三峡库区消落带土壤淹水过程中汞的释放及甲基化特征

为探索三峡库区消落带土壤淹水期汞的环境化学行为,利用模拟试验,设置A(15℃,低溶解氧(DO))、B(30℃,低DO)、C(15℃,高DO)3组处理,在人工气候培养箱中进行消落带土壤淹水过程中汞的释放与甲基化特征研究,淹水试验共进行了40 d.结果表明,淹水初期(0—10 d)土壤汞呈释放趋势,A、B、C等3组处理水体中总汞浓度逐渐增加,而土壤中总汞含量相应降低;随淹水时间的延长(10 d),二者达到平衡.淹水后,A、B、C处理上覆水甲基汞浓度随淹水时间的延长而升高,且分别在第15天、第8天、第15天达到峰值,第30天基本达到平衡;土壤甲基汞含量随淹水时间的延长而增高,并在第30天达到平衡,平衡时土壤及上覆水甲基汞浓度规律均表现为BAC.土壤-上覆水系统温度的适当升高利于土壤汞的释放及甲基化;高溶解氧利于土壤汞的释放,低溶解氧则更利于汞的甲基化.     

数字化人机界面监视过程影响因子的可靠性测试研究

在数字化人机界面中,监视过程扮演了重要角色,因为监视过程是引发人因事故的重要原因之一.针对这种状况,以监视过程重要影响因子为研究对象来分析这些因素的可靠度,从而不断改进和完善这些影响因子,达到减少由监视引起人因事故的目的.在研究中,每个影响因子分成3种不同的水平,每个影响因子的每一水平均通过相应的模拟试验平台进行可靠度测试.试验结果表明,经验因子在监视时间和失误率方面有重要影响;对时间方面最有影响的因子是心理压力;任务复杂度在失误率和监视时间方面也有影响.     

加氢装置开工过程中的HSE管理

列举了加氢装置开工过程中HSE危害识别及风险控制措施,指出了HSE管理在加氢装置开工过程中必须要体现务实并具有可操作性的管理特点,总结了加氢装置开工过程中的HSE管理工作体会.     

家庭太阳能发电系统维护和保养

<正>一、外观检查,请仔细检查组件是否存在外观缺陷。重点观察以下几点:a)组件玻璃是否有破损;b)是否有尖锐物体接触组件表面;c)组件是否被障碍物、异物遮挡;d)电池片栅线附近是否有腐蚀情况。这种腐蚀情况是由于组件表面封装材料在安装或运输过程中遭到破损,导致水汽渗透到组件内部所造成;e)观察组件背板是否有烧穿的痕迹;f)检查组件与支架间固定螺丝是否松动或损坏,     

Experimental study on the impact of temperature on the dissipation process of supersaturated total dissolved gas

Water temperature not only affects the solubility of gas in water but can also be an important factor in the dissipation process of supersaturated total dissolved gas （TDG）. The quantitative relationship between the dissipation process and temperature has not been previously described. This relationship affects the accurate evaluation of the dissipation process and the subsequent biological effects. This article experimentally investigates the impact of temperature on supersaturated TDG dissipation in static and turbulent conditions. The results show that the supersaturated TDG dissipation coefficient increases with the temperature and turbulence intensity. The quantitative relationship was verified by straight flume experiments. This study enhances our understanding of the dissipation of supersaturated TDG. Furthermore, it provides a scientific foundation for the accurate prediction of the dissipation process of supersaturated TDG in the downstream area and the negative imp）acts of high dam projects on aquatic ecosystems.     

