of biofilm carrier.In this dissertation, crystal structure is first used to clarify the configuration and structure of heavy metals in river sediment ceramisite. Heavy metals in the river sediment and sewage sludge are solidified in the ceramisite after high temperature sintering and a series of transaction. They are stabilized in the ceramisite and not easy to release to the environment again to arouse secondary pollution, which eliminate the apprehension during its application. And analysis of the performance of heavy metals in the product makes this clarified.Biological Aerated Filters (BAFs) with biofilm media of ceramisite made from river sediment, ceramisite for comparison, and paniculate Activate Carbon are designed to treat the simulated wastewater. When the inflow CODcr and NH3-N are 85.81mg/L~171.76mg/L and 7.28mg/L-37.04mg/L , the average efficiency is about 64.75% and 96.17% respectively. So it is feasible to be biofilm carrier in BAF for ceramisite made of river sediment.Effluent of Tianshan Sewage Treatment Works is also done by the three BAFs. NH3-N can be 1.0mg/L below and average efficiency of CODcr removal is about 46.60% after treatment, which enhance the efficiency of sewage treatment works to meet the effluent standards, and also the water reuse standards.