板坯火焰清理机烟气治理技术

介绍了国产板坯火焰清理机烟气的治理系统及湿式电除尘器的结构和技术特点.结果表明,该烟气治理系统及湿式电除尘器能够满足火焰清理机工况和烟气排放的环保要求,完全可以替代同类进口设备.     

山阴水砷中毒区地下水砷的富集因素分析

通过对山阴地区66个地下水样中常量元素、微量元素及有机物分析,研究了山阴高砷地下水的水化学特性并在此基础上,结合该地区含水层沉积物矿物分析,探讨了地下水中砷富集的影响因素.结果表明,山阴地下水平均pH为8.09,磷酸根含量为0.71mg/L,溶解性有机物含量为5.14 mg/L,以及地下水处于还原环境.高pH值、高磷酸根含量及还原环境不利于含水介质对以阴离子形式存在的砷的吸附,高溶解性有机物含量则增加了砷的活性这些因素促使了含水介质中砷的解吸和迁移.     

三维电极电催化氧化法处理废水的研究进展

综述了近几年国内外在三维电极电化学反应器方面的最新研究进展,分析了电源的输出形式、阴阳极板的布置方式、粒子电极的填充方式等因素对废水处理效果的影响,探讨了碳纳米材料等新材料在粒子电极载体上的应用,最后介绍了三维电极法与其他技术联用的最新研究,并指出了三维电极法存在的问题及今后的研究方向。     

Assessment of hydrocarbon emissions from diesel invert mud residues treated in a bioreactor

Hydrocarbon emissions from a diesel invert mud residue (DIMR) were monitored while the hydrocarbons were being biodegraded in a solid‐phase bioreactor. Five to twenty percent of the reduction in diesel hydrocarbons was attributed to evaporation depending on the treatment, i.e. homogenization, cultivation, and aeration. Most of these volatile hydrocarbons were linear C₈ — C₁₂ alkanes and one‐ring aromatics. Of the treatments aeration had the largest effect on emissions; forced air through the bottom of the bioreactor cells increased emissions by three times over that of the non‐aerated cells. Cultivation increased hydrocarbon emission concentration as much as twofold over the pre‐cultivation value, however, emissions returned to the original levels within 12 hours. Homogenization had the least effect of all treatments. Diurnally, the emission rate was 40% higher in late afternoon than at midnight; the cause of which was probably atmospheric fluctuations such as temperature and solar radiation. The effects of daily atmospheric fluctuations were empirically modeled and taken into account for determining the total volume of emissions.     

印染废水处理过程及排放水对草履虫遗传毒性评价

草履虫作为指示生物评估印染废水处理过程及排放水的毒性效应。急性毒性结果显示,原水、厌氧工段印染废水、好氧工段印染废水对草履虫的半数致死浓度(24h-LC₅₀)分别为54%、41%、98%;遗传毒性结果显示,印染废水原水、经处理的排放水在6.25%、12.25%稀释梯度下对草履虫造成的DNA损伤较对照组呈显著升高(p<0.01),而排放水对草履虫的DNA损伤较原水无显著性差异;草履虫增殖速率结果显示,印染废水排放水50%稀释梯度下对草履虫增殖速率有抑制作用。暴露于印染废水排放水中10%的草履虫其游动行为发生改变。以上结果表明,印染废水在经过处理后,理化指标均达到国家印染废水行业排放标准,但排放水仍对草履虫产生急性毒性,且遗传毒性较原水没有显著降低。水生生物毒性测试能有效补充理化指标评价,为印染废水行业全面达标排放提供依据。     

Removal of sulfadiazine from aqueous solution on kaolinite

The adsorption of sulfadiazine onto kaolinite clay as an alternative adsorbent was examined in aqueous solution, hnpacts of the contact time, pH, temperature, ionic strength and coexistent surfactants on the adsorption process were evaluated. The pH significantly influenced the adsorption process, with adsorption being promoted at lower pH due to the cation exchange mechanism. Decreasing ionic strength in the solution was favorable for adsorption, and the addition of cationic and anionic surfactants had negative effects on the adsorption capacity of sulfadiazine on kaolinite. Kinetic experiments showed that the adsorption followed the pseudo-second-order model. The equilibrium adsorption was well described by both Freundlich and Dubinin-Radushkevich （DR） models. According to the DR model, the adsorption mechanism was determined by cationic exchange and weak physical forces. The thermodynamic study showed that sulfadiazine adsorption onto kaolinite was a sponta- neous and endothermic reaction.     

潖江蓄滞洪区洪灾风险分析及避难转移安置研究

以潖江蓄滞洪区洪灾避难转移安置为研究对象,利用Mike21技术,建立潖江蓄滞洪区洪水演进数值模型,模拟北江遭遇300年一遇洪水时,在潖江口泄洪,潖江蓄滞洪区内洪水演进,分析潖江蓄滞洪区洪灾风险.通过实地调查,结合历史洪水情况,利用潖江蓄滞洪区DEM数据、Google地图及最快避难转移安置时间分析法,详细设计了潖江蓄滞洪区内各行政村落遭遇洪灾时避难转移与人员安置,为潖江蓄滞洪区启用预案科学编制及防洪减灾提供科学依据.     

Evidence for a mutual effect of biofilms, suspended particles and sediments on DDT sorption

This report shows that biofilms and suspended particles double DDT sorption capacity on surface sediments. Sorption of pollutants by solid materials, such as biofilms, suspended particles and sediments, is a major process controlling the fate of hydrophobic pollutants in natural waters. Most previous studies focused on the sorption of hydrophobic pollutants by single-solid material, whereas few studies considered the mutual effect of different solids on the sorption. Various solid materials often interact with each other when they coexist in the same system. Therefore, pollutants sorption could be different from that in the single-solid sorption system. Here we studied the mutual effect of biofilms, suspended particles and surface sediments on the sorption of dichlorodiphenyltrichloroethane (DDT). Results showed that biofilms and suspended particles double DDT sorption capacity on surface sediments. The different effects were mainly determined by distinct components and structures of the three solid materials, particularly by organic components. Here we show the mutual effect of biofilms, suspended particles and sediments on DDT sorption.     

Urea formation from carbon dioxide and ammonia at atmospheric pressure

Urea synthesis, currently the largest use of carbon dioxide in organic synthesis, is conventionally operated at high pressure and high temperature. Here, we report for the first time that urea forms at atmosphere and ambient temperatures by negative corona discharge in gas phase. The conversion of CO₂ and yields of a solid mixture of urea and ammonium carbamate, which was identified by the ¹³C NMR spectrum, rise with reducing temperatures and increasing molar ratios of NH₃/CO₂ and discharge frequencies. The conversion of carbon dioxide was found to be 82.16?% at 20?°C and 1?atm with a molar flow ratio of n(NH₃)/n(CO₂) of 2.5. High pressure and high temperature as energy inputs are not necessary.