Cadmium accumulation and Cd-binding proteins in marine invertebrates--a radiotracer study

Tissue and subcellular accumulation of cadmium were studied in different tissues of three marine invertebrates (blue mussel Mytilus edulis, the tunicate Ciona intestinalis and the sea star Asterias rubens) using radioactive ¹⁰⁹Cd as a tracer. The organisms were exposed to 0.05, 2 and 50 μg Cd l⁻¹ for 21 days. Quantitative data were obtained by dissecting, weighing and subsequently measuring radioactivity in organs and tissues. Differences between each exposure and each tissue with regard to the amount of radioactivity and metallothionein (MT) content were evaluated. Obvious interspecies differences in Cd accumulation were observed, as well as differences between tissues of the three species. The highest concentrations of Cd in all exposure treatments were found in the hepatopancreas of M. edulis and body wall of A. rubens. Taking all treatments into account, Cd accumulation in the tunic of C. intestinalis was high compared to other tissues from this species. Over 60% of Cd was present in the S50 fraction in all treatments in all three species. Metallothionein levels were increased at the highest Cd-exposure in all species and tissues, except in branchial pharynx of C. intestinalis where the highest MT level was reached following exposure to 2 μg Cd l⁻¹. The most surprising finding was that even the lowest Cd exposure concentration (0.05 μg Cd l⁻¹) caused MT induction in pyloric caeca of A. rubens, but there was no dose-dependent increase in MT at higher exposure levels.     

Shades of blue: what do competing interpretations of the Blue Economy mean for oceans governance?

The ‘Blue Economy’ is an increasingly popular term in modern marine and ocean governance. The concept seeks to marry ocean-based development opportunities with environmental stewardship and protection. Yet different actors are co-opting this term in competing, and often conflicting ways. Four conceptual interpretations of the Blue Economy are identified, through examination of dominant discourses within international Blue Economy policy documents and key ‘grey’ literature. The way the Blue Economy is enacted is also examined, through an analysis of the Blue Economy ‘in practice’, and the actors involved. Finally, the scope of the Blue Economy is explored, with a particular focus on which particular marine industries are included or excluded from different conceptualizations. This analysis reveals areas of both consensus and conflict. Areas of consensus reflect the growing trend towards commodification and valuation of nature, the designation and delimitation of spatial boundaries in the oceans and increasing securitization of the world's oceans. Areas of conflict exist most notably around a divergence in opinions over the legitimacy of individual sectors as components of the ‘Blue Economy’, in particular, carbon-intensive industries like oil and gas, and the emerging industry of deep seabed mining.     

Photooxidative removal of the herbicide Acid Blue 9 in the presence of hydrogen peroxide: modeling of the reaction for evaluation of electrical energy per order (EEO)

The present work deals with photooxidative removal of the herbicide, Acid Blue 9 (AB9), in water in the presence of hydrogen peroxide (H₂O₂) under UV light illumination (30 W). The influence of the basic operational parameters such as amount of H₂O₂, irradiation time and initial concentration of AB9 on the photodegradation efficiency of the herbicide was investigated. The degradation rate of AB9 was not appreciably high when the photolysis was carried out in the absence of H₂O₂ and it was negligible in the absence of UV light. The photooxidative removal of the herbicide was found to follow pseudo-first-order kinetic, and hence the figure-of-merit electrical energy per order (E_Eo) was considered appropriate for estimating the electrical energy efficiency. A mathematical relation between the apparent reaction rate constant and H₂O₂ used was applied for prediction of the electricity consumption in the photooxidative removal of AB9. The results indicated that this kinetic model, based on the initial rates of degradation, provided good prediction of the E_Eo values for a variety of conditions. The results also indicated that the UV/H₂O₂ process was appropriate as the effective treatment method for removal of AB9 from the contaminated wastewater.     

Socioeconomic benefits of conserving Iran’s water resources through modifying agricultural practices and water management strategies

Sustainable development requires modifying the current consumption pattern of natural resources. This study investigates efficient tactics for reducing the unsustainability and inefficiency of human’s food-related blue water consumption alongside improving national environmental and socioeconomic status. As a case study for Iran, 15 alternative management scenarios (AMS) were defined compared to the current on-farm management, and their effects were assessed on a monthly scale. Based on the results, 45.5 billion m³ y⁻¹ (BCM) blue water is consumed within the croplands, 78% and 34% of which are unsustainable and inefficient, respectively. AMCs reduces the unsustainable and inefficient blue water consumption by 2–17 BCM and 2–13 BCM, respectively. The combination of yield gap closure, drip irrigation, soil mulching, and deficit irrigation has the largest effect on blue water saving; it releases or changes the status of monthly blue water scarcity in 11 provinces; increases field-employees by 132%, food security by 9%, international food-export by 87%, and gross domestic production by 54%. However, it doesn’t fully address blue water overconsumption in the summer period; hence, further measures are needed to reduce blue water scarcity to the sustainable level in these environmental hotspots.     

