| At present, with the development of industry and the increases of population, the output of wastewater and sewage sludge has been increasing greatly. For the environmental protection, Treatment and disposal of the sludge has become a question of world in order to minimize its harm and to make effective use of it. The text study on the compost experiment in the laboratory, planting lawn and cottons combine together. Because there are a lot of nutrient and organic matter, the experiment will provide the theories and practice. There will be the important meaning for recycling the sewage sludge and protecting ecosystem environment. Main conclusions are as following: (1) The experiment indicated that adjusting C/N 24 was a good sludge composting condition, adjusting sewage sludge coal fly ash and the carbon source for 10:3:3 can receive a good composting result, coal fly ash can reduce active heavy metals, the aspergillus niger can abbreviate the time that getting the highest temperature, the result showed prominence, it can increase the speed quickly ,it can perish part of pathogens but can not die out completely (2) The sewage sludge composting exerted a good influence on the turf -grass growth .With the increases of the ratios of composting among 5%-10%, the over -ground biomass of turf -grass strongly raised , turf -grass' chlorophyll content get a raise. The lawn receive the better biological effect by using the composting as substrate . Compost promoted turf-grass to absorb the heavy metals But it did not hazard the lawn within the proportion 5%-10%. (3) The cotton received better biological effect :the living creature and the flowers are increasing with using more and more composting from 5% to 40% the over -ground biomass of the cotton strongly raised ,but the cotton is resisted when using more and more composting as substrate (4) Compost substrate had a clear effect on improving the physicochemical properties of substrate . The content of substrate organic matter increased remarkably and the value of pH reduced to be close to suitability to plant grown owing to applying compost. With the increasing amount of compost ,bulk density is decreased and field capacity is getting a raise. High -amount compost increased the salinity of the substrate .The high salinity of the substrate affected the germination and the growth of plants. When the soluble salt in compost was high ,it should be adopt somemeasures to reduce salt ,for example ,leach with water before seeding et al . composting from 5% to 10% is a good proportion for lawn but the proportion 10% is the best .All of the criterion of grass is the best .For cotton it is a appropriate proportion from 5% to 40% ,more composting result into destroy .?The composting provides fertilization for grass and cotton ,and it escape the food chain ,it can perish the hazard .the composting is able to replace much of fertilization . The method not only settles pollution but also organic manure of agriculture. Composting is becoming a more acceptable and economical method of treating sewage sludge. This paper offer new process and meantime for urban sludge composting ,the experiment have economic results and society benefits... |
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