Population genetic structure of the neon damselfish (<Emphasis Type="Italic">Pomacentrus coelestis</Emphasis>) in the northwestern Pacific Ocean

The population genetic structure of the neon damselfish (Pomacentrus coelestis) in the northwestern Pacific Ocean was revealed by the hypervariable control region of the mitochondrial gene (343 bp). In total, 170 individuals were sampled from 8 localities distributed between Taiwan and Japan, and 71 haplotypes were obtained through sequence alignment. High haplotype diversity (h = 0.956 ± 0.008) with low nucleotide diversity (π = 0.010 ± 0.006) was observed, and the results of the mismatch distribution test suggested that a historical population expansion after a period of population bottleneck might have occurred among P. coelestis populations. Based on the results of the UPGMA tree and AMOVA (Φct = 0.193, P < 0.05) analyses, fish populations from eight localities could be divided into two groups: one includes populations from localities around mainland Japan, and the other includes those from Okinawa and southern Taiwan. A genetic break was found between populations from mainland Japan and Okinawa, and this break was congruent with the pattern of phenotypic variations documented in previous studies. This evidence supports the latitudinal variation of reproductive traits among P. coelestis populations likely being genetically based. It is suggested that the changes in sea level and sea surface temperatures during past glaciations might have resulted in population bottlenecks in P. coelestis and the modern populations in the northern West Pacific are likely the results of recolonization after such events. The Kuroshio Current acts not only as a vehicle for larval transport along its pathway (between populations in southern Taiwan and Okinawa) but also as a barrier for larval dispersal across the Kuroshio axis (between populations in mainland Japan and Okinawa). Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Sorption of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) by clays and organoclays

This study focused on the sorption isotherms of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (p,p'-DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE) on different original clays (i.e., zeolite, montmorillonite and attapulgite) and organoclay complexes. Sorption of organic pollutants was determined using gas chromatographic (GC) techniques to investigate the sorption behavior, and characterize the effect of, different organic cations. The original clays only sorbed low amounts of p,p'-DDT and p,p'-DDE, and the sorptive curves can be classified as L-shaped. Organoclays exhibited higher amounts of p,p'-DDT and p,p'-DDE sorption. The p,p'-DDT and p,p'-DDE sorption increased with increasing total organic carbon (OC) content of the organoclays. For hexadecyltrimethylammonium (HDTMA)-modified organoclays, the dominant adsorptive medium showed the partitioning sorption of hydrophobic-hydrophobic interaction, indicating no competitive sorption. The sorptive curves can be classified as C-shaped of constant partition (CP). However, benzyltrimethylammonium (BTMA)-modified organoclays exhibited competitive sorption. The sorption isotherm curves can be classified as S-shaped. The sorptive capacity of the HDTMA-modified organoclays for p,p'-DDT were higher than those for p,p'-DDE, but the BTMA-modified organoclays showed a reverse trend. This can be attributed to the different structures and shapes of organic cations, giving different sorptive mechanisms. The p,p'-DDT and p,p'-DDE sorption onto HDTMA-modified organoclays were caused by chemical interaction, with the BTMA modified organoclays occuring due to physical sorption.     

Persistence and dissipation of synthetic pyrethroid pesticides in red soils from the Yangtze River Delta area

Laboratory incubation trials were conducted to investigate the effects of several factors on the persistence as well as the dissipation of three synthetic pyrethroid pesticides in red soils obtained from the Yangtze River Delta region in China. The pyrethroids selected for investigation were cypermethrin, fenvalerate, and deltamethrin, which continue to be used extensively to control pests on farmland in the region despite the concern that they are highly toxic to certain vertebrate and mammalian species. Data from this exploratory study showed that the dissipation half-lives (T _1/2) tended to correlate with soil pH and soil organic matter contents, but not with soil cation-exchange capacity. The T _1/2 values were seen to be shorter in soil samples fertilized with glucose than without. The rates of pyrethroid dissipation also tended to increase with increasing initial soil concentration, but were largely unaffected by whether the pesticides were present in the soil separately or as a mixture. Another noteworthy observation is that microbial activity appeared to dominate the degradation process. Findings of this type could offer valuable clues for future research directions in reducing pesticide persistence in soil, which in turn could lead to the ultimate reduction of environmental pollution caused by pyrethroid application to farmland in the region. Project supported by Chinese Academy of Sciences (Project No. KSCX2-YW-N-038) and the National Key Basic Research Support Foundation (973), China (No. 2002CB4108010).     

憎水性污染物在表面活性剂溶液中的增溶动力学

为了解表面活性剂溶液对憎水性污染物增溶过程的影响因素,研究六氯乙烷在Ｔｗｅｅｎ２０溶液中的增溶动力学过程,建立了六氯乙烷在表面活性剂溶液中增溶的传质模型．模型表明当六氯乙烷总表面积固定时,其溶解速率同六氯乙烷在表面活性剂溶液中的表观溶解度和表观传质系数呈正相关．发现六氯乙烷在表面活性剂溶液中的表观传质系数和纯水中的相比降低了,但由于表面活性剂对六氯乙烷的增溶作用导致其溶解速率总体上是提高的     

无机离子SO42-对小麦幼苗积累稀土的影响

采用ＭＩＮＴＥＱＡ 程序计算出在无机离子SO₄^2-存在下,轻（Ｌａ）、中（Ｇｄ）、重（Ｙ）３ 种稀土元素在溶液中的形态分布．研究了在水培条件下ＳＯSO₄^2-对３种稀土元素在小麦幼苗根、茎和叶部的积累规律．热力学实验表明,小麦幼苗在加SO₄^2-的稀土元素溶液中培养３０ｄ 后,小麦根部对Ｌａ、Ｇｄ 的积累受抑制,而对Ｙ的积累却明显提高;加入SO₄^2-后茎叶部对Ｌａ、Ｙ积累值改变不明显,但对Ｇｄ的积累有所增加．生长动态实验表明,在SO₄^2-存在下,小麦幼苗根部对稀土的积累随时间增加而增加,其积累值符合线性递增函数方程,相关系数ｒ＞ ０．９４;而茎叶部最初积累能力较强,SO₄^2-的加入对小麦植株动态吸收稀土规律无明显影响．     

