【作者】 李淑展；

【导师】 施周；

【作者基本信息】 湖南大学 ， 市政工程， 2007， 博士

【摘要】 本文参照普通陶瓷砖的生产工艺,利用城市污水处理厂脱水污泥为原料烧制了污泥陶质地砖试块。通过对烧后试件抗压性能检测及其主要影响因素分析,探讨了利用城市污水厂脱水污泥烧制室外用地砖的可能性,确定了污泥制地砖的基本工艺流程和配方参数。研究表明:烧制试件的抗压强度随着污泥含量增加而显著下降,适宜的坯料配方为高岭土:污泥粉:长石粉=4:1:2。采用细颗粒污泥配料（粒径小于0.15mm）,烧后试件较致密,有利于抗压强度的增加。成型条件对污泥制地砖烧后试件抗压强度存在较大影响,抗压强度随所试含水率、压制压强的增加而增加,适宜的含水率和压强范围为9%～15%和24MPa～45MPa。2h保温可以保障坯料充分发生物理化学反应。采用三层复合材料结构可提高烧制成品的抗压强度,优于单一材料结构:底层采用细颗粒污泥配料的复合结构烧后试件抗压强度达到27.38MPa,底层采用粗颗粒污泥配料的复合结构烧后试件抗压强度达23.70MPa,分别满足《烧结普通砖强度等级（GB5101-93）》中MU25和MU20的强度等级。通过城市污水厂脱水污泥制砖烧后试件抗折强度检测及影响因素分析,进一步探讨和确定污泥制地砖适宜的配方配料和工艺参数。在此基础上,通过成分分析、吸水率、抗压强度、抗折强度、抗磨损性、抗腐蚀性等性能检测,对其性能进行全面评估,并通过浸出液腐蚀性、重金属固化作用检测,检测其对环境的影响。研究表明:优选的坯料含水率为11%,烧结温度为1200℃。随污泥含量增加虽然烧制成品的抗折强度略有增加但抗压强度显著下降,适宜的污泥掺量为14.3%。细粒径污泥粉配料烧后试件较致密,有利于提高试件整体强度。14.3%污泥掺量下,采用细颗粒（粒径小于0.15mm）和粗颗粒（粒径为0.15～0.63mm）污泥配料烧后试件的抗压强度分别满足烧结普通砖强度等级中MU30号和MU20砖强度等级;污泥制砖的抗折强度远大于粘土砖的强度指标。通过烧结,污泥制地砖坯料的矿物组成发生了巨大变化。烧后试件属于陶质砖范围,抗磨损性能优于普通砖,满足陶质砖的耐化学腐蚀性要求。这种砖的水浸出液pH值都在6.4～6.9之间,不具有腐蚀性能。研究发现,烧制对污泥中的重金属Mn﹑Cu有明显的固化作用。通过渗透试验,探讨了城市污水厂污泥制作复合土作为卫生填埋场防渗衬层材料的可行性,研究表明:最佳污泥掺入量为40%,抗渗透性能随复合土干密度增加而增强。在最佳掺量下,当干密度达到1.08 g/cm3,复合土的渗透系数达到10-7cm/s数量级,符合垃圾填埋场防渗衬层标准要求。渗滤液性质对渗透性能存在较大影响,当电解质浓度较大时,复合土渗透性能随之提高。此外,污泥复合土可以有效吸附去除垃圾渗滤液中的重金属Cu²⁺、Zn²⁺。进行了向城市污水厂脱水污泥同高岭土复合料中添加土壤固化酶TZ的防渗实验研究。研究表明:TZ酶的加入对污泥复合土的最佳含水率影响不大,均在20%左右。添加土壤固化酶能够显著改善污泥复合土初期抗渗透性能。在最佳酶掺入量0.4mL/10kg土,300kPa压实压强下,24h后污泥填埋土垂直渗透系数比不加酶的减小36%,达到10-7 cm/s数量级,满足垃圾填埋场防渗衬层材料标准。总言之,城市污水厂脱水污泥制造陶质地砖和填埋场防渗衬层材料具有可行性。更多还原

