Fered-Fenton法处理石化废水反渗透浓水

以Ti金属网为阴极、Ti负载RuO2金属网为阳极,构建Fered-Fenton反应系统,处理石化废水反渗透膜法浓水.考察H2O2浓度、Fe2+浓度、初始pH值和电流密度等因素对废水处理效果的影响,并分析了废水可生化性及污染物降解规律.结果表明,在H2O2浓度为75.0 mmol/L,Fe2+浓度为7.5 mmol/L,初始pH值为3.0,电流密度为5.1 mA/cm2的条件下,反应120 min后废水TOC可由198.2 mg/L降到99.6 mg/L,有机污染物矿化率达到49.7％,BOD5/COD由0.11提高至0.31,废水可生化性明显改善.三维荧光光谱(EEM)分析结果表明,Fered-Fenton法对废水中类蛋白、类富里酸等荧光有机物去除率达到66.7％,该类大分子难降解有机物的氧化降解有利于改善废水可生化性,为进一步的生化处理创造了良好的条件.     

磁性纳米γ-Fe2O3/SiO2去除水中亚甲基蓝

以纳米γ-Fe₂O₃为磁性介质制备了磁性纳米γ-Fe₂O₃/SiO₂,并将其用于水中亚甲基蓝的吸附。表征结果显示：制备的γ-Fe₂O₃/SiO₂呈不规则核壳结构,平均粒径为38 nm,比表面积为74.35 m²/g,比饱和磁化强度为55 A·m²/kg。实验结果表明：γ-Fe₂O₃/SiO₂对亚甲基蓝的吸附适宜在中碱性条件下进行,4 h即可达吸附平衡;在初始亚甲基蓝质量浓度为180 mg/L、γ-Fe₂O₃/SiO₂加入量为2 g/L、初始溶液pH为7.0、吸附温度为298 K的条件下,吸附量最高为25.4 mg/g;共存金属离子会降低吸附效率,而少量的腐殖酸则会促进吸附;吸附过程符合准二级动力学方程,颗粒内扩散不是唯一的控速步骤;等温吸附满足Langmuir模型,该吸附是一个物理吸附过程;用乙醇洗涤的γ-Fe₂O₃/SiO₂重复使用4次时仍能保持约80%的原吸附量。     

氧化石墨烯负载纳米零价铁的制备及其对亚甲基蓝的吸附

采用液相还原法制备氧化石墨烯负载纳米零价铁吸附剂(Fe0/GO),并用于吸附去除溶液中的亚甲基蓝(MB)。考察了溶液p H、吸附温度、吸附时间、初始MB质量浓度对Fe0/GO吸附MB的影响。SEM等表征结果显示:Fe0以球形或短链形负载在GO上,增加了材料的反应活性位点;Fe0/GO的比表面积为158.32 m2/g,等电点为3。实验结果表明:在溶液p H为6、吸附时间5 h、吸附温度25℃的最佳条件下,加入400 mg/L的Fe0/GO,处理初始MB质量浓度为160 mg/L的MB溶液,MB去除率为89.26%,吸附量为125.5 mg/g;Langmuir等温吸附方程和Frenudlich等温吸附方程均能较好地描述Fe0/GO对MB的吸附过程;Fe0/GO对MB的吸附行为遵循准二级动力学方程;计算得出吸附温度为25℃、初始MB质量浓度为160 mg/L时的饱和吸附量为201.2 mg/g,平衡吸附量为124.3 mg/g。     

苯甲酸生产残液中锰、钴和镍的提取及分离

探讨了苯甲酸生产残液中锰、钴和镍的提取及分离方法。首先采用酸溶液提取残液中的金属元素;然后通过氨水沉淀法分离锰;最后使用p507萃取剂分离钴和镍。实验结果表明:当苯甲酸生产残液中锰、钴和镍的质量分数分别为0.085 0%,0.307 1%,0.015 5%时,在硫酸浓度为2.0 mol/L、过氧化氢溶液质量分数为25%的条件下,锰、钴和镍的提取率分别为88.59%,87.77%,86.50%;当氨水浓度为2 mol/L时,锰的沉淀率达94.24%;在平衡水相p H为4、p507萃取剂皂化率为60%、油相中p507萃取剂的体积分数为15%的条件下,钴萃取率达87.53%,镍萃取率仅为8.46%,钴镍分离系数为68.70。     

Occurrence and human dietary assessment of sulfonamide antibiotics in cultured fish around Tai Lake,China

As the most important fishery medicines, sulfonamides are widely used to prevent diseases caused by pathogens in aquaculture. However, relatively little is known about the residues and dietary risks associated with cultured fish around Tai Lake. In the present study, a sampling strategy for a complete aquaculture period was conducted. Specifically, 12 selected sulfonamide antibiotics were measured among 116 fish samples recruited from four sampling periods, four species, four areas, and 18 fish ponds. All 12 antibiotics were detected at detection frequencies of 4.31–28.45%. Total sulfonamides were detected in 77.59% of the fish samples, with 57.76% of fish samples containing from 0.1 to 10 μg kg^?1. Sulfadiazine (SDZ), sulfamethoxazole (SMZ), sulfamethazine (SDD), and sulfamonomethoxine (SMM) were the main types of antibiotics used, and these were present at high concentrations (>100 μg kg^?1) with high occurrences, especially in the middle of the aquaculture season. Dietary assessment showed that residual antibiotics in all fish that were being sent to market were far below the maximum residue limit (MRL) of total sulfonamides and that there was almost no risk associated with fish consumption. The results of the present study will facilitate development of effective measures to produce safe aquatic products and meaningful suggestions for consuming aquatic products.     

