Insights into the mechanism of the deterioration of mainstream partial nitritation/anammox under low residual ammonium

Residual ammonium is a critical parameter affecting the stability of mainstream partial nitritation/anammox (PN/A), but the underlying mechanism remains unclear. In this study, mainstream PN/A was established and operated with progressively decreasing residual ammonium. PN/A deteriorated as the residual ammonium decreased to below 5 mg/L, and this was paralleled by a significant loss in anammox activity in situ and an increasing nitrite oxidation rate. Further analysis revealed that the low-ammonium condition directly decreased anammox activity in situ via two distinct mechanisms. First, anammox bacteria were located in the inner layer of the granular sludge, and thus were disadvantageous when competing for ammonium with ammonium-oxidizing bacteria (AOB) in the outer layer. Second, the complete ammonia oxidizer (comammox) was enriched at low residual ammonium concentrations because of its high ammonium affinity. Both AOB and comammox presented kinetic advantages over anammox bacteria. At high residual ammonium concentrations, nitrite-oxidizing bacteria (NOB) were effectively suppressed, even when their maximum activity was high due to competition for nitrite with anammox bacteria. At low residual ammonium concentrations, the decrease in anammox activity in situ led to an increase in nitrite availability for nitrite oxidation, facilitating the activation of NOB despite the dissolved oxygen limitation (0.15–0.35 mg/L) for NOB persisting throughout the operation. Therefore, the deterioration of mainstream PN/A at low residual ammonium was primarily triggered by a decline in anammox activity in situ. This study provides novel insights into the optimized design of mainstream PN/As in engineering applications.     

循环式活性污泥法中厌氧生物选择区的运行条件研究

研究了循环式活性污泥法中厌氧生物选择区的停留时间、进水有机物浓度和系统中泥龄、曝气时间等运行参数对选择区内厌氧释磷以及有机物的吸收贮存的影响。结果表明，选择区停留时间lh，系统泥龄5d，曝气2h，进水有机物浓度COD／TP=60--70，选择器中释磷效果及微生物的吸附性能最优，可去除进水中78％的COD。而且污泥沉降性能良好，试验运行过程中，SVI一直保持在30--40ml／g左右。     

城市污水高效低耗生物脱氮工艺研究

采用活性污泥与生物膜法相结合工艺处理城市生活污水，可以高效去除污水中的有机物和NH4^ -N。研究结果表明：水力停留时间为7．5h、回流比为1．5、无外加碳源时，COD的去除率大于90％，NH4^ -N的去除率大于99％；平均出水COD小于40mg／L，NH4^ -N小于1mg／L，TN的去除率60％左右；反硝化过程的适宜C／N为4～5。     

Recovery of heavy metals from electroplating sludge and stainless steel pickle waste liquid by ammonia leaching method

１　ＩｎｔｒｏｄｕｃｔｉｏｎＥｌｅｃｔｒｏｐｌａｔｉｎｇｓｌｕｄｇｅ，ｃｏｎｔａｉｎｉｎｇＣｕ，Ｎｉ，Ｚｎ，Ｃｒ，Ｆｅ，ｅｔｃ．，ｉｓｈａｒｍｆｕｌｗａｓｔｅｍａｔｅｒｉａｌｐｒｏｄｕｃｅｄｂｙｇａｌｖａｎｉｚａｔｉｏｎｉｎｄｕｓｔｒｙ．Ｔｈｅｒｅｉｓｓｔｉｌｌｎｏｅｆｆｅｃｔｉｖｅｍｅｔｈｏｄｔｏｒｅｃｏｖｅｒｒｅｓｏｕｒｃｅａｎｄｃｏｎｔｒｏｌｐｏｌｌｕｔｉｏｎｂｏｔｈａｔｈｏｍｅａｎｄａｂｒｏａｄ．Ｔｈｅｍｅｔａｌｓｄｉｓｃａｒｄｅｄｂｙｇａｌｖａｎｉｚａｔｉｏｎｉｎｄｕｓｔｒｙａｍｏｕｎ…     

