Effect of Fe loading quantity on reduction reactivity of nano zero-valent iron supported on chelating resin

In this study, nanoscale zero-valent iron (NZVI) were immobilized within a chelating resin (DOW 3N). To investigate the effect of Fe loading on NZVI reactivity, three NZVI-resin composites with different Fe loading were obtained by preparing Fe(III) solution in 0, 30 and 70% (v/v) ethanol aqueous, respectively; the bromate was used as a model contaminant. TEM reveals that increasing the Fe loading resulted in much larger size and poor dispersion of nanoscale iron particles. The results indicated that the removal efficiency of bromate and the rate constant (K_obs) were decreased with increasing the Fe loading. For the NZVI-resin composite with lower Fe loading, the removal efficiency of bromate declined more significantly with the increase of DO concentrations. Under acidic conditions, decreasing the pH value had the most significant influence on NZVI-R3 with highest Fe loading for bromate removal; however, under alkaline conditions, the most significant influence of pH was on NZVI-R1 with lowest Fe loading. The effects of co-existing anions NO3−, PO43− and HCO3− were also investigated. All of the co-existing anions showed the inhibition to bromate reduction.     

基于Multi-agent的非常规突发事件下个体应激演化模型

为深入研究非常规突发事件下个体应激反应,为突发事件应急管理提供理论依据,基于复杂系统理论（CAS）和多主体建模方法（ABMS）,构建了应激演化模型;利用NetLogo仿真平台,并根据个体所处的社会环境,动态模拟了非常规突发事件、群体、个体行为间的相互制约关系。研究表明:公众应激反应演化系统是一种复杂的自适应系统;非常规突发事件应激反应在三个不同阶段呈现出不同的特征。因此,在非常规突发事件的应急管理中,要根据个体在每个阶段不同的特征采取与之相适应的措施。     

基于Multi-agent的矿工情绪稳定性模型构建

为解决由矿工情绪稳定性水平低下引起的不安全行为问题,基于复杂适应系统（CAS）理论和多主体建模与仿真（ABMS）的方法,构建矿工情绪稳定性水平提升模型。通过调节班组协调程度、组织公平程度、安全心理培训水平、受教育程度、个性特征和作业环境舒适度,在NETLOGO仿真平台上分析矿工意志强度、情绪安全倾向度以及管理者领导能力对矿工情绪稳定性水平的影响。研究表明:矿工的情绪稳定性水平提升系统是一种典型的复杂适应系统,矿工情绪稳定性水平是各主体属性相互作用的结果,作用程度存在差异。因此,煤炭企业应考虑各种因素,通过控制和改善各主体的行为以提高矿工情绪稳定性水平。     

文南油田注水管线防污染清洗技术研究

针对文南油田注水管线内壁结垢对油田注水的危害,以及管线清洗过程中存在的环境污染和硫化氢中毒问题,分析消除硫化氢的反应机理,研究抑硫清洗剂,改进管线清洗工艺,开发注水管线防污染清洗技术,在推广应用中取得了较好的环保效果。     

高含硫气田地面集输系统防腐技术综合应用浅析

针对高含硫气田地面集输系统中H2S、CO2严重腐蚀管道和容器的问题,分析了腐蚀产生机理和破坏形式。以四川省境内的普光气田为例,阐述了实际采取的各种防腐措施,主要包括:选择抗蚀材料,严格控制焊接工艺,对输送的天然气进行保温外输,使用缓蚀剂,防止冷凝水析出以及避免管道弯头和突出部位的紊流。在此基础上,分析了目前主要的在线腐蚀监测方法的特点,介绍了普光所用的在线监测技术及其监测系统。各种防腐和在线监测技术的综合应用,对于保障高含硫气田安全生产和运行具有重要意义。     

Efficient removal of heavy metals from electroplating wastewater using polymer ligands

Poly(hydroxamic acid)-poly(amidoxime) chelating ligands were synthesized from poly(methyl acrylate-co-acrylonitrile) grafted acacia cellulose for removing toxic metal ions from industrial wastewaters. These ligands showed higher adsorption capacity to copper (2.80 mmol?g⁻¹) at pH 6. In addition, sorption capacities to other metal ions such as iron, zinc, chromium, and nickel were also found high at pH 6. The metal ions sorption rate (t_1/2) was very fast. The rate of adsorption of copper, iron, zinc, chromium, nickel, cobalt, cadmium and lead were 4, 5, 7, 5, 5, 8, 9 and 11 min, respectively. Therefore, these ligands have an advantage to the metal ions removal using the column technique. We have successfully investigated the known concentration of metal ions using various parameters, which is essential for designing a fixed bed column with ligands. The wastewater from electroplating plants used in this study, having chromium, zinc, nickel, copper and iron, etc. For chromium wastewater, ICP analysis showed that the Cr removal was 99.8% and other metal ions such as Cu, Ni, Fe, Zn, Cd, Pb, Co and Mn removal were 94.7%, 99.2%, 99.9%, 99.9%, 99.5%, 99.9%, 95.6% and 97.6%, respectively. In case of cyanide wastewater, the metal removal, especially Ni and Zn removal were 96.5 and 95.2% at higher initial concentration. For acid/alkali wastewater, metal ions removing for Cd, Cr and Fe were 99.2%, 99.5% and 99.9%, respectively. Overall, these ligands are useful for metal removal by column method from industrial wastewater especially plating wastewater.     

