国Ⅳ天然气公交车实际道路颗粒物排放特性

采用车载排放测试系统对国Ⅳ天然气公交车进行了实际道路排放测试,研究其颗粒物排放特征及粒径分布随车速、加速度及比功率的变化规律.结果表明,天然气公交车的颗粒物数量和质量排放率随车速的增加均逐渐升高,而排放因子均逐渐减小;怠速、低速、中速和高速工况下颗粒数量浓度均呈多峰对数分布,核态颗粒数在总颗粒数中占大多数比例.随加速度的增大,颗粒物排放率逐渐升高;快加速工况颗粒物排放率明显高于匀速和慢减速工况,而后二者之间相差不大.颗粒物的高排放集中在高车辆比功率(VSP)区间内,并随VSP绝对值的增大逐渐升高.     

Effect of alkalinity on nitrite accumulation in treatment of coal chemical industry wastewater using moving bed biofilm reactor

Nitrogen removal via nitrite （the nitrite pathway） is more suitable for carbon-limited industrial wastewater. Partial nitrification to nitrite is the primary step to achieve nitrogen removal via nitrite. The effect of alkalinity on nitrite accumulation in a continuous process was investigated by progressively increasing the alkalinity dosage ratio （amount of alkalinity to ammonia ratio, mol/mol）. There is a close relationship among alkalinity, pH and the state of matter present in aqueous solution. When alkalinity was insufficient （compared to the theoretical alkalinity amount）, ammonia removal efficiency increased first and then decreased at each alkalinity dosage ratio, with an abrupt removal efficiency peak. Generally, ammonia removal efficiency rose with increasing alkalinity dosage ratio. Ammonia removal efficiency reached to 88% from 23% when alkalinity addition was sufficient. Nitrite accumulation could be achieved by inhibiting nitrite oxidizing bacteria （NOB） by free ammonia （FA） in the early period and free nitrous acid in the later period of nitrification when alkalinity was not adequate. Only FA worked to inhibit the activity of NOB when alkalinity addition was sufficient.     

Combination of heterogeneous Fenton-like reaction and photocatalysis using Co-TiO2 nanocatalyst for activation of KHSO5 with visible light irradiation at ambient conditions

A novel coupled system using Co–Ti O2 was successfully designed which combined two different heterogeneous advanced oxidation processes, sulfate radical based Fenton-like reaction（SR-Fenton） and visible light photocatalysis（Vis-Photo）, for degradation of organic contaminants. The synergistic effect of SR-Fenton and Vis-Photo was observed through comparative tests of 50 mg/L Rhodamine B（Rh B） degradation and TOC removal. The Rhodamine B degradation rate and TOC removal were 100% and 68.1% using the SR-Fenton/Vis-Photo combined process under ambient conditions, respectively. Moreover, based on XRD, XPS and UV-DRS characterization, it can be deduced that tricobalt tetroxide located on the surface of the catalyst is the SR-Fenton active site, and cobalt ion implanted in the Ti O2 lattice is the reason for the visible light photocatalytic activity of Co–Ti O2. Finally, the effects of the calcination temperature and cobalt concentration on the synergistic performance were also investigated and a possible mechanism for the synergistic system was proposed. This coupled system exhibited excellent catalytic stability and reusability,and almost no dissolution of Co2＋was found.     

Seasonality of selected surface water constituents in the Indian River Lagoon, Florida

Seasonality is often the major exogenous effect that must be compensated for or removed to discern trends in water quality. Our objective was to provide a methodological example of trend analysis using water quality data with seasonality. Selected water quality constituents from 1979 to 2004 at three monitoring stations in southern Florida were evaluated for seasonality. The seasonal patterns of flow-weighted and log-transformed concentrations were identified by applying side-by-side boxplots and the Wilcoxon signed-rank test (p < 0.05). Seasonal and annual trends were determined by trend analysis (Seasonal Kendall or Tobit procedure) using the U.S. Geological Survey (USGS) Estimate TREND (ESTREND) program. Major water quality indicators (specific conductivity, turbidity, color, and chloride), except for turbidity at Station C24S49, exhibited significant seasonal patterns. Almost all nutrient species (NO(2)-N, NH(4)-N, total Kjeldahl N, PO(4)-P, and total P) had an identical seasonal pattern of concentrations significantly greater in the wet than in the dry season. Some water quality constituents were observed to exhibit significant annual or seasonal trends. In some cases, the overall annual trend was insignificant while opposing trends were present in different seasons. By evaluating seasonal trends separately from all data, constituents can be assessed providing a more accurate interpretation of water quality trends.     

