铬渣秸秆共热解产物铬稳定性研究

生物质铬渣共热解工艺是新型的铬渣处理工艺,该工艺能有效地将铬渣中的Cr(Ⅵ)还原为Cr(Ⅲ).而由于共热解产物总铬含量较高,因此考察了铬渣与秸秆共热解过程中铬稳定性.通过考察共热解产物成分及形态分析、pH影响实验、淋洗实验及长期稳定性实验,对共热解铬渣的铬环境安全性进行评估.结果表明:(1)共热解温度对铬渣形态有较大影响,可交换态及碳酸盐结合态铬含量随共热解温度升高而逐渐降低,800℃时候可交换态铬降至＜0.1％(质量分数,下同),碳酸盐结合态铬为1.2％;共热解后最稳定的残渣态铬含量随共热解温度升高而逐渐升高.(2)当pH＞7时,两种共热解产物总铬溶出量极低,基本都小于6mg/kg;当pH≤7时,总铬的溶出量显著增加,最高超过500 mg/kg.但由于解毒铬渣的酸中和能力极强,因此铬释放风险较低.(3)共热解产物的总铬累积溶出量极低,根据拟合结果计算出其100年填埋时间的总铬溶出量不超过1.3 mg/kg.长期稳定性实验表明,自然堆置过程中共热解产物的Cr(Ⅵ)含量逐渐降低.     

Sustainability, substance flow management and time. Part I Temporal analysis of substance flows

Flows of chemical substances need to be managed in a sustainable way. Sustainable development as a whole and the sustainable management of substance flows in particular are both time issues. These include the importance of the dynamics of substance flows and the way these interconnect with the use of resources, the avoidance of environmental pollution, and their effects on health and food production. Another prerequisite for the proper management of substance flows is justice within and between generations. This requires a systematic approach and a systematic analysis of the issues as well as of the actions to be taken. One tool for such a systematic approach is temporal analysis. It brings the temporal aspects of the substances themselves and of their intended use, as well as factors affecting the stakeholders, such as decision makers, producers and consumers, into focus. In the past, timing factors were rarely taken into account. Knowledge of the temporal dynamics of substance flows and their resultant outcomes, as well as of their interaction with ecological, economic and social systems, is a basic requirement for successful substance flow management. The need to include temporal aspects into substance flow management and how to do so is outlined here. Included are not only politicians but also practitioners and scientists who must explicitly take into account adequate time scales, points in time, breaks and other forms of time in planning and acting.     

Wastewater management in small- and medium-size enterprises: case studies

Wastewater management in small and medium-sized enterprises representing the chemical and food industries was investigated. The results showed that wastewater discharged from an ink-production factory was highly contaminated with organic pollutants. Anaerobic biological treatment followed by chemical coagulation using ferric chloride aided with lime proved to be very effective and produced an effluent that complied with national regulatory standard for wastewater discharge into public sewage network. Also, management of wastewater from a confectionery factory representing the food sector was carried out. Aerobic biological treatment using plastic-packed trickling filter proved to be an effective treatment method. However, application of in-plant control measures alleviated the requirement for the construction of a wastewater treatment plant. The applied pollution prevention and cleaner production measures involved good housekeeping, recovery of spent chocolate, modification of floor cleaning and installation of suction devices for the removal of sugar and starch powders. All improvement measures were documented by cost/benefit analysis.     

生活小区供暖系统的问题及对策

针对神龙襄樊生活小区的供暖现状,结合襄樊基地供热管网的运行情况,就小区普遍存在的供暖个别单体不热、冷暖不均、管网失调、系统存气等问题,作了具体分析,并提出解决办法以供探讨.     

The sex in short supply for matings varies over small spatial scales in a katydid (Kawanaphilanartee, Orthoptera: Tettigoniidae)

In katydids such as Kawanaphilanartee, a female bias in the operational sex ratio (OSR) results in female competition for mates and male choice of mates. Previous work showed that the excess of sexually active females occurs when food availability is low, in part because less food increases the propensity of females to mate as they forage for the large edible spermatophores produced by males. In this study with K.nartee, a pollen-feeding species, we estimate natural variation in numbers of sexually active males and females by assessing male calling activity and the propensity of females to respond to experimental calling males. We found an excess of sexually active males at a site with many flowers and an excess of sexually active females at a site with few flowers about 900 m away. Between-site differences in gut masses of calling males were consistent with the hypothesis that pollen availability controls OSR. Finally, at a third site where flowers were at first scarce, we found that the initial excess in sexually active females changed to an excess of sexually active males after a clump of grass-trees flowered. The mean gut mass of all sampled males from this site increased after flowering. The large variation in OSR that we document for K. nartee highlights the importance of identifying the appropriate spatial and temporal scales over which OSRs are measured in studies of factors controlling sexual selection. Received: 13 May 1997 / Accepted after revision: 27 October 1997     

Hybrid governance tensions fuelling self-reflexivity in Alternative Food Networks: the case of the Brussels GASAP (solidarity purchasing groups for peasant agriculture)