新型气体灭火剂七氟丙烷的性能及其应用

介绍七氟丙烷气体灭火剂的基本性质及特点,阐述七氟丙烷气体灭火剂的灭火原理,分析讨论七氟丙烷气体灭火剂的环境效益、安全可靠性、经济适用性,并对其适用条件进行了说明。     

Comparative effects of five chelating agents on testicular toxicity in mice induced by acute exposure to cadmium

The aim of this study was to develop new antidotes for cadmium (Cd) since this metal is known to produce mammalian toxicity. N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), N-benzyl-D-glucamine dithiocarbamate (BGD), diethyldithiocarbamate (DDTC), 2,3-dimercaptopropanol (BAL), and ethylenediamine-tetraacetic acid (EDTA) were studied for their ability to inhibit the adverse effects induced by Cd on mouse testes. The parameters examined included concentrations of Cd, calcium (Ca), iron (Fe), and zinc (Zn) in testes, lipid peroxidation (LPO) levels in testes, lactate dehydrogenase (LDH) activity in serum and reproductive ability of male mice. Mice injected intraperitoneally (ip) with CdCl₂ (2.5?mgCd?kg^?1) after 30?min or 24?h, were then injected ip with chelating agents (400?µmol?kg^?1). Cd increased the concentrations of testicular Ca, Cd, Fe, Zn, and LPO levels as well as the activity of LDH in serum. HBGD and BGD effectively prevented the increase in above indices, and improved the reproductive ability weakened by exposure to Cd. The results suggested that HBGD and BGD are more effective detoxificants in the case of testicular toxicity in mice induced by acute exposure to Cd.     

Toxic effects of dietary of Al3+ ions in tilapias (Oreochromis niloticus) and protective effect of Zn2+ ion

The lethal effects of aluminum ion (Al³⁺) in tilapia (Oreochromis niloticus) raised in concrete tanks were investigated. Tilapias were fed daily with commercial feed enriched with known concentrations of Al³⁺ and analyzed by differential pulse anodic stripping voltammetry (DPASV). The concentrations of Al³⁺ in feces, water, muscle tissue, viscera, and heads were determined every 3 months for a period of 365 days. The Tilapia head was the most affected tissue by Al³⁺. In general, Al³⁺ bioaccumulation reached the lethal dose (LD₅₀) after 335 days of experiment as follows: 34.9?mg?kg^?1 (muscle tissue), 88.2?mg?kg^?1 (viscera), and 126.9?mg?kg^?1 (head without gills). After determining Cu²⁺, Zn²⁺, and Ca²⁺ by absorption spectrometry, a decrease in the Ca²⁺ concentration was noted in the head during the experimental period. These observations were associated with the occurrence of a decalcification in the bone tissue in the presence of Al³⁺. In contrast, it was found that Zn²⁺ ions may act as a protective agent against Al³⁺-induced contamination.     

Chelant-assisted pulse flushing of a field Pb-contaminated soil

Laboratory experiments on a lead-contaminated soil were carried out to test the effects of chelant addition on metal leachability using column tests. Tests were aimed at studying metal mobilisation upon application of two different chelating agents (ethylenediaminetetraacetic acid [EDTA] and ethylenediaminedisuccinic acid [EDDS]). Column operation was arranged to simulate a flushing treatment in which the chelating agent is applied in a pulse mode to the soil for one bed volume, while deionised water was continuously introduced for the rest of the experiment. Two different concentrations (3 and 5 mmol·kg ^?1 respectively) of the two chelating agents and a control solution (deionised water) were tested in separate experiments; pH, total organic carbon and the total concentrations of Pb, Zn, Fe, Cd, Cu and Ni were monitored during each run. A seven-step sequential extraction procedure was used to evaluate metal partitioning and concentration in the contaminated soil after treatment as a function of depth. The results showed the effect of the nature of flushing solution on the hydraulic behaviour of the columns. Metal concentrations in the leachate increased considerably upon the application of chelants, thus indicating their suitability for metal extraction from contaminated soils. In view of full-scale application of soil flushing, particular concern should also be devoted to ensuring a homogeneous distribution of the solution within the contaminated area and an efficient collection of the exhausted extracting solution, as well as to recovering and recycling the chelating agent used.