Formation of iodo-trihalomethanes, iodo-haloacetic acids, and haloacetaldehydes during chlorination and chloramination of iodine containing waters in laboratory controlled reactions

Iodine containing disinfection by-products (I-DBPs) and haloacetaldehydes (HALs) are emerging disinfection by-product (DBP) classes of concern. The former due to its increased potential toxicity and the latter because it was found to be the third most relevant DBP class in mass in a U.S. nationwide drinking water study. These DBP classes have been scarcely investigated, and this work was performed to further explore their formation in drinking water under chlorination and chloramination scenarios. In order to do this, iodo-trihalomethanes (I-THMs), iodo-haloacetic acids (I-HAAs) and selected HALs (mono-HALs and di-HALs species, including iodoacetaldehyde) were investigated in DBP mixtures generated after chlorination and chloramination of different water matrices containing different levels of bromide and iodide in laboratory controlled reactions. Results confirmed the enhancement of I-DBP formation in the presence of monochloramine. While I-THMs and I-HAAs contributed almost equally to total I-DBP concentrations in chlorinated water, I-THMs contributed the most to total I-DBP levels in the case of chloraminated water. The most abundant and common I-THM species generated were bromochloroiodomethane, dichloroiodomethane, and chlorodiiodomethane. Iodoacetic acid and chloroiodoacetic acid contributed the most to the total I-HAA concentrations measured in the investigated disinfected water. As for the studied HALs, dihalogenated species were the compounds that predominantly formed under both investigated treatments.     

平庄西露天矿露井联采高陡长大 边坡稳定性监测研究

为掌握平庄西露天矿露井联采顶帮边坡的岩移规律与稳定性状态,揭示地下开采对边坡稳定性的影响,基于对典型滑坡位移-时间特征的 认识,提出用位移历时曲线与位移加速度历时曲线形态判断边坡稳定性状态,并详细对比分析了布置在井工开采边界以及边坡走向与倾向方向 上各监测线的地表位移监测数据。结果表明,平庄西露天矿顶帮现状边坡整体处于稳定状态,II区凸边坡为相对不稳定区域;边坡岩移规律及 稳定性主要受断层、弱层、边坡平面形态、地下开采及其引起的断层活化等因素综合控制;地下开采对边坡稳定性影响范围的边界大约在边坡 表面出露标高+572m。     

Concentration levels of disinfection by-products in 14 swimming pools of China

Swimming has become a popular exercising and recreational activity in China but little is known about the disinfection by-products (DBPs) concentration levels in the pools. This study was conducted as a survey of the DBPs in China swimming pools, and to establish the correlations between the DBP concentrations and the pool water quality parameters. A total of 14 public indoor and outdoor pools in Beijing were included in the survey. Results showed that the median concentrations for total trihalomethanes (TTHM), nine haloacetic acids (HAA9), chloral hydrate (CH), four haloacetonitriles (HAN4), 1,1-dichloropropanone, 1,1,1-trichloropropanone and trichloronitromethane were 33.8, 109.1, 30.1, 3.2, 0.3, 0.6 µg∙L⁻¹ and below detection limit, respectively. The TTHM and HAA9 levels were in the same magnitude of that in many regions of the world. The levels of CH and nitrogenous DBPs were greatly higher than and were comparable to that in typical drinking water, respectively. Disinfection by chlorine dioxide or trichloroisocyanuric acid could substantially lower the DBP levels. The outdoor pools had higher TTHM and HAA9 levels, but lower trihaloacetic acids (THAA) levels than the indoor pools. The TTHM and HAA9 concentrations could be moderately correlated with the free chlorine and total chlorine residuals but not with the total organic carbon (TOC) contents. When the DBP concentration levels from other survey studies were also included for statistical analysis, a good correlation could be established between the TTHM levels and the TOC concentration. The influence of chlorine residual on DBP levels could also be significant.     

