南京市典型地区大气多环芳烃污染特征及健康风险评价

采用气相色谱-质谱法,于2016年9月和12月对南京市2个典型地区大气中16种多环芳烃(PAHs)的质量浓度进行分析,并开展了PAHs组成特征、来源解析及人体健康风险评价研究。结果表明,工业区(六合区)和生活区(江宁区)大气(气态和可吸入颗粒态)中16种PAHs的质量浓度分别为914.82和712.27 ng/m~3,苯并[a]芘毒性等效浓度分别为274.1和309.84 ng/m~3,且呈现冬季高、秋季低的特征。比值法源解析结果表明,燃煤污染是六合区PAHs污染主要来源,而江宁区主要表现为交通污染。人体健康风险评价结果表明,六合区和江宁区人群通过大气吸入PAHs的超额致癌风险分别为5.17×10~(-5)和5.85×10~(-5),均略高于可接受水平10~(-6)。     

铅在搬迁企业原址场地土壤中的空间分布及生态风险

对重庆市某实施搬迁的烧结厂原址场地土壤中的铅进行了测定.采用富集系数法,研究了该企业原址场地土壤中铅的空间分布;采用Hakanson潜在生态危害指数法,评价了土壤铅的生态风险.研究表明,土壤总铅含量在23.4-8.90×10<'3>mg·kg<'-1>之间,其最大含量严重超过国家相应标准(HJ350-2007).土壤铅...     

聚丁二酸丁二醇酯（PBS）生物降解过程对植物生长的影响评价

通过苏丹草（Sorghum sudanense Stapf）、籽粒笕（Amaranthus hypochondriacus L.）、豇豆（Vigna sesquipedalis Wight）种子的发芽试验及其盆栽试验,考察了PBS在土壤浸提液中的生物降解性能,探讨了PBS高聚物、低聚物和合成单体对植物的发芽和生长影响。研究结果表明：①在土壤浸提液中微生物对PBS有一定的降解作用,且在降解过程中,降解液的pH变化不明显;②PBS高聚物的降解产物对植物生长没有影响;③P BS低聚物在降解初期抑制部分植物的幼苗生长,后期对植物的生长没有影响;④当丁二酸的质量浓度低于200 mg.L^-1时,对植物种子的发芽和幼苗生长不会产生影响,当质量浓度高于500 mg.L^-1时,将抑制幼苗生长;当1,4-丁二醇的质量浓度低于2 000 mg.L-1时,对种子的发芽和生长没有影响。     

太湖和巢湖夏季蓝藻水华期间产毒微囊藻和非产毒微囊藻种群丰度的空间分布

应用荧光定量PCR技术对蓝藻水华暴发期间太湖和巢湖水体中产毒微囊藻和总微囊藻种群丰度的空间分布进行了研究.分别以微囊藻毒素合成基因基因家族成员mcyD和小核糖体16S rDNA序列构建定量PCR标准曲线,研究产毒微囊藻和总微囊藻种群丰度.结果表明:太湖和巢湖微囊藻种群由产毒微囊藻和非产毒微囊藻组成;蓝藻水华暴发期间,微囊藻种群组成及其丰度分布具有明显的空间差异性:太湖产毒微囊藻种群丰度为9.89×104～4.51×106 copies mL-1,产毒微囊藻占总微囊藻种群的比例为20.5%～38.1%;巢湖产毒微囊藻种群丰度为4.12×104～5.44×106 copies mL-1,其占总微囊藻种群的比例为8.4%～96.6%.总的来说,富营养化严重的湖区总微囊藻和产毒微囊藻种群丰度较高,产毒微囊藻占总微囊藻种群的比例也较高.图7表3参29     

Analysis of water quality factors influencing the speciation of inorganic nitrogen using GRA

