中间球海胆、光棘球海胆自繁和杂交后代幼体发育及对高温的反应

对中间球海胆Strongylocentrotus intermedius(Si)和光棘球海胆S.nudus(Sn)进行完全双列杂交,通过对自繁后代(Si♀×Si♂、Sn♀×Sn♂)和杂交子代(Si♀×Sn♂、Sn♀×Si♂)的幼体发育进行观察,详细描述了幼体发育各个阶段的形态特征,并在18、22、26、30℃4个温度下对自繁和杂交子代的受精率、孵化率、各幼体时期的畸形率和生长状况进行了测量和分析。结果表明:杂交海胆的受精率均显著低于自繁海胆(P<0.05),Si♀×Sn♂杂交海胆在18℃时的孵化率与自繁海胆无显著性差异(P>0.05);Si♀×Sn♂杂交海胆幼体形态融合了两种自繁幼体的特征;温度对光棘球海胆自繁和杂交海胆子代的受精率、孵化率均有显著影响(P<0.05),中间球海胆在22℃下的受精率和孵化率最高,而光棘球海胆的最适受精和孵化温度为18℃,Si♀×Sn♂杂交海胆最适受精温度为22℃,而最适孵化温度为18℃;温度对海胆幼体发育的畸形率和生长均有显著影响(P<0.05),3种海胆幼体的最适生长水温均为18℃,Si♀×Sn♂杂交海胆在四腕幼体时期的畸形率最低,体长最小,除在八腕幼体时期畸形率最高外,在六腕幼体和八腕幼体时期的畸形率和生长性状均是介于自繁幼体之间。研究表明,Si♀×Sn♂杂交海胆在胚胎发育早期具有母本的热耐受性和生长劣势,但是随着幼体的生长发育,母性效应逐渐减弱,其在生长方面逐渐体现出父本的生长优势。     

六种海胆及四种杂交海胆管足骨片类型和数量

为研究不同种类海胆Echinoidea管足内骨片类型和数量,利用光学显微镜对6种海胆(中间球海胆Strongylocentrotus intermedius、紫海胆Anthocidaris crassispina、光棘球海胆Mosecentrotus nudus、海刺猬Glyptocidaris crenularis、高腰海胆Mespilia globulus、马粪海胆Hemicentrotus pulcherrimus)及4种杂交海胆(中间球海胆♀×紫海胆♂S.intermedius♀×A.crassipine♂、中间球海胆♀×马粪海胆♂S.intermedius♀×H.pulcherrimus♂、中间球海胆♂×马粪海胆♀S.intermedius♂×H.pulcherrimus♀、中间球海胆♀×光棘球海胆♂S.intermedius♀×A.crassipine♂)管足的骨片进行了观察统计并分析。结果表明:10种海胆共有C形体、S形体、杆状体、三叉形体、海马状体5种骨片类型,且不同种海胆骨片类型和数量存在显著性差异;杂交海胆未产生新的骨片类型,拥有双亲的部分骨片类型,在骨片数量上倾向于双亲的平均值。研究表明,利用海胆管足内骨片类型和数量可完全区分出这10种海胆,本研究结果可为海胆分类提供理论依据,也可为杂交种的鉴定提供参考。     

六种海胆及四种杂交海胆管足骨片类型和数量

为研究不同种类海胆Echinoidea管足内骨片类型和数量,利用光学显微镜对6种海胆(中间球海胆Strongylocentrotus intermedius、紫海胆Anthocidaris crassispina、光棘球海胆Mosecentrotus nudus、海刺猬Glyptocidaris crenularis、高腰海胆Mespilia globulus、马粪海胆Hemicentrotus pulcherrimus)及4种杂交海胆(中间球海胆♀×紫海胆♂S.intermedius♀×A.crassipine♂、中间球海胆♀×马粪海胆♂S.intermedius♀×H.pulcherrimus♂、中间球海胆♂×马粪海胆♀S.intermedius♂×H.pulcherrimus♀、中间球海胆♀×光棘球海胆♂S.intermedius♀×A.crassipine♂)管足的骨片进行了观察统计并分析。结果表明:10种海胆共有C形体、S形体、杆状体、三叉形体、海马状体5种骨片类型,且不同种海胆骨片类型和数量存在显著性差异;杂交海胆未产生新的骨片类型,拥有双亲的部分骨片类型,在骨片数量上倾向于双亲的平均值。研究表明,利用海胆管足内骨片类型和数量可完全区分出这10种海胆,本研究结果可为海胆分类提供理论依据,也可为杂交种的鉴定提供参考。     