Sorption of organic pollutants by marine sediments: implication for the role of particulate organic matter

The objective of this study was to quantify sorption properties for kerogen/black carbon (BC)-bearing sediments. Single-solute sorption isotherms were measured for five pristine marine sediments using phenanthrene, naphthalene, 1,3,5-trichlorobenzene, and 1,4-dichlorobenzene as the sorbates. The results showed that the sorption isotherms were nonlinear and that the organic carbon normalized single point K_OC values were comparable to those reported in the literature for the purified keorgen and BC, but are much higher than the data reported for HA and kerogen/BC-containing terrestrial soils and sediments. It is likely that koergen and BC associated with these pristine marine sediments may not be encapsulated with humic acids or Fe and Mn oxides and hydroxides as often do in terrestrial soils and sediments. As a result, they may be fully accessible to sorbing molecules, exhibiting higher sorption capacities. The study suggests that competition from background HOCs and reduced accessibility when kerogen and BC are associated with terrestrial sediments may dramatically increase variability of sorption reactivities of geosorbents. Such variability may lead to large uncertainties in the prediction of sorption from the contents of kerogen and/or BC along with TOC.     

不同湿地植物凋落物对汞铊矿废弃物浸出酸性废水中重金属的吸附研究

研究了不同湿地植物(稻草(Oryza sativa L.)、风车草(Cyperus involucratus Rottb.)、芦竹(Arundo donax L.)、美人蕉(Canna indica L.)、水葱(Scirpus validus Vahl.)、香蒲(Typha orientalis C.Presl)和鸢...     

Occurrence and removal of six pharmaceuticals and personal care products in a wastewater treatment plant employing anaerobic/anoxic/aerobic and UV processes in Shanghai,China

The occurrence and removal of six pharmaceuticals and personal care products (PPCPs) including caffeine (CF), N, N-diethyl-meta-toluamide (DEET), carbamazepine, metoprolol, trimethoprim (TMP), and sulpiride in a municipal wastewater treatment plant (WWTP) in Shanghai, China were studied in January 2013; besides, grab samples of the influent were also taken every 6 h, to investigate the daily fluctuation of the wastewater influent. The results showed the concentrations of the investigated PPCPs ranged from 17 to 11,400 ng/L in the WWTP. A low variability of the PPCP concentrations in the wastewater influent throughout the day was observed, with the relative standard deviations less than 25 % for most samples. However, for TMP and CF, the slight daily fluctuation still reflected their consumption patterns. All the target compounds except CF and DEET, exhibited poor removal efficiencies (<40 %) by biological treatment process, probably due to the low temperature in the bioreactor, which was unfavorable for activated sludge. While for the two biodegradable PPCPs, CF, and DEET, the anaerobic and oxic tank made contributions to their removal while the anoxic tank had a negative effect to their elimination. The tertiary UV treatment removed the investigated PPCPs by 5–38 %, representing a crucial polishing step to compensate for the poor removal by the biologic treatment process in winter.     

超声辅助CaO脱除赤泥中钠钾的反应特性及其机理

以拜耳法赤泥为研究对象,通过试验研究了超声辅助CaO脱除赤泥中Na、K的反应特征及其机理.结果表明:超声辅助CaO脱除赤泥中Na、K的效率优于单纯使用CaO;超声条件下增加CaO投加量、升高温度以及增加浸出时间均有助于提高赤泥中Na、K的脱除率;当CaO投加量为20％、温度为80℃、超声辅助浸出时间为180min时,赤泥中Na、K的脱除率分别达到81.78％、86.37％,赤泥中Na2O/SiO2 (N/S)由0.354减小到0.064;超声辅助CaO脱除赤泥中Na、K的动力学机制为赤泥中矿物质(钠钾钙霞石、钙霞石、硫酸钙霞石等)与CaO进行钙化反应,浸出Na、K,同时形成更加稳定的矿物质(钙霞石、加藤石等),Na、K的浸出动力学过程受内扩散控制.     

四川红豆杉属植物及其保护与利用

本文报道了四川红豆杉属植物的形态特征、种类、分布、有效成分及其综合利用，并就合理的开发与保护进行了初步研讨。     

三峡库区中小城镇城市降雨径流污染特征及现状研究

本研究采用从微观到宏观，在库区沿岸城镇诸多相关因素相似前提下，选择涪陵市为典型试验区；从水文因素，街道地表物累积冲刷规律研究着手，建立累积、冲刷计算模式，计算出涪陵市年降雨径流污染负荷和库区污染荷载因子，同时选择具有代表性的集水闭合小区进行水质、水量同步观测试验进行验证；确定外推因子，计算三峡库区城市降雨径流年冲刷入长江的总固体，ＳＳ，ＢＯＤ５，ＣＯＤ，Ｔ－Ｎ，Ｔ－Ｐ３量分别为５３９６８吨，３８０