木沥河流域氮素污染及其污染源解析

为甄别粤港澳大湾区木沥河流域氮污染物来源,本研究应用铵盐同位素示踪技术、硝酸盐同位素示踪技术和多元线性混合模型等方法有效识别了该流域氮素来源的变化.结果表明,木沥河流域氮素污染严重,木沥河水体NH~+_4-N和NO~-_3-N浓度显著高于上游两条支流;除此之外,大坑山支流断面和木沥河下游养殖区断面虽无明显人口居住,仍然面临较高的氮素污染风险.铵盐同位素和硝酸盐同位素定性分析结果表明,木沥河流域氮素污染主要来源于土壤、肥料、大气颗粒物和动物及人排泄物;多元线性混合模型计算结果显示,大坑山支流上流处氮素主要来源为大气沉降,其贡献率在80%左右;鸡笼坑支流上游土壤有机氮平均贡献率可达33%,大于大坑山支流(9%)和木沥河(24%);大坑山支流下游、鸡笼坑支流下游和木沥河中上游污水及粪肥对氮素污染贡献率最高可达70%;值得注意的是,养殖区断面远离人口聚集地,各种养殖已被清理,但污水及粪肥的贡献率仍高达56%,远高于木沥河下游的淡水河水闸断面(3%),这可能要归咎于沉积物中残留的禽畜排泄物.本研究定性和定量地分析了木沥河流域氮素来源,为大湾区的水质管理和污染源治理提供了理论依据.     

Fast start-up anammox process using Acyl-homoserine lactones (AHLs) containing supernatant

N-dodecanoyl homoserine lactone (C₁₂-HSL) was detected in the supernatant of an anammox granular sludge reactor (AGSR). C₁₂-HSL could enhance the specific anammox activity of anammox biomass. Adding C₁₂-HSL-containing AGSR supernatant into the continuously stirred tank reactors reduced the start-up time of the anammox process from 80 to 66 days. Moreover, the nitrogen loading rate was also enhanced to 1.6 times that of the control reactor. AHLs could increase the secretion of extracellular polymeric substances and anammox obtained better enrichment with the addition of AHLs-containing AGSR supernatant. Denaturing gradient gel electrophoresis analysis further revealed that AHLs played a role in mediating microbial community parameters. In conclusion, adding AHL-containing supernatant could be an effective and economical way to accelerate the start-up of anammox.     

三级绿狐尾藻表面流人工湿地对养殖废水处理效应研究

提高人工湿地对养殖废水的处理效果是当前人工湿地需要解决的重要问题。本文以绿狐尾藻（Myriophyllum aquaticum Gaudich）为湿地植物,在野外构建三级表面流人工湿地,以高污染养猪废水为处理对象,分析废水中铵态氮（NH₄⁺-N）、总氮（TN）、总磷（TP）和化学需氧量（COD）在人工湿地中的去除效应,并解析它们与水体温度、溶解氧（DO）、pH和氧化还原电位（Eh）等指标的关联性。结果表明,绿狐尾藻人工湿地对NH₄⁺-N、TN、TP和COD平均去除率分别为88.3%、86.4%、76.3%和82.3%,出水平均浓度分别为45、86、14和188 mg/L。人工湿地进水负荷与人工湿地去除负荷呈显著的正相关关系（R² ≥ 0.80,P< 0.01）,去除负荷随进水负荷增加而增加。根据Pearson相关分析,人工湿地对NH₄⁺-N、TN、TP的去除率与水体DO、Eh和温度有显著相关性（P<0.01）,而对COD的去除率仅与温度存在显著的相关关系（P < 0.05）,说明人工湿地对不同污染物的去除机制存在差异。主成分分析发现水体温度是人工湿地对NH₄⁺-N、TN、COD去除的主要影响因素,水体Eh对人工湿地去除TP的关联性最大。这对改善人工湿地对污染物的去除效应至关重要。     

大空间内机械排烟效果的实验研究

在一个全尺寸的大空间火灾实验厅内,进行了不同补风口位置和补风口面积下的机械排烟试验.结果表明,由于烟气的温度较低,烟气和补充的空气较易混合,烟气和空气在交界处存在着较强的质量交换.排烟过程中,烟气是边稀释边被排放,很难和空气实现完全置换.低温烟气进行机械排烟时,区域模拟思想不适用,较难将烟气控制在理论高度.补气口位置和面积对烟气排放及火源燃烧状况具有一定的影响.     

Fractal characteristics of filamentous bacteria in activated sludge and its significance

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紊动水体复氧规律研究

根据紊动扩散理论及气液界面质量传递过程，在对流场精确描述和对表面传质系数充分研究的基础上，建立了三维紊动水体复氧模型。模型充分考虑了流场及紊动特性对复氧影响。     

ZL-1与PAM联用治理煤泥水的研究

针对煤泥水难以自然沉降的问题，研究了煤泥水的性质，提出了新的混凝剂ZL—1与PAM联用的治理方法。该方法简单，处理效果好，处理后上清水完全回用于洗煤，实现了洗水闭路循环。     

电厂温排水对浮游动物的影响

长山电厂温排水对库里泡湖浮游动物种类组成和数量变化的影响表明,增温对浮游动物的种类和数量增加有促进作用,多样性指数增大;强增温区(31—39.6℃)其种类和数量则减少,多样性指数下降.电厂冷却系统对浮游动物的机械损伤率为66—78％,但这种损伤对其数量未产生明显的危害.由浮游动物量估算了鳙鱼鱼产力,强增温可使水体鱼产力下降,弱增温则促进鱼产力提高.     

起始缓冲容量作为评价土壤对酸雨的敏感性参数

酸雨诱发的土壤酸化首先是外部H~+对土壤溶液的作用,而土壤酸化过程取决于土壤溶液对H~+的缓冲能力。本文从土壤悬液的酸碱滴定曲线实验出发,提出了土壤对H~+的起始缓冲容量(β)的概念,以作为评价土壤对酸雨的敏感性参数。对我国东南部几种土壤的实验研究表明,参数基本上符合实际情况。     

Nickel phosphide on Ni foam as anode and peroxymonosulfate as the chemical oxidizer for effective direct urea fuel cell

The direct urea fuel cell (DUFC) is a low cost and competitive approach for contemporaneous urine or urea-contaminated wastewater treatment and electricity generation. However, the lack of efficient urea oxidation reaction (UOR) electrocatalysts and suitable electron acceptors remains a challenge for practical applications. Here, we developed a DUFC system using Ni₂[email protected] foam as the anode and peroxymonosulfate (PMS) as the chemical oxidizers. The Ni₂[email protected] foam anode showed a high oxidation activity for UOR with an onset potential of 0.30 V vs. Ag/AgCl and Tafel slope of 34.4 mV/dec. PMS with high theoretical potential improved the cell voltage to 1.43 V. A power density of DUFC up to 4.91 mW/cm² was achieved using PMS at room temperature, which was approximately twice as high as using H₂O₂ (2.38 mW/cm²). Ni^II/Ni^III was the redox active species on the Ni₂P anode in the DUFC process, and Ni^II was electrochemically oxidized to Ni^III, which reverted to Ni^II by urea reduction. When real human urine was used as the fuel, a power density of 4.46 mW/cm² can be achieved at room temperature. This DUFC with high cell performance showed potential application in urea wastewater treatment.