中间球海胆与马粪海胆杂交后代幼胆期耐热性研究

为探明中间球海胆Strongylocentrotus intermedius(Si)和马粪海胆Hemicentrotus pulcherrimus(Hp)杂交后代(Si♀×Hp♂和Hp♀×Si♂)的耐热性能,分别对两亲本及其正反交后代的幼海胆进行了快速升温试验,通过观察生存状态并测量生存时间,比较了两亲本及其正反交后代幼胆期的耐热指数(Upper thermal tolerance, UTT)差异,并计算了两种杂交海胆生长早期在耐热指数上的杂种优势。结果表明:在快速升温条件下,4种海胆开始死亡时的温度由高到低依次为Hp(31.5℃)、Hp♀×Si♂(30℃)、Si♀×Hp♂(29.5℃)和Si(28℃),杂交后代Hp♀×Si♂和Si♀×Hp♂分别较中间球海胆高2、1.5℃,分别较马粪海胆低1.5、2℃;生存分析表明,总体生存时间分布由长至短依次为Hp、Hp♀×Si♂、Si♀×Hp♂和Si,4种海胆生存时间两两间均存在极显著性差异(P<0.01);4种海胆的耐热指数由高到低依次为Hp(6864.44℃·h)、Hp♀×Si♂(4955.42℃·h)、Si♀×Hp♂(4136.46℃·h)和Si(1167.42℃·h),不同种类的耐热指数相互之间均存在显著性差异(P<0.05);杂交后代Hp♀×Si♂和Si♀×Hp♂在耐热指数上分别表现出23.39%和3.00%的中亲杂种优势;两种杂交后代虽然相较于马粪海胆分别表现出-39.74%～-27.81%的单亲杂种劣势,但相较于中间球海胆均表现出254.23%～324.37%的单亲杂种优势。研究表明,中间球海胆与马粪海胆正反交后代均可作为培育耐高温海胆新品种的候选种类。     

饲料脂肪水平对中间球海胆幼胆生长、消化酶和热胁迫后抗氧化酶活力的影响

为了确定中间球海胆Strongylocentrotus intermedius幼胆饲料中适宜的脂肪水平,采用摄食生长试验探讨了饲料中脂肪水平(3%、6%、9%、12%和15%)对海胆幼胆存活、生长、消化酶和热胁迫后抗氧化酶活力的影响,试验共进行96 d。结果表明:试验结束时,6%饲料脂肪水平组海胆增重率最高,显著高于15%脂肪组(P<0.05);随着饲料脂肪水平的升高,中间球海胆消化道中脂肪酶活力显著升高(P<0.05),淀粉酶活力显著下降(P<0.05),胃蛋白酶活力有下降趋势(P>0.05);饲料脂肪水平显著影响热胁迫后海胆体腔液中抗氧化酶活力,其中热胁迫2 h后,12%脂肪组超氧化物歧化酶(SOD)活力最高,显著高于15%脂肪组(P<0.05);热胁迫6 h后,海胆体腔液过氧化氢酶(CAT)活力最高值出现在6%脂肪组,且高于12%和15%脂肪组。研究表明,6%饲料脂肪水平时中间球海胆幼胆的生长速率最快,6%¹2%饲料脂肪水平能够显著提高热胁迫后海胆的抗氧化能力。     