络合萃取法与生物法处理含酚废水技术经济比较

从技术经济角度对络合萃取法与生物法处理含酚废水进行了比较。建立了投资及净现值与处理量和浓度的关系式。结果表明：当浓度小于265mg/L时,络合萃取法与生物法随处理量的不同在投资上存在差别;当浓度大于265mg/L时,无论处理量为多少,络合萃取法的投资始终小于生物法的投资。对于处理量较大、浓度较高的废水,采用络合萃取法能获得较大的净现值（NPV）;当回收酚时,盈亏平衡点的浓度为1000mg/L,高于此浓度,络合萃取法处理为盈利项目。     

乡镇工业小区能源综合利用与污染控制

根据工业小区内企业的用能强度与生活布局的相互关系,首次对各类乡镇工业小区进行用能类型划分,将乡镇工业小区作为一个系统,工业小区内的用能企业和排污企业作为子系统,通过对不同用能类型的工业小区内重点耗能企业用能效率和重点污染企业综合治理的评价,找出适合乡镇企业特点,并在经济技术上可行的能源综合利用与污染集中控制的措施,提出以下几点政策建议：小区的基础设施建设和污染治理设施进行统筹考虑;能源环境综合治理应纳入小区总体规划之中;根据国家有关节能法规,制定不同类型工业小区能源综合利用效率标准和相应的产品单耗标准,推广清洁生产和污染物资源化处理技术     

Holographic quantitative structure-activity relationship for prediction acute toxicity of benzene derivatives to the guppy (Poecilia reticulata)

Holographic quantitative structure-activity relationship(HQSAR) is an emerging QSAR technique with the combined application of molecular hologram, which encoded the frequency of occurrence of various molecular fragment types, and the subsequent partial least squares(PLS) regression analysis. In this paper, the acute toxicity data to the guppy( poecilia reticulata) for a series of 56 substituted benzenes, phenols, aromatic amines and nitro-aromatics were subjected and this resulted in a model with a high predictive ability. The influence of fragment size and fragment distinction parameters on the quality of HQSAR model was investigated. The robustness and predictive ability of the model were also validated by leave-one-out (LOO) cross-validation procedure and external testing data set.     

Binding of pyrene to dissolved organic matters: fractionation and characterization

Based on a modified Leenheer DOM fractionation scheme, fractionation of DOM from the paddy soil was conducted by using XAD-8 resin into hydrophobic bases ( HOB), hydrophobic acids ( HOA), acid-insoluble matter ( AIM), hydrophobic neutrals ( HON ) and hydrophilic matter(HIM). In total carbon content of DOM, 35.32% were the HIM and only 0.73% the HOB. However, HOA and AIM altogether occupied 53.45%, while the HON fraction represented 10%. The sorption experiments were conducted to determine the sorption capacity of pyrene on unfractionated DOM and its fractions. Elemental analysis, ^1H-NMR and FTIR spectra were carried out on unfractionated DOM and its fractions to examine the relationship between the structure of DOM and partition coefficients( Kac ). The results showed that HON had a greater affinity for binding pyrene than other fractions. While HON was characterized by large long-chain alkylate (aliphatic structure). AIM exhibited relative higher Kac values than HOA and HIM, due to much aromatic structure in AIM, while the high content of carboxylic groups of HOA and HIM depressed their binding capacity. This study demonstrated HON is a key subcomponents of DOM in binding of pyrene, in other words, aliphalic structure in DOM play an important role in binding of pyrene.     

Light-induced variation in environmentally persistent free radicals and the generation of reactive radical species in humic substances

• Light irradiation increased the concentration of free radicals on HS. • The increased spin densities on HS readily returned back to the original value. • The “unstable” free radicals induced the formation of reactive radical species. • Reactive radicals’ concentration correlated strongly with EPFRs’ concentration. Environmentally persistent free radicals (EPFRs) in humic substances play an essential role in soil geochemical processes. Light is known to induce EPFRs formation for dissolved organic matter in aquatic environments; however, the impacts of light irradiation on the variation of EPFRs in soil humic substances remain unclear. In this study, humic acid, fulvic acid, and humin were extracted from peat soil and then in situ irradiated using simulated sunlight. Electron paramagnetic resonance spectroscopy results showed that with the increasing irradiation time, the spin densities and g-factors of humic substances rapidly increased during the initial 20 min and then gradually reached a plateau. After irradiation for 2h, the maximum spin density levels were up to 1.63 × 10¹⁷, 2.06 × 10¹⁷, and 1.77 × 10¹⁷ spins/g for the humic acid, fulvic acid, and humin, respectively. And the superoxide radicals increased to 1.05 × 10¹⁴–1.46 × 10¹⁴ spins/g while the alkyl radicals increased to 0.47 × 10¹⁴–1.76 × 10¹⁴ spins/g. The light-induced EPFRs were relatively unstable and readily returned back to their original state under dark and oxic conditions. Significant positive correlations were observed between the concentrations of EPFRs and reactive radical species (R² = 0.65–0.98, p<0.05), which suggested that the newly produced EPFRs contributed to the formation of reactive radical species. Our findings indicate that under the irradiation humic substances are likely to be more toxic and reactive in soil due to the formation of EPFRs.