腐殖质含量对填料净化污水效能的影响

掺入与腐殖垃圾级配相同的砂配置腐殖质含量分别为1.09%、0.87%、0.65%、0.44%和0.01%的5种填料,装填0.5 m厚度的试验柱,构建人工快速渗滤系统处理生活污水,并测定饱和水力渗透系数,研究腐殖质含量对填料净化污水效能的影响。结果表明,在相同的水力负荷（1 m/d）和污染负荷下,5种腐殖质填料对COD和TP的平均去除率存在明显差异,腐殖质含量为1.09%、0.87%和0.65%的3种填料对COD的去除率较腐殖质含量为0.01%的填料均高出14%以上。腐殖质含量与TP去除率呈现正相关性。腐殖质含量最高的填料（1#）其初始K值最大达3.23×10^-2 cm/s,约为腐殖质含量最低的填料（5#）的5倍,其稳定运行时间最长。     

Distribution,enrichment mechanism and risk assessment for fluoride in groundwater: a case study of Mihe-Weihe River Basin,China

● High fluorine is mainly HCO₃·Cl-Na and HCO₃-Na type. ● F⁻ decreases with the increase of depth to water table. ● High fluoride is mainly affected by fluorine-containing minerals and weak alkaline. ● Fluorine pollution is mainly in the north near Laizhou Bay (wet season > dry season). ● Groundwater samples have a high F⁻ health risk (children > adults). Due to the unclear distribution characteristics and causes of fluoride in groundwater of Mihe-Weihe River Basin (China), there is a higher risk for the future development and utilization of groundwater. Therefore, based on the systematic sampling and analysis, the distribution features and enrichment mechanism for fluoride in groundwater were studied by the graphic method, hydrogeochemical modeling, the proportionality factor between conventional ions and factor analysis. The results show that the fluorine content in groundwater is generally on the high side, with a large area of medium-fluorine water (0.5–1.0 mg/L), and high-fluorine water is chiefly in the interfluvial lowlands and alluvial-marine plain, which mainly contains HCO₃·Cl-Na- and HCO₃-Na-type water. The vertical zonation characteristics of the fluorine content decrease with increasing depth to the water table. The high flouride groundwater during the wet season is chiefly controlled by the weathering and dissolution of fluorine-containing minerals, as well as the influence of rock weathering, evaporation and concentration. The weak alkaline environment that is rich in sodium and poor in calcium during the dry season is the main reason for the enrichment of fluorine. Finally, an integrated assessment model is established using rough set theory and an improved matter element extension model, and the level of groundwater pollution caused by fluoride in the Mihe-Weihe River Basin during the wet and dry seasons in the Shandong Peninsula is defined to show the necessity for local management measures to reduce the potential risks caused by groundwater quality.     

Trends in the occurrence of human and veterinary antibiotics in the sediments of the Yellow River, Hai River and Liao River in northern China

The occurrence of four classes of 17 commonly used antibiotics (including fluoroquinolones, tetracycline, sulfonamides, and macrolides) was investigated in the sediments of the Yellow River, Hai River and Liao River in northern China by using rapid resolution liquid chromatography-tandem mass spectrometry. Higher concentrations were detected for most antibiotics in the sediments of the Hai River than in the sediments of the other rivers. Norfloxacin, ofloxacin, ciprofloxacin and oxytetracycline in the three rivers were most frequently detected with concentrations up to 5770, 1290, 653 and 652 ng/g, respectively. High frequencies and concentrations of the detected antibiotics were often found in the downstream of large cities and areas influenced by feedlot and fish ponds. Good fitted linear regression equations between antibiotic concentration and sediment physicochemical properties (TOC, texture and pH) were also found, indicating that sediment properties are important factors influencing the distribution of antibiotics in the sediment of rivers.     

SPE-GC/MS法测定水中对硝基氯苯和2,4-二硝基氯苯

采用SPE-GC/MS法测定水中对硝基氯苯和2,4-二硝基氯苯,优化了试验条件.对硝基氯苯在1.00 mg/L～80.0 mg/L之间线性关系良好,2,4-二硝基氯苯在1.00 mg/L～50.0 mg/L之间线性关系良好,方法检出限对硝基氯苯为0.6 μg/L,2,4-二硝基氯苯为2.1 μg/L,回收率对硝基氯苯为86.2%～94.7%,2,4-二硝基氯苯为87.3%～95.4%.     

以污泥为载体的金属氧化物脱硝催化剂的研究

以城市污水处理厂剩余污泥为原料,用氯化锌、硝酸锰和硝酸铁化学浸渍、高温热解制备脱除NO的催化剂.用微型气固相催化反应装置考察了该催化剂在CO选择性催化还原NO中的应用效果及寿命.实验结果表明:在350～550℃时的催化活性较高,在450℃时NO的最大转化率可达97.1%;催化剂的活性良好,经660 min的活性测试,催化剂的活性只降低了约3%.对该催化剂进行了BET、X射线衍射和扫描电镜分析,结果表明,该催化剂具有丰富的晶体结构,而且表面及空隙间负载的活性粒子较多,这些特征也表明该催化剂具有良好的催化性能.     