【Abstract】 Refer to processes of common ceramic tile production, outdoor ground tiles made from dehydrated wastewater treatment sludge were produced on bench scale, and the feasibility was explored through measuring their compressive strength and evaluating main strength influencing factors. The results showed that the compressive strength of the sintered tiles decreased as the sludge contents increased, and the optimum recipe was suggested as kaolin: sludge: feldspar powder = 4:1:2. It was found that tiles made from sludge with fine particles (diameter is less than 0.15mm) were denser and its compressive strength was greater than the tiles made from sludge with coarse particles (diameter is between 0.15mm and 0.63mm). Molding condition of had great influence on compressive strength of sintered tiles whose compressive strength increased as the water content and shape-forming pressure increased. Suitable water content and shape-forming pressure ranged 9%-15% and 24MPa-45MPa, respectively, holding 2h to benefit fully physicochemical reaction of stock was suggested. Further, the sandwich structure was better than single structure in enhance tile’s compressive strength: the compressive strength of tiles with the sandwich structure and final particle sludge was 27.38MPa while the strength of tiles with the sandwich structure and coarse particle sludge was 23.70MP. The strength of the two kinds of tiles respectively meet the strength grade of MU25 and MU20 in“Sintered Brick Strength Grade(GB5101-93)”.The flexural strength and influencing factors were tested to further explore and confirm the component recipe and processing parameter of the sludge tiles. The composition analysis, water absorption, compressive strength, flexural strength, abrasion-resistance strength, corrosion resistance were examined to comprehensively evaluate the nature of sludge tiles. Corrosiveness of leaching liquid from the tile and the efficiency of heavy metal sealing in the tiles were also tested to estimate the environmental impacts if applied practically. The results showed that the optimum water content and sintered temperature were 11% and 1200℃, respectively. With the sludge content increased, the compressive strength of the sludge-tile dropped rapidly though flexural strength increased slightly, the optimum sludge content was proposed as 14.3%. The tiles made from fine particle sludge were denser and overall nature was better than that made from coarse particle sludge, indicating decrease of the sludge particle size could enhance the strength of tiles. With the 14.3% sludge content, the compressive strength of tiles made of fine particle sludge and coarse particle sludge meet the strength grade of MU30 and MU20, respectively. The flexural strength of the sludge tiles was much greater than that of common bricks. The mineral compositions of tiles body were greatly changed after sintering. The sintered tiles can be classified as clay-pottery, and it was found that abrasion-resistance property of the sludge tiles was better than common bricks and the tiles could meet the requirements to resistant chemical attack. The leaching liquid from sludge tiles was almost no corrosive for it’s pH varied between 6.4 and 6.9, and the heavy metals Cu and Mn containing in sludge could be well sealed up in the tiles.Anti-permeate experiments had been performed to evaluate the possibility of using urban sewage sludge to substitute the compound clay as the major constituent for liner material in waste landfill. It was found that anti-permeability could strengthen with the dry density increasing, and the optimal content of the sludge was 40%. At the optimal content and 1.08 g/cm3 dry density, the permeating coefficient of compound clay reaches 10-7cm/s level which meets the criterion of liner material in waste landfill. The property of permeating liquid could greatly affect the permeating coefficient of the sludge liner, the permeating coefficient of the liner increased with as the concentration of electrolyte increased. The sludge liner clay could also absorb its bearing Cu2+、Zn2+ effectively.Permeability resisting experiments had been performed for composite of urban sewage sludge and Kaolin with addition of solidifying enzyme TZ. It was found that though the enzyme TZ had little effect on the optimum moisture content of the composite which was about 20%, the initial permeability resistance of the composite was well improved. Comparing permeating coefficient of the enzyme added composite (0.4mL/10kg composite) pre-molded at 300kPa with that of the non-enzyme added composite, the permeating coefficient of the enzyme added composite decreased by 36% after adding enzyme for 24h, and reached 10-7cm/s level which meet the criterion for the anti-permeable liner material of landfill.The make use of urban sewage sludge as tiles and liner material in waste landfill was feasible.更多还原