改良UCT分段进水工艺处理生活污水性能优化研究

在某大型污水处理厂采用中试规模的改良UCT分段进水脱氮除磷工艺处理低COD/N生活污水,重点研究了流量分配比和原水营养元素比（COD/N、COD/P和TN/P）对工艺脱氮除磷性能的影响,目的是分析探索工艺对有机物和氮磷去除机制和污泥特性.连续运行试验表明,该工艺取得稳定高效的去除性能.在进水COD负荷为0.79～0.9...     

南方某城市供水管网红水原因调查与研究

针对南方某城市供水管网经常出现红水现象,对实际供水管网进行了调查.从某城市供水管网中连续取样检测溶解氧、余氯、铁浓度、锰浓度、铁细菌和亚硝酸菌等重要水质指标,目的是探讨管网出现红水的原因.结果表明,管网出现红水地区的沉淀物主要成分为铁、锰,出厂水存在锰超标现象（Mn最大值达到0.33 mg.L-1）,4个水厂出厂水拉森指数均〉1,4个水厂供水量及硫酸盐、电导率等供水水质指标存在较大的差别,管网中铁细菌及亚硝酸菌（100～103MPN.mL-1）存在水平较高.因此,出厂水本身腐蚀性是导致管网出现红水的潜在原因;其次,各水厂供水量和水质差异导致管网水在低溶解氧及低余氯条件下易发生红水现象;再者,管网中硝化作用严重,诱发微生物腐蚀供水管道.为此,针对上述原因提出控制管网红水现象的主要措施.     

晚期垃圾渗滤液短程硝化生物动力学研究

通过对亚硝化反应器中的氨氮、亚硝酸盐氮变化趋势的试验研究,认为渗滤液中存在着可以转化成氨氮的有机氮,但有机氮的转化不是在瞬时完成的。利用劳伦斯-麦卡蒂模式求得模型参数为氨氮vmax=4.67 mg/(mg.d),Ks=464.4 mg/L,Y=0.1966 mg/mg,Kd=0.55384/d,通过模型得出了反应器内生物量浓度、出流水质与污泥龄的关系,以期为实际工程中垃圾渗滤液生物脱氮提供借鉴。     

Effects of urea and (NH4)2SO4 on nitrification and acidification of Ultisols from Southern China

The mechanisms for the effects of ammonium-based fertilizers on soil acidification in subtropical regions are not well understood. Two Ultisols collected from cropland and a tea garden in Anhui and Jiangxi Provinces in subtropical southern China, respectively, were used to study the effects of urea and (NH₄)₂SO₄ on the nitrification and acidification of soils with incubation experiments. Nitrification occurred at very low pH with no N fertilizer added and led to lowering of the soil pH by 0.53 and 0.30 units for the soils from Jiangxi and Anhui, respectively. Addition of urea accelerated nitrification and soil acidification in both Ultisols; while nitrification was inhibited by the addition of (NH₄)₂SO₄, and greater input of (NH₄)₂SO₄ led to greater inhibition of nitrification. Ammonia-oxidizing bacteria (AOB) played an important role in nitrification in cropland soil under acidic conditions. Addition of urea increased the soil pH at the early stages of incubation due to hydrolysis and stimulated the increase in the AOB population, and thus accelerated nitrification and soil acidification. At the end of incubation, the pH of Ultisol from Jiangxi had decreased by 1.25, 1.54 and 1.84 units compared to maximum values for the treatments with 150, 300 and 400 mg/kg of urea-N added, respectively; the corresponding figures were 0.95, 1.25 and 1.69 for the Ultisol from Anhui. However, addition of (NH₄)₂SO₄ inhibited the increase in the AOB population and thus inhibited nitrification and soil acidification. Soil pH for the treatments with 300 and 400 mg/kg of (NH₄)₂SO₄-N remained almost constant during the incubation. AOB played an important role in nitrification of the cropland soil under acidic conditions. Addition of urea stimulated the increase in the AOB population and thus accelerated nitrification and soil acidification; while addition of (NH₄)₂SO₄ inhibited the increase in the AOB population and thus inhibited nitrification.     

