补水景观湖水生态系统构建对水质的影响及因子分析

以广州市最大补水人工景观湖白云湖水生态系统构建示范区为对象,利用综合污染指数评价了以沉水植被构建为主的修复措施对示范区水体水质改善的影响,并应用因子分析法对各水质指标和生态因子之间的相互关系进行了研究。综合污染分析结果表明,恢复沉水植物后,示范区水体各项污染物浓度大幅降低,水质从V-劣V类提高到III-IV类,水体综合污染状态由严重污染改善为轻污染。因子分析显示,10项水质指标可划分为四类主因子来反映水质状况,其中,第一主因子主要反映水体营养盐指数,第二主因子反映水体有机污染指数,第三主因子反映温度变化对水质的影响,第四主因子反映水体的酸碱度;综合评分结果说明了生态系统构建后水质综合评分可大幅降低,且月评分结果呈现温度越高、水质越优的特点,水体特征呈现向草型水体发展的趋势。上述结果表明,水生态系统构建可有效改善示范区水质,是保障城市河道补水水源安全的有效方法。     

荆州市浅层地下水环境质量综合评价与分区

通过实地调查荆州市浅层地下水环境,合理选择评价指标集（16项）,分别采用模糊数学综合评价法和F值法对该浅层地下水环境质量进行综合评价,分析对比两种方法的评价结果,对浅层地下水环境进行分区和污染分析。评价结果表明：浅层地下水环境质量不容乐观,整体状况较差。浅层地下水中主要超标组分为Fe、Mn、NO-3、NO-2、As、Ba等,对比分析荆州市2006~2011年主要超标组分的平均含量,可知6 a来,Fe、Mn、NO-2的平均含量均超过地下水Ⅲ类水质标准,NO-3、As、Ba的平均含量虽然均未超过地下水Ⅲ类水质标准,但其平均含量呈现随着年份递增的趋势。浅层地下水环境质量分区结果显示：严重区面积为2 623 km2约占305%,较严重面积为1 33128 km2约占1548%,合格区面积为3 07192 km2约占3572%,较好区面积为1 5738 km2仅占183%。浅层地下水环境质量在很大程度上不仅受当地特有的区域原生地质环境影响,还与人类活动有密切关系     

Characterization of endophytic Rahnella sp. JN6 from Polygonum pubescens and its potential in promoting growth and Cd,Pb, Zn uptake by Brassica napus

Microbe-assisted phytoremediation has been considered as a promising measure for the remediation of heavy metal-polluted soils. In this study, a metal-tolerance and plant growth-promoting endophytic bacterium JN6 was firstly isolated from roots of Mn-hyperaccumulator Polygonum pubescens grown in metal-contaminated soil and identified as Rahnella sp. based on 16S rDNA gene sequence analysis. Strain JN6 showed very high Cd, Pb and Zn tolerance and effectively solubilized CdCO₃, PbCO₃ and Zn₃(PO₄)₂ in culture solution. The isolate produced plant growth-promoting substances such as indole-3-acetic acid, siderophore, 1-aminocyclopropane-1-carboxylic deaminase, and also solubilized inorganic phosphate. Based upon its ability in metal tolerance and solubilization, the isolate JN6 was further studied for its effects on the growth and accumulation of Cd, Pb and Zn in Brassica napus (rape) by pot experiments. Rape plants inoculated with the isolate JN6 had significantly higher dry weights, concentrations and uptake of Cd, Pb and Zn in both above-ground and root tissues than those without inoculation grown in soils amended with Cd (25 mg kg^?1), Pb (200 mg kg^?1) or Zn (200 mg kg^?1). The isolate also showed a high level of colonization in tissue interior of rapes. The present results demonstrated that Rahnella sp. JN6 is a valuable microorganism, which can cost-effectively improve the efficiency of phytoremediation in soils contaminated by Cd, Pb and Zn.     

移动床生物膜反应器预处理含酚废水

采用两级移动床生物膜反应器（MBBR）预处理高挥发酚含量的石化厂汽提净化水,考察了HRT和DO对废水中挥发酚和COD去除效果的影响。实验结果表明：在两级MBBR总HRT为10 h、MBBR中部废水DO 为1~3 mg/L的条件下, 装置连续运行处理ρ（挥发酚）=110~201 mg/L、COD=644~1 827 mg/L、BOD₅/COD=0.15~0.69的废水,两级MBBR处理后出水平均ρ（挥发酚）为17.6 mg/L,挥发酚去除率达87.9%;平均COD为745 mg/L,COD去除率为32.7%;出水BOD₅/COD平均为0.68,表明经过两级MBBR处理后,废水的可生化性有所提高,有利于废水的后续生化处理。     

Impact of haze and air pollution-related hazards on hospital admissions in Guangzhou,China

