Modelling and optimization of rotating belt filter for wastewater treatment

在初级处理过程中去除城市污水中的悬浮固体对于污水厂的有效运行和最小的环境影响至关重要。通过在生物处理之前去除可通过物理机制（例如过滤）容易地沉降或去除的固体部分，在下游生物工艺中降低能量需求方面存在很大影响。旋转带式过滤器（RBF）是传统初级澄清池的创新替代品，具有以下切实的好处：（i）物理占地面积明显更小，（ii）资本成本更低，（iii）安装和扩展更容易，（iv）控制固体去除过程的机会更大。控制RBF中的固体分离过程的能力打开了设计筛分过程的机会，以便选择性地去除对应于下游单元过程的操作以及能量和营养物回收的最佳要求的颗粒部分。Trojan Technologies是Salsnes Filter品牌下的RBF制造商和全球分销商，因此对建模和预测RBF性能有浓厚的兴趣，以便设计更好的产品，降低投标风险，并量化RBF系统的好处。由于过滤器上的水力学和固体积聚之间的复杂相互作用，RBF的建模和优化已被证明具有挑战性，因为过滤器上的固体质量直接决定了去除的颗粒尺寸以及去除效率。因此，Trojan投入了大量资金开发能够预测当前RBF设计的RBF过滤的计算流体动力学（CFD）模型，并寻求与西方大学合作，将这一开发活动提升到实施水平。

Removal of suspended solids from municipal wastewater during primary treatment processes is critical for efficient operation of wastewater plants with minimal environmental impact. By removing the fraction of solids that can be readily settled or removed by physical mechanisms such as filtration, prior to biological treatment, there is a great impact in terms of reduced energy demand in downstream biological processes. Rotating belt filters (RBFs) are an innovative alternative to traditional primary clarifiers, with the following tangible benefits: (i) a significantly smaller physical footprint, (ii) lower capital cost, (iii) easier installation and expansion, (iv) greater opportunities to control the solids removal process. The ability to control the solids separation process in RBFs opens up the opportunity to engineer the sieving process in order to selectively remove particulate fractions corresponding to optimal requirements for operation of downstream unit processes and for energy and nutrient recovery. Trojan Technologies is a manufacturer and worldwide distributer of RBFs under the brand name of Salsnes Filter, and therefore has a strong interest in modelling and predicting performance of RBFs in order to design better products, reduce risk in bidding, and quantify the benefits of RBF systems. Modelling and optimization of RBFs has proven challenging due to the complex interplay between hydraulics and accumulation of solids on the filter, since the mass of solids on the filter directly determines the particle sizes removed as well as the removal efficiency. As a result, Trojan has invested significantly in developing a computational fluid dynamics (CFD) model capable of predicting RBF filtration for current RBF designs and seeks to collaborate with Western University to take this development activity to the level of implementation.