典型城市臭氧污染源贡献及控制策略费效评估

东莞是珠三角O_3污染最严重的城市,使用RSM/CMAQ(曲面响应模型)法分析了珠三角区域人为排放的NO_x和VOCs对东莞市O_3浓度变化源贡献.2014基准年分析结果表明,扣除模型域外区域传输及天然源排放对O_3本底浓度贡献(41.00%)后,东莞本地VOCs排放对O_3贡献最大(18.50%),珠三角区域NO_x减排率13%时可持续降低东莞市O_3浓度.进一步使用ABa CAS-SE(空气污染控制成本效益与达标评估系统)对2017、2020、2025东莞市3个未来年O_3污染控制情景进行了费效评估.评估结果显示,NO_x和VOCs控制比例相对较低的2017年控制情景人体健康效益/区域控制成本比约为1.1;而控制比例相对较高的2025年东莞O_3达标情景效益成本比仅为0.1.这说明,在高减排率情景下,以末端治理为主的控制措施经济可行性较差,需综合采取产业/能源结构调整、清洁生产等措施实现NO_x和VOCs的大比例减排,实现东莞O_3的稳定达标.今后将进一步研究NO_x和VOCs减排对PM_(2.5)环境浓度及健康效益影响,开展多目标污染物协同控制费效评估.     

活性炭纤维对水中罗丹明B的吸附性能

研究了活性炭纤维对水中罗丹明B的吸附.结果表明,pH=2时,罗丹明B的吸附量最大,并随着pH的增高吸附量随之降低;离子强度对吸附的影响不大;Langmuir等温线更适合于描述罗丹明B的吸附行为;活性炭纤维对罗丹明B的吸附量随着温度的升高逐渐增加;热力学数据表明,较高温度下,活性炭纤维对罗丹明B的吸附是自发行为,且为吸热反应;吸附动力学符合假二级动力学模型;吸附过程可以很好地用内扩散模型来说明.     

SF6气体绝缘设备的放电特性研究

采用间接边界元法,给出了层状半空间中沉积谷地对斜入射平面SV波的三维散射解答,并通过与已有结果的比较,验证了本文解答的正确性。进行数值计算,研究了斜入射角度对散射效应的影响,并以基岩上单一土层为例,讨论了基岩刚度和覆盖土层厚度对沉积谷地附近地表位移的影响。研究表明,三维散射与二维散射之间存在本质差别,不能简单地将斜入射平面SV波分解到沉积谷地横截面的面内方向,然后按平面问题进行计算;基岩与土层刚度比对沉积附近地表位移幅值有着较大的影响,但对位移幅值的空间分布影响不大;土层厚度变化不仅影响地表位移幅值的大小,还会改变地表位移幅值的空间分布。     

Influence of arsanilic acid,Cu2+, PO43− and their interaction on anaerobic digestion of pig manure

The methanogenesis was severely inhibited with 0.46 mM ASA addition.PO₄³⁻ didn’t attenuate the methanogenesis inhibition in the existence of ASA.ASA was transformed to As(III), As(V), MMA and DMA in anaerobic digestion.Cu²⁺ mitigated the methanogenesis inhibition via impeding the degradation of ASA.Arsanilic acid (ASA), copper ion (Cu²⁺) and phosphate (PO₄³⁻) are widely used as feed additives for pigs. Most of these three supplemented feed additives were excreted in feces and urine. Anaerobic digestion is often used for the management of pig manure. However, the interaction of ASA with Cu²⁺ or PO₄³⁻ on anaerobic digestion is still not clear. In this study, the influence of ASA, Cu²⁺, PO₄³⁻ and their interaction on anaerobic digestion of pig manure and the possible mechanisms were investigated. The initial concentrations of ASA, Cu²⁺ and PO₄³⁻ were 0.46 mM, 2 mM and 2 mM in the anaerobic digester, respectively. The methanogenesis was severely inhibited in the assays with only ASA addition, only Cu²⁺ addition and ASA+ PO₄³⁻ addition with the inhibition index of 97.8%, 46.6% and 82.6%, respectively, but the methanogenesis inhibition in the assay with ASA+ Cu²⁺ addition was mitigated with the inhibition index of 39.4%. PO₄³⁻ had no obvious impacts on the degradation of ASA. However, Cu²⁺ addition inhibited the degradation of ASA, mitigating the methanogenesis inhibition. The existence of ASA would inhibit methanogenesis and generate more toxic inorganic arsenic compounds during anaerobic digestion, implying the limitation of anaerobic digestion for ASA- contaminated animal manure. However, the co-existence of ASA and Cu²⁺ could mitigate the inhibition. These results could provide useful information for the management of anaerobic digestion of pig manure containing ASA with Cu²⁺.     