光棘球海胆性腺氨基酸组成的研究

于2006年5、6、8月测定了光棘球海胆Strongylocentrotus nudus雌、雄个体性腺中氨基酸含量及组成。结果表明:光棘球海胆氨基酸含量为30.75%⁴8.52%(质量分数,下同),其中鲜味氨基酸含量为15.33%48.52%(质量分数,下同),其中鲜味氨基酸含量为15.33%²1.84%,必需氨基酸含量占氨基酸总量的42.67%21.84%,必需氨基酸含量占氨基酸总量的42.67%⁵2.50%,鲜味氨基酸含量占总氨基酸含量的43%以上。光棘球海胆中甘氨酸含量最高(3.76%52.50%,鲜味氨基酸含量占总氨基酸含量的43%以上。光棘球海胆中甘氨酸含量最高(3.76%⁵.02%),谷氨酸含量(2.99%5.02%),谷氨酸含量(2.99%⁴.79%)次之;雌、雄个体以及排放精、卵时其氨基酸组成变化较大;过熟及迟熟的海胆无论是氨基酸总量,还是必需氨基酸、鲜味氨基酸含量都低于早期成熟海胆;雄性海胆性腺鲜味氨基酸含量高于雌性,因此雄性更美味。研究表明,生产中采集海胆最好在海胆早期成熟阶段,在海胆成熟后期自然排放之前采收完毕。     

杂交海胆与两亲本性腺一般营养成分及脂肪酸组成的分析比较

采用毛细管色谱柱,对以中间球海胆Strongylocentrotus interm edius为母本、光棘球海胆S.nudus为父本的杂交海胆及其两亲本性腺脂肪酸进行了检测,并用常规方法检测其一般营养成分。结果表明:杂交海胆与父、母本的一般营养成分有一定差异,其必需脂肪酸含量显著高于父、母本;旅顺杂交海胆与獐子岛海胆的脂肪酸有差异,主要是由于海域位置不同所致。     

中间球海胆抗病家系的筛选及其生长性能分析

为筛选中间球海胆Strongylocentrotus intermedius抗病家系并分析其生长性能,在建立34个中间球海胆全同胞家系的基础上,采用自然感染的方法对海胆进行病变综合征、掉棘病和黑嘴病的感染并测量这3种疾病下海胆的存活率,通过对不同疾病下的存活率进行加权求和构建了复合抗病指数(CDRI),根据存活率和抗病指数排名筛选出抗病家系,分析抗病家系在幼胆期(7～9月龄)和在不同水温环境下(常温和低温)养成期(14～17月龄)的体质量特定生长率(SGR)与易感家系、所有家系间的差异,并筛选出抗病速生家系。结果表明:病变综合征、掉棘病和黑嘴病自然感染下,各家系的存活率分别为30.9%～95.5%、10.0%～100.0%和5.6%～84.2%,不同家系下海胆的存活率有显著性差异(P<0.05);筛选出F7211-1等家系具有较强的抗病变综合征能力,F7214-1等家系具有较强的抗掉棘病能力,F7214-1等家系具有较强的抗黑嘴病能力;各家系的复合抗病指数为0.29～0.78,家系F7209-1等具有较高的复合抗病能力;相对于选择特定抗病家系,选择复合抗病家系会对幼胆期和不同水温养殖下的养成期生长速度带来更稳定的正向选择差;无论成胆期养殖于常温池还是低温池,F7211-1、F7203-2、F7209-1和F7214-1等家系均兼具抗病和速生的能力,可从中选择种胆用于后代抗病速生群体的培育。研究表明,家系选择可应用于中间球海胆的抗病育种,通过构建复合抗病指数可实现对抗病和生长速度的复合选择。     