This paper applies the concept of Hybrid Governance to the analysis of the GASAP (Groupe d’Achats Solidaires de l’Agriculture Paysanne), a solidarity-based producers–consumers network established in Brussels in 2006. The Hybrid Governance concept allows to capture the role of key governance tensions in driving the self-organisation, scaling out and self-reflexive dynamics of Alternative Food Networks (AFNs). The approach provides a multifaceted and sound socio-political account of the ways AFNs arise, self-organise, associate and build networks in the pursuit of their food allocation objectives, often facing a contradictory socio-institutional environment. Three types of governance tensions, i.e. organisational, resource, and institutional, as well as the interactions among them, are analysed throughout the life-course of the GASAP network. The analysis identifies three phases in the GASAP’s life-course, showing how governance tensions and their interrelations arise and play a critical role in conditioning the overall development of the organisation through time. The paper concludes with highlighting prospective values of the hybrid governance approach for the analysis of AFNs in general. These values relate to: the role of the hybrid approach in illuminating on key drivers behind the scaling out of AFNs; the hybrid governance as a tool to conceptualise and sustain the self-reflexive capacity of local food initiatives and the ways by which this approach unravels challenges to build cooperative alliances and networks among a diversity of agents in the food arena.     

代森锰锌在柑橘橘肉、橘皮及土壤中的残留分析

确立了柑橘橘肉、橘皮及土壤中代森锰锌残留量的气相色谱分析方法,采用反应后恒温处理以及代森锰锌工作曲线法进行测定并计算,消除了由于CS2-代森锰锌的质量转换系数不确定所带来的困难.结果表明,柑橘样品中代森锰锌平均回收率为86.46%～95.82%,变异系数为1.04%～7.69%,最小检出量为1.8×1010g,最低检测浓度为0.025mg/kg.     

Penicillin fermentation residue biochar as a high-performance electrode for membrane capacitive deionization

● We have provided an activated method to remove the toxicity of antibiotic residue. ● PFRB can greatly improve the salt adsorption capacity of MCDI. ● The hierarchical porous and abundant O/N-doped played the key role for the high-capacity desalination. ● A new field of reuse of penicillin fermentation residue has been developed. Membrane capacitive deionization (MCDI) is an efficient desalination technology for brine. Penicillin fermentation residue biochar (PFRB) possesses a hierarchical porous and O/N-doped structure which could serve as a high-capacity desalination electrode in the MCDI system. Under optimal conditions (electrode weight, voltage, and concentration) and a carbonization temperature of 700 °C, the maximum salt adsorption capacity of the electrode can reach 26.4 mg/g, which is higher than that of most carbon electrodes. Furthermore, the electrochemical properties of the PFRB electrode were characterized through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) with a maximum specific capacitance of 212.18 F/g. Finally, biotoxicity tests have showed that PFRB was non-biotoxin against luminescent bacteria and the MCDI system with the PFRB electrode remained stable even after 27 adsorption–desorption cycles. This study provides a novel way to recycle penicillin residue and an electrode that can achieve excellent desalination.     

Development of an analytical method for analysis of flubendiamide,des-iodo flubendiamide and study of their residue persistence in tomato and soil

Flubendiamide is a new insecticide that has been found to give excellent control of lepidopterous pests of tomato. This study has been undertaken to develop an improved method for analysis of flubendiamide and its metabolite des-iodo flubendiamide and determine residue retention in tomato and soil. The analytical method developed involved extraction of flubendiamide and its metabolite des-iodo flubendiamide with acetonitrile, liquid-liquid partitioning into hexane-ethyl acetate mixture (6:4, v v^?1) and cleanup with activated neutral alumina. Finally the residues were dissolved in gradient high pressure liquid chromatography (HPLC) grade acetonitrile for analysis by HPLC. The mobile phase, acetonitrile-water at 60:40 (v v^?1) proportion and the wavelength of 235 nm gave maximum peak resolution. Using the above method and HPLC parameters described, nearly 100 % recovery of both insecticides were obtained. There was no matrix interference and the limit of quantification (LOQ) of the method was 0.01 mg kg^?1. Initial residue deposits of flubendiamide on field-treated tomato from treatments @ 48 and 96 g active ingredient hectare^?1 were 0.83 and 1.68 mg kg^?1,respectively. The residues of flubendiamide dissipated at the half-life of 3.9 and 4.4 days from treatments @ 48 and 96 g a.i. ha^?1, respectively and persisted for 15 days from both the treatments. Des-iodo flubendiamide was not detected in tomato fruits at any time during the study period. Residues of flubendiamide and des-iodo flubendiamide in soil from treatment @ 48 and 96 g a.i. ha^?1 were below detectable level (BDL, < 0.01 mg kg^?1) after 20 days. Flubendiamide completely dissipated from tomato within 20 days when the 480 SC formulation was applied at doses recommended for protection against lepidopterous pests.