电镀重金属污泥的处理及综合利用现状

简要综述了目前工重金属污泥近几年的处理及综合利用状况，包括固化，填海等方法，其中重点介绍了铁氧化体法固化电镀污泥重离子的湿法、干法工艺流程，以及用污泥生成的铁氧体为原料，可生产颜料、油漆和磁性探伤粉等较高档产品。     

小诺霉素发酵废水好氧生物处理试验研究

对具有强抑制性污染物的抗生素小诺霉素发酵废水，选择活性污泥、粉末活性炭（ＰＡＣＴ）、纯氧曝气等３种好氧生物处理法进行了比较试验。根据实验结果，小诺霉素发酵废水的生物降解呈抑制动力学，采用Ｍａｒｑｕａｒｔ方法对动力学模式进行参数估计。ＰＡＣＴ能够有效地降低降解过程中微生物受到的抑制作用，从而明显地改善了生物处理过程动力学。     

青岛地区大气气溶胶海洋因子贡献研究

本文对青岛地区大气气溶胶海洋因子的贡献进行了分析研究，得出以下结构：（１）复季受海洋影响要比冬季明显得多；（２）就质量浓度而言，ＩＰ（ｉｎｈａｌａｂｌｅ ｐａｒｔｉｃｌｅ）中的海盐源要高于ＴＳＰ（ｔｏｔａｌ ｓｕｓｐｅｎｄｅｄ ｐａｒｔｉｃｕｌａｔｅｓ）；（３）海洋影响的程度和离海边的距离有关。离海逾远，受海洋影响就逾小；离海连逾近，受其影响就逾大；（４）ＩＰ冬季海盐源为２％－４％，夏季为１０％－     

污水处理厂污泥脱水滤液循环利用的研究

对污水处理厂污泥机械脱水滤液进行了循环利用研究。将滤液与剩余污泥（mlsss≤13000mg／l）按1比4的比例均匀混合。然后加入到沉淀器中进行重力浓缩试验，结果表明：它能够改善污泥的浓缩脱水性能，加快污泥的沉淀速度，增大浓缩污泥的浓度；生产运行数据分析显示：污泥脱水滤液与剩余污泥混合液进入浓缩池后，上清液更加清澈，污泥的固体负荷率显著提高，这既可降低污泥的处理成本，亦可减少污泥处理系统的基建投资，为污泥处理系统的工艺优化开辟了新途径。     

脱水污泥高含水率条件下好氧发酵过程的研究

在仓式反应器内,用木屑作为调理剂,对上海市某污水处理厂的脱水污泥进行一次好氧发酵试验。试验结果表明:用木屑作为调理剂的条件下,含水率控制在70%～75%时脱水污泥的一次好氧发酵过程能顺利进行。     

长江中下游稀土元素的水环境地球化学特征

采用中子活化分析技术同步研究了稀土元素在长江干流中下游水体各要素中的含量分布及其赋存形态。结果表明，稀土元素在河水中以悬浮态为主，溶解态含量极微。溶解态在中下游各河段呈均匀分布，与不同地带的河流也基本一致。而悬浮态含量较高，变幅较大。各河段的悬浮物或沉积物中稀土元素含量相近，悬浮物与沉积物中相应各稀土元素含量也基本一致。各河段悬浮物与沉积物的稀土元素分布模式均为轻稀土富集、铕亏损型，各稀土元素赋存形态特征相似，均以结晶态为主，各形态所占比例的排序均为结晶态》有机结合态、铁锰氧化物态＞碳酸盐结合态＞＞可交换态。各稀土元素相对比较，中稀土元素Ｅｕ、Ｓｍ、Ｔｂ的结晶态较轻、重稀土的结晶态所占比例低、而其它态相反。