低碳排放的生物絮凝中试系统污染物去除特性及污泥EPS变化

用中试规模生物絮凝工艺处理含化学絮凝剂的生活污水，分别研究了HRT和进水SS对生物絮凝系统污染物去除特性、剩余污泥产量、污泥特性和温室气体排放的影响。结果表明：生物絮凝系统对COD、TN和TP有较好的去除效果，且污染物去除效果受进水SS影响较大；生物絮凝系统平均污泥产量和平均有机物产量最高可达 53.63 kg·d⁻¹和21.14 kg·d⁻¹；污泥胞外聚合物EPS浓度和PN/PS均与有机负荷呈反比；化学絮凝剂通过影响PN/PS和EPS浓度，可间接影响污泥的沉降性能；生物絮凝系统与AAO工艺相结合，可降低50.12 g·m⁻³温室气体的排放。因此，生物絮凝工艺可为污水处理厂节能降耗运行奠定基础，有望得到广泛应用。

Pollutant removal characteristics and sludge EPS changes of bioflocculation pilot system with low carbon emission

The pilot-scale bioflocculation process was used to treat domestic wastewater containing chemical flocculants. The performance of the bioflocculation system in terms of contaminants removal, excess sludge production, sludge characteristics and carbon emission reduction were investigated under variations of hydraulic retention time (HRT) and the influent suspended solids (SS). The experimental results showed that the bioflocculation system had a good removal effect on insoluble chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP), and the pollutant removal effect was greatly affected by the influent SS. The average sludge yield and predicted average organic matter production (in terms of acetic acid) were up to 53.63 kg MLSS·d−1 and 7.08 kg·d−1, respectively. Both the extracellular polymeric substances (EPS) content and PN/PS were negatively correlated with the organic loading rate. In addition, the chemical flocculant had an indirect effect on the settling property of bioflocculation sludge through influencing the EPS content and PN/PS. The combination of bioflocculation process and AAO process could reduce 50.12 g·m−3 carbon dioxide (CO2) emission. Moreover, greenhouse gas emission could decrease along with the anaerobic fermentation process through acid production. Therefore, the bioflocculation process can lay a foundation for the energy saving and consumption reduction operation in wastewater treatment plants, will be widely used in practice.