Guangzhou is a metropolitan in south China with unique pollutants and geographic location. Unlike those in western countries and the rest of China, the appearance of haze in Guangzhou is often (about 278 days per year on average of 4 years). Little is known about the influence of these hazes on health. In this study, we investigated whether short-term exposures to haze and air pollution are associated with hospital admissions in Guangzhou. The relationships between haze, air pollution, and daily hospital admissions during 2008–2011 were assessed using generalized additive model. Studies were categorized by gender, age, season, lag, and disease category. In haze episodes, an increase in air pollutant emissions corresponded to 3.46 (95 % CI, 1.67, 5.27) increase in excessive risk (ER) of total hospital admissions at lag 1, 11.42 (95 % CI, 4.32, 18.99) and 11.57 (95 % CI, 4.38, 19.26) increases in ERs of cardiovascular illnesses at lags 2 and 4 days, respectively. As to total hospital admissions, an increase in NO₂ was associated with a 0.73 (95 % CI, 0.11, 1.35) and a 0.28 (95 % CI, 0.11, 0.46) increases in ERs at lag 5 and lag 05, respectively. For respiratory illnesses, increases in NO₂ was associated with a 1.94 (95 % CI, 0.50, 3.40) increase in ER at lag 0, especially among chronic obstructive pulmonary disease. Haze (at lag1) and air pollution (for NO₂ at lag 5 and for SO₂ at lag3) both presented more drastic effects on the 19 to 64 years old and in the females. Together, we demonstrated that haze pollution was associated with total and cardiovascular illnesses. NO₂ was the sole pollutant with the largest risk of hospital admissions for total and respiratory diseases in both single- and multi-pollutant models.     

Degradation of sulfonamides antibiotics in lake water and sediment

Degradation of three sulfonamides (SAs), namely sulfamethoxazole (SMX), sulfamethazine (SMZ), and sulfadimethoxine (SDM) in surface water and sediments collected from Taihu Lake and Dianchi Lake, China was investigated in this study. The surface water (5–10 cm) was collected from the east region of Taihu Lake, China. Two sets of degradation experiments were conducted in 3-L glass bottles containing 2 L of fresh lake water and 100 μg/L of individual SAs aerated by bubbling air at a rate of approximately 1.2 L/min, one of which was sterilized by the addition of NaN₃ (0.1 %). Sediment samples were taken from Taihu Lake and Dianchi Lake, China. For the sediment experiment, 5 g of sediment were weighed into a 50-mL glass tube, with 10 mg/kg of individual SAs. Different experimental conditions including the sediment types, sterilization, light exposure, and redox condition were also considered in the experiments. The three SAs degraded in lake water with half-lives (t _1/2) of 10.5–12.9 days, and the half-lives increased significantly to 31.9–49.8 days in the sterilized water. SMZ and SDM were degraded by abiotic processes in Taihu and Dianchi sediments, and the different experimental conditions and sediments characteristics had no significant effect on their declines. SMX, however, was mainly transformed by facultative anaerobes in Taihu and Dianchi sediments under anaerobic conditions, and the degradation rate of SMX in non-sterile sediment (t _1/2 of 9.6–16.7 days) were higher than in sterilized sediment (t _1/2 of 18.7–135.9 days). Under abiotic conditions, degradation of SMX in Dianchi sediment was faster than in Taihu sediment, probably due to the higher organic matter content and inorganic photosensitizers concentrations in Dianchi sediment. High initial SAs concentration inhibited the SAs degradation, which was likely related to the inhibition of microorganism activities by high SAs levels in sediments. Results from this study could provide information on the persistence of commonly used sulfanomides antibiotics in lake environment.     

卡拉胶、膨润土改性PVA包埋小球

对PVA+卡拉胶包埋小球和PVA+海藻酸钠包埋小球的性能进行比较,并首次使用PVA+卡拉胶+膨润土混合包埋材料制作包埋小球.结果表明,PVA+海藻酸钠包埋小球在制作过程中有一定的拖尾现象,红墨水到达小球中心的时间为80 min,6d可去除50％的COD;PVA+卡拉胶包埋小球更容易成球,而且红墨水到达小球中心的时间为50 min,6d可去除56％的COD.此外,在PVA+卡拉胶包埋材料中添加适量的膨润土可以将红墨水到达小球中心的时间由50 min缩短到30 min.因此,使用PVA+卡拉胶+膨润土的混合材料制作包埋小球是可行的.最后,通过包埋小球处理抗生素废水的正交实验,得出包埋材料中各组分的最佳配比:PVA浓度11％、卡拉胶浓度0.5％、膨润土浓度2.5％.在这种配比下,包埋小球对抗生素废水中COD的去除率可以达到65％左右.     

铈离子光催化降解茜素绿的性能和机理简

主要研究了简单铈离子（Ce³⁺）在紫外光（UV）的作用下对蒽醌染料茜素绿（AG）的光催化降解效果和反应机理。结果表明,UV/Ce³⁺体系能够有效降解AG,初始反应速率随AG浓度的倒数值和Ce³⁺浓度的增加而线性增加,随初始溶液pH的增加先降低后增加,在酸性条件下有很高的TOC去除率。荧光探针实验表明,反应过程中可以产生·OH自由基。UV/Ce³⁺体系对其他类型染料和对硝基苯酚都有较好的降解效果。     

Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age

Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd) and Al concentrations as well as values of Ca/Al in the tip, middle, base sections and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al.