高速公路路面雨水径流污染物排放特征研究

为了深入了解高速公路面源污染特征,本文对高速公路路面径流进行了监测分析.尽管径流过程中总悬浮物（TSS）、总化学需氧量（TCOD_Cr）、总氮（TN）和总磷（TP）的浓度以及颗粒物的丰度具有较大的变化幅度,但这些污染物的峰值浓度和颗粒物的峰值丰度基本上出现在径流开始后的10~30 min以内.TSS与TCOD_Cr、TN和TP的浓度之间存在着明显的相关性（r=0.444~0.955;p< 0.005）,意味着有相当数量的有机物和营养盐以颗粒物结合态存在.生化需氧量（BOD₅）与TCODcr的关系表明径流中的有机污染物可生化性较差.当降雨量和降雨强度在不同的范围变化时,其对径流污染物事件平均浓度的影响不同.绝大多数情况下,所研究的高速公路都会发生污染物的初期冲刷效应.前30%的径流可以携带46%±15%的TSS、54%±17%的TCOD_Cr、47%±13%的氮、52%±12%的磷以及在数量上占比为51%±12%的颗粒物.按照面源管理实践中80%的悬浮物的削减量的要求,应截留70%的径流,同时可以减少84%的有机物、78%的氮和81%的磷排放负荷.     

平行磁场下电极材料对DBD降解亚甲基蓝的影响

采用介质阻挡放电等离子体技术,以镍,铁,钼,不锈钢4种材料作为电极,分别在有平行磁场和无平行磁场的条件下,考察了不同电极材料对亚甲基蓝降解率和能量利用率的影响.实验中发现电极材料的不同会影响亚甲基蓝的降解效果,其中镍电极在处理8min后亚甲基蓝降解率可达99%,降解效果最好,电极材料还会影响平行磁场对亚甲基蓝降解的促进效果,铁和镍电极的能量利用率相比无磁场时提高了约20%,而钼和不锈钢只有5%~10%.通过研究介质阻挡放电等离子体的产生机理和二次电子发射原理,发现这些差异是由电极材料的二次电子发射系数和磁导率的不同导致的,4种材料中铁的二次电子发射系数最大,电子雪崩过程中产生的高能电子更多,因此降解效果最好,铁和镍的磁导率最大,放电空间内的磁感应强度更高,因此平行磁场对亚甲基蓝降解率和能量利用率的提升更大.     

煤化工企业高盐废水的“零排放”技术

采用“混凝沉淀-微滤-组合反渗透”工艺对某煤化工企业的高盐废水进行浓缩处理,浓水通过蒸发结晶进行脱水,产水采用常规反渗透进行水回收。运行结果表明,经30 d运行,水回收率保持在85%以上,脱盐率稳定在95%以上,常规反渗透产水水质稳定,产水电导率、浊度、Cl^-质量浓度和COD的平均值分别为12.5 μs/cm,0.1 NTU,7.8 mg/L,1.8 mg/L,满足《炼化企业节水减排考核指标与回用水质控制指标》（Q/SH0104-2007）中污水回用于循环冷却水的水质指标和设计产水水质要求,实现了废水的近“零排放”。     

典型北方滨海核电厂温排水混合区边缘温升限值研究

随着我国电力事业的快速发展,电厂循环冷却水(温排水)的余热排放对受纳水体生态环境造成的负面热影响(即热污染)已日益引起社会关注。基于国内现有的温排水排放控制标准可执行性不强的现状,对我国电厂温排水的热污染控制标准的基础技术要素——温排水混合区边缘温升限值进行了研究。以我国北方某典型滨海核电厂址邻近海域的代表性海洋生物为研究对象,以各季节不同受试物种最大临界温度(CTM)的统计分析结果,作为确定该厂址温排水混合区边缘温升限值的主要依据。并结合法规调研法,最终确定该典型滨海核电厂址温排水混合区边缘温升限值的推荐值为3.6℃。     

