曝气加氢氧化钙复合技术抑制底泥磷释放及对底泥微生物多样性的影响

底泥磷释放是导致水体富营养化的主要原因之一,本文通过在样泥中分别投加0、0.01和0.02 mol·L-1Ca(OH)2溶液,同时进行微臭氧曝气(0.6 g·min-1),研究了曝气加氢氧化钙复合技术抑制底泥磷释放的效果及对底泥微生物多样性的影响.结果显示,投加0.02 mol·L-1Ca(OH)2组上覆水中总磷(TP)浓度的最终值与对照组相比,抑制率达到34%;从各形态磷的角度进一步分析发现,与对照组相比,该组底泥中可溶性磷和铁磷含量分别降低了92%和60%,其最终转化为钙磷是该技术的关键.通过聚合酶链式反应-变性梯度凝胶电泳技术(PCRDGGE)研究发现,各试验组微生物相似性在65%~85%之间;Berger-Parker优势度指数、Margalef丰富度指数、Shannon多样性指数变化不明显,表明该技术不会影响底泥微生物多样性.     

Intermittently aerated EMMC-Biobarrel (entrapped mixed microbial cell with Bio-barrel) process for concurrent organic and nitrogen removal

The PEMMC-Biobarrel (packed-bed of entrapped mixed microbial cells with Bio-barrel) process and MEMMC-Biobarrel (moving EMMC-Biobarrel) process were investigated for enhancing concurrent organic and nitrogen removal with applied intermittent aeration. For the PEMMC-Biobarrel process, the EMMC-Biobarrel carriers were employed at a packing ratio of 20%. In the MEMMC-Biobarrel process, the EMMC-Biobarrel carriers with a packing ratio of 10% were added along with the activated sludge (AS) in the bioreactor. Three different hydraulic retention times (HRTs) of 9, 6 and 4 h were applied. Aeration was provided intermittently at time schedules of 1 h air on/1 h air off, 1 h on/1.5 h off and 1 h on/2 h off. Nitrogen removal in the PEMMC-Biobarrel system was not improved by increasing the intermittent non-aeration time period. On the other hand, the MEMMC-Biobarrel process enhanced nitrogen removal with increasing non-aeration time even though the SCOD/N(TIN) ratio decreased from 6 to 4. Significant denitrification during the aeration cycle was observed in the MEMMC-Biobarrel process. The MEMMC-Biobarrel process demonstrated the most efficient organic and nitrogen removal at an HRT of 6 h with an intermittent aeration time schedule of 1 h on/2 h off. Nitrogen removal of 80% was achieved, which was about 15% higher compared to the AS system. TCOD and SCOD removal efficiencies were 80% and 75%, respectively.     

高硫酸盐难降解废水高温厌氧处理中限量曝气的应用及影响

由于硫酸盐还原的影响,普通高温UASB反应器处理亚硫酸盐纸浆厂排出的高硫酸盐难降解废水过程中甲烷菌活性受到了严重抑制.考虑到空气对硫化氢的吹脱和对硫化物的氧化作用可能减轻硫化物对甲烷菌的抑制,本研究在厌氧反应器中引入限量曝气措施.试验结果表明,反应器的运行稳定性和处理能力均得到大幅提高.在有机负荷提高到原来2倍的情况下,曝气后COD去除率仍有提高,从40%～50%提高到60%～70%.试验证明部分甲烷菌可以耐氧,而某些种类的水解酸化细菌则对不完全厌氧环境比较敏感.     

INDUCED OXIDATION OF STREAMS AND WATER QUALITY CONTROL INSTITUTIONS1

The proof is rapidly mounting that instream aeration is a technically and economically feasible supplement to secondary treatment of wastes, an alternative to tertiary waste treatment. Some phenomena remain unexplained; and competing technologies, especially those employing molecular oxygen, are being explored vigorously. However, there are convincing arguments in favor of aeration on theoretical grounds, proved technology is available; and the first installations have already been made. While remaining questions are being further investigated, it is time to consider in more detail the broader aspects, as to the institutional, legal, and political hurdles to be overcome before advantage can be taken of the new technology. This paper first summarizes the state-of-the-art as far as technology is concerned; and then outlines the institutional problem.     