中间球海胆与紫海胆种间杂交的受精、孵化和幼体发育研究

为探明中间球海胆Strongylocentrotus intermedius(Si)与紫海胆Anthocidaris crassispina(Ac)种间杂交的受精、孵化和幼体发育规律,对中间球海胆和紫海胆进行种间杂交,检测了不同水温和精子种类对海胆受精卵卵径、受精率和孵化率的影响,并对自繁和杂交海胆幼体发育时间和体长进行了测定和比较。结果表明:受精前中间球海胆卵径(86.64μm±4.21μm)极显著小于紫海胆(95.62μm±3.80μm)(P<0.01);在21℃和24℃下,自交组Si♀×Si♂受精卵卵径显著或极显著大于杂交组Si♀×Ac♂(P<0.05或P<0.01),而杂交组Ac♀×Si♂和自交组Ac♀×Ac♂受精卵卵径则不受水温(24℃和26℃)的影响;相同温度下,种间杂交受精率均极显著低于自繁受精率(P<0.01),Si♀×Si♂组(或Si♀×Ac♂组)受精率在21℃和24℃下无显著性差异(P>0.05),而杂交组Ac♀×Si♂在26℃下的受精率极显著高于24℃下(分别为38.91%±8.25%和0.79%±1.11%)(P<0.01);杂交组Si♀×Ac♂在21℃下的孵化率(87.96%±4.18%)极显著低于自交组Si♀×Si♂(99.64%±0.81%)(P<0.01),而在24℃下,这两组海胆均不能孵化,杂交组Ac♀×Si♂在24℃下的孵化率(9.32%±4.33%)极显著低于自交组Ac♀×Ac♂(100%)(P<0.01),而在26℃下则不能孵化;Ac♀×Ac♂组和Ac♀×Si♂组在24℃下经5 d即可发育至八腕幼体,Si♀×Ac♂组在21℃下经9 d发育至八腕幼体,Si♀×Si♂在21℃下经12 d发育至八腕幼体。研究表明,杂交组Si♀×Ac♂适宜在24℃下受精,21℃下孵化,而杂交组Ac♀×Si♂则适宜在26℃下受精,24℃下孵化,杂交组Ac♀×Si♂可能更具备高温耐受能力,可作为耐高温品种培育的重点材料进行进一步研究。     

中间球海胆繁殖前后性腺中脂类和脂肪酸含量变化

为研究中间球海胆Strongylocentrotus intermedius繁殖前后性腺中脂类和脂肪酸含量的变化,采用毛细管气相色谱法对排精/卵前后的中间球海胆性腺中脂类和脂肪酸组成进行了分析比较。结果表明:中间球海胆排精/卵前,雌、雄个体在性腺指数和性腺含水率上无显著性差异(P>0.05),雌性个体性腺中脂类含量显著高于雄性个体(P<0.05);排精/卵前后,海胆性腺中磷脂含量均较高,是海胆脂类的重要组分,排精/卵后,海胆性腺中游离脂肪酸和甘油三酯显著下降(P<0.05),胆固醇在雌性性腺中出现了显著升高(P<0.05);雌、雄海胆性腺中脂肪酸组成种类基本相同,共检测到24种脂肪酸,其中C_(20∶4(n-6))和C_(20∶5(n-3))是主要的不饱和脂肪酸组分,排精/卵后,雄性个体性腺中C_(18∶1(n-9))含量显著升高(P<0.05),雌性个体C_(18∶0)含量显著升高(P<0.05)。本研究结果可为海胆亲本营养繁殖学的研究提供基础数据和理论依据。     

Characterization of PEI-modified biomass and biosorption of Cu(II), Pb(II) and Ni(II)

The objective of this work is to develop a surface-modified biosorbent with enhanced sorption capacity for heavy metal ions. The biomass of Penicillium chrysogenum was modified with polyethylenimine (PEI) and then crosslinked with glutaraldehyde. The crosslinked PEI was chemically bonded on the biomass surface through the amine and carboxylate groups on the pristine biomass. The presence of the amine group was confirmed by X-ray photon spectroscopy (XPS) and Fourier transform infrared (FTIR) analysis, and the concentration of the amine groups on the biomass surface was found to be 2 mmol/g through potentiometric titration. The rugged morphology of the biomass surface after the modification was observed by scanning electron microscope (SEM). Compared with the pristine biomass, the modified biomass with amine groups showed a significant increase in sorption capacity for three metal ions, namely, copper, lead and nickel. The sorption isotherms of the biomass for three metals were well described by Langmuir equation, with a maximum sorption at 92 mg copper, 204 mg lead and 55 mg nickel per g biomass. The binding sites for the three metals attributed to the amine groups on the biomass surface were verified by FTIR analysis.     

