真空电渗联合动载技术处置给水污泥的机理研究

Focusing on the theme of "vacuum electro-osmosis dehydration and dynamical consolidation technology of water supply sludge disposition", this funding project conducts the research on energy efficiency and main influencing factors of water supply sludge vacuum electro-osmosis dehydration and dynamical consolidation, so as to reveal the technical feasibility. Research the inorganic salt removal principles of water supply sludge on the basis of vacuum electro-osmosis method; reveal the inorganic salt ions dynamic migration disciplinarian and removal efficiency in sludge solidification processes; determine the effectiveness of cyclic enhanced vacuum electro-osmosis measurement in view of electro-osmosis late effects, including electrodes interface resistance, corrosion reaction and sludge moisture heterogeneous distribution. Carry out the heavy metal removing mechanism researches for vacuum electro-osmosis enhanced method; study the heavy metals migration and transformation disciplinarian under the influence of key indicators; propose stabilization measurements for the very small amount of residual heavy metals. Establish the technology architecture of vacuum electro-osmosis dehydration and dynamical consolidation technology of water supply sludge disposition with objection of "water supply sludge consolidation as well as remarkably reduction inorganic salt and heavy metal contents in disposition products"; provide scientific basis and technical supports for water supply sludge resourcing utilization as turning "waste" into "treasure".

针对产量大、成分复杂的给水污泥，开展真空电渗联合动载挤密固化给水污泥效能及主要影响因素研究，确定影响真空电渗技术污泥脱水的特征因子及动载挤密固化关键指标，揭示真空电渗联合动载处置给水污泥的机理；开展真空电渗技术去除给水污泥中重金属机理研究，揭示重金属在关键指标影响下迁移转化规律，提出极少量残留重金属稳定化处理措施；开展真空电渗技术对给水污泥中无机盐去除原理研究，揭示无机盐在污泥固化过程中动态迁移规律、去除效率，确定电渗后期效应影响下无机离子去除的循环真空电渗强化措施的效能；综合上述研究内容，构建以"固化给水污泥的同时降低固化成品中重金属含量和无机盐浓度"为核心的真空电渗联合动载处置给水污泥技术体系，为给水污泥变"废"为"宝"的资源化利用提供科学依据和技术支撑。

给水污泥含水率高，给水污泥脱水能够明显减小给水污泥处置的技术难度和施工费用。因此，探求一种高效的给水污泥脱水技术是解决给水污泥处理处置的前提。电动脱水是一种高效的污泥脱水技术，给水污泥电动脱水后含水率低。本研究将真空抽滤脱水技术和电渗脱水技术相结合强化给水污泥脱水效果，降低能耗。.本研究针对真空抽滤对给水污泥脱水效果影响，考察真空抽滤过程中给水污泥pH值、真空压力对给水污泥真空抽滤脱水效果的影响，探讨给水污泥真空抽滤脱水技术的工况优化途径，分析真空抽滤过程中给水污泥pH值对给水污泥絮体的破坏以及真空压力对提高给水污泥真空抽滤脱水速度的影响规律。结果表明，pH=5.3时，给水污泥絮体被破坏，给水污泥颗粒大小分布呈现小分子颗粒增多，大分子颗粒减少。真空抽滤过程中真空压力越大，电极土工布表面富集的泥饼厚度增加，增厚的泥饼降低了土工布的透水性能，结果表明，真空压在0.05Mpa时，土工布表面富集的泥饼不仅起到了防止污泥颗粒透过土工布的作用，同时土工布也有很好的水分透过性能。.研究电渗工况条件对给水污泥电渗脱水效果的影响，优化电渗参数，探究电渗脱水工艺中水分子去除机理。结果表明，1~4v/cm，电渗过程中提高电势梯度可以增强给水污泥脱水速度，4~5v/cm，继续提高电势梯度脱水后给水污泥含水率保持在63%，同时，较大的电势梯度导致污泥电渗过程中温度上升带来的散热增大、电渗功率增大，从而提高脱水能耗，结果表明电势梯度从1.25v/cm提高到5v/cm，污泥温度上升引起的散热是电渗能耗的主要组成部分。污泥在弱酸性条件下不仅可以破坏污泥Al(OH)3絮体，基于电渗强度公式，弱酸条件下强化了水分子的电渗作用，增强污泥中水分子电渗迁移作用，结果表明，降低污泥pH值可以提高zeta电位，pH从8.6降低到6.2，污泥zeta电位从-35mv降低到-23mv，污泥电渗脱水后最终含水率从65.7%降低到59.4%。.研究真空电渗工况优化方案提高给水污泥脱水效果。给水污泥真空电渗脱水能耗主要来自真空抽滤能耗和电渗能耗，通过优化真空压力降低真空抽滤时间来达到真空抽滤能耗降低效果。给水污泥真空电渗脱水29h后，给水污泥土体产生大量裂缝，特别是电极附近产生了大裂缝，这些裂缝使土体接触电阻从200Ω攀升至2000Ω以上，从而增强了真空电渗能耗，通过灌浆法方案可以使新鲜的污泥填补缝隙从而减小电阻，相较于