Effect of heavy metals (Cu, Pb, and As) on the ultrastructure of Sargassum pallidum in Daya Bay, China

Concentrations of Cu, Pb, and As were determined in seawater, surface sediment, Sargassum pallidum collected from the Daya Bay, China. The influence of metal contamination on the marine alga was investigated at chemical and ultrastructural level. Mean concentrations of Cu (19.44 mg kg^?1) and Pb (33.99 mg kg^?1) were found to be high in sediment, whereas concentration of As (122.29 mg kg^?1) in S. pallidum was higher than that in water and sediment. The ultrastructure of S. pallidum cells was anomalous and aberrant. Energy-dispersive x-ray spectroscopic analysis revealed that the nanometal particles in the form of comparatively high-electron density substance diffused in the cell structures constituted by Cu, Pb, As, etc. There is a remarkable similarity or correspondence in the anomalous elements between the geochemistry and the botanic cell, and the heavy metals have potential hazardous effect on the ocean ecology system in Daya Bay.     

Robust Regression with Data-Dependent Regularization Parameters and Autoregressive Temporal Correlations

We introduce robust procedures for analyzing water quality data collected over time. One challenging task in analyzing such data is how to achieve robustness in presence of outliers while maintaining high estimation efficiency so that we can draw valid conclusions and provide useful advices in water management. The robust approach requires specification of a loss function such as the Huber, Tukey’s bisquare and the exponential loss function, and an associated tuning parameter determining the extent of robustness needed. High robustness is at the cost of efficiency loss in parameter loss. To this end, we propose a data-driven method which leads to more efficient parameter estimation. This data-dependent approach allows us to choose a regularization (tuning) parameter that depends on the proportion of “outliers” in the data so that estimation efficiency is maximized. We illustrate the proposed methods using a study on ammonium nitrogen concentrations from two sites in the Huaihe River in China, where the interest is in quantifying the trend in the most recent years while accounting for possible temporal correlations and “irregular” observations in earlier years.     

Nutrients Availability Shapes Fungal Community Composition and Diversity in the Rare Earth Mine Tailings of Southern Jiangxi,China

Russian Journal of Ecology - The present study characterized the nutrients availability of three rare earth tailings deserted in different time stages in Southern Jiangxi of China, and revealed the...     

Spatial simulation and LCA evaluation on the plastic waste recycling system in Tianjin

With the rapid economic development in China, the amount of plastic waste (PW) generated has greatly increased and much of the waste is currently not treated. To reduce greenhouse gas (GHG) emissions from recycling of PW, we estimated the PW flow and considered methods to improve the household PW recycling system in Tianjin by adjusting processes during transportation and establishing a PW recycling factory in Zi’ya Industrial Park. The goal of the study was to identify reasonable improvements for the recycling system and clarify the environmental load. Geographic information system (GIS) technology was used to simulate transport processes for comparing GHG emissions from the transport processes between the present case and an improved case. Life cycle assessment (LCA) was used to compare GHG emissions between a projected scenario and a baseline scenario. Estimated GHG emissions during transport processes in the improved case were reduced by about 12,197 t CO₂ eq per year compared to the present case, equivalent to about 65.9 % of the total emissions in the present case. GHG emissions in the projected scenario were about 101,738 t CO₂ eq less per year than the baseline scenario, equivalent to about 75.5 % of the total emissions in the baseline scenario.     

Copper recovery from waste printed circuit boards concentrated metal scraps by electrolysis

Copper recovery is the core of waste printed circuit boards (WPCBs) treatment. In this study, we proposed a feasible and efficient way to recover copper from WPCBs concentrated metal scraps by direct electrolysis and factors that affect copper recovery rate and purity, mainly CuSO₄·5H₂O concentration, NaCl concentration, H₂SO₄ concentration and current density, were discussed in detail. The results indicated that copper recovery rate increased first with the increase of CuSO₄·5H₂O, NaCl, H₂SO₄ and current density and then decreased with further increasing these conditions. NaCl, H₂SO₄ and current density also showed a similar impact on copper purity, which also increased first and then decreased. Copper purity increased with the increase of CuSO₄·5H₂O. When the concentration of CuSO₄·5H₂O, NaCl and H₂SO₄ was respectively 90, 40 and 118 g/L and current density was 80 mA/cm², copper recovery rate and purity was up to 97.32% and 99.86%, respectively. Thus, electrolysis proposes a feasible and prospective approach for waste printed circuit boards recycle, even for e-waste, though more researches are needed for industrial application.