Removal of As(III) and As(V) by Tin(II) compounds

The retention capacity for arsenic species of new nanomaterials based on tin(II) inorganic oxides or hybrid (inorganic and organic) materials was studied. The synthesis of a polymer-metal complex was performed with poly(acrylic acid) and tin(II) chloride. Poly(AA)-Sn(II) with 10 and 20 wt% of tin and a structure with a mol ratio tin:carboxylate group of 1:1, were characterized. These compounds with 10 and 20 wt% of tin content were used to compare the arsenic removal capability through the liquid-phase polymer-based retention, (LPR), technique. Also, tin oxide was prepared by adding alkaline solution to tin(II) chloride salt. The intermediate tin compound was studied by UV-Vis spectroscopy at different pH values and quantified by potentiometric titration. The solid structure is characterized by Fourier transformed infrared spectroscopy, X-ray diffraction, and specific area BET (N₂). Removal of arsenite and arsenate species from solution by hydrolysated tin was carried out by LPR technique with ultrafiltration membranes and a fixed-bed column unsupported or supported on SiO₂. In all these cases, a washing method at constant pH was applied. The arsenic retention ability depended on the class of tin compounds prepared, with a higher efficiency for arsenic being observed at basic pH for soluble complex poly(AA)-Sn(II) than that for tin hydroxide or hydrolysate of Sn⁺².     

Cu^2＋、Cd^2＋和Cr^6＋对孔雀鱼的单一与联合毒性效应

采用静水生物测试法研究了Cu、Cd和Cr等重金属对孔雀鱼的单一与联合毒性效应。单一毒性试验结果表明：暴露时间为24,48,72和96h时,Cu^2＋对孔雀鱼的LC50分别为5．70,4．02,2．95和2．36mg／L,Cd^2＋对孔雀鱼的LC50分别为23．24,20．15,18．07和17．71mg／L,Cr^6＋对孔雀鱼的LC50分别为88．56,65．21,47．81和43．40mg／L。3种重金属离子对孔雀鱼均为高毒性,毒性大小为Cu^2＋〉Cdh〉Cr^6＋。联合毒性试验表明：当浓度比为1：1或1：1：1,Cu^2＋与Cd^2＋、Cu^2＋与Cr6＋、Cd^2＋与Cr^6＋以及Cu^2＋、Cd^2＋与Cr^6＋共存时的联合毒性均为毒性增强的协同作用．     

Pb(II)、Cu(II)、Cd(II)在黄土上二元竞争吸附特性研究

铅、铜、镉是3种具有代表性的重金属污染物,可用于模拟多重离子复合污染情况。研究了离子浓度、土水比等因素对3种元素在黄土上二元竞争吸附特性的影响。等温吸附模型Langmuir、Freundlich和D-R模型都能在一定程度上解释Pb(II)-Cu(II)、Pb(II)-Cd(II)、Cu(II)-Cd(II)在黄土上的竞争吸附性能。黄土对Pb(II)、Cu(II)、Cd(II)的选择顺序为Pb(II)>Cu(II)>Cd(II)。相比单一吸附,黄土对每种离子的吸附容量均有不同程度的下降。溶液的初始浓度越大,3种离子在单位黄土上的最大吸附量也随之增大,吸附效率随之降低;适当增大土水比可提高离子的去除效率。试验结果为黄土作为防污屏障和污水处理材料提供了依据。     

