A decentralized wastewater treatment system using microbial fuel cell techniques and its response to a copper shock load

Bench-scale decentralized wastewater treatment systems using microbial fuel cell (MFC) techniques were constructed for simultaneous removal of carbonaceous and nitrogenous pollutants and electricity production from wastewater. The MFC was operated in continuous mode and immobilized <em>Paracoccus pantotrophus</em> cells were added in the cathodic compartment to achieve simultaneous nitrification&ndash;denitrification. After 150-day operation, the MFC system could effectively remove &gt;96% COD and 100% ammonium, with 60&ndash;80% total nitrogen removal and around 0.2&nbsp;V voltage production. The results of copper (Cu) shock load showed that although 125&nbsp;mg&nbsp;L^{<font size="1">&minus;1</font>} Cu (II) would deteriorate the effluent quality and completely inhibit the electricity production, the microbial populations restored their ability to treat wastewater and produce electricity after a period around 30&nbsp;days. Community analysis by the 454 pyrosequencing technique showed that the microbial compositions were significantly different and decreased in diversity after the Cu shock load

离心分离内插管

<p class="th">一种离心分离内插管，口部敞开，底部留有小孔，管内接近底部小孔处有一过滤片。内插管外径尺寸与市售的离心管内径相一致，可以插入普通离心管中后不留空隙。内插管口部边缘向外突出，突出尺寸与普通离心管壁厚度相一致，插入离心管后口部边缘刚好卡住普通离心管口。与普通离心管配合使用，离心时通过过滤片截住团状或块状吸水性载体物质，分离液体。</p

A microbial fuel cell driven capacitive deionization technology for removal of low level dissolved ions

The microbial fuel cell (MFC) is an emerging technology, which uses exoelectrogenic microorganisms to oxidize organic matter in the wastewater to produce electricity. However, the low energy output limits its application in practice. Capacitive deionization (CDI), an electrochemically controlled method for deionization by the adsorption of ions in the electrical double layer region at an electrode&ndash;solution interface, requires a low external power supply. Therefore, in this study, we investigated the MFC driven CDI (MFC&ndash;CDI) technology to integrate deionization with wastewater treatment and electricity production. Taking advantage of the low potential requirement of CDI, voltage generated from a continuous flow MFC could be used to drive the CDI to achieve removal of the electrolyte to a stable status. The results indicated that among the three connection types of MFCs including single-, series-, and parallel-configuration, the parallel connection of two MFCs resulted in the highest potential (0.63&nbsp;V) applied to CDI and the conductivity removal of NaCl solution was more than 60%. The electrosorption capacities under different electrolyte concentrations of 50, 100 and 150&nbsp;mg&nbsp;L^{<font size="1">&minus;1</font>} were 150, 346 and 295&nbsp;&mu;g&nbsp;g^{<font size="1">&minus;1</font>}, respectively. These results suggest that the new MFC&ndash;CDI technology, which utilizes energy recovery from the wastewater, has great potential to be an energy saving technology to remove low level dissolved ions from aqueous solutions for the water and wastewater treatment processes

Influence of pretreated activated sludge for electricity generation in microbial fuel cell application

Influence of different pretreated sludge for electricity generation in microbial fuel cells (MFCs) was investigated in this study. Pre-treatment has shown significant improvement in MFC electricity productivity especially from microwave treated sludge. Higher COD reduction in the MFC has been revealed from microwave treated sludge with 55% for total and 85% for soluble COD, respectively. Nonetheless, longer ozonation treatment did not give additional advantage compared to the raw sludge. On the other hand, samples from anodes were analyzed using the 16S rRNA gene-based pyrosequencing technique for microbial community analysis. There was substantial difference in community compositions among MFCs fed with different pretreated sludge. <em>Bacteroidetes</em> was the abundant bacterial phylum dominated in anodes of higher productivity MFCs. These results demonstrate that using waste sludge as the substrate in MFCs could achieve both sludge reduction and electricity generation, and proper pre-treatment of sludge could improve the overall process performance

Urban water metabolism efficiency assessment: Integrated analysis of available and virtual water

Resolving the complex environmental problems of water pollution and shortage which occur during urbanization requires the systematic assessment of urban <em>water metabolism efficiency</em> (WME). While previous research has tended to focus on either available or virtual water metabolism, here we argue that the systematic problems arising during urbanization require an integrated assessment of available and virtual WME, using an indicator system based on <em>material flow analysis</em> (MFA) results. Future research should focus on the following areas: 1) analysis of available and virtual water flow patterns and processes through urban districts in different urbanization phases in years with varying amounts of rainfall, and their environmental effects; 2) based on the optimization of social, economic and environmental benefits, establishment of an indicator system for urban WME assessment using MFA results; 3) integrated assessment of available and virtual WME in districts with different urbanization levels, to facilitate study of the interactions between the natural and social water cycles; 4) analysis of mechanisms driving differences in WME between districts with different urbanization levels, and the selection of dominant social and economic driving indicators, especially those impacting water resource consumption. Combinations of these driving indicators could then be used to design efficient water resource metabolism solutions, and integrated management policies for reduced water consumption

一种大气中不同形态汞样品的热脱附及分析装置

<p>本实用新型提供一种大气中不同形态汞样品的热脱附及分析装置，包括质量流量控制器、两位三通电磁阀及其控制板、四路温控仪、开闭式加热炉、原子荧光检测器以及计算机等组成。通过质量流量控制器调整载气氩气的流量，切换两位三通电磁阀的状态以控制气体流路，分别实现不种形态汞样品的测定；四路温控仪可对四组开闭式加热炉进行升温控制，确保三个模块的形态汞能以最大效率的热脱附出来；高灵敏度的原子荧光检测器对不种形态汞的准确测定，提供了可靠保证，并通过专用软件对各个分析模块的升温程序进行参数设置、电磁阀的阀位控制以及数据的采集，实现程序化控制的目的。</p

