菲律宾蛤仔的呼吸与排泄对三种重金属慢性毒性的反应

作者测定了菲律宾蛤仔的耗氧率、氨氮排泄率和Ｏ／Ｎ比值；探讨了体重和温度等生态因子对其的影响。反映了蛤仔代谢率对Ｈｇ２＋、Ｃｕ２＋和Ｚｎ２＋的慢性毒性反应。结果表明：三种金属及其不同混合方式均对蛤仔的呼吸、排泄和Ｏ／Ｎ比有明显影响；０．０１～０．０６９ｍｇ／ＬＣｕ２＋和０．１～１．５８ｍｇ／ＬＺｎ２＋对蛤仔的耗氧率、氨氮排泄率和Ｏ／Ｎ比影响相对较小；浓度在０．１５８ｍｇ／ＬＣｕ２＋和６．３１ｍｇ／ＬＺｎ２＋以上时，对其代谢将产生显著影响；Ｈｇ２＋在０．００５～０．０５ｍｇ／Ｌ范围内，对蛤仔耗氧率和氨氮排泄率有抑制作用，并使Ｏ／Ｎ比值显著降低。

固相微萃取在评价沉积物中菊酯类农药生物有效性及生物累积中的仿生研究

菊酯类农药已广泛用于农用、卫生、渔业等领域,因高疏水性累积于沉积物中的此类污染物的生物有效性评价对环境风险研究具有重要意义。采用PDMS（聚二甲基硅氧烷）高聚物作为固相微萃取材料,基于热力学平衡微损耗性方法测定了沉积物孔隙水中高效氯氟氰菊酯、联苯菊酯、氯菊酯和甲氰菊酯的自由溶解态浓度（Cfree）;同时将PDMS上菊酯类农药的浓度与菲律宾蛤仔体内生物累积浓度的相关性进行了比较研究。结果表明,该方法可以准确测定菊酯类农药在沉积物孔隙水中的Cfree（23.3~255 ng·L-1）并用于评价此类物质（菊酯类农药）的生物有效性;菲律宾蛤仔对四种菊酯类农药的富集系数（BCF）为27.8~301,相对较小;菊酯类农药在PDMS上的浓度和菲律宾蛤仔体内的浓度满足lg Cb,lip=11.64lg CPDMS-51.29（R2=0.980）的定量关系,相关性极显著（P=0.009）。但生物—沉积物富集系数（BSAF）和PDMS-沉积物富集系数（PSAF）的分析比较发现,基于PDMS和生物体内菊酯浓度极显著相关的仿生应用还有待污染物在菲律宾蛤仔体内生物转化数据的进一步补充和校正。

Evaluating the bioavailability of heavy metals in natural-zeoliteamended aquatic sediments using thin-film diffusive gradients

The effectiveness of natural zeolite amendment of sediments as a restorative material was studied,as was the feasibility of utilizing thin-film gradient diffusion(DGT)as a proxy for the accumulation of heavy metals in Venerupis philippinaram.The results showed that addition of natural zeolite to sediment,significantly decreased the equilibrium partitioning of Cu,Pb,Cd,Cr and As between the sediment pore water and natural zeolite over 24 h by 67%,81%,72%,62%and 71%,respectively.Furthermore,the accumulation of Cu,Pb,Cd,Cr and As in V.philippinaram in the zeolite-amended sediments decreased by 44%,37%,54%,30%and 59%,respectively after 28 days and the absorption rates also declined.The amount of heavy metals enriched into the DGT film and V.philippinaram over 28 days showed a significant correlation(P<0.001)and indicated that DGT has the potential as a proxy to predict the bioaccumulation of heavy metals in benthic organisms in sediments amended by natural zeolite.Further studies focused on the modification of natural zeolite and the predictive ability of DGT in different sediments/organism scenarios are warranted.

Stabilization of heavy metals in sediments:A bioavailability-based assessment of carbon adsorbent efficacy using diffusive gradients in thin films

This study investigated the effectiveness of carbon adsorbents as remediation material for sediments contaminated with heavy metals and the feasibility of utilizing diffusive gradients in thin films(DGT)as a biomimetic tool to estimate the accumulation of heavy metals in Venerupis philippinaram(Manila clam).The results showed that carbon materials had significant inhibitory effects(14.0-53.0%)on the enrichment of heavy metals in organisms and the order of increasing overall inhibitory effect was:charcoal,peat,activated carbon,and biochar.There were significant correlations(P<0.0001)between the four heavy metals accumulated in Venerupis philippinaram and those accumulated in DGT devices after 28 days in the laboratory.Observed concentrations of heavy metals enriched in DGT(5.4-42.0%)were less than accumulations in Venerupis philippinaram.The results of in situ DGT applications showed significant correlations between the amount accumulated in DGT and the acid-soluble portion in sediments for both Cu and Pb,with positive linear correlations and R-squares of 0.97 and 0.92,respectively.These results supported the notion that a DGT device can be used as a biomimetic tool that predicts and monitors the accumulation of heavy metals in aquaculture ponds.Future studies should focus on improving the stabilization of heavy metals in sediments using different types of carbon sorbents,as well as minimizing simulation deviations using DGT.