Sorption kinetics of Fe(II), Zn(II), Co(II), Ni(II), Cd(II), and Fe(II)/Me(II) onto hematite

The reactions of Fe(II) and other divalent metal ions including Zn, Co, Ni, and Cd on hematite were studied in single and competitive binary systems with high sorbate/sorbent ratios in 10 mM PIPES (pH 6.8) solution under strict anoxic conditions. Adsorbed Me(II) was defined as extractable by 0.5 N HCl within 20 h, and fixed Me(II) was defined as the additional amount that was extracted by 3.0 N HCl within 7 days. Binary systems contained Fe(II) plus a second metal ion. The extent of uptake of divalent metal ions by hematite was in order of Fe> or =Zn>Co> or =Ni>Cd. For all metals tested, there was an instantaneous adsorption followed by a relatively slow stage that continued for the next 1-5 days. This sequence occurred in both single and binary systems, and could have been due to a variety of sorption site types or due to slow conversion from outer- to inner-sphere surface complexes due to increasing surface charge. Sorption competition was observed between Fe(II) and the other metal ions. The displacement of Fe(II) by Me(II) was in order of Ni approximately Zn>Cd, and the displacement of Me(II) by Fe(II) was in order of Cd>Zn approximately Ni>Co. Fixed Fe(II) was in order of Fe+Co (20%)>Fe+Cd (6%)>Fe approximately Zn (4%)>Fe approximately Ni (4%) after 30 days. There was no fixation for the other metals in single or binary systems.     

The sorption of copper(II), manganese(II), zinc(II) and arsenic(III) onto human hair,and their desorption

Human hair has been studied in relation to sorption from aqueous solutions of Cu²⁺, Mn²⁺, Zn²⁺ and AsO₃^3?. At an equilibrium concentration of 0.3 μg ml^?1 the sorptions are relatively low for Mn (1.1 μg g^?1) and As (0.1 μg g^?1), and higher for Zn (10 μg g^?1) and Cu (35 μg g^?1). But only in the case of copper is the sorption significant relative to the indigenous levels of the elements in the hair. The greater sorption of Cu²⁺ may be correlated with better binding to the hair fibre, probably both electrostatically and to the sulphur in the keratin. There appears to be at least three modes of attachment, or three mechanisms of attachment of Cu²⁺ to the hair. An inter-element effect was observed, where Cu²⁺ severely inhibits the sorption of Zn²⁺ and Mn²⁺. Also the total sorption of Cu²⁺ is reduced on zinc or manganese-treated hair. Some comments are made regarding the results and the problems of exogenous contamination of human hair.     

Sorption of Zn(II), Pb(II), and Co(II) using natural sorbents: equilibrium and kinetic studies

Natural Jordanian sorbent (consisting of primary minerals, i.e., quartz and aluminosilicates and secondary minerals, i.e., calcite and dolomite) was shown to be effective for removing Zn(II), Pb(II) and Co(II) from aqueous solution. The major mineral constitutions of the sorbent are calcite and quartz. Dolomite was present as minor mineral and palygorskite was present as trace mineral. The sorbent has microporous structure with a modest surface area of 14.4 m(2)g(-1). pH(zpc) (pH of zero point charge) of the sorbent was estimated by alkaline-titration methods and a value of 9.5 was obtained. The sorption capacities of the metals were: 2.860, 0.320, 0.076 mmol cation g(-1) for Zn(II), Pb(II) and Co(II) at pH 6.5, 4.5 and 7.0, respectively. The shape of the experimental isotherm of Zn(II) was of a "L2" type, while that of Pb(II) and Co(II) was of a "L1" type according to Giles classification for isotherms. Sorption data of metals were described by Langmuir and Freundlich models over the entire concentration range. It was found that the mechanism of metal sorption was mainly due to precipitation of metal carbonate complexes. The overall sorption capacity decreased after acid treatment, as this decreased the extent of precipitation on calcite and dolomite. The effect of Zn(II) ions concentration on sorption kinetics was investigated. Kinetic data were accurately fitted to pseudo-first order and external diffusion models which indicated that sorption of Zn(II) occurred on the exterior surface of the sorbent and the contribution of internal diffusion mechanism was insignificant. Furthermore, the sorption rate of Zn(II) was found to be slow, where only 10-20% of the maximum capacity was utilized in the first 30 min of interaction.     

