2008年罕见低温冻害对广西甘蔗及蔗糖业的影响

运用统计分析和实地调查方法,结合EOS/MODIS卫星遥感监测结果,分析2008年广西出现罕见低温冻害天气的特征、成因及其对广西甘蔗及蔗糖生产造成的具体影响,为相关部门定量评估这次灾害和制定相应防御对策提供决策参考.     

宽叶香蒲表面流人工湿地脱氮除磷效果研究

以运行A/O工艺的生化反应器出水为处理对象,在中试规模上研究了宽叶香蒲表面流人工湿地的脱氮除磷效果及影响因素.结果表明,在工况Ⅰ条件下,COD去除率为43.2%,COD面积负荷去除率为4.79 g/(m2·d),COD面积负荷去除率常数为0.18 m/d,SS、NH4+-N和NO-3-N的去除率分别为41.2%、9.4%、3.4%,TN去除率为11.8%,TN面积负荷去除率为1.36g/(m2·d),TN面积负荷去除率常数为0.04 m/d,TP去除率为30.1%,TP面积负荷去除率为0.29 g/(m2·d),TP面积负荷去除率常数为0.13 m/d;在工况Ⅱ条件下,COD去除率为18.7%,COD面积负荷去除率为1.19 g/(m2·d),COD面积负荷去除率常数为0.06 m/d,SS、NH4+-N、NO2--N、NO3--N的去除率分别为31.6%、29.8%、65.0%,29.2%.TN去除率为31.4%,TN面积负荷去除率为2.33 g/(m2·d),TN面积负荷去除率常数为0.12 m/d,TP去除率为29.4%,TP面积负荷去除率为0.22 g/(m2·d),TP面积负荷去除率常数为0.11 m/d.在COD面积负荷去除率,TN面积负荷去除率、TP面积负荷去除率分别为4.90～9.80、2.76～8.83、0.57～1.39 g/(m2·d),水力停留时间(HRT)为0.4～1.1 d条件下,随HRT,水温、(NO2+-N+NO3--N)/TN的增加,表面流人工湿地的TN面积负荷去除率线性增加.     

Concentrations, transport, fate, and releases of polybrominated diphenyl ethers in sewage treatment plants in the Pearl River Delta, South China

Wastewater has proved to be a significant source of polybrominated diphenyl ethers (PBDEs) in the environment. Seventeen congeners from tri- to deca-BDEs were determined to characterize the occurrence, fate, and transport of PBDEs in two sewage treatment plants in the Pearl River Delta, South China. The PBDE concentrations varied substantially from 13.3 to 2496.4 ng L(-1) in the raw wastewater, depending on the wastewater types and contents of the suspended particulate matter (SPM). The concentrations declined to 0.9 to 4.4 ng L(-1) in the treated effluent and were closely associated with SPM contents. BDE-209 was the predominant congener in the wastewater and sewage sludge. Most of PBDEs might have ended up in the sewage sludge, with <4.7% being discharged with the treated effluent. The results revealed that PBDEs were not significantly degraded by biological treatment and chlorination in the STPs. An annual release of PBDEs was estimated at 2280 kg/year through wastewater from the Pearl River Delta.     

污染源自动监控系统常见的作弊方式及监管对策

介绍了污染源自动监控系统的工作原理和排污单位在采样子系统、分析子系统、数据采集和通讯子系统常见的作弊方式.作弊方式包括:让采样子系统采不到企业真实排放的污染物样品;使分析子系统测量值偏低,设置检测上限;对数据采集和通讯子系统进行设置,模拟假数据上传.针对符种作弊方式提出了相应的监管对策.     

Applying Zonation Methods and Tabu Search to Improve the Ground‐Water Modeling1

Abstract: An optimization procedure combining zonation methods with the Tabu Search method is proposed to identify the spatial distribution of hydraulic conductivity field. Three zonation methods, Voronoi diagram (VD), multiplicatively weighted Voronoi diagram (MWVD), and pattern zonation are adopted for the parameterization purposes. With the consideration of the homogeneity and the heterogeneity, there are four spatial distributions of hydraulic conductivity designed to test whether the parameter structure can be successfully identified. The fitting residual error is first considered to determine an adequate number of zones without over parameterization. Then, the parameter uncertainty is evaluated the decision of the number of zones. The results indicate that the MWVD performs better than other two methods because the MWVD has better flexibility in describing the zonal boundaries with small number of decision variables.     

Alternative immunofluorescent labeling of Cryptosporidium parvum in water samples using semiconductor quantum dots

The application of immunofluorescent labeling using quantum dots for detection of inactivated Cryptosporidium parvum oocysts in spiked water samples (reservoir water, treated wastewater effluent, permeate of a membrane bioreactor, and tap water) provided more consistent results compared with the organic fluorophores label. The varying degree of particles present in the different water samples (with turbidity ranging from 0.2 to 6.1 NTU) in nonconcentrated water samples had insignificant interference on the labeled counts (2-sample t-tests, p > 0.236) using the quantum dot label, while the quantum dot label provided an advantage of approximately 50% lower interference in concentrated water samples compared with the organic fluorophores label.     

