Adsorptive removal of mercury from acid mine drainage: a comparison of silica and maghemite nanoparticles

Mercury adsorption by silica and maghemite nanoparticles (NPs) was studied with the aim of comparing their performance in the remediation of acid mine drainage (AMD) contaminated water. Calculated distribution coefficients (K_d) showed that both NPs are exceptional adsorbents. However, adsorbate coverage per unit area was 30 times higher for maghemite than for silica NPs, despite the latter having a surface area ～15 times greater. Maghemite adsorbed 75% of available Hg compared to 56% by silica, making it a more efficient sorbent than silica under AMD conditions. Kinetics and isotherm data for both adsorbents were fitted by the pseudo-second-order (R² = 1) and the Freundlich (R² ≥ 0.98) models, implying that adsorption to both NP types was by chemisorption. Adsorption increased with NP concentrations and pH and was enhanced in the presence of manganese and sulfate ions although adsorption to silica was inhibited in 1:2 Hg-to-Mn systems. Importantly, trends in simulated wastewater were replicated in actual AMD-contaminated water samples. This study highlights the fact that properties besides surface area and charge of adsorbents determine adsorbent performance, and superior attributes may not always lead to higher adsorption efficiencies.     

金谷煤业在矿区生态环境保护和治理上的探索与实践

随着煤矿开发强度不断加大,矿山环境影响也日益加大,亟需保护和治理.文中就矿山环境保护与治理工作进行了简要论述,为同类矿山企业的环境保护和治理提供了一种有效途径.参1.     

冀东铁矿2种恢复模式植被演替过程中群落结构及生物多样性比较研究

油松（Pinus tabulaeformis）耐低温、干旱和贫瘠,是我国北方温性针叶林中分布最广的森林群落,也是我国北方广大地区最主要的本土造林树种之一,火炬（Rhus typhina Linn.）根萌蘖力强,耐寒、耐旱、耐盐碱,是一种适应周围环境能力极强的外来引入种树种。采用空间代替时间的方法,以冀东铁矿不同年份种植的人工火炬林和人工油松林群落为研究对象,采用样方法进行调查取样,分析了2种恢复模式不同演替阶段群落结构的变化,群落动态,同时采用Pielou均匀度指数、Margalef丰富度指数、Shannon-Wiener多样性指数分析了物种多样性在群落演替过程中的动态变化,在此基础上,对比分析了2种恢复模式在生态效益方面的优劣。主要结果如下：1）短期来看,火炬可以迅速提高植被盖度,增加生物量,但是,长期来看,随着火炬的快速萌集繁殖和林分的郁闭,林下草本急剧减少,形成火炬单优群落,而不能形成稳定的顶级群落。2）短期来看,油松生长缓慢,其生态效益远小于火炬群落,但是油松群落经过11年的演替形成了乔-灌-草3层结构,群落结构逐渐完善。3）演替初期火炬群落优势种以猪毛蒿（Artemisia scoparia）、狗尾草（Setaria viridis）等耐干旱的植物为主,演替后期林下物种迅速减少以至大量消失;油松群落经过11年的恢复,群落草本层植物种数逐渐增大,从一年生先锋植物占优势过渡到以白羊草（Bothriochloa ischaemun）和硬质早熟禾（Poa sphondylodes）为建群种,并出现了黄刺玫（Rosa xanthina）和胡枝子（Lespedeza bicolor）等多年生灌木。4）演替初期Margalef丰富度指数、Pielou均匀度指数和Shannon-Wiener指数表现为：火炬群落﹥油松群落,演替后期则相反,这主要是由群落内种间竞争关系和水热环境的差异造成。4）综合植物群落盖度、物种多样性和群落未来的演替趋势,火炬长期的生态效益远不及油松树种。     

Utility optimization strategy of safety management capability of coal mine - A case study of JCIA