同时硝化/反硝化除磷工艺的脱氮除磷效能

为实现同时硝化/反硝化除磷(SNDPR),在序批式活性污泥反应器(SBR)中,采用厌氧/好氧和厌氧/缺氧/好氧2种运行模式驯化污泥,并考察了厌氧/低氧模式下SNDPR过程中COD、PHB、TP、TN、DO和电化学参数的变化规律。结果表明,经2阶段驯化,反硝化聚磷菌比例提升至85.9%,硝化速率达5.97 mg(/L.h),实现了反硝化除磷菌和硝化菌的良好共存;在厌氧/低氧模式下,SNDPR对低碳城市污水具有良好脱氮除磷效果,TP、TN和COD去除率达到93.7%、79%和87.7%;PHB与COD降解、TN降解和TP吸收有良好的相关性,也是SNDPR过程的碳源驱动力;pH和ORP曲线上"谷点"预示厌氧释磷结束,pH曲线"折点"指示SNDPR结束。     

Effect of selected herbicides on activities of microorganisms in soils

Abstract

With the exception of EPTC, herbicide treatments showed inhibitory effects on bacterial colony counts in a sandy loam soil for the first week. Monolinuron and simazine were stimulatory to the growth of fungi in the organic soil after 2 wk. None of the herbicide treatments affected nitrification during the first week of incubation. Except the treatment of EPTC in organic soil, all herbicides inhibited nitrification after 2 wk in both soils. All herbicide treatments stimulated SO₄ formation during the 8‐wk period in the sandy loam soil. Simazine and tridiphane also stimulated sulfur oxidation after 4 wk in an organic soil. With the exception of EPTC and nitrapyrin, no significant inhibitory effect on the amount of biomass‐C was observed in the organic soil. A stimulatory effect on denitrification was observed with EPTC for 2 wk and monolinuron for 1 wk in the sandy loam soil and with simazine and tridiphane after 2 wk in the organic soil. It is apparent that the indigenous soil microorganisms can tolerate the effects of the chemicals for control of soil weeds.     

Novel strategy of nitrogen removal from domestic wastewater using pilot Orbal oxidation ditch

A pilot-scale Orbed oxidation ditch was operated for 17 months to optimize nitrogen removal from domestic wastewater of average COD to total nitrogen ratio of 2.7, with particular concern about the roles of dissolved oxygen （DO）, mixed liquor suspended solids （MLSS） and return activated sludge （RAS） recycle ratio. Remarkable simultaneous nitrification and denitrification （SND） was observed and mean total nitrogen （TN） removal efficiency up to 72.1% was steadily achieved, at DO concentration in the out, middle and inner channel of 0.1, 0.4 and 0.7 mg/L, respectively, with an average M LSS of 5.5 g/L and RAS recycle ratio of 150%. Although the out channel took the major role in TN removal, the role of middle channel should never be ignored. The denitrification potential could be fully developed under low DO, high MLSS with adequate RAS ratio. The sludge settleability was amazingly improved under low DO operation mode, and some explanations were tried. In addition, a scries of simplified batch tests were done to determine whether novel microorganisms could make substantial contribution to the performance of nitrogen removal. The results indicated that the SND observed in this Orbal oxidation ditch was more likely a physical phenomenon.     

膜生物反应器处理氨氮废水的研究进展

综述了膜生物反应器处理氨氮废水的三种工艺：常规活性污泥工艺、SBR工艺和A／O工艺。总结了国内外研究的工艺特征、技术参数和处理效果，并分析了其未来的研究方向和应用前景。     

高效藻类塘氮磷去除机理的研究进展

首先介绍了高效藻类塘的发展历史和特点，其次简述了高效藻类塘的生物特性和物理化学变化规律，并重点论述了高效藻类塘的氮磷去除机理及其影响因素，最后对高效藻类塘在控制非点源污染中的应用前景进行展望。