生态城市建设中的生态农业对策--以南京为例

建设生态城市是城市发展的必然要求。都市生态农业是建设生态城市的必要条件。本文以南京为例，讨论建设都市生态农业的具体对策。     

Metagenomic insights into responses of microbial population and key functional genes to fulvic acid during partial nitritation

The long-term impact of fulvic acid (FA) on partial nitritation (PN) system was initially examined in this study. The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulation rate (NAR nearly 100%) and ammonium removal rate (ARR 56.85%), while FA over 50 mg/L decreased ARR from 56.85% to 0.7%. Sludge characteristics analysis found that appropriate FA (<50 mg/L) exposure promoted the settling performance and granulation of PN sludge by removing Bacteroidetes and accumulating Chloroflexi. The analysis of metagenomics suggested that the presence of limited FA (0-50 mg/L) stimulated the generation of NADH, which favors the denitrification and nitrite reduction. The negative impact of FA on the PN system could be divided into two stages. Initially, limited FA (50-120 mg/L) was decomposed by Anaerolineae to stimulate the growth and propagation of heterotrophic bacteria (Thauera). Increasing heterotrophs competed with AOB (Nitrosomonas) for dissolved oxygen, causing AOB to be eliminated and ARR to declined. Subsequently, when FA dosage was over 120 mg/L, Anaerolineae were inhibited and heterotrophic bacteria reduced, resulting in the abundance of AOB recovered. Nevertheless, the ammonium transformation pathway was suppressed because genes amoABC and hao were obviously reduced, leading to the deterioration of reactor performance. Overall, these results provide theoretical guidance for the practical application of PN for the treatment of FA-containing sewage.     

硼泥处理含氟废水的研究

在一定温度下将硼泥活化处理，用于处理５０ｍｇ／Ｌ的含氟废水，加入量为４‰，最佳吸附Ｆ－的ｐＨ值为１０．０～１１．４，去除率达９３％。吸附平衡浓度与吸附量关系符合Ｌａｎｇｍｕｉｒ吸附等温式，求出２０℃、２５℃、３０℃时的饱和吸附量和吸附系数。其吸附速度符合鲛岛吸附动力学方程式。     

固液界面吸附机制与模型——“环境水质学前沿专栏”序言

固液界面吸附是环境水化学及水处理技术研究中的一项重要内容.本文阐述了目前固液界面吸附研究方面取得的主要进展,对吸附剂表面性质、吸附络合物形态、表面反应描述中使用的一些重要实验技术、理论计算方法和模型模拟手段进行了系统的介绍,并展望了固液界面吸附研究的发展趋势.表面表征技术、理论计算及表面络合模型的发展、应用和结合有力地促进了人们对各种固液界面体系吸附机制的深入理解,对于阐明污染物在水环境中迁移转化规律,及开发新型吸附剂有着重要的科学意义.     

生物脱氮处理城市污水初探

本文介绍了城市污水生物脱氮的基本原理，研究现状和进展。     

垃圾渗滤液深度处理技术及其分析

介绍了化学氧化、化学混凝、活性炭吸附、反渗透、光氧化、催化电解氧化六种渗滤液深度处理技术的原理、国内外研究的现状和发展趋势，并分析其应用于实际的渗滤液深度处理中必须解决的技术问题。     

Nitrate removal from aqueous solutions by magnetic cationic hydrogel: Effect of electrostatic adsorption and mechanism