Enhanced anaerobic fermentation with azo dye as electron acceptor： Simultaneous acceleration of organics decomposition and azo decolorization

Accumulation of hydrogen during anaerobic processes usually results in low decomposition of volatile organic acids（VFAs）. On the other hand, hydrogen is a good electron donor for dye reduction, which would help the acetogenic conversion in keeping low hydrogen concentration. The main objective of the study was to accelerate VFA composition through using azo dye as electron acceptor. The results indicated that the azo dye serving as an electron acceptor could avoid H2 accumulation and accelerate anaerobic digestion of VFAs. After adding the azo dye, propionate decreased from 2400.0 to 689.5 mg/L and acetate production increased from 180.0 to 519.5 mg/L. It meant that the conversion of propionate into acetate was enhanced. Fluorescence in situ hybridization analysis showed that the abundance of propionate-utilizing acetogens with the presence of azo dye was greater than that in a reference without azo dye. The experiments via using glucose as the substrate further demonstrated that the VFA decomposition and the chemical oxygen demand（COD） removal increased by 319.7 mg/L and 23.3% respectively after adding the azo dye. Therefore, adding moderate azo dye might be a way to recover anaerobic system from deterioration due to the accumulation of H2 or VFAs.     

Mechanism of Cu(Ⅱ) adsorption inhibition on biochar by its aging process

Biochar exposed in the environment may experience a series of surface changes, which is called biochar aging. In order to study the effects of biochar aging on Cu（Ⅱ） adsorption, we analyzed the surface properties before and after biochar aging with scanning electron microscopy（SEM） coupled to an energy-dispersive X-ray spectrometer（EDX） and diffuse reflectance infrared Fourier transform spectroscopy（DRIFTS）, and then explored the influence of the aging process on Cu（Ⅱ） adsorption by batch experiments. After the aging process, the oxygen concentration, phenolic hydroxyl groups, aromatic ethers and other oxygen-containing functional groups on the biochar surface increased, while carboxyl groups slightly decreased. Thus, over a range of pH, the cation exchange capacity（CEC） and adsorption capacity of Cu（Ⅱ） on the aged biochar were smaller than those of new biochar,indicating that when biochar is incubated at constant temperature and water holding capacity in the dark, the aging process may inhibit Cu（Ⅱ） adsorption. Meanwhile, the dissociation characteristics of oxygen-containing functional groups changed through the aging process, which may be the mechanism by which the biochar aging process inhibits the Cu（Ⅱ） adsorption. Carboxyl groups became more easily dissociated at low pH（3.3–5.0）,and the variation of maximum adsorption capability（qm） of Cu（Ⅱ） on the old biochar was enlarged. Phenolic hydroxyl groups increased after the aging, making them and carboxyl groups more difficult to dissociate at high pH（5.0–6.8）, and the variation of qmof Cu（Ⅱ） on the aged biochar was reduced.     

采用TOT模式的城镇污水处理厂项目实施过程分析

以某城镇污水处理厂TOT项目为例,介绍了城镇污水处理厂项目TOT实施流程,对关键实施过程逐一进行了分析.结果表明,在实施城镇污水处理厂TOT项目时,对项目进行尽职调查、技术分析、财务分析和风险分析是实施的关键过程,为相关工程项目具体操作提供参考.     

排污费改税的法律思考

排污税与宏观因素息息相关,在商品经济流转过程中税负可随产品转嫁给消费者,有效减少环境污染成本较高的产品购买量,实现了资源的再分配利用,引导绿色消费取向。     

固定流量过程高浓度废水回用水网络设计

现有的水系统直观优化设计研究以新鲜水用量最小为目标,优先回用低浓度水源,考虑废水处理能力较少。文章基于多杂质固定流量问题,提出完全回用特殊高浓度水源的新方法——累积杂质负荷相减法(cumulative contaminant load reduction algorithm,CCLRA)。设计时,首先确定特殊高浓度水源及可回用该水源的需水流,然后从需水累积杂质负荷中除去该部分水源所含杂质负荷,最后按照关键杂质浓度由低到高的顺序回用其他水源。通过实例比较不同设计思路所得水网络,证明新方法设计过程简单,可兼顾高浓度水源回用和新鲜水用量最小目标,适用于含有其他工艺过程可消耗高浓度水源的水网络优化设计。