钢渣吸附剂吸附机理的研究

采用间歇振荡法,研究了钢渣吸附模式、选择性以及等温吸附方程。结果表明,钢渣对阳离子的吸附容量远远大于对阴离子的吸附容量,其吸附模式属于离子交换;其对重金属离子具有一定的吸附选择性,其选择性能与离子的电性、电价、离子半径和水化热等因素有关;钢渣吸附Pb²⁺是单层吸附,符合Langmuir等温吸附方程。     

Trichoderma atroviride F6 improves phytoextraction efficiency of mustard (Brassica juncea (L.) Coss. var. foliosa Bailey) in Cd, Ni contaminated soils

Trichoderma atroviride F6, isolated from decaying feather and resistant to 100 mg l(-1) Cd2+ and 250 mg l(-1) Ni2+, was applied for rhizoremediation of Cd, Ni and Cd-Ni combination contaminated soils through association with Brassica juncea (L.) Coss. var. foliosa. The strain significantly alleviated the cellular toxicity of cadmium and nickel to plants. Inoculation of B. juncea (L.) Coss. var. foliosa with T. atroviride F6 resulted a 110%, 40% and 170% increase in fresh weight in Cd, Ni and Cd-Ni contaminated soils, respectively (P<0.05). The translocation factors and metal bioconcentration factors calculated for the inoculated plant were increased compared to the noninoculated plants. The results indicated that the efficiency of phytoextraction for B. juncea (L.) Coss. var. foliosa enhanced after inoculating with T. atroviride F6. The fungal treated plants grown in Cd-Ni combination contaminated soils showed higher phytoextraction efficiency than those in Cd or Ni contaminated soils. Thus, it is suggested that the fungus T. atroviride F6 endowed with organic-degrading capabilities could be exploited for fungi-assisted phytoremediation of mixed organic-metal contaminated soils.     

全氟辛酸(PFOA)对菲律宾蛤仔体内酶活性的影响

采用半静态毒性实验方法,将菲律宾蛤仔(Ruditapes philippinarum)分别暴露于0.2、2、20μg·L-1的全氟辛酸(perfluorooctanoic acid,PFOA)中,在处理后第1、3、6、10、15、21天分别取样,测定整体组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、谷胱甘肽-S-转移酶(GST)、7-乙氧基异吩噁唑酮脱乙基酶(EROD)活性和过氧化脂质(LPO)含量。酶活性分析结果显示:PFOA对菲律宾蛤仔组织SOD、CAT和POD活性均呈现先促进后抑制的作用;低浓度组SOD活性在暴露第1天达到最高,显著高于对照组(P<0.01);中高浓度组SOD活性在暴露第6天达到最低;暴露1~15 d,低浓度组CAT活性均显著高于对照组(P<0.05);高浓度组CAT活性在暴露第6天得到显著诱导,其余时间基本处于抑制状态;中浓度组POD活性在暴露第3天即达到最高,高浓度组POD活性基本一直处于抑制状态;随着PFOA暴露时间的延长,菲律宾蛤仔组织LPO含量呈现了先降低后升高的趋势;各浓度组中EROD的活力都显著被诱导(P<0.01),与处理浓度呈正相关;中高浓度组的GST活性在胁迫期间变化比较显著,呈现诱导-抑制的变化规律。研究表明,PFOA暴露能够引起菲律宾蛤仔组织抗氧化酶和生物转化酶的变化,可以与其他敏感性指标一起作为指示早期海洋PFOA污染的生物标志物。     

新烟碱类杀虫剂呋虫胺对意大利蜜蜂的安全性评价

呋虫胺作为新一代烟碱类农药,究竟会给蜜蜂造成何种影响尚不清楚。本研究选取意大利蜜蜂为研究对象,分别测定呋虫胺对蜜蜂的急性毒性、慢性毒性以及幼虫发育毒性,并通过其危害商值(hazard quotient,HQ)初步评价呋虫胺对蜜蜂的生态风险,综合评价呋虫胺对蜜蜂的安全性。结果表明,急性经口毒性48 h半数致死剂量(48 h-LD50)为0.033μg·蜂-1,对蜜蜂高毒;慢性毒性10 d半数致死剂量(10 d-LDD50)为0.010μg·蜂-1,慢性毒作用带比值为3.5,存在慢性中毒的风险;幼虫7 d半数致死剂量为577 ng·幼虫-1,高剂量呋虫胺对蜜蜂幼虫存活率、化蛹率和羽化率均存在影响,处理剂量越高,存活率、化蛹率和羽化率越低,呈高度负相关(r=-0.98,-0.89,-0.80)。风险评价结果表明,呋虫胺对蜜蜂为中等风险到高风险。研究可为呋虫胺的合理使用提供科学参考。