摘要
焦化废水处理中预处理蒸氨工艺不稳定容易引起生物处理出水NH4+-N的波动,为了在有机物去除的同时提高生物系统对NH4+-N的去除效果和稳定性,采用对NH4+-N有良好吸附性能的天然斜发沸石为生物填料构建沸石床多级生物膜系统,考察了进水负荷对系统运行稳定性的影响、抗冲击负荷能力以及系统的功能分区和污染物迁移转化规律.结果表明,当系统进水NH4+-N负荷≤0.21kg/(m3.d)、COD负荷≤1.35kg/(m3.d)时,出水NH4+-N和COD的平均浓度分别为(2.2±1.2)mg/L和(228±60)mg/L,平均去除率分别达(99.1±0.5)%和(86.0±2.6)%.在低、高两次NH4+-N冲击负荷[0.03kg/(m3.d)和0.06kg/(m3.d)]条件下,系统对NH4+-N的平均去除率仍然分别高达99.0%和92.9%,高于对比系统的96.8%和89.3%,表现出良好的抗NH4+-N冲击负荷性能与处理稳定性.系统好氧单元反应器沿程出现脱碳/硝化功能区(C/N区)和硝化功能区(N区),其中N区的NH4+-N降解速率为C/N区的2～8倍.系统进水中相对分子质量<1×103、1×103～1×104、>1×104的TOC浓度分别为227.6、104.8和35.0mg/L,处理出水中的TOC浓度分别为31.2、22.9和31.5mg/L,其中相对分子质量<1×103和1×103～1×104这2个范围的有机物降解良好,出水残余物质主要为相对分子质量>1×103的有机物.
The practical ammonia stripping effectiveness of coke-plant wastewater treatment may vary widely, and high NH4^＋-N shock loading will lead to the fluctuation of residual NH4^＋-N concentration of biological effluent. A zeolite media packed multistage-biofllm system （ZMBS） was used for coke-plant wastewater treatment for enhancing the NH4^＋-N treatment ability of the bio-system to shock loading, as well as achieving high COD removal efficiency. Treatment performance during steady-state and shock loading and transformation of organic pollutants in the system were investigated systematically. The experiment results indicated that when the system was operated at NH4^＋-N loading ≤ 0.21 kg/（ m^3 · d） and COD loading≤ 1.35 kg/（m^3 ·d） ,the average effluent NH4^＋-N and COD concentrations were （2.2 ± 1.2）mg/L, （228 ± 60）mg/L with average removalefficiencies of （99.1 ± 0.5）% and （86.0 ± 2.6）%. During the twice NH4^＋-N shock loadings [0.03 kg/（m^3·d） and 0.06 kg/（ m^3 · d）] , ZMBS showed a strong resisting ability with average removal efficiencies of 99.0 % and 92.9 % higher than those of a compared system＇ s 96.8 % and 89.3 % . By monitoring the change of water quality along the length of the ZMBS＇ s cells, two function zones for different pollutant removal were found to exist,named as deearbonization/nitrification （C/N） zone and nitrification （N） zone, and the NH4^＋-N removal rate in N zone was 2-8 times as that in C/N zone. TOC concentrations of organic matters with relative molecular weight 〈 1 × 10^3 , 1 × 10^3 to 1 × 10^4 , and 〉 1 × 10^4 , were 227.6, 104.8 and 35.0 mg/L in raw wastewater, and 31.2, 22.9 and 31.5 mg/L in the effluent, respectively. Organic matters with relative molecular weight 〈 1 × 10^3 and 1 × 10^3 to 1 × 10^4 in raw wastewater were removed effectively by ZMBS, but those with relative molecular weight 〉 1 × 10^3 were the main remained substances in the effluent.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第2期594-599,共6页
Environmental Science
基金
国家杰出青年科学基金项目(50725827)
关键词
焦化废水
沸石
多级生物膜
NH4^+-N去除稳定性
分子量分布
coke-plant wastewater
zeolite
muhistage-biofilm system
NH4^＋-N removal stability
molecular weight distribution
