反向电渗析（Reverse electrodialysis，RED）技术能够利用盐差能（可再生能源）进行产电。但耗水量大、产电成本较高等问题制约了该技术的实用化。生物电化学系统（Bioelectrochemical system，BES）能够在净化污水的同时将污水中的化学能转化为电能或有价物质，是一种具有潜力的新型污水处理技术。然而，该技术生产有价物质时需要消耗大量电能。针对以上问题，本论文将碳酸氢铵溶液用于RED电池，并将碳酸氢铵-RED膜堆与BES进行耦合，以盐差能驱动耦合系统在净化污水的同时，生产有价物质（氢气、过氧化氢和甲烷）。 本论文考察了运行条件及构型对碳酸氢铵-RED电池产电性能的影响。研究表明，碳酸氢铵-RED电池的最优运行条件为：淡水浓度为 0.02 M，进水流量为800 mL/min；其最佳构型为：采用5对离子交换膜以及S-0.2隔板。经过优化，装置的最大功率密度可达0.85 W/m2。实验中能量效率稳定于30%左右。基于研究结果，提出了将碳酸氢铵-RED电池与蒸馏柱耦合形成利用废热进行产电的新工艺。本论文成功将碳酸氢铵-RED膜堆与BES结合，搭建了产氢、产过氧化氢及产甲烷的三种耦合系统。针对产氢耦合系统，考察了膜对数量对其性能的影响，解决了氨氮向阳极室迁移的问题。研究表明，采用5对离子交换膜时，该耦合系统的氢气产量、能量效率以及库仑效率均最高。在此基础上，向阳极室与膜堆之间增加了一个淡水室，使得氨氮向阳极液的迁移量减少了60%，该耦合系统的库仑效率提升了26%、氢气产量进一步提升至3.5 mol氢气/mol乙酸钠。 针对产过氧化氢耦合系统，考察了阴极催化剂种类、催化剂负载量以及膜对数量对其性能的影响。活性炭催化剂的使用会导致产生的过氧化氢完全分解，因而不适宜作为阴极催化剂。碳黑催化剂的最佳负载量为120 mg。综合考虑装置性能及成本，最佳膜对数为3，此时过氧化氢生产速率为0.99 ± 0.10 mM/h。 针对产甲烷耦合系统，考察了阴极材料对其性能的影响，通过电化学手段深入解析了其产甲烷机理。采用不锈钢生物阴极时，耦合系统的甲烷产量最大（0.60 ± 0.01 mol甲烷/mol乙酸钠），此时的甲烷生产效率为60%。电化学测试结果表明，对于该耦合系统而言，直接和非直接电子传递产甲烷同时存在。 本论文建立了输出电流-膜对数量模型。该模型表明，耦合系统输出电流的增长速度随膜对数的增加而减小，因此膜对数的增加无法无限提升系统的输出电流。此外，对三种耦合系统的有价物质生产效率也进行了对比分析。

Reverse electrodialysis (RED) is a novel technology which can convert the salinity gradient energy (a kind of renewable energy) into electricity. Nevertheless, the high capital costs and the need for large amounts of high concentration (HC) and low concentration (LC) solutions limit the practical application of RED. Bioelectrochemical system (BES) is a promising method for capturing the energy in wastewater as electricity or value-added products during wastewater treatment. However, electrical energy input is required for the production of value-added products. To eliminate the limitations for RED and BES, the use of ammonium bicarbonate as HC and LC solutions for RED stack was proposed in this dissertation. The RED stack utilizing ammonium bicarbonate solutions was then coupled with BES to form integrated systems. Salinity gradient energy was used to drive these integrated systems to produce value-added products (H2, H2O2 and CH4) during wastewater treatment.The effect of operating conditions and configurations on the power output of the RED stack utilizing ammonium bicarbonate solutions was studied. The concentration of LC solution and flow rate of feed solutions were optimized to be 0.02 M and 800 mL/min respectively. The optimal configuration of the RED stack contained 5 cell pairs and the S-0.2 spacer. A maximum power density of 0.85 W/m2 was achieved for the RED stack. The energy efficiency of the RED stack stabilized at about 30%. Based on the above results, a novel system for the conversion of waste heat to electricity was proposed by coupling the RED stack with a distillation column.Three integrated systems for the production of value-added products (H2, H2O2 and CH4) were successfully established by coupling the RED stack utilizing ammonium bicarbonate solutions with BES. For the hydrogen-producing integrated system, the effect of number of cell pairs on its performance was investigated, and the limitation of ammonia crossover into anolyte was eliminated. The largest hydrogen yiled, energy efficiency and coulombic efficiency were obtained with 5 cell pairs. An extra LC chamber was further added between the anode chamber and the membrane stack, which decreased ammonia nitrogen losses into anolyte by 60%, increased the coulombic efficiency by 26%, and improved the hydrogen yield to a maximum of 3.5 mol H2/mol acetate.The effect of catalyst type and catalyst loading and the influence of number of cell pairs on the performance of hydrogen peroxide-producing integrated system were studied. The use of activated carbon catalyst resulted in the decomposition of produced hydrogen peroxide, which demonstrated that activated carbon couldn’t be used as catalyst in the integrated system. The optimal loading of carbon black catalyst was determined to be 120 mg. The number of cell pairs was optimized to be three based on reactor performance and a desire to minimize capital costs. A maximum hydrogen peroxide production rate of 0.99 ± 0.10 mM/h was obtained. For the methane-producing integrated system, the effect of cathode material on its performance was investigated, and electrochemical tests were carried out to explore the methanogenesis mechanism. A maximum methane yield of 0.60 ± 0.01 mol CH4/mol acetate was achieved using the stainless steel biocathode, with an overall efficiency of 60%. Electrochemical tests demonstrated that methane was generated in the integrated system via both the direct and indirect electron transfer.A model which described the relationship between the generated current and the number of cell pairs was established. This model showed that the increase rate of integrated system’s current decreased gradually with the addition of cell pairs. Thus, adding cell pairs couldn’t result in an infinite improvement of current. Additionally, the overall efficiencies of three integrated systems were compared.