Optimization Research Of Mechanical Dewatering Of Sludge With High Pressure And Resource Usage

The amount wastewater treatment plants are rapidly increased due to the development, which increase the quantity of sludge. Traditional mechanical sludge dewatering is limited by technology and the defects of the filter itself, the moisture content of filter sludge after processing is still as high as80%above, and can’t meets the requirement of subsequent disposal. This experiment based on filter-pressing test by self-made constant pressure filtration device, optimization research the conditions of mechanical dewatering of sludge and explore the possibility of fabricate the Sludge-Biomass-Coal mixed fuel, make sure sludge disposal in meet the principle of reduction, harmless and finally realize resource utilization.Through filter-pressing test by self-made constant pressure filtration device to simulate the sludge mechanical dewatering, study the dehydration performance of the self-made device, and further study the influence of the filtration pressure, filtration time, and filter cloth on sludge dewatering effect. The research results show that the self-made constant pressure filtration device is better compare with the traditional sludge filter device, the moisture content decrease to75.30%after filter. The self-made device has higher filter efficiency, it can completed rapid dehydration stage in the process of pressure filtration dehydration in10min, its working filter pressure range from0-6MPa. The best optimal filter conditions of the self-made constant pressure filtration device are:3927type filter cloth,16aperture water hole, pressure2MPa,10min pressure time.Use the self-made device to study the influence of the inorganic salt conditioner and biomass conditioner for sludge dewatering effect. The research results show that the FeCl3is the best inorganic salt conditioner, the moisture content decrease to63.38%when adding3%FeCl3. Sawdust has the best effect in biomass conditioner, sludge with sawdust at the ratio of2:1mixture, the apparent and true moisture content of the filter-pressured sludge cake is43.83%and58.73%. When FeCl3and sawdust synergistic at the optimum conditions, the apparent and true moisture content of the filter-pressured sludge cake is39.16%and55.78%, the effect Superior to add only a single conditioner.Explore the possibility of fabricate the Sludge-Biomass-Coal mixed fuel, when sludge with sawdust at the ratio of2:1, adding3%FeCl3to making compound, mixture the compound with the coal at the ratio3:1to making mixed fuel, the heat value of the mixed fuel is17340J/g,77.62%of the coal’s heat value, reach the normal combustion standard, save coal and reduce air pollution, the Sludge-Biomass-Coal mixed fuel is feasible.