氯代阻燃剂得克隆对纤细裸藻的生态毒性效应

得克隆(Dechlorane Plus,DP)作为全球广泛使用的氯代阻燃剂,具有POPs特性和环境毒性,但其生物毒性数据非常有限。本文选择水生初级生产者纤细裸藻(Euglena gracilis)作为研究对象,通过检测藻细胞生长状况、光合色素水平、抗氧化酶活性、谷胱甘肽(GSH)和丙二醛(MDA)含量变化,研究了不同浓度DP对其生态毒性效应的影响。结果显示,低浓度DP对纤细裸藻生长具有一定促进作用,但差异不显著;DP浓度较低时(0.1和0.5 mg·L-1DP)类胡萝卜素含量受到轻微抑制;较高浓度DP暴露导致超氧化物歧化酶(SOD)、过氧化物酶(POD)和谷胱甘肽(GSH)水平显著增加,同时高浓度DP(8 mg·L-1)下MDA含量显著上升,提示膜结构受到损伤;表明较高实验浓度范围内,DP对纤细裸藻的生长及抗氧化系统均产生一定影响,结果将为DP的环境生态风险评价提供科学依据。     

毒死蜱对紫金山森林土壤酶活力及微生物毒性影响研究

毒死蜱是有机磷类农药,对乙酰胆碱酯酶具有抑制作用,在农业虫害防治中应用广泛。为掌握毒死蜱对森林土壤酶活力和土壤微生物生态效应,选择紫金山森林土作为受试土壤,采用室内培养法,研究了毒死蜱对土壤蔗糖酶、脲酶、酸性磷酸酶和过氧化氢酶,以及土壤呼吸强度和氮素硝化作用的影响。结果表明:试验期间,1.25 mg a.i.·kg-1、12.5 mg a.i.·kg-1和125 mg a.i.·kg-1毒死蜱对土壤脲酶、酸性磷酸酶总体表现为抑制作用;对土壤蔗糖酶和过氧化氢酶的影响与暴露剂量和暴露时间有关,在60 d时,Z1低剂量处理组(1.25 mg a.i.·kg-1)蔗糖酶和过氧化氢酶可恢复,Z100高剂量处理组(125 mg a.i.·kg-1)抑制作用不能解除。试验初期,毒死蜱对土壤呼吸强度有一定刺激作用随后逐渐恢复;对土壤氮硝化作用影响表现为先促进后抑制,且抑制作用有长期影响。由此可知,毒死蜱使用对紫金山森林土的土壤酶活性和土壤微生物产生毒性效应,具有一定生态风险。     

Hyperaccumulation of zinc by Corydalis davidii in Zn-polluted soils

A field survey was conducted to identify potential Zn accumulators from an artisanal Zn smelting area in southwest China’s Guizhou Province. Hydroponic and soil culture experiments were performed to investigate the accumulation ability of Zn in Corydalis davidii. Zn concentrations in roots, stems and leaves of C. davidii in the smelting site were 1.1-3.5, 1.2-11.2, and 3.3-14 mg g⁻¹, respectively, whereas Zn concentrations in roots, stems and leaves of C. davidii in the contaminated site impacted by the Zn smelting were 1.0-2.4, 1.9-6.5, and 3.0-1.1 mg g⁻¹, respectively. Zn concentrations in leaves and stems of C. davidii were observed at above 10 mg g⁻¹ that refers to the threshold of Zn hyperaccumulator. The concentration distribution of Zn in C. davidii was leaf > stem > root, and the Zn bioaccumulation factors of C. davidii were above 1. It is concluded that C. davidii has high tolerance to concentrate Zn stress, and that C. davidii is a newly discovered Zn-hyperaccumulator with high biomass in the aboveground parts. Based on the cultivation experiments, C. davidii could reduce Zn concentration by 26.6, 21.2, and 10.2 mg kg⁻¹yr⁻¹ by phytoextraction from the smelting slag, Zn-contaminated soil, and background soil, respectively.     

低温胁迫对番茄光合特性及抗氧化酶活性的影响

根据番茄对低温的反应,于2010年10月-2011年3月间,设计了人工控制试验系统以研究低温胁迫(5℃,7℃,9℃,11℃)对设施番茄光合色素含量、最大光合速率、叶绿素荧光参数、抗氧化酶活性的影响,为设施番茄低温致灾气象指标的确定提供依据。结果表明:不同低温胁迫下叶绿素a,Chla/Chlb和最大光合速率均存在不同程度的降低,而叶绿素b和类胡萝卜素含量则有所升高。低温5℃处理3 d和7℃处理4 d后番茄最大光合速率均为负值,经过25℃恢复5 d后仍无显著升高;低温9℃、11℃胁迫下番茄最大光合速率随处理天数的增加而降低,且经过5 d的恢复处理后最大光合速率可以基本恢复至正常水平。叶绿素荧光参数分析表明,低温胁迫降低了PSII的原始光能转换效率和潜在活性,番茄的Fv/Fm,qP,ETR均显著降低,且随胁迫温度和胁迫时间的不同,Fv/Fm,qP,ETR的变化程度有所不同。不同低温胁迫使得番茄SOD,POD,CAT,MDA酶的活性均有不同程度升高,且温度越低,处理时间越长,升高幅度越大。因此,低温5℃处理3 d或者低温7℃处理4 d是番茄发生严重冷害的临界指标,该研究结果可为作物低温灾害防御及气象灾害预警提供参考。     