5种不同晶型的纳米二氧化钛对金属铜生物积累的影响

纳米二氧化钛(nTiO_2)作为一种具有独特物理化学性质的纳米材料被广泛应用。然而,在生产、使用的过程中,nTiO_2会不可避免地进入于水环境中。重金属是水体中常见的污染物之一,nTiO_2进入水体后是否会与水体中的重金属发生相互作用,进而影响重金属的生物积累,目前相关报道还很少。本论文以大型溞为模式生物,考察了5种不同晶型nTiO_2对常见的重金属铜生物积累影响。结果表明,nTiO_2对Cu2+的吸附降低了试验液中Cu2+浓度。但5种不同晶型nTiO_2的吸附能力并不一样,其中锐钛矿晶型(A-S)的吸附能力最高,这可能是由于结构缺陷和表面羟基的存在,为Cu2+提供了更多的结合位点,从而提高了A-S的吸附能力。nTiO_2的存在降低了金属铜在大型溞体内的积累,这可能是由于nTiO_2对金属铜的吸附,降低了自由Cu2+的生物可利用性。由于nTiO_2样品之间比表面积的差异,不同晶型之间单位nTiO_2引起的铜积累有显著性差异性(P0.05),其中锐钛矿和金红石之比为4:1混合晶型(M1)最高,A-S最低。     

基于互联网的地震预警问题的社会调查与分析

通过互联网对地震预警问题进行了社会调查,统计和分析问卷10 349份.结果表明,绝大多数的被调查者接受通过地震预警来减轻地震灾害的方式,认同地震预警的主要目标是减少人员伤亡,表示在信息公开及掌握应对措施的情况下,在地震预警时不会产生恐慌.同时,51.2%的被调查者认为,由地震部门发布预警更合适,而政府的责任是根据预警做好应急准备.72.1%的人表示对地震科普知识了解较少的现实表明,我国的地震知识普及率仍然很低.而公众能否理性地接受地震预警的实践,与地震知识普及程度关系很大.     

水污染治理迫在眉睫

涉及水污的一些新的权威信息 水是一切生物生存、发展之本。水污染是大多环境污染之根,是许多污染之源,它必将引发环境污染和安全事故,直接或间接地导致人的死亡。我们的水环境质量已严重下降,水环境污染现象触目惊心。     

Fate of polybrominated diphenyl ethers in the environment of the Pearl River Estuary, South China

Ninety-six riverine runoff samples collected at eight major outlets in the Pearl River Delta (PRD), South China, during 2005-2006 were analyzed for 17 brominated diphenyl ether (BDE) congeners (defined as Σ₁₇PBDE). Fourteen and 15 congeners were detected, respectively, in the dissolved and particulate phases. These data were further used to elucidate the partitioning behavior of BDE congeners in riverine runoff. Several related fate processes, i.e. air-water exchange, dry and wet deposition, degradation, and sedimentation, within the Pearl River Estuary (PRE), were examined to estimate the inputs of Σ₁₀PBDE (sum of the target BDE congeners, BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, and -183) and BDE-209 from the PRD to the coastal ocean based on mass balance considerations. The results showed that annual outflows of Σ₁₀PBDE and BDE-209 were estimated at 126 and 940 kg/year, respectively from the PRE to coastal ocean. Besides sedimentation and degradation, the majority of Σ₁₀PBDE and BDE-209 discharged into the PRE via riverine runoff was transported to the coastal ocean.     

CuO/γ-Al_2O_3负载型催化剂催化燃烧处理油烟

采用等体积漫渍法制备不同CuO负载量的CuO/γ-Al2O3负载型催化剂,用X射线衍射仪、扫描电镜对该催化剂负载层活性组分的表面形态、晶相结构和颗粒大小进行表征,考察了该催化荆催化燃烧处理油烟的催化活性(以油烟净化效率表征).结果显示,催化活性随CuO负载量的增加.反应温度的升高而提高,但随烟气流量的增大而降低;在CuO负载量为20%(质量分数)、反应温度为350℃.烟气流量为5 L/min的最佳实验条件下,CuO/γ-Al2O3负载型催化剂的油烟净化效率最高.可达88.6%.该催化剂对油烟的催化燃烧具有较高的催化活性.