一种非曝气生物阴极微生物燃料电池反应器及其阳极

一种非曝气生物阴极微生物燃料电池反应器，由阳极室、阴极室组成，阴阳室壁皆为镂空。阳极室与阴极室由阳离子交换膜隔开。所述阳极室内放置有阳极，所述阴极室内置有生物阴极。该微生物燃料电池的特征在于：其主体由两个直径不一的圆筒组成；其主体分为三部分，利用方便的制造及组装；可通过选择内外圆筒的直径调节阴极室的径向尺寸，控制阴阳极的最佳距离使产电量最大化；阴极微生物利用空气中主动透过的氧气作为电子受体，节约常规好养生物阴极微生物燃料电池中曝气带来的成本；阴极室设有电解液出入口，可利用阳极出水作为阴极电解液；通过开关阴极室进水口设置的阀门方便地转换阴极室的运作模式（连续流式或批式）；阳极为新构型碳纤维电极，其具体构造为将碳纤维植入不锈钢网中，既可以为阳极微生物的附着提供大的比表面积，又可通过不锈钢网自身的弹性将其附着于阳极室壁，方便于控制阴阳极距离

Fabrication of polyethersulfone-mesoporous silica nanocomposite ultrafiltration membranes with antifouling properties

<p>Fouling is regarded as the bottleneck in membrane filtration process. One of the practical strategies to decrease fouling is the use of advanced anti-biofouling membrane material. In this study, mesoporous silica (MS) particles was synthesized as inorganic fillers, and fabricated with polyethersulfone (PES) to achieve nanocomposite membranes with antifouling properties by phase inversion method. The effect of the MS particles on the microstructure and properties of the resulting hybrid membranes were investigated by scanning electron microscopy (SEM), thermal gravitational analysis (TGA), and ultrafiltration (UF) experiments. The results indicated that the nanocomposite membrane with 2% MS exhibited excellent hydrophilicity, water permeability and good antifouling performance. In addition, the TGA results showed that the introduction of the MS particles improved the thermal stability of the nanocomposite membranes. The protein adsorption on the membrane surface decreased significantly from 45.8&nbsp;&mu;g/cm^{<font size="1">2</font>} to 21.4&nbsp;&mu;g/cm^{<font size="1">2</font>} when the MS content increased from 0% to 2%. Most importantly, the protein UF experiments revealed that the incorporation of MS particles reduced membrane fouling, especially irreversible fouling, which reduced dramatically. No benefit was gained from higher MS content (4%), which resulted in significant particle agglomeration.</p

PFOS induced precocious hatching of Oryzias melastigma–From molecular level

Perfluorooctane sulfonate (PFOS) showed a risk of causing adverse effects including hatching of animals.However, there are no systematical studies about the effects of PFOS on fish embryo hatching. In this study, a precocious hatching was detected in Oryzias melastigma embryos upon PFOS exposure. The average<br />hatching time was shortened and the hatching rate increased after PFOS exposure. The subsequent survival rate decreased significantly in the larvae hatching from the PFOS-treated embryos compared to the control. The influence occurred in a PFOS concentration-dependent manner. To further elucidate the inner molecular change, full length cDNAs of hatching enzymes HCE and LCE were first cloned in O. melastigma by degenerate RT-PCR and RACE. PFOS elicited a transcriptional response of both HCE<br />and LCE. The expressions of both genes were significantly up-regulated earlier in the PFOS-treated group than in the control group. The activity of hatching enzyme also significantly increased upon exposure. In all, our results showed that exposure to PFOS could induce the hatching enzyme both at transcriptional and enzymatic activity level and further lead to the precocious hatching of O. melastigma embryos, which induced the decrease of the subsequent larvae survival

Integrated assessment of biomarker responses in caged shrimps (Litopenaeus vannamei) exposed to complex contaminants from the Maluan Bay of China

<p class="a-plus-plus">The marine shrimp <em class="a-plus-plus">Litopenaeus vannamei</em> were used as an active biomonitoring organism to assess the bioavailability and impact of metal contaminants in seven study sites along the Maluan Bay of China. Metal concentrations in the hepatopancreas of shrimps were determined in conjunction with four biomarkers responses after a 7&nbsp;day in situ cage exposures. The results showed that contaminant tissue burdens at the deployment sites were greater than those of the reference site, and antioxidant enzyme activities were strongly inhibited compared to those of reference organisms. Variations in these biomarker responses were correlated significantly (<em class="a-plus-plus">p</em>&nbsp;&lt;&nbsp;0.05 or <em class="a-plus-plus">p</em>&nbsp;&lt;&nbsp;0.01) with the specific metal pollutants at the study sites, but no significant correlations existed between catalase activity responses and the metal contaminants. This suggests the presence of undetermined contaminants or other exposure routes that may be responsible for the decreased catalase activity. Multivariate analysis revealed a causal relationship between contaminants at each deployment site and the biochemical &ldquo;response&rdquo; of the caged shrimps at these sites and demonstrated the presence of two contaminant &ldquo;hot&rdquo; spots. This investigation suggested that the incorporation of chemical data on trace metal concentrations with the analysis of antioxidant enzymatic activities in caged shrimps can be a useful tool for the identification of causal toxic contaminants in complex mixtures.</p