石灰(石)湿法烟气脱硫的化学原理及化学动力学特性并探讨该法的应用

本工作从理论上分析了石灰（石）湿式洗涤法脱烟气中二氧化硫的化学原理并结合实验进行了该法的化学动力学特性、再碳酸化问题及洗涤液循环系统的研究,结果表明：净化器内洗涤温度控制在６０℃以下,液气比大于４０Ｋｇ／ｍ３,洗涤液ｐＨ值控制在７９的情况下,脱硫效果较佳     

京津地区大气中非甲烷烃(NMHCs)质量浓度水平和反应活性研究

2006年8月15日—9月15日同时在北京和天津对大气中的非甲烷烃（NMHCs）进行了同步观测,利用最大增量反应活性（MIR）计算了两地NMHCs的臭氧生成潜势以估计其对臭氧生成的影响. 结果表明,北京大气中ρ（NMHCs）平均值比天津高78.0 　μg/m3.用上午的ρ（NMHCs）计算了京津地区臭氧生成潜势,分别为1 470 和814 　μg/m3,其中苯系物对臭氧生成的影响最大,分别占总臭氧生成潜势的75%和73%,其次是烯烃（占13%和11%）和烷烃（占12%和16%）. 比较两地ρ（NMHCs）和NMHCs的反应活性可知,北京地区大气中NMHCs的组成比天津的稳定,且其反应活性强于天津. 结合臭氧浓度发现,北京地区大气的氧化能力比天津强.      

不同钝化剂对鸡粪堆肥重金属钝化效果及其腐熟度指标的影响

为探究不同钝化剂对畜禽粪便处理效果,以鸡粪和稻草秸秆为原料,采用高温酵素快速堆肥方法,研究添加海泡石(SE)、钙镁磷肥(NP)、生物炭(BI)单一及复配钝化剂海泡石+钙镁磷肥(S+N)、海泡石+生物炭(S+B)、钙镁磷肥+生物炭(N+B)、海泡石+钙镁磷肥+生物炭(SNB)对鸡粪有机肥的理化性质、重金属形态分布及有机质变化的影响.结果表明,添加不同钝化剂堆肥后显著增加鸡粪有机肥pH(P <0. 05),种子发芽率有所增加(80%以上),发芽抑制率相应降低,而电导率(EC)、有机碳全氮含量和碳氮比(C/N)均较堆肥前有所降低,各项指标均达到有机肥腐熟标准.但堆肥后各组间差异为:在pH方面复配处理pH增加较高,在电导率方面单一海泡石和钙镁磷肥处理下EC值降幅较大,而有机碳全氮含量和碳氮比各组差异不明显.虽然由于"浓缩效应"导致鸡粪有机肥重金属总量有所增加,但鸡粪有机肥中重金属可溶态比例下降,残渣态比例均有所增加,添加钝化材料后发现复配钝化剂对重金属钝化效果好于单一钝化剂,其中SNB处理对Ni、Zn、As和Pb钝化效果最好.堆肥处理后,腐殖酸(HS)和胡敏酸(HA)浓度均显著上升(P ...     

硫酸盐对污泥高级厌氧消化过程中甲基汞迁移转化的影响

为研究污泥高级厌氧消化过程中甲基汞的迁移转化特征以及硫酸盐对污泥厌氧消化过程中汞形态迁移转化的影响,本研究以高温热水解污泥的厌氧消化为研究对象,考察了不同硫酸盐投加浓度下污泥厌氧消化过程中甲基汞的迁移转化特征.结果表明,污泥厌氧消化初期(第1～3 d)发生了汞的甲基化作用,平均甲基汞/总汞比例由0.024%(比值范围为0.019%～0.033%)增加到0.038%(比值范围为0.030%～0.048%),甲基汞净增量分别增加了3.97、 6.09、 0.17、 3.71和1.66倍,随后第3～5 d却发生了明显的汞去甲基化作用,甲基汞净增量降低了71.25%(范围为67.42%～75.10%).硫酸盐对厌氧消化初期汞的甲基化有一定的抑制,而厌氧消化后期,硫酸盐对汞甲基化影响并不明显,这与带电基团HgHS^-₂、 HgS₂^2-降低了中性汞络合物的生物有效性及铁硫化物、硫化汞等对S^2-和生物可利用态汞的固定作用有关.通过冗余分析,汞的甲基化受到多种环境因素的影响,丙酸、异丁酸和异戊酸...     

基于广州塔观测的城市近地面甲醛垂直分布特征

为探究珠江三角洲城区大气甲醛的垂直分布特征,本研究首次在广州塔上3个不同高度点开展了甲醛的同步观测.在2018年秋季连续32 d使用2,4-二硝基苯肼(DNPH)法采集午间1 h甲醛样品,并通过高效液相色谱(HPLC)进行分析.结果表明,广州塔地面、118 m点和488 m点的甲醛浓度均值分别为(5.10±1.93)、(6.61±2.84)和(5.33±2.55)μg·m^-3.3个高度观测点的甲醛浓度均与大气氧化剂Ox存在正相关性(R为0.65～0.75),表明光化学过程是广州市城区甲醛的重要来源.甲醛垂直浓度廓线依据分布形状分为3类,出现频率最高的一类为上下低中间高,发生在边界层对流较为温和、光化学反应活跃的状态下,中高层(118 m)可能受到来自较远处的工业高架源传输影响.根据垂直浓度梯度估算出广州塔点的甲醛垂直柱浓度均值为(11.23±4.80)×10¹⁵molecules·cm^-2,比同期卫星提供的甲醛柱浓度低19%,和已有报道值数量级一致.