This article describes optimization strategy of SMCCM from perspective of utility of coal miner with the method of empirical research. Four elements of SMCCM are put forward which consist of “employee safety knowledge”, “equipment safety knowledge”, “environment safety knowledge” and “rule safety knowledge”. Eight elements of utility are put forward which consist of “benefit satisfaction”, “promotion satisfaction”, “job satisfaction”, “enterprise satisfaction”, “management satisfaction”, “colleague satisfaction”, “relationship satisfaction” and “communication satisfaction”. Then hypotheses of influence path between SMCCM and utility are proposed. JCIA is chosen as the sample to carry out survey, which questionnaire is designed based on the likert six-point scale to avoid the middle tendency of the test samples. Data analysis is done from following angles: analysis of the structure and utility of test samples, variables analysis of SMCCM and utility, model analysis of interaction between SMCCM and utility. And then results are obtained from the analysis of elements of SMCCM and elements of utility. Conclusions: first, “rule safety knowledge” should be strengthened above all; second, “job satisfaction” should be paid more attention to; third, coal miner’s benefit should be concerned specially.     

综掘工作面除尘技术研究与应用

主要分析了通风除尘、除尘器除尘、喷雾除尘、煤层注水除尘、控尘技术、泡沫除尘的技术特点。新型泡沫抑尘技术在邢台煤矿的现场应用证明了泡沫抑尘技术具有除尘效率高、能改善作业环境等特点,尤其对呼吸性粉尘能有效抑制,具有较好的推广应用前景。     

矿井瓦斯液相催化氧化制甲醇的理论初探

提出了以瓦斯气中的氧气作为氧化剂,选用适当的催化剂对瓦斯气中的甲烷进行直接催化氧化合成甲醇的研究思路。从甲烷液相催化氧化反应机理入手,围绕着矿井瓦斯部分氧化制甲醇的热力学、甲烷液相部分氧化制甲醇的研究基础、瓦斯中氮气的防爆惰化作用及构建的实验系统几个方面对矿井瓦斯液相催化氧化制甲醇的可行性进行了探讨。     

矿井通风网络的社团结构及灾害控制研究

为研究矿井通风网络的社团结构特征和有效控制灾害在通风网络中的传播范围,根据通风网络的连接特点对传统的GN算法进行改进,以淮南某矿井的通风网络结构为例进行说明,发现矿井通风网络具有较强的社团结构特征;引入强弱社团结构和外内连接边数比后,社团结构的划分更符合实际。根据矿井通风网络社团间的连接关系,就会找到灾害传播的关键分支与节点并加以控制,降低灾害对相邻社团危害程度,控制灾害的蔓延范围。     

草原煤矸石堆放的生态环境问题及其治理措施综述

综述了内蒙古自治区煤矸石排放对草原生态系统造成的危害,比较了物理、化学和生物学方法对治理煤矸石的优缺点,重点分析了丛枝菌根真菌技术在煤矸石山生态重建中的应用及其意义,并提出了当前研究工作中存在的问题及以后的研究重点。     

平地型铀尾矿库氡大气扩散数值模拟及环境效应分析

以平地型铀尾矿库为研究对象,采用数值模拟方法,分析了铀尾矿库下风向的氡扩散和浓度分布,并预测了该地区常年主导风向下氡对公众所致的年有效剂量。结果表明,风速从0.5 m/s变化到2.0m/s时,氡在尾矿库下风向的积聚范围由5 000 m缩减为2 500 m,尾矿库下风向2 500 m距离以内的氡浓度降低较快,随着距离的增大,近地面区域氡浓度不断降低,5 000 m外氡浓度变化渐趋平缓。U10=0.5m/s时尾矿库下风向地区的氡浓度比其他风速下最高高出近43%。对照公众个人的年有效剂量标准,考虑风频风速影响,对氡的环境效应分析表明,低风速下现行标准中铀尾矿库防护距离的规定值偏小,应进行适当调整。     

体积含水率对铀尾矿氡析出率影响的试验研究

选取我国南方某铀尾矿库的自然尾矿样品,分析了其粒径分布和主要化学成分,设计并制作了测定铀尾矿氡析出率的室内试验装置,采用RAD7氡检测仪测定氡浓度,SM200水分仪测定铀尾矿的体积含水率,并阐述了试验步骤。采用对照试验的方法研究了体积含水率对铀尾矿氡析出率的影响规律。结果表明,随着体积含水率的增加,氡的析出率先上升,当铀尾矿体积含水率达到10%~12%时,氡析出率最高;之后,氡析出率随着铀尾矿体积含水率增加而下降。