Sediment Parameters of Northwest Black Sea Shelf and Slope: Implications for Transport of Heavy Metals and Radionuclides

In June 1990, sediment cores were obtained from several locations in the Northwest Black Sea shelf and slope by a joint US/USSR scientific team aboard the survey vessel R/V VODYANITSKY. the goal of this investigation was to determine the distribution and levels of radioactivity resulting from the Chernobyl 1986 nuclear accident. the sediment was characterized for texture, mineral composition, redox state, heavy metals, and radionuclides. Correlations emerging from these data reveal paths of dispersal and transport of materials from river sources to deposition sites on the shelf and slope. Kaolinite in the clay mineral suite clearly reflects a dispersal pattern originating in the Danube River and progressing in an easterly direction across the shelf. Sand-size gypsum and the elemental heavy metals Zn, Cu, Cr, and Pb (probable industrial source) as well as the elements Al and Mg (probable terrigenous source) also show a dispersal pattern from the Danube station location in an easterly direction across the shelf. the dispersal direction indicated by these materials is not in conflict with recent existing notions concerning the hydrology of the Northwest Black Sea. Barium anomalies at a midshelf location may be related to operations in the Lebada oil fields situated updrift. Heavy mineral dispersal reflect the Danube and -Crimean Provinces established for the shelf and relate to terrestrial source areas. in addition, the heavy mineral monazite correlates with the radioactive Th 232 found most abundantly in the Crimean Province. Local anomalies of Mn, Fe and U in the sediment at station locations are related to redox (Eh) conditions and other factors. Cs^134/137 data, reported by Curtis and Broadway (1991), correspond to transport and dispersal patterns implicit in the mineralogic, anthropogenic indicators, and sediment characteristics of the study area.     

麦草浆黑液提取性能试验

采用真空吸滤和挤压过滤两段组合式提取装置两次提取麦草浆黑液，能获得高且稳定的黑液提取率。探讨了黑液提取率与浆料洗涤时间、水量的关系及洗后浆所达到的洗净程度等。     

焙烧态镁铝水滑石处理阴离子染料废水研究

采用传统过饱和双滴法合成出Mg/Al为3的碳酸根型水滑石(LDH),经500℃高温煅烧制备出焙烧产物(CLDH),用x-射线、红外光谱和电镜对它们进行了表征。分别考察了焙烧温度、反应时间、pH、投加量、反应温度和初始浓度等因素对焙烧态水滑石吸附酸性铬蓝K模拟废水效果的影响。结果表明,对于100mg/L的铬蓝K溶液,500℃焙烧态水滑石,投加量为0.06g,在pH=3.5左右,室温下反应1h,去除率最高可达98%以上。四次回收重复利用的CLDH对铬蓝K的去除率仍为90%以上,CLDH是一种良好的环保吸附材料。     

Heavy metal monitoring of marine algae from the Turkish Coast of the Black Sea, 1998-2000

Concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in macroalgae samples collected from the Turkish Coast of the Black Sea. Certain algae species were chosen among the green, brown and red algae species at Sile and Sinop sampling stations from 1998 to 2000. In general, as regards the influence of the collection sites on the whole metal accumulation, Sinop is considered to be more polluted than Sile. The concentrations of the heavy metals in Cystoseira barbata algae are compared with previous studies in the same stations. The results showed that all metal levels have gradually decreased during past years. At the same time, Cd, Co, Cr, Cu, Fe, Ni and Pb levels in the present study are lower than in Bosphorus and Marmara Sea algae. However, Mn and Zn concentrations are higher than Bosphorus but lower than at Marmara. According to these findings the heavy metal pollution decreased in Turkish Coast of the Black Sea during the years investigated.     

Bioavailability of hydrophobic organic contaminants and quality of organic carbon

U.S. laws require that contaminant bioaccumulation potential be evaluated before dredged material can be recycled. Simple fugacity models, e.g. organic contaminant aqueous partition coefficient (K _oc)-derived theoretical bioaccumulation potential, are commonly used to estimate the partitioning of hydrophobic organic contaminants between sediment organic matter and organism lipid. K _oc-derived models, with or without the addition of a soot carbon term, did not accurately or consistently predict total polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls partitioning of eight sediments from ongoing dredging operations onto C₁₈-coated filter paper. These models also failed to predict the partitioning of individual PAHs from these eight sediments. These data underscore the trade-offs between the ease of using simple models and the uncertainty of predicted partitioning values.     

黑液电渗析碱回收的研究

针对造纸黑液的碱性及污染严重的特点，采用单阳膜电渗析法对黑液中的碱加以回收．并研究了电渗析操作中如电流密度，黑液浓度，温度等因素的影响．综合考虑得到电流密度３５０Ａ／ｍ２，电流效率８５％～９０％，碱回收率７０％～７５％，耗电量５０００～６０００ＫＷＨ／ｔ碱的结论     

用厌氧折流板反应器处理碱法草浆黑液

在不添加氮、磷营养盐和不调节进水ＰＨ值条件下，用厌氧折流板反应器（ＡＢＲ）处理碱法草浆黑液。结果表明，在ＨＲＴ＝１０．６ｄ、Ｎｖ＝５．３ｋｇＣＯＤｃｒ／ｍ＾３．ｄ、ＰＨ＝１３．６和ＣＯＤ.ｒ＝５６１００ｍｇ／Ｌ时，ＣＯＤ.ｒ去除率为４２％，达到厌氧处理法的最大去除率的８４％。     