Aggravation of membrane fouling and methane leakage by a three-phase separator in an external anaerobic ceramic membrane bioreactor

The existence of three-phase separator did not affect COD removal in the EAnCMBR. The existence of three-phase separator aggravated methane leakage of EAnCMBR. The existence of three-phase separator aggravated membrane fouling rate of EAnCMBR. Start-up of EAnCMBR equipped three-phase separator was slightly delayed. The three-phase separator is a critical component of high-rate anaerobic bioreactors due to its significant contribution in separation of biomass, wastewater, and biogas. However, its role in an anaerobic membrane bioreactor is still not clear. In this study, the distinction between an external anaerobic ceramic membrane bioreactor (EAnCMBR) unequipped (R1) and equipped (R2) with a three-phase separator was investigated in terms of treatment performance, membrane fouling, extracellular polymers of sludge, and microbial community structure. The results indicate that the COD removal efficiencies of R1 and R2 were 98.2%±0.4% and 98.1%±0.4%, respectively, but the start-up period of R2 was slightly delayed. Moreover, the membrane fouling rate of R2 (0.4 kPa/d) was higher than that of R1 (0.2 kPa/d). Interestingly, the methane leakage from R2 (0.1 L/d) was 20 times higher than that from R1 (0.005 L/d). The results demonstrate that the three-phase separator aggravated the membrane fouling rate and methane leakage in the EAnCMBR. Therefore, this study provides a novel perspective on the effects of a three-phase separator in an EAnCMBR.     

铝厂工人尿中1-羟基芘的变化

分别对炼铝厂工人、铝厂附近小学生和对照组人群尿中的1-羟基芘进行了测定.铝厂工人尿中的1-羟基芘为小学生的7.6倍;为对照组人群的43倍.结合多环芳烃的污染情况讨论了用尿中1-羟基芘作为评价铝厂多环芳烃污染的人体接触指标的可行性。     

室内小煤炉采暖对尿中1-羟基芘的影响

用尿中1-羟基芘作为指标,观察了室内用小煤炉采暖、暖气采暖和非采暖季节时相同人群尿中1-羟基芘的变化,自身对照和人群对比的测定结果,经数理统计检验后均证明:用小煤炉采暖时人尿中的1-羟基芘显著高于甩暖气采暖或不采暖时的结果,表明用小煤炉采暖造成了室内空气中多环芳烃的严重污染,用尿中1-羟基芘可做为人体接触空气中多环芳烃污染的一个特异、灵敏的指标。     

Thermochemical pretreatment of meat and bone meal and its effect on methane production

Since the solubilization of meat and bone meal (MBM) is a prerequisite in many MBM disposal approaches, enhancement of the solubilization by means of thermochemical pretreatment was investigated in this study at two temperatures (55°C and 131°C) and six sodium hydroxide (NaOH) concentrations (0, 1.25, 2.5, 5, 10 and 20 g/L). The MBM volatile solid (VS) reduction ratio was up to 66% and 70% at 55°C and 131°C, respectively. At the same temperature, the VS reduction ratio increased with the increase in the dosage of NaOH. The study on the methane (CH₄) production potential of pretreated MBM shows that the addition of NaOH at 55°C did not cause the inhibition of the succeeding CH₄ production process. However, CH₄ production was inhibited by the addition of NaOH at 131°C. The CH₄ production potential was in the range of 389 to 503 mL CH₄/g VS MBM and 464 to 555 mL CH₄/g VS MBM at 55°C and 131°C, respectively.     

起220kV金属氧化物避雷器受潮缺陷及故障分析

在例行试验中,发现一起220kV金属氧化物避雷器(MOA)在运行电压下,三相阻性电流分量较历史数据及同组间其他金属氧化物避雷器的测量结果有明显增大迹象。通过停电诊断试验,判定A相避雷器上下节和B相避雷器上节存在内部受潮现象。经现场对A相避雷器解体发现,金属密封法兰盘紧固螺丝断裂、松动,密封垫变形,致使金属密封法兰盘密封不严,内部受潮,且在绝缘筒下端有黑色放电烧蚀痕迹。针对此缺陷,进行了故障分析,并提出预防措施。