2种组配改良剂对稻田土壤重金属有效性的效果

为研究2种组配改良剂LS(碳酸钙+海泡石)和HZ(羟基磷灰石+沸石)对土壤重金属的生物有效性以及水稻吸收累积重金属的影响,在湘南某矿区附近污染稻田中施用了不同添加量(0,2,4,8g/kg)的两种组配改良剂,并进行了水稻种植的田间试验.结果表明,施用2~8g/kg组配改良剂LS和HZ均能使土壤pH值和CEC含量显著增加,有机质含量变化不明显,LS比HZ更能提高土壤pH值和CEC含量.施用2~8g/kg组配改良剂LS能使土壤中Pb、Cd、Cu和Zn的TCLP提取态含量分别降低25.7%~52.2%、12.7%~25.7%、6.4%~17.2%和8.6%~23.4%,施用2~8g/kg HZ使土壤中Pb、Cd、Cu和Zn的TCLP提取态含量分别降低57.6%~80.1%、7.0%~40.9%、2.3%~22.7%和4.5%~33.2%.两种组配改良剂能显著降低土壤中Pb、Cd、Cu和Zn的生物有效性,抑制水稻植株对Pb和Cd的吸收,土壤Pb、Cd和Cu的TCLP提取态含量与水稻根系和糙米中Pb、Cd和Cu的含量之间存在显著或极显著的正相关关系,TCLP提取态含量能较好的表示重金属在土壤中的生物有效性.     

Modeling of Ce（IV） transport through a dispersion flat combined liquid membrane with carrier P507

A mathematical model for the transport of Ce （IV） from hydrochloric acid solutions through dispersion flat combined liquid membrane （DFCLM） with contain 2- ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester （P507） as the carrier, dissolved in kerosene as the membrane solution have been studied. This process of facilitated transport, based on membrane technology, is a variation on the conventional technique of solvent extraction and may be described mathematically using Fick＇s second law. The equations for transport velocity are derived considering the diffusion of P507 and its metallic complexes through the liquid membrane. In this work, the system is considered to be in a transient state, and chemical reaction between Ce（IV） and the carrier to take place only at the solvent-aqueous interfaces. Model concentration profiles are obtained for the Ce（IV）, from which extraction velocities are predicted. The experimental and simulated Ce（IV） extractions showed similar tendencies for a high Ce （IV） concentration and acidity case.The model results indicate that high initial Ce（IV） concentrations and acidity both have detrimental effects on Ce（IV） extraction and stripping. The diffusion coefficient of Ce（IV） in the membrane and the thickness of diffusion layer between feed phase and membrane phase are obtained and the values are 6.31 × 10-8m2·s-1 and 31.2 μm, respectively. The results are in good agreement with experimental results.     

低污染水生态净化组合技术应用

为有效提升低污染水体环境质量,采用生态净化组合技术,通过对环境基底改造、水质生物强化、水生植物恢复、水景观构建等处理技术的集成与优化,构建以活水为基础、以生态净化为核心、兼顾景观提升的低污染水体水环境组合整治系统. 结果表明,该组合技术成功恢复大型水生植物18种,水生植物覆盖率达90%,形成由挺水植物、浮水植物和沉水植物组成的良性水生态系统. 组合生态净化工程实施后,底泥pH由6.80~7.60升至7.30~7.90,E_h(氧化还原电位)由-210~-150 mV升至-62~31 mV,底质生境得到显著改善;水体透明度由15~35 cm显著升至83~145 cm,下层水体ρ(DO)由0.48~1.03 mg/L升至3.43~15.61 mg/L,ρ(TN)、ρ(NH₃-N)和ρ(TP)的削减率分别达到76%、85%和92%;水体浮游植物总数和总生物量分别减少了84.0%和90.6%,浮游植物群丛类型由富营养蓝藻(平裂藻)型转变为中-富营养混合型. 因此,水生态净化组合技术可有效净化低污染水的同时,还可提高水生态系统多样性.      