Photo-catalytic decolourisation of toxic dye with N-doped titania: A case study with Acid Blue 25

Dyes are one of the hazardous water pollutants.Toxic Acid Blue 25,an anthraquinonic dye,has been decolourised by photo-catalysing it with nitrogen doped titania in aqueous medium.The photo catalyst was prepared from 15% TiCl 3 and 25% aqueous NH 3 solution as precursor.XRD and TEM revealed the formation of well crystalline anatase phase having particle size in the nano-range.BET surface area of the sample was higher than that of pure anatase TiO 2.DRS showed higher absorption of radiation in visible range compared to pure anatase TiO 2.XPS revealed the presence of nitrogen in N-Ti-O environment.The experimental parameters,namely,photocatalyst dose,initial dye concentration as well as solution pH influence the decolourisation process.At pH 3.0,the N-TiO 2 could decolourise almost 100% Acid Blue 25 within one hour.The influence of N-TiO 2 dose,initial concentration of Acid Blue 25 and solution pH on adsorption-desorption equilibrium is also studied.The adsorption process follows Lagergren first order kinetics while the modified Langmuir-Hinselwood model is suitably fitted for photocatalytic decolourisation of Acid Blue 25.     

双管板换热器的设计与制造

根据双管板换热器的结构特点,从设计、制造、监造与使用维护方面全过程要点剖析,对主要重点进行系统性进行阐述,并与业内人士全方位交流与要点探讨。     

山东半岛蓝色经济区海域生态环境综合评价

海域生态环境评价作为承载力研究的基础,在近海生态管理中得到了广泛关注. 针对海洋生态环境研究中评价指标体系简单、标准相对单一及不利于实际应用等问题,以生态系统为研究视角构建了基于环境因子和生态响应的近海生态环境综合评价指标体系与指数计量方法,根据环境因子指数和生态响应指数在交叉判断矩阵中的位置,将近海生态环境状态分为优、良、中、差和劣5个等级,并将该方法应用于山东半岛蓝色经济区海域评价. 结果表明:研究海域整体环境因子指数为0.41~0.84(平均值为0.67),生态响应指数为0.17~0.75(平均值为0.45),综合评价等级为良,但已非常接近中等级别;其生态环境问题主要表现为溶解无机氮负荷较高、重金属和浮游动物密度负荷过低. 不同海域生态环境状态存在明显差异,25个近岸海域中等级优和良的共占60%,主要分布在山东半岛东部和西南部;海域等级为中和差的各占16%,另有8%海域等级为劣. 该评价模型与方法从生态环境整体性揭示海域存在问题,可为山东半岛蓝色经济区建设提供科学依据.      

HAP/UV催化降解活性艳蓝K-3R的研究

用化学沉淀法合成羟基磷灰石(HAP),并用XRD、SEM、FT-IR对其进行分析。以活性艳蓝K-3R为降解底物,研究HAP对其光催化降解性能。探讨了HAP煅烧温度、通气量、投加量、初始浓度等因素对光催化降解活性艳蓝K-3R效果的影响。研究表明化学沉淀法合成的HAP粒度均匀,HAP对活性艳蓝的吸附作用较强,30min之内即能达到吸附平衡,其对初始浓度为100mg/L的活性艳蓝的吸附率可达17.5%。适当的煅烧有利于提高HAP的催化活性,以200℃煅烧2h最佳。在投加量为4g/L,鼓气量为300L/h和pH=6的试验条件下,HAP(200℃)对初始浓度为100mg/L的活性艳蓝K-3R 3h的降解率达68%。降解反应动力学研究表明,HAP/UV光催化降解活性艳蓝K-3R的过程符合Langmuir-Hinshel-wood一级动力学方程,降解速率常数k随着活性艳蓝K-3R浓度的增大而减小。     

酶法原位制备过氧乙酸对活性艳蓝KN-R氧化脱色的工艺

利用过水解酶催化合成过氧乙酸,过氧乙酸原位氧化活性艳蓝KN-R脱色.在单因子试验的基础上,通过正交优化试验确定活性艳蓝KN-R的最佳脱色条件为:在5 m L反应体系中,最适p H 5.0,加酶量为20 U·反应-1,乙酸乙酯对过氧化氢的摩尔比率为40∶1和活性艳蓝KNR的浓度为80 mg·L-1.在此条件下反应6 h后,活性艳蓝KN-R的脱色率为81.11%,24 h后的脱色率为91.96%.在50倍放大试验中,该工艺24小时的脱色率为84.55%.     

Evaluation of Abelmoschus esculentus (lady's finger) seed as a novel biosorbent for the removal of Acid Blue 113 dye from aqueous solutions

The use of a new biosorbent derived from Abelmoschus esculentus (A. esculentus) seed for the removal of Acid Blue 113 (AB113) in aqueous solutions was investigated in batch mode. Biosorption studies were carried out under varying operational parameters including initial pH, biosorbent dosage, contact time, initial dye concentration and temperature. The results indicated that the biosorption properties were strongly dependent on initial pH. Fourier transform infrared spectroscopy analysis revealed that hydroxyl, carboxylic and amide functional groups present on the biosorbent surface were involved in the dye removal process. Equilibrium data were best fitted by the Langmuir model. The maximum biosorption capacity was 169.9 ± 3.1 mg g⁻¹ at 25 °C and initial pH 5.5. The kinetic data were in good agreement with the pseudo-second-order kinetic model. The process was controlled by diffusion through boundary layer at the initial stage followed by intra-particle diffusion at the later stage. Thermodynamic evaluation showed that the process was endothermic and spontaneous. The present study suggests that A. esculentus seed with maximum biosorption capacity which compared well with values reported in the literature can be a potential biosorbent for AB113 dye removal.