The rapid expansion of the aquaculture industry has brought about a heightened focus on the waste produced by high intensity fish farming. In closed-containment, recirculating aquaculture systems (RAS), fish solids are mechanically separated and/or coagulated before being disposed as waste. Subsequent revalorization is typically limited to the direct dispersal of aquaculture solids onto agricultural fields. Here, we developed a novel, continuous flow, low-cost solids waste treatment system for freshwater and saline RAS. Rotating drum filter backwash was collected as the primary feedstock for anaerobic digestion. A laboratory scale set up was used to monitor the conversion of the solids into a methane-rich (60–80% purity) biogas stream. Iron supplementation (ferric iron at 100 mg/L and 1000 mg/L) improved salt tolerance of the methanogenic community, leading to higher methane yields in a supplemented (FeCl₃ at 1000 mg/L) saline treatment than the saline control. The application of iron additionally improves pH stability and volatile fatty acid utilization. The methane yield ranged from 0.1 to 0.4 NL CH₄/ g VS across the three freshwater treatments and the iron-supplemented saline treatment, however, it was significantly lower for the saltwater control: ranging between 0.08 and 0.25 NL CH₄/ g VS. These values correspond to a percentage yield of 57–86% of the total biomethane potential. Overall, implementing anaerobic digestion for RAS waste valorization may generate significant amounts of biomethane to be used in electricity and heating for large-scale aquaculture facilities, while even for smaller facilities it may off-set costs and mitigate environmental impacts of the waste streams.

水产养殖业的迅速扩张使人们更加关注高强度养鱼产生的废物。在封闭式循环水产养殖系统 (RAS) 中，鱼固体在作为废物处理之前被机械分离和/或凝结。随后的重新定价通常仅限于将水产养殖固体直接散布到农田上。在这里，我们开发了一种用于淡水和盐水 RAS 的新型、连续流、低成本固体废物处理系统。收集转鼓过滤器反洗液作为厌氧消化的主要原料。实验室规模设置用于监测固体转化为富含甲烷（60-80% 纯度）的沼气流。₃在 1000 mg/L) 生理盐水处理优于生理盐水对照。铁的应用还提高了 pH 稳定性和挥发性脂肪酸的利用率。三种淡水处理和补铁盐水处理的甲烷产量范围为 0.1 至 0.4 NL CH _{4 / g VS，然而，盐水控制的甲烷产量明显较低：介于 0.08 至 0.25 NL CH 4之间}/克比。这些值对应于总生物甲烷潜力的 57-86% 的百分比产量。总体而言，为 RAS 废物增值实施厌氧消化可能会产生大量生物甲烷，用于大型水产养殖设施的电力和供暖，而即使对于较小的设施，它也可能抵消成本并减轻废物流对环境的影响。