不同存放时间太湖蓝藻产沼气潜力

对不同存放时间蓝藻(新鲜蓝藻、存放3个月、6个月和9个月)进行厌氧消化处置,分析反应过程中沼气量、代谢产物和酶活等变化,获得各自的产沼气潜力。研究结果表明,存放6个月蓝藻组的产沼气率最大,为120.5 mL/g TS,是新鲜蓝藻组的1.29倍。Gompertz模型拟合表明,随着存放时间的延长,最大产沼气量(Pmax)先增大后减小,最大比产气率一直增加。存放3个月蓝藻组的VFA在第6天达到最大,为1 575.4 mg/L,而存放9个月蓝藻组的VFA在第2天达到最大,为1 116.5 mg/L。存放3个月蓝藻组的最大中性蛋白酶酶活为1 203.4μg/(g TS.h),比新鲜蓝藻组提高212.8μg/(gTS.h)。脱氢酶酶活随着蓝藻存放时间的增加呈现先增加后减小的趋势。     

复合型杀菌剂对生物粘泥处理效果的研究

为了解决循环冷却水系统中生物粘泥大量滋生的问题,设计实验,考察了一定浓度的复合酶制剂与常规杀菌剂复配使用对生物粘泥的处理效果。研究结果表明,在酶制剂的辅助下,杀菌剂苯扎溴胺对生物粘泥的作用效果明显增加。180 mg/L是苯扎溴胺与酶复配的最佳浓度;酶与醋酸氯已定复配后对生物粘泥的杀菌效果有所增高,80 mg/L是醋酸氯...     

Cd、Zn、Pb单因素及复合污染对土壤酶活性的影响

通过Ｃｄ、Ｚｎ、Ｐｂ单因素处理和复合因素处理的对比性研究发现,无论是单因素或复因素对土壤酶活性的抑制效应顺序均为 Ｃｄ＞ Ｚｎ＞ Ｐｂ;在所研究的 ４种土壤酶中,脲酶受重金属的抑制作用最为敏感; Ｃｄ、 Ｚｎ、 Ｐｂ复合污染与各单因素的影响有较大差异,同时,Ｃｄ、Ｚｎ、Ｐｂ复合污染对４种土壤酶活性的影响效应亦不同。其复合污染对脲酶表现出协同抑制负效应的特征;对过氧化氢表现出一定的屏蔽作用或拮抗作用;转化酶和碱性磷酸酶主要因Ｃｄ浓度的变化而变化。     

基于利益相关者理论的企业环境绩效影响因素研究

基于利益相关者理论,通过构建企业环境绩效与企业受到各利益相关者环境压力的计量模型,并在江苏常熟地区展开问卷调查,分析了影响企业环境绩效的利益相关者,结果表明:在该实证区域,以主动性环境管理行为度量企业环境绩效时,投资者、竞争者、消费者和社区居民等外部利益相关者对企业环境绩效的提高有显著的正影响;政府虽然给企业造成了很高的环境压力,但并不是造成企业之间环境绩效差异的原因;媒体和环保非政府组织等外部利益相关者作用尚不明显.结论说明:我国政府通过引入利益相关者参与企业环境治理,已经取得一定成效.建议我国政府继续推动环境政策创新,积极创造更多利益相关者成长的制度空间,为我国企业环境绩效的提高提供更多动力.     

Ecotoxicological responses of the earthworm Eisenia fetida exposed to soil contaminated with HHCB

Although polycyclic musks have been shown to cause lethal and sub-lethal effects on organisms, their biochemical toxicity to earthworms is not well understood. In the current study, we investigated the responses of antioxidant systems and lipid peroxidation after exposing Eisenia fetida to soil contaminated with 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta-γ-2-benzopyran (HHCB). Significant increase in lipid peroxidation level was observed on day 14 at two high concentrations, 50 and 100 mg kg⁻¹. Among antioxidant enzymes, the primary response to chronic HHCB exposure can be attributed to superoxide dismutase (SOD) and catalase (CAT). Of the two enzymes, SOD exhibited more sensitive response to HHCB stress. In addition, these two enzymes could have a combined effect on fighting damage by reactive oxygen species, evidenced by a marked relationship between lipid peroxidation and enzyme activity. On the other hand, dose-dependent inhibition of peroxidase (POD) activity has been observed throughout the test. The results suggest that the variations in investigated parameters of E. fetida could be used as responsive biomarkers for oxidative stress caused by HHCB in a soil environment.     

Assessment of typical pollutants in waterborne by combining active biomonitoring and integrated biomarkers response

Organic pollutants, heavy metals and pharmaceuticals are continuously dispersed into the environment and have become a relevant environmental emerging concern. In this study, a situ assay to assess ecotoxicity of mixed pollutants was carried out in three typical sites with different priority contaminations in Guangzhou, China. Chemical analysis of organic pollutants, metals and quinolones in three exposure sites were determined by GC-ECD/MS, ICP-AES and HPLC, as well as, a combination of biomarkers including: ethoxyresorufin O-deethylase (EROD); aminopyrine N-demethylase (APND); erythromycin N-demethylase (ERND); glutathione S-transferase (GST); malondialdehyde (MDA); CYP1A; and P-glycoprotein (P-gp) mRNA expressions were evaluated in Mugilogobius abei. Results of chemical analysis in sediment samples revealed that the dominant chemicals were organic pollutants and heavy metals in Huadi River while quinolones in the pond. Bioassays indicated that differences among sites were in relation to some specific biomarkers. EROD and GST activities significantly increased after 72 h in situ exposure, but no difference was observed among the exposure sites. APND, ERND and MDA exhibited dissimilar change patterns for different priority pollutants. CYP1A and P-gp mRNA expressions were significantly induced at all exposure sites, whilst P-gp activity was typical for S2 with the highest levels of quinolones. The molecular biomarkers seemed to be more susceptible than enzyme activities. These assays confirmed the usefulness of applying a large array of various combined biomarkers at different levels, in assessing the toxic effects of mixed pollutants in a natural aquatic environment.