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Ni2 +对活性污泥活性及群落多样性的影响简

通过检测活性污泥的电子传递体系活性以及生物多样性,研究Ni²⁺对活性污泥微生物活性及群落多样性的影响。结果表明：与对照系统相比,5 mg/L的Ni²⁺对2,3,5-triphenylteltrazolium chloride（TTC-ETS）活性未产生显著的影响;但当Ni²⁺的浓度进一步增大到10、20和40 mg/L后,其对序批式反应器内活性污泥TTC-ETS活性的抑制率分别达到（36.79±11.14）%、（55.88±13.90）%和（70.97±6.78）%。低浓度Ni²⁺能增强活性污泥微生物对碳源的利用,但高于10 mg/L的Ni²⁺则显著抑制了活性污泥微生物对碳源的利用。各个SBR系统中微生物群落最常见的物种相近,物种丰富度和均一性则均有所不同,其中群落物种丰富度随着Ni²⁺浓度的增加而逐渐减小。TTC-ETS活性、平均每孔颜色变化率、Shannon指数和Simpson指数,与Ni²⁺的胁迫浓度之间的显著相关性表明,它们均可有效地表征Ni²⁺胁迫对活性污泥微生物活性及群落多样性的影响程度。     

Fenton法处理垃圾渗滤液MBR-NF浓缩液

采用Fenton法处理MBR-NF浓缩液,考察了FeSO4·7H2O投加量、n(H2O2)/n(Fe2+)投加比、初始pH对渗滤液MBR-NF浓缩液处理效果的影响,并在最佳实验条件下,探讨浓缩液富里酸(FA)、亲水性有机物(HyI)组分在Fenton氧化前后组成的变化。研究结果表明,在FeSO4·7H2O投加量为0.055 mol/L、n(H2O2)/n(Fe2+)投加比为4、初始pH为7.58时,对COD、腐植酸(UV254)、色度(CN)的去除率分别为79.6%、93.7%和97.8%。Fenton氧化后,浓缩液中有机物组分含量发生了较大变化,腐植酸含量下降,HyI成为渗滤液溶解性有机物主要成分。紫外-可见光谱表明,Fenton法对FA去除效果较好,而对HyI氧化效果较差;傅立叶红外光谱显示,经Fenton氧化后,FA的结构发生了明显变化,而HyI则变化不明显。     

The Wind-Frequency Allocation Method on Discharge Loading of Function Zones

Abstract

This paper introduces a new allocation method on discharge loading of each function zone in a total emission control region. The wind frequency, the position of each district, and the pollutant’s influence area were taken into account in this new method. The concept of “average downwind distance” was brought forward in this paper. The method here is more reasonable than the original method of area distribution, which was proposed by the “A-value” method in regulation of total emissions in China, by means of the simulation of annual average concentration in the total emission control region.     

Characteristics and management of domestic waste in a rural area of the Tibetan Plateau

In the rural area of the Tibetan Plateau (RATP), the characteristics of domestic waste, people’s environmental awareness, people’s willingness to pay and their influence factors were firstly studied by questionnaires, field samplings and laboratory tests. The results showed that, in the RATP, the generation of domestic waste was 85 g?d-1 per capita and it was mainly composed of plastics, inert waste, kitchen waste, glass and paper. The waste bulk density, moisture content, ash, combustible and low calorific value were 65 kg?m-3, 19.25%, 44.90%, 35.85% and 10,520 kJ?kg-1 respectively. These characteristics are influenced by income sources and geographical position to some extent. Classified collection should be promoted widely on the household and the village basis. Compost, fermentation, landfill, bioreactor landfill and semi-aerobic landfill have been approved as effective techniques to treat domestic waste, except incineration. The distance of 50–800 m between each collection facility and the disposal fee of around $0.8 per month per household are suggested. For suburbs or large population villages, it’s better to treat domestic waste by the centralized way. But for the remote rural areas, a decentralized way is proposed. Significantly, the educational and economic influence should be considered into an effective domestic waste management program.

Implications:?The current situatio n of the environment in the rural areas of the Tibetan Plateau (RATP) was surveyed. There, the generation of organics and moisture of domestic waste were low but ash, recyclables, and combustibles were high. People’s knowledge of domestic waste was absent but their participation in management was strong. Based on the current situation, compost, fermentation, and landfill were effective but incineration was inappropriate. Also, a localized mini landfill for a cluster of villages and or settlements was the best method there.