Based on the water quality data from 2006 to 2008, grey relational analysis (GRA) is used to analyze factors that may have influence on the speciation of inorganic nitrogen in the Chengdu section of middle Min river. The results show that water temperature, changing from 20.2 +/- 2.7, 13.4 +/- 5.7 and 16.8 +/- 5.6 degrees C, is the first restrictive factor for the speciation of inorganic nitrogen; it is negatively correlated with the ratio of total ammonia nitrogen to total inorganic nitrogen contents [m(AN)/m(TIN)] in three different periods of wet season, dry season and year-round. The average pH values for years, in wet and dry periods are 7.6 +/- 0.4, 7.3 +/- 0.3 and 7.8 +/- 0.2, respectively, and have different influences in different seasons. It is the second restrictive factor and positive correlation between pH and m(AN)/m(TIN) in wet season and through the year yet it is the fourth factor in dry seasons. The values of dissolved oxygen (DO), which are 4.6 +/- 1.4, 4.6 +/- 2.4, 4.6 +/- 2.0 respectively, is the third factor and negatively correlates with m(AN)/m(TIN) in third different periods. The chemical oxygen demand (COD) indirectly inhibits the nitrifying bacteria because the DO is depleted in the decomposition of organic matter by heterotrophic bacteria, showing the positive correlation.As the alkalinity can meet the requirement of nitrification in wet season and through the year, it is not restrictive factor. However, it is the second restrictive factor in dry season because of low content of alkalinity inhibiting the growth of nitrifying bacteria.     

Effect of arsenic species on the growth and arsenic accumulation in Cucumis sativus

The effects of arsenic (As) species, such as As(III), As(V) and dimethylarsinic acid (DMA), on the accumulation of As in cucumber (Cucumis sativus), as well as on its growth in a soil mesocosm were evaluated. When Cucumis sativus was cultivated in soils contaminated with 20 and 50 mg/kg of As(III), As(V) or DMA for 40 days, the growth was markedly inhibited by the inorganic As (As(III) and As(V)) rather than the organic As (DMA). Irrespective of the As species, the As concentrations accumulated in Cucumis sativus increased with increasing As concentration in the soil. The As bioaccumulation factors from soil into the tissue of Cucumis sativus were 17.5-35.4, 29.3-42.7 and 17.6-25.7 for As(III), As(V) and DMA, respectively. In addition, the As translocation factors from the roots to shoots were 0.025-0.031, 0.018-0.032 and 0.014-0.026 for As(III), As(V) and DMA, respectively. In conclusion, Cucumis sativus mainly accumulated As in its roots rather than its shoots and easily accumulated inorganic rather than organic As from the soil into its tissue.     

密度和品种对玉米田杂草及玉米产量的影响

通过对玉米田杂草的调查,研究了不同密度和品种对玉米田杂草种类和生物量变化及玉米产量的影响。结果表明：在玉米全生育期内共发现以稗草（Echinochloa colonum（Linn.）Link）、水花生（Alternanthera philoxeroides）、水芹（Lepidiumsativum）等为主的21种杂草,以水芹的重要值最高;随密度的增加杂草的总数量和鲜质量减少;半紧凑型品种对杂草数量和生物量的抑制作用大于紧凑型品种,且产量高出了21.99%。密度对玉米产量的影响差异不显著,以B3（57 000株/hm2）产量最高,比常规密度B1（42 000株/hm2）和高密度B4（64 500株/hm2）的产量提高了14.17%和0.6%。可见,应根据玉米的品种类型,因地制宜地确定适宜的种植密度,以利于高产稳产。     

丘陵地区水稻田使用毒死蜱对水体的污染及其生态风险

选择丘陵地区的小规模水稻田作为试验地,调查毒死蜱在该区域水稻田中的使用时间和使用量,监测不同时期水稻田进出水中毒死蜱残留水平.结果显示,毒死蜱使用后水稻田出水中毒死蜱残留水平高于进水,最高达26.07μg.L-1.从河流引入的进水中也存在毒死蜱残留,最高达3.23μg·L-1,说明上游农田已经对河水产生了污染.毒死蜱对斑马鱼(Brachydanio rerio)、大型溞(Daphnia magna)和斜生栅列藻(Scenedesmus obliquus)的急性毒性测定结果分别为:斑马鱼,ρ(96h,LC50)为1.11mg·L-1;大型溞,ρ(48 h,EC50)为1.44μg·L-1;斜生栅列藻,ρ(72 h,EC50)为0.193 mg·L-1.根据欧盟急性毒性风险评价标准进行评估,结果表明毒死蜱对水稻田周边水体中鱼类和藻类为低风险,对大型溞为有风险.     

三峡库区水体磷浓度对蓝藻垂直迁移的影响木

通过建立蓝藻细胞内部营养状态磷份额模型和水体磷浓度对蓝藻聚集体垂直迁移影响模型,模拟计算了水体中不同磷浓度对蓝藻聚集体垂直迁移速度及迁移距离的影响.结果表明,蓝藻细胞内磷份额与水体中的磷浓度密切相关.当水体磷浓度为0.075 mg·L-1时,水华暴发压力不大;当水体中磷浓度达到0.090 mg·L-1时,最大迁移距离已...