Identification of close relationship between atmospheric oxidation and ozone formation regimes in a photochemically active region

Understanding ozone (O₃) formation regime is a prerequisite in formulating an effective O₃ pollution control strategy. Photochemical indicator is a simple and direct method in identifying O₃ formation regimes. Most used indicators are derived from observations, whereas the role of atmospheric oxidation is not in consideration, which is the core driver of O₃ formation. Thus, it may impact accuracy in signaling O₃ formation regimes. In this study, an advanced three-dimensional numerical modeling system was used to investigate the relationship between atmospheric oxidation and O₃ formation regimes during a long-lasting O₃ exceedance event in September 2017 over the Pearl River Delta (PRD) of China. We discovered a clear relationship between atmospheric oxidative capacity and O₃ formation regime. Over eastern PRD, O₃ formation was mainly in a NO_x-limited regime when HO₂/OH ratio was higher than 11, while in a VOC-limited regime when the ratio was lower than 9.5. Over central and western PRD, an HO₂/OH ratio higher than 5 and lower than 2 was indicative of NO_x-limited and VOC-limited regime, respectively. Physical contribution, including horizontal transport and vertical transport, may pose uncertainties on the indication of O₃ formation regime by HO₂/OH ratio. In comparison with other commonly used photochemical indicators, HO₂/OH ratio had the best performance in differentiating O₃ formation regimes. This study highlighted the necessities in using an atmospheric oxidative capacity-based indicator to infer O₃ formation regime, and underscored the importance of characterizing behaviors of radicals to gain insight in atmospheric processes leading to O₃ pollution over a photochemically active region.     

国内外硫磺回收工业发展现状对比与展望

通过对国内外硫磺回收工业发展现状的对比分析，提出了２０００－２０１５年我国硫回收工业的发展战略目标。     

Emission inventory and control policy for non-road construction machinery in Tianjin

Environmental Science and Pollution Research - The establishment of a non-road construction machinery emission inventory forms the basis for the analysis of pollutant emission characteristics and...     

Cooperative carbon emission reduction through the Belt and Road Initiative

Environmental Science and Pollution Research - Carbon emission reduction under the Belt and Road Initiative has great significance on China’s goal of carbon peak. To better promote carbon...     

酸化油水解废水脱酸处理工艺研究

酸化油是生产生物柴油的原料,其生产过程中产生的水解废水有机物含量高且具有强酸性,直接排放会严重污染环境。因此,对酸化油水解废水处理工艺进行研究有重要意义。通过对酸化油水解废水脱酸处理的条件及影响因素进行研究,并通过L9(34)正交实验确定了脱酸的最佳工艺条件。pH值为10,搅拌时间为15 min,温度为30℃是脱酸处理的最佳条件。     

一体化膜生物反应器处理低C/N污水试验研究

研究一体化连续流间歇曝气膜生物反应器(IMBR)处理低C/N城市污水的工艺效能。试验结果表明:反应器在曝气2 h、搅拌2 h的运行模式下,对COD、NH4+-N、TN和SS的平均去除率分别达到了87%,83.4%,75.4%和97.81%,各出水质量浓度平均值分别为17.5,4.59,7.63和2 mg/L,出水水质达到了GB/T18920-2002《城市污水再生利用城市杂用水水质》标准。     

城市污水处理计算机控制系统的应用研究

本文通过对污水处理行业所采取的计算机控制系统进行比较分析 ,得出结论 :采用基于现场总线的PC +PLC分级分布式控制形式 ,能够使系统具有很高的性能 /价格比。同时 ,将此结构进行拓展 ,成功应用于我国第一座自主开发的城市污水处理厂———沈阳南部污水处理示范厂。在系统中采用就地操作BIU +MFP(基本接口单元 +微现场处理单元 )与主PLC相结合的控制结构 ,通过GeniusBus(现场总线 )技术实现通讯处理 ,达到节约投资、提高系统安全性的目的     

流域开发规划环境影响评价的战略意义——以岷江上游紫坪铺水库工程与都江堰保护问题为例

文章在分析岷江上游水电开发规划与流域环境问题的基础上提出对都江堰美学、经济、文化价值的再认识和对其进行保护的基本要求,讨论了紫坪铺水库工程与都江堰保护的战略抉择问题,并论述了流域开发规划环境影响评价的重要意义。     

含碳氨水回收集成分离技术的研究与应用

在研究NH3－CO2－H2O三元体系基础上,将解吸、精馏和防结晶技术相结合,开发出集成分离技术,并成功地将其用于原有含碳氨水回收装置的改造,取得了十分显著的经济与环保效益。     

ClO_2对活性艳红K—2G和分散蓝2BLN染料的脱色研究

本论文主要利用自制高纯二氧化氯对两种常用且结构具有代表性的活性艳红K— 2G和分散蓝 2BLN料染 ,进行氧化脱色研究 ,作了温度 ,pH值 ,二氧化氯用量等条件试验 ,并用实际印染废水进行了实验 ,取得了良好的效果。在室温时 ,t =5min～ 7min ,pH值偏碱性条件下 ,单一染料溶液及混合染料溶液的脱色率均达到 90 %以上 ,实际印染废水的脱色也在 90 %左右。pH值、温度和ClO2 用量等多种因素对脱色率均有一定的影响 :pH值越高 ,染料脱色率越高。ClO2 用量存在一最佳值 ,与活性艳红K— 2G及分散蓝 2BLN染料的最佳摩尔比分别为 4 0及 2 0左右。ClO2 耗量随染料起始浓度的增大而增加 (脱色率相同时 )