Liao, Z.L.1, Zhang, R.B.2, Chen, Y.J.3, Huang, O.4, and Weng, Y.5
1Cambi Group AS, Norway, 2 Beijing Drainage Group, China, 3 Beijing Drainage Construction Co. Ltd., China, 4 Beijing General Design Institute for Municipal Engineering, China, 5 Purac Environmental System (Beijing) Co. Ltd., China(free)
In this paper, we describe the strategy formulation of sludge treatment in Beijing Drainage Group with “1-5-1” symbol: 1-one main technological solution with Thermal Hydrolysis Advanced Digestion, 5-five large scale sludge projects, and 1-one disposal solution with biosolids for land application. As one of the first projects implemented for upgrading, Xiaohongmen WWTP has upgraded the existing traditional sludge digestion with five egg-shaped digesters into Thermal Hydrolysis Advanced Digestion based on pre-dewatering of both primary sludge and secondary sludge, CambiTHP® system, upgrading of existing egg-shaped digesters, installation of chamber filter presses, and reject water treatment with ReNoCar® deammonification process developed by Beijing Drainage Group. This paper is focusing on the main design issues for Xiaohongmen sludge treatment, the construction procedure, and the primary results of commissioning since 18 July 2016.
Advanced Digestion, Biogas Utilization, Biosolids, Chamber Filter Press, Commissioning, Egg-shaped Digesters, Land Application, Sewage Sludge, Thermal Hydrolysis, Xiaohongmen WWTP.
In 2014 Beijing Drainage Group took a great action to upgrade and expand existing WWTPs to “Water Reclamation Plants” to treat 4.13 million m3 wastewater per day in Beijing Downtown area. As part of this action plan, five sludge projects, Gaobeidian in the eastern area, Xiaohongmen in the southern area, Qinhge II in the northern area, Huaifang in the southwest area, and Gaoantun in the northeast area, will be constructed with Advanced Anaerobic Digestion with CambiTHP® as pre-treatment until 2017 to treat approximately 6100 t/d wet sludge at 20% dry solids (DS), corresponding to 1200 tDS/d. The five projects will treat sludge from 13 WWTPs in Beijing Downtown area, as shown in the Figure 1. The projects’ design includes sludge production increase when all existing plants will be upgraded to water reclamation level with tertiary treatment, so the current status of sludge production is somewhat lower than the numbers shown above.
In the “Three Years Action” for solving sludge treatment and disposal issue in Beijing, a profound feasibility study was carried out to analyse various combination of different treatment processes. In the end the study concluded to conduct sludge treatment and disposal as follows: