厂网联排对某污水处理厂设计进水参数优化分析

Optimized Analysis of Influent Parameters Design of a WWTP under Combined Drainage System of Plant-Network

厂网联排是厂网一体化新形势下污水处理厂进水设计的重要条件。苏北某市开发区新建污水处理厂同厂外新建污水主干管网和改建现状污水管网同步实施,污水厂近期规模为5万m^(3)/d,出水执行一级A标准。因现状纳污范围含有工业排放尾水(B/C值约为0.35),设计通过新建污水泵站、互联互通管网、现状泵站改造等手段协同调度污水水量,不同组合工况下可实现工业尾水最高比例由>85.0%降低至30.9%,增强进水水质均匀度,最不利条件下进水COD_(Cr)质量浓度变化幅度由414.88 mg/L降低至128.61 mg/L,氨氮质量浓度变化幅度由18.21 mg/L降低至5.65 mg/L,最大收窄幅度达69%。厂网联排下优化进水水量和水质可为不适用于分质处理的污水收集处理项目提供设计参考。

Combined drainage system of plant-network is an important condition for influent design of wastewater treatment plant(WWTP)under the new situation of plant-network integration.The WWTP to be built in Northern Jiangsu Province is implemented simultaneously with the newly-built wastewater main pipe network outside the WWTP and the reconstructed existing wastewater pipe network.The recent scale of the WWTP is 50000 m^(3)/d,and the effluent is subject to first class A criteria.Due to industrial discharge water within the current receiving range(B/C value was about 0.35).It was designed to enhance the uniformity of influent quality by new built pump stations,interconnected pipe networks,reconstruction of existing pump stations and other means.The proportion of industrial tail water could be reduced from over 85%to 30.9%under different combined working conditions,enhancing the uniformity of influent quality.Under the most unfavorable conditions,the variation range of influent COD_(Cr) can be reduced from 414.88 mg/L to 128.61 mg/L,ammonia nitrogen could be reduced from 18.21 mg/L to 5.65 mg/L,with a max decrease up to 69%.The optimization of influent quantity and quality under the condition of combined plant-network drainage could provide design reference for sewage collection and treatment projects that are not suitable for quality-based wastewater treatment.