独立分格推流式活性污泥法的动力学分析

在严格控制试验条件的基础上,对独立分格式活性污泥法进行了定量的试验研究与动力学分析.结果表明,底物比降解速率常数K值并不是常数,而是随着易降解底物的降解去除逐渐变小;据此修正了该系统的传统动力学公式及相应的设计计算方法;给出了工艺设计时曝气池分格数的划分及其容积确定的基本原则.     

间歇式活性污泥法处理啤酒废水

在实验研究基础上，成功地应用间歇式活性污泥法（以下简称ＳＢＲ法）处理啤酒生产废水。实践证明该工艺具有总投资省、处理效果好，对废水水质适应性强、工艺稳定、能耗低等优点。     

循环活性污泥法处理生活污水的脱氮性能实验研究

本以城市生活污水为处理对象，通过在主反应器前设置缺氧选择器，同时改变运行周期和进水-曝气方式，研究CAST工艺的生物降解过程及脱氮机理，并考察该工艺去除有机碳和脱氮的性能。结果表明，CAST生物脱氮工艺中最佳周期为4h。其出水CODCr质量浓度为61.80mg／L，去除率为84．52％；出水TN质量浓度平均为25．17mg／L，去除率为54．56％。非限制性曝气没有太大优势。建议采用限制性曝气与非连续性进水方式，以节约能耗和提高脱氮效果。     

Microbial Inoculants on Woody Legumes to Recover a Municipal Landfill Site

Tree and shrubby legumes have great potential in degraded land rehabilitation because of their ability to form symbiotic associations with nitrogen fixing rhizobia and mycorrhizal fungi. Extensive soil disturbance reduces natural microbial propagules thus preventing the formation of beneficial plant-microbes symbiosis. Reintroduction of selected microbial symbionts may improve the recovery rate of disturbed ecosystems. We inoculated selected rhizobia and arbuscular mycorrhizal fungi on two woody legume species, the mediterranean shrub Spartium junceumL. and the exotic tree Acacia cyanophylla Lindl. in order to recover a sealed municipal landfill (Palermo, Sicily, Italy). Inoculated plants showed shoot growth parameters 2 to 12-fold higher than uninoculated plants. After transplanting on the municipal landfill site, inoculated plants showed no transplant shock and low mortality (6–15%). The chemical analysis of P and N plant content showed no differences between inoculated and uninoculated plants suggesting that a dilution effect occurred due to higher biomass production of the inoculated plants. The beneficial effects of mycorrhization and rhizobium inoculum on growth parameters were still detectable one year after transplanting in S. junceum.     

Greenhouse gas production and efficiency of planted and artificially aerated constructed wetlands

Greenhouse gas (GHG) emissions by constructed wetlands (CWs) could mitigate the environmental benefits of nutrient removal in these man-made ecosystems. We studied the effect of 3 different macrophyte species and artificial aeration on the rates of nitrous oxide (N₂O), carbon dioxide (CO₂) and methane (CH₄) production in CW mesocosms over three seasons. CW emitted 2-10 times more GHG than natural wetlands. Overall, CH₄ was the most important GHG emitted in unplanted treatments. Oxygen availability through artificial aeration reduced CH₄ fluxes. Plant presence also decreased CH₄ fluxes but favoured CO₂ production. Nitrous oxide had a minor contribution to global warming potential (GWP < 15%). The introduction of oxygen through artificial aeration combined with plant presence, particularly Typha angustifolia, had the overall best performance among the treatments tested in this study, including lowest GWP, greatest nutrient removal, and best hydraulic properties.     

T型氧化沟提高脱氮效率的技术改造

采用延长边沟闷曝时间的方法对BOD降解模式T型氧化沟进行提高脱氮效率的改造。结果表明,边沟闷曝时间由0.5 h增至1 h,系统反硝化和硝化运行时间比t_DN/t_N由0.56调整至0.50时,提高了系统的NH₃-N的硝化效率,强化了脱氮能力。工艺改造后出水NH3-N浓度由改造前15.5 mg/L显著降低至10.4 mg/L,达到了广东省地方标准（DB 44/26-2001）第一时段的二级排放要求;系统脱氮效率由改造前52.1%显著提高到68.3％,有效地解决了污水厂出水NH₃-N浓度过高的问题;具有投资少、效果明显的特点,有一定的推广价值。