Removal of antimony(V) and antimony(III) from drinking water by coagulation-flocculation-sedimentation (CFS)

Antimony occurs widely in the environment as a result of natural processes and human activity. Although antimony is similar to arsenic in chemical properties and toxicity, and a pollutant of priority interest to the USEPA and the EU, its environmental behaviors, control techniques, and even solution chemistry, are yet barely touched. In this study, antimony removal from drinking water with coagulation-flocculation-sedimentation (CFS) is comprehensively investigated with respect to the dependence of both Sb(III) and Sb(V) removal on the initial contaminant-loading level, coagulant type and dosage, pH and interfering ions. The optimum pH for Sb(V) removal with ferric chloride (FC) was observed at pH 4.5-5.5, and continuously reduced with further pH increase. Over a broad pH range from 4.0 to 10.0, effective Sb(III) removal with FC was obtained. Contrary to the effective Sb removal with FC, the degree of both Sb(III) and Sb(V) removal with aluminum sulfate (AS) was very low, indicating the impracticability of AS application for antimony removal. The presence of phosphate and humic acid (HA) markedly impeded Sb(V) removal, while exhibited insignificant effect on Sb(III) removal. The effects of coagulant type, Sb species and pH are more pronounced than the effects of coagulant dose and initial pollutant concentration. After preliminarily excluding the possibility of precipitation and the predominance of coprecipitation, the adsorption mechanism is used to rationalize and simulate Sb/FC coagulation with good result by incorporating diffuse-layer model (DLM).     

Bioconcentration and elimination of bis(tributyltin)oxide (TBTO) and triphenyltin chloride (TPTC) in several marine fish species

Pagrus major, Mugil cephalus and Rudarius ercodes were exposed to bis(tributyltin)oxide (TBTO) and triphenyltin chloride (TPTC) for 8 weeks in a flow-through aquarium system. The bioconcentration factors (BCFs) of TBTO and TPTC and the elimination rate constant of TBTO for these fish were determined. The BCF of TBTO ranged from 2400 to 11,000 depending on the fish species and the concentration in the rearing seawater. Out of the three, P. major had the smallest elimination rate constant (0.024 day⁻¹) and bioconcentrated the largest amount of TBTO (BCF: 9400–11,000). On the other hand, the BCF of TPTC of the two fish species examined was similar: 3100–3300 for P. major and 4100 for R. ercodes. These BCFs of TBTO and TPTC of P. major were larger than the values previously reported. TBTO and TPTC were the least accumulated in muscle among the tissues and organs of P. major examined, and no correlation was found between the lipid content and the accumulated TBT or TPT content.     

Chemical substitution reaction between Cu(II) and Hg(II) and hydrous CdS(s)

The chemical reaction between hydrous CdS(s) and Cu(II) and Hg(II) were studied by electrophoretic mobility measurements and adsorption experiments. The results show that cation exchange, following readsorption of the released Cd(II) ions onto the freshly-formed CuS(s) and cadmium hydroxide precipitation reactions occur when CdS particles come into contact with these metal ions which have sulfide precipitates less soluble than CdS(s). The effect of organic ligands on the ion exchange reaction, exemplified by EDTA (a strong complexing ligand) and phthalic acid (a weak complexing ligand), was also investigated. Both organic compounds have little effect on the lattice ion exchange reaction unless a large amount of strong complexing agent is present in the system. The dissolution of CdS(s), however, is slightly hindered in the presence of weak complex former such as phthalic acid and greatly enhanced in the presence of strong complex former such EDTA.