A novel strategy of tannery sludge disposal –converting into biochar and reusing for Cr(Ⅵ)removal from tannery wastewater

Tannery sludge with high chromium content has been identified as hazardous solid waste due to its potential toxic effects.The safety disposal and valorization of the tannery sludge remains a challenge.In this study,the chromium stabilization mechanism was systematically investigated during chromium-rich tannery sludge was converted to biochar and the removal performance of the sludge biochar (SBC) for Cr(Ⅵ) from tannery wastewater was also investigated.The results showed that increase in pyrolys...     

低温对CANON型序批式生物膜反应器脱氮的影响

探究了4种低温水平下基于亚硝化的全程自养脱氮（CANON）型序批式生物膜反应器（SBBR）的运行效果及其氮素转化机制.结果表明,当CANON型SBBR在不同的低温水平下稳定运行后,其脱氮微生物优势菌群发生了不同程度的变化,随之改变了系统的氮素转化途径及其脱氮性能.当温度>15℃时,SBBR中AOB和anammox菌的丰度与活性未受到明显抑制,CANON作用始终是系统脱氮的主要途径,SBBR对TN的平均去除率亦较为理想;而当温度<15℃时,anammox菌的丰度与活性在10,5℃下分别出现不同程度的降低,进而改变了SBBR的氮素转化途径,使其脱氮性能出现不同程度的恶化.在10℃时,NOB的增殖及其活性的提高使硝化/反硝化作用取代CANON作用成为SBBR脱氮的主要途径,此时系统对TN的去除率骤降至（16.87±4.79）%;在5℃时,反硝化过程中第1步还原反应的停滞与反硝化菌对NO₂^--N利用率的提高使SBBR中氮素的去除依赖于CANON作用和短程硝化/反硝化作用的协同,系统对TN的去除率为（54.83±3.68）%.     

序批式生物膜法的脱氮特性及机理研究

对序批式生物膜法工艺中所表现出来的脱氮特性进行了探讨，并提出了过量储存－SND脱氮作用机理。厌氧段脱氮主要靠生物膜对含碳氮有机物的过量储存作用；好氧段脱氮主要靠生物膜的SND作用，反硝化的有机碳源主要为生物膜中在厌氧段过量储存的有机碳源。     

A novel multistage anoxic/aerobic process with sludge regeneration zone (R-MAO) for advanced nitrogen removal from domestic sewage

To achieve advanced nitrogen removal from actual municipal sewage, a novel multistage anoxic/aerobic process with sludge regeneration zone (R-MAO) was developed. The reactor was used to treat actual domestic sewage and the nitrogen removal capacity of the sludge regeneration zone (R zone) was investigated during the long-term operation. The best performance was obtained at the R zone's Oxidation-Reduction Potential (ORP) of -50±30 mV and hydraulic residence times (HRT) of 1.2 hr. The average effluent COD, TN, NH₄⁺-N and NO₃⁻-N of the R-MAO process were 18.0±2.3, 7.5±0.6, 1.0±0.5 and 4.6±0.4 mg/L, respectively, with the corresponding removal efficiency of COD, TN and NH₄⁺-N were 92.9%±1.0%, 84.1%±1.5% and 97.5%±1.1%. Compared to the sole MAO system, the TN removal efficiency of the R-MAO increased by 10.1%. Besides, under the optimal conditions, the contribution of the R zone in the R-MAO that removal COD, TN, NH₄⁺-N and NO₃⁻-N were 0.36, 0.15, 0.032 and 0.82 g/day. High-throughput sequencing results showed that uncultured_bacterium_f_Burkholderiaceae (5.20%), OLB8 (1.04%) and Ottowia (1.03%) played an important role in denitrification in the R zone. This study provided effective guidance for the design and operation of the R-MAO process in domestic sewage treatment.     

MBBR工艺中SNEDPR的启动及性能研究

为探究同步硝化内源反硝化除磷(SNEDPR)强化移动床生物膜反应器(MBBR)工艺脱氮除磷的可行性,采用连续曝气和搅拌/曝气交替运行的MBBR反应器,以磁性填料作为载体处理模拟生活污水,考察了SNEDPR启动过程中的脱氮除磷性能,并结合荧光显微镜和高通量测序技术对各个功能菌群结构变化情况进行了分析.结果表明,经两阶段运行后,氨氮和磷去除率分别达到97.6%和85.37%,出水NO₂^-—N、NO₃^-—N和COD浓度分别为1.3949,3.88和20.4mg/L,同步硝化内源反硝化率(SNEDR)由0.07%逐渐升高至86.35%.好氧阶段同步硝化内源反硝化率的提高,使出水NO_x^-—N浓度下降,提高了系统的脱氮性能和厌氧阶段内碳源的储存量.荧光显微镜和高通量测序结果表明,经过53d的运行,微生物群落多样性呈显著提高,系统内GAOs、AOB、NOB丰度的提高(分别由接种污泥中的3.3%、0.84%和0.66%提高至系统内的27.08%/20.48%、1.45%/1.76%和1.05%/0.85%)和PAOs、DPAOs的存在,保证了系统的脱氮除磷性能,在MBBR工艺中实现了EBPR与SNED的耦合.     

On-line controlling system for nitrogen and phosphorus removal of municipal wastewater in a sequencing batch reactor (SBR)

The objectives of this study were to establish an on-line controlling system for nitrogen and phosphorus removal synchronously of municipal wastewater in a sequencing batch reactor (SBR). The SBR for municipal wastewater treatment was operated in sequences: filling, anaerobic, oxic, anoxic, oxic, settling and discharge. The reactor was equipped with on-line monitoring sensors for dissolved oxygen (DO), oxidation-reduction potential (ORP) and pH. The variation of DO, ORP and pH is relevant to each phase of biological process for nitrogen and phosphorus removal in this SBR. The characteristic points of DO, ORP and pH can be used to judge and control the stages of process that include: phosphate release by the turning points of ORP and pH; nitrification by the ammonia valley of pH and ammonia elbows of DO and ORP; denitrification by the nitrate knee of ORP and nitrate apex of pH; phosphate uptake by the turning point of pH; and residual organic carbon oxidation by the carbon elbows of DO and ORP. The controlling system can operate automatically for nitrogen and phosphorus efficiently removal. __________ Translated from Water & Wastewater Engineering, 2006, 26(5): 728–733 [译自: 给水排水]