Excessive nitrate(NO_3~-) is among the most problematic surface water and groundwater pollutants.In this study,a type of magnetic cationic hydrogel(MCH) is employed for NO_3~-adsorption and well characterized herein.Its adsorption capacity is considerably pHdependent and achieves the optimal adsorption(maximum NO_3~--adsorption capacity is95.88±1.24 mg/g) when the pH level is 5.2-8.8.The fitting result using the homogeneous surface diffusion model indicates that the surface/film diffusion controls the adsorption rate,and NO_3~-approaches the center of MCH particles within 30 min.The diffusion coefficient(D_s) and external mass transfer coefficient(k_F) in the liquid phase are1.15 × 10~(-6) cm~2/min and 4.5 × 10~(-6) cm/min,respectively.The MCH is employed to treat surface water that contains 10 mg/L of NO_3~-,and it is found that the optimal magnetic separation time is 1.6 min.The high-efficiency mass transfer and magnetic separation of MCH during the adsorption-regeneration process favors its application in surface water treatment.Furthermore,the study of the mechanism involved reveals that both-N~+(CH_3)_3 groups and NO_3~-are convoluted in adsorption via electrostatic interactions.It is further found that ion exchange between NO_3~-and chlorine occurs.     

夏秋季节北京市居家室内微生物多样性的变化特征

室内空气中过高浓度的生物粒子有害人体健康.空气中的微生物通常与灰尘结合在一起,然而目前对家庭室内灰尘微生物多样性及其随季节变化特征的报道较少.本研究在北京市选择1户家庭,在夏季和秋季定期采集灰尘样品,通过高通量测序研究细菌和真菌群落组成及多样性,并分析细菌-真菌的网络互作特征.结果显示,室内灰尘细菌和真菌群落Shannon指数及Chao1指数夏季均显著高于秋季（p<0.05）.此外,室内灰尘细菌群落结构夏季与秋季无显著差异（p>0.05）,主要类群为假单胞菌属（Pseudomonas）、考克氏菌属（Kocuria）和芽孢杆菌属（Bacillus）;真菌群落结构夏季与秋季则明显不同（p<0.05）,夏季优势类群为曲霉属（Aspergillus）、链格孢属（Alternaria）和裂褶菌属（Schizophyllum）,而秋季曲霉属占绝对主导地位.室内灰尘微生物网络互作具有明显的季节特征,夏季微生物互作主要为细菌-细菌,以及细菌-真菌的正相互作用;而秋季微生物互作比夏季更紧密,以细菌-细菌的正相互作用为主.这些结果可为构建健康的居家环境提供参考依据.     

异步周期换向电凝聚法处理活性艳蓝X-BR模拟染料废水及其机理研究

针对传统电凝聚法处理废水过程中易出现的电极表面钝化和极化而影响处理效果的现象,采用铝和铁板作为两极同步换向方法,通过周期性改变电流方向使电极钝化和极化现象得以减缓或消失,并实现两极均可溶,利用铝、铁系无机絮凝剂共存时可提高处理效果的特点,对活性艳蓝X-BR模拟染料废水进行处理;通过正交试验,获得了该方法的最佳处理条件.在此基础上,为避免金属铝成分在废水中出现剩余影响水质,采用异步周期换向方式加以改进,考察了铝、铁电极不同通电时间对处理效果的影响,并利用紫外-可见光分光光度法、高效液相色谱法、ICP法、高分辨质谱技术、激光粒度分析仪等手段对废水处理过程主导因素和污染物去除机理以及该方法对强化处理效果的作用机理进行了分析.研究表明,最佳条件下采用异步换向周期电凝聚法处理活性艳蓝X-BR模拟染料废水30 min可使模拟废水脱色率接近100%,COD去除率可达76%以上;处理过程中起主导作用的是电凝聚过程而非电氧化还原过程;除大部分染料分子被电凝聚气浮或沉降导致脱色外,其余的活性艳蓝X-BR染料分子在电解作用下首先断裂生成了1,4-二氨基蒽醌-2-磺酸根,之后1,4-二氨基蒽醌-2-磺酸根又被直接絮凝上浮或沉降,或者在氢离子作用下发生了加氢反应使双键消失而脱色,模拟废水脱色是上述作用的综合结果.采用改进后的异步周期换向电凝聚法可以使铝铁离子凝聚过程形成的絮体具有更为合理的粒度和结构特性,从而更易于被去除,因此处理效果略优于同步换向和定向电流电凝聚过程,且可以实现处理后废水中铝离子含量降低到无法检出,避免其在处理后的废水中出现剩余影响水质.