E. coli and bacteriophage MS2 disinfection by UV,ozone and the combined UV and ozone processes

The combination of low-dose ozone with ultraviolet （UV） irradiation should be an option to give benefit to disinfection and reduce drawbacks of UV and ozone disinfection. However, less is known about the disinfection performance of UV and ozone （UV/ozone） coexposure and sequential UV-followed-by-ozone （UV- ozone） and ozone-followed-by-UV （ozone-UV） expo- sures. In this study, inactivation of E. coli and bacterioph- age MS2 by UV, ozone, UV/ozone coexposure, and sequential UV-ozone and ozone-UV exposures was investigated and compared. Synergistic effects of 0.5-0.9 log kill on E. coli inactivation, including increases in the rate and efficiency, were observed after the UV/ozone coexposure at ozone concentrations as low as 0.05 mg-L-1 in ultrapure water. The coexposure with 0.02-mg.L-1 ozone did not enhance the inactivation but repressed E. coli photoreactivation. Little enhancement on E. coli inactivation was found after the sequential UV-ozone or ozone-UV exposures. The synergistic effect on MS2 inactivation was less significant after the UV/ozone coexposure, and more significant after the sequential ozone-UV and UV-ozone exposures, which was 0.2 log kill for the former and 0.8 log kill for the latter two processes, at ozone dose of 0.1 mg. t-1 and UV dose of 8.55 mJ. cm 2 in ultrapure water. The synergistic effects on disinfection were also observed in tap water. These results show that the combination of UV and low-dose ozone is a promising technology for securing microbiological quality of water.     

大变形巷道弹性锚喷混凝土耦合支护技术研究及应用

为提高层理地质条件下大变形巷道的稳定性,延长巷道使用寿命,采用具有较大变形承载能力的喷钢纤维混凝土与弹性锚杆耦合支护技术加固围岩。首先研究层理状地质条件下高应力软岩巷道的破坏特点及规律,确立支护结构和时效耦合的关系,并通过钢纤维混凝土试样的动静荷载试验,研究混凝土强度与钢纤维掺量的关系,得到喷钢纤维混凝土合理的钢纤维掺量。此外,针对大变形巷道开挖初期变形量大、破坏速度快的特点,设计具有让压吸能作用的新型弹性锚杆,并将此弹性锚杆结合喷钢纤维混凝土技术进行工业试验,试验的位移监测结果表明:该方案位移量比原方案减小约50%,且支护10个月后未出现裂缝。     

IIFLNs-AHP及其在煤矿安全状况评价中的应用

为了评价煤矿的安全现状,同时实现对各类安全隐患的排查,构建了基于层次分析法(AHP) 耦合区间直觉模糊语言数（IIFLNs）进行计算的IIFLNs-AHP评价模型。首先提出了区间直觉模糊语言关联混合几何 (R-IIFLNHG)算子,并由其算出评价权重向量;其次结合层次分析法（AHP）运用提出的权重聚合计算公式来确定各层次指标重要程度,并对指标进行排序。以某煤矿为例,运用IIFLNs-AHP进行计算,同时根据计算结果找到了隐含的各类安全隐患,其计算分析结果与现场情况及前人研究结论基本一致,从而验证了IIFLNs-AHP的正确性。结果表明,IIFLNs-AHP能够较好地对煤矿各类安全评价指标进行排序,有助于确定指标体系中的薄弱环节,并可据此实现对安全管理有针对性的改进与完善。     

河蚬或藻存在下组合扰动对内源磷迁移的影响

为阐明河蚬(Corbicula fluminea)或铜绿微囊藻(Microcystis aeruginosa)存在下,物理和摇蚊幼虫组合扰动对内源磷再生和迁移转化的影响,以太湖梅梁湾上覆水和沉积物为研究对象,分析了上覆水、间隙水、沉积物中不同形态磷的变化规律.结果表明,与摇蚊幼虫扰动和组合扰动相比,河蚬或藻类的出现都会使得上覆水中不同形态磷(总磷、溶解性总磷、溶解性磷酸盐、颗粒态磷)显著增加.河蚬或藻类均导致间隙水DIP明显降低,并致使DIP峰值区域向更深处迁移(3~4cm变为4~5cm),而对照试验则相反.与对照试验相比,河蚬或藻存在下组合扰动均导致0~4cm沉积物NH₄Cl-P含量及其占总磷百分比降低,Fe/Al-P含量及其占总磷百分比增加,并且河蚬或藻对NH₄Cl-P降低和Fe/Al-P增加的影响基本一致.在多种扰动因素存下,摇蚊幼虫对上覆水中DTP和DIP贡献最大,后者可能源于摇蚊幼虫显著降低了间隙水中DIP含量及沉积物中NH₄Cl-P含量.这暗示了在组合扰动基础上叠加河蚬或者藻类,均进一步促进了内源磷再生和迁移.