Evaluation of RothC model using four Long Term Fertilizer Experiments in black soils, India

Carbon content in soils changes depending on the land use system, type of management practice and time. There is an increasing concern about the soil quality vis-à-vis organic carbon content in soils due to global warming and enhanced CO₂ concentration in the atmosphere. This has led to estimate carbon stock in soils at global and regional levels. The objective of the present study was to evaluate RothC model to estimate total organic carbon (TOC) changes under four long term fertilizer experimental sites representing sub-humid moist (Sarol and Nabibagh), sub-humid dry (Panjri) and semi-arid (Teligi) climate in India. The plant carbon input rate was calibrated using organic carbon and other soil parameters using RothC. The results showed that RothC could simulate changes in TOC in two contrasting eco-sites for surface soil layers. The root mean square error (RMSE) considered as modelling error ranged from 11.50 to 15.01, 4.70 to 11.60, 2.14 to 6.52 and 1.45 to 13.74 in the surface layers of Sarol, Nabibagh, Panjri, and Teligi sites, respectively. The simulation biases expressed by M (relative error) by Student‘t’ value for all the treatments at these sites were non-significant with two exceptions. Observed trends in TOC consist of an increase for all the four treatments in the sub-humid site of Sarol and Nabibagh; while manures alone or in combination increase TOC appreciably in Teligi and Panjri. TOC remained, however, almost similar over years for the control (no fertilizer or manure) and NPK treatments in all the four sites. Analysis of RothC output data showed that this model could be used as a tool to arrive at different threshold values of rainfall to influence decomposition rate modifier and thus to find out rate of organic carbon sequestration in various bioclimatic systems.     

Black Sea beaches vulnerability to sea level rise

Integrated Coastal Zone Management (ICZM) aims to promote sustainable management of coastal zones based on ecosystem and holistic management approaches. In this context, policies have to consider the complex interactions that influence the fragile equilibrium of coastal ecosystems. Beaches represent both valuable and vulnerable natural resources because of the various ecosystem services they provide and their sensitivity to climate change and sea level rise.We present the first comprehensive digital record of all Black Sea beaches and provide a rapid assessment of their erosion risk under different scenarios of sea level rise. Through the digitisation of freely available remote-sensed images on the web, we provide broad information on the spatial characteristics and other attributes of all Black Sea beaches (e.g. photo-based visual estimation of the sediment type, presence of coastal defences, urban development). These data have been assembled and stored in full Spatial Data Infrastructure (SDI) – allowing spatial queries, visualisation and data sharing – and are therefore particularly interesting to feed/supply web-GIS portals (coastal atlases) for visualisation purpose, spatial queries or spatial indicators calculations.The resulting Black Sea beaches database contains 1228 beaches, with a total coastline length of 2042 km with an area of 224 km². The majority of the Black Sea beaches have been found to have small widths (61% have maximum widths less than 50 m), whereas 47% of all beaches presented coastal defence schemes, suggesting an already serious beach erosion problem.The erosion risk of the Black Sea beaches was assessed through the comparison of their maximum widths with estimations of the sea level rise-induced retreat by an ensemble of six 1-D analytical and numerical morphodynamic models. Following more than 17,000 experiments using different combinations of wave conditions, beach sediment textures and slopes and 11 scenarios of sea level rise (up to 2 m), the means (best fits) of the lowest and highest projections by the model ensemble were estimated; these were then compared to the maximum widths of the Black Sea beaches. The analysis showed that sea level rise will have highly significant impacts on the Black Sea beaches, as for a 0.5 m sea level rise 56% of all beaches are projected to retreat by 50% of their maximum width. For a 0.82 m sea level rise (the high IPCC estimate for the period 2081–2100) about 41% are projected to retreat by their entire maximum width, whereas for 1 m sea level rise about 51% of all Black Sea beaches are projected to retreat by (drowned or shifted landward by) their entire maximum width, if the high mean of the model ensemble projections is used.Results substantiate the risk of beach erosion as a major environmental problem along the Black Sea coast, which therefore needs to be taken into account in any future coastal management plans, as a matter of urgency. As these scenarios consider only sea level rise, they are considered to be conservative. Although the present results cannot replace detailed studies, the database and projections may assist Black Sea coastal managers and policy makers to rapidly identify beaches with increased risk of erosion, valuate accordingly coastal assets and infrastructure, estimate beach capacity for touristic development purposes, and rapidly assess direct and indirect costs and benefits of beach protection options. They also provide the necessary inputs to advance discussions relevant to the Black Sea ICZM.     

Enhanced mixing state of black carbon with nitrate in single particles during haze periods in Zhengzhou, China

Black carbon（BC） plays an important role in air quality and climate change, which is closely associated with its mixing state and chemical compositions. In this work the mixing state of BC-containing single particles was investigated to explore the evolution process of ambient BC particles using a single particle aerosol mass spectrometer（SPAMS） in March 2018 in Zhengzhou, China. The BC-containing particles accounted for 61.4% of total detected ambient single particles and were classified into f...