基于绿色合成法的纳米铁/活性碳复合材料对甲基橙的降解动力学研究

为了综合处理废水中的甲基橙,以绿茶萃取液为还原剂、活性炭为载体,采用液相还原法绿色合成了纳米铁/活性炭复合材料,研究了活性炭投放量、甲基橙溶液的初始浓度、溶液初始p H值及反应时间对甲基橙去除率的影响,探讨了不同影响因素下甲基橙的降解动力学。结果表明:甲基橙的降解反应近似符合一级反应动力学,反应速率常数为0.0047~0.0158 L/(mol·min)。在纳米铁/活性炭复合材料去除甲基橙的过程中,通过纳米铁的还原和活性炭的吸附共同作用,其中纳米铁对甲基橙的降解起主要作用。     

湿式电除尘器给排水技术的研究与应用

湿式电除尘器是作为燃煤电厂大气污染治理的终端精处理设备的首选,但湿式电除尘器存在耗水量巨大、排出的灰水存在二次污染、内部件腐蚀严重等问题,严重影响了湿式电除尘器在国内燃煤电厂上的大型化应用。为此,对湿式电除尘器的喷淋给水、水质、灰水循环利用、废水排放等进行了研究分析并结合实际工程应用经验加以阐述,提出了科学合理的给水和排水方式,实现了湿式电除尘器在燃煤电厂工艺系统上的零水耗,有效解决了内部件腐蚀问题。     

Robust reliability and electrical performances by the bulk-contact modulation in 60-V p-channel LDMOS power components

To increase reliability and electrical performance, shallow-trench isolation (STI) (or called field-oxide (FOX)) structures were inserted in the bulk-contact region of 60-V high-voltage p-channel lateral-diffused MOSFET (pLDMOS) devices in this study. As the FOX ratio increased with the addition of FOX segments, the value of the secondary breakdown current (I_t2) was enhanced. Therefore, the anti-electrostatic discharge ability of a pLDMOS device can be efficiently improved using this novel method. In addition, when the weighting ratio of FOX structures increased, variation values in the trigger voltage (V_t1) and holding voltage (V_h) of the corresponding samples remained within the range of approximately 1–4 V. The R_on value decreased because of more uniform conduction. The experimental data for the FOX structures added to the bulk revealed that the I_t2 value was improved by approximately 13.98%, V_h values were greater than 60 V (which is favorable for latch-up immunity), and the R_on value was decreased by approximately 12.62% compared with a reference device under test (without FOX segments in the bulk-contact region).     

贵州省县域废水排放与社会经济发展的相关分析

随着社会经济的加速发展，废水排放量也在不断的增加，使得环境质量大大降低，从而反作用于社会经济发展，影响社会经济的可持续发展。对于一个欠发达地区而言，协调社会经济与环境保护之间的关系至关重要。以贵州省2005、2010年88个县级面板数据为依据，利用空间计量方法，探究影响废水排放量的主要因子，建立贵州省废水排放量变化的经典线性回归模型和空间滞后模型，结果显示，第三产业的发展是导致贵州废水排放量增加的主要原因。     

Sewage fluxes and seasonal dynamics of physicochemical characteristics of the Bhagirathi-Hooghly River from the lower stretch of River Ganges,India

ABSTRACT

To understand the temporal variations of the physicochemical characteristics of the Bhagirathi-Hooghly River (BHR), three locations representing three districts of West Bengal were selected. The material fluxes from 34 drains during pre-monsoon season was quantified. The analysis of variance (ANOVA) revealed that no significant spatial variations were observed for the physicochemical parameters, whereas seasonal variations were significant. The mean discharge was found to be highest (247.2?×?10³?m³?d^?1) in the midstream drains. Highest mean concentrations of dissolved oxygen (DO) (7.35?mg?L^?1) and nitrate (0.81?mg?L ^?1) were observed during the post-monsoon season followed by the monsoon and pre-monsoon. According to the BIS, WHO and the European standard of water quality (pH, 6.5–8.5; Nitrate, 0–2.5?mg?L^?1;DO, ≥5?mg?L^?1), the results of the respective parameters revealed the BHR system is maintained at high to good water quality, meaning that the BHR system is slightly altered from its pristine environment. The mean concentrations of biological and chemical oxygen demands were found to be high during the monsoon season, revealing that a large quantity of refractory organic matter is transported to the eastern Bay of Bengal from the Ganges.