Photodegradation of malachite green under natural sunlight irradiation: kinetic and toxicity of the transformation products

This article describes the photolytic degradation of malachite green (MG), a cationic triphenylmethane dye used worldwide as a fungicide and antiseptic in the aquaculture industry. Photolysis experiments were performed by direct exposure of a solution of MG in water to natural sunlight. The main transformation products (TPs) generated during the process were identified by liquid chromatography time-of-flight mass spectrometry (LC–TOF-MS) and gas chromatography mass spectrometry (GC–MS). The 28 TPs identified with this strategy indicate that MG undergoes three main reactions, N-demethylation, hydroxylation and cleavage of the conjugated structure forming benzophenone derivatives. These processes involve hydroxyl radical attack on the phenyl ring, the N,N-dimethylamine group and the central carbon atom. The Vibrio fischeri acute toxicity test showed that the solution remains toxic after MG has completely disappeared. This toxicity could be assigned, at least in part, to the formation of 4-(dimethylamine)benzophenone, which has an EC_50,30 min of 0.061 mg l⁻¹, and is considered “very toxic to aquatic organisms” by current EU legislation.     

黄浦江生物膜中汞的分布及形态分析

生物膜对于水环境中痕量重金属的迁移、最终归宿、生物可利用性和生物毒性的过程,起着非常重要的作用。该文采集了黄浦江中的生物膜样品,分析了其中不同生长时间、不同深度、不同季节的总汞含量;提取了生物膜中不同形态的汞,并和底泥中不同形态汞的分布做了对比。结果表明,随着生长天数的增加,生物膜中的汞含量也随之增加;表层生物膜中的汞含量大于水深1m处生物膜中的汞含量;生物膜中的汞含量夏季最高,冬季最低;生物膜中生物可利用态的汞,远大于底泥中生物可利用态汞,更容易进入食物链,从而造成更大的生态危害。     

Analyzing REDD+ as an experiment of transformative climate governance: Insights from Indonesia

This paper contributes to an emerging body of literature on policy experimentation and governance transformation processes. We use the example of REDD+ as consisting of policy experiments in an emerging domestic policy domain to understand obstacles to transformations in forest and climate governance. We ask two interlinked questions: to what extent did the establishment of the REDD+ Agency challenge ‘business as usual’ in Indonesia’s forest and climate policy arena?; and what does this mean for a transformation away from policies and governance that enable deforestation and forest degradation? We draw on the transformation literature to better understand the role of REDD+ to achieve a transformative shift in climate governance. As an experiment of transformative climate governance, the study of REDD+ provides important insights for other forest or climate programs. Our analysis shows that the REDD+ Agency was successful in some extend in introducing an alternative governance mechanism and in shaking the governance structures but we also note that some of the key actors thought that greater ownership was achieved when the REDD+ Agency was dissolved and the mandate was returned to the ministries. We conclude that policy experimenting is a process, and while the creation of novel policies and their experimentation is important, also their assimilation may lead to new opportunities.     

柳州以酸雨治理促城市生态转型——柳州市以环保促经济升级城市转型服务民生的示范作用

柳州市这个十雨九酸的工业城市在经济升级、城市转型的过程中,完美实现了向生态宜居城市的战略转变。1994年国家有关部门把柳州市酸雨治理列为第四批日本海外经济协力基金贷款项目。这一项目开启城市环境治理新纪元,带动柳州经济发展方式的转变,促进柳州从污染城市到创建环保模范城市的跨越,贷动了柳州是从政府部门环保对策、城市环保质量到公众环保意识的全面提升,助力酸雨柳州的生态转变,在西部地区经济与环境协调发展和促进资源节约型和环境友好型工业城市发展方面具有重要的示范作用。     

Degradation of carbendazim by UV/H<Subscript>2</Subscript>O<Subscript>2</Subscript> investigated by kinetic modelling

The transformation of the fungicide carbendazim (methyl-2 benzimidazole carbamate) induced by hydroxyl radical generated by the UV photolysis of H₂O₂ has been studied in dilute aqueous solution. The efficient reaction of hydroxyl radicals with carbendazim led to the rapid degradation of carbendazim. The study of reaction kinetics yielded a second order rate constant of 2.2±0.3 10⁹ M⁻¹ s⁻¹ for HO^· radicals with carbendazim. This value is in agreement with a high reactivity of HO^· radicals with carbendazim. Most degradation products were identified by high performance liquid chromatography mass spectrometry (HPLC-MS). In the presence of hydrogenocarbonate and carbonate ions, hydroxyl radicals were quenched and in turn carbonate radicals CO₃ ^·− were formed. Carbonate radicals are indeed known to react efficiently with compounds containing electron-rich sites such as nitrogen or sulfur atoms. The use of a kinetic modelling software gave evidence for the occurrence of such reactions with carbendazim. The second order rate constant of carbonate radical with carbendazim was equal to 6±2 10⁶ M⁻¹ s⁻¹. Electronic Publication     

提高含硫污水汽提装置的处理能力

长岭炼油化工总厂的含硫污水汽提装置存在装置处理能力不够 ,净化水排放质量不达标等问题 ,通过系列技术改造 ,成功地将装置的处理能力提高到 90 t/ h,且净化水排放达标。     

有机锡污染物在海洋沉积物中的迁移和转化

有机锡是普遍存在于港口海域中的毒性化合物，沉积物是其重要的栖息地。本文综述了有机锡在部分海域沉积物中的分布，介绍了可能存在的吸附和转化机理，以及影响及附和转化的因素。     

Carbamazepine degradation by heterogeneous activation of peroxymonosulfate with lanthanum cobaltite perovskite: Performance, mechanism and toxicity

The widely used carbamazepine(CBZ) is one of the most persistent pharmaceuticals and suffers insufficient removal efficiency by conventional wastewater treatment.A synthesized Co-based perovskite(LaCoO_3) was used to activate peroxymonosulfate(PMS) in order to degrade CBZ.Results showed that LaCoO_3 exhibited an excellent performance in PMS activation and CBZ degradation at neutral pH,with low cobalt leaching.The results of FT-IR and XPS verified the high structurally and chemically stability of LaCoO_3 in PMS activation.Electron spin resonance(ESR) analysis suggested the generation of radical species,such as sulfate radicals(SO_4·~-) and hydroxyl radicals(·OH).Radical quenching experiments further revealed the responsibility of SO_4·~-as the dominant oxidant for CBZ oxidation.Ten products were detected via the oxidation of CBZ,with the olefinic double bond attacked by SO_4·~-as the initial step.Hydroxylation,hydrolysis,cyclization and dehydration were involved along the transformation of CBZ.The toxicity of CBZ solution was significantly reduced after treating by PMS/LaCoO_3.     

试音室建筑声学缺陷查找及音质改造工程案例分析

对某试音室进行建筑声学测试、体验,对存在的颤动回声、低频共振等建筑声学缺陷及问题进行分析,在此基础上,根据试音室的功能使用需求,提出建筑声学音质改造方案,以此为例阐明了建筑声学缺陷的查找和修正方法。     

影响有机污染物在土壤中的迁移、转化行为的因素

本文介绍了有机污染物在土壤中的吸附与解吸附、渗滤、挥发和降解等行为过程。探讨了吸附与解吸附机理、土壤有机质含量和类型、水分含量及温度等对此过程的影响。依据某些典型的化合物行为模型,论述了影响土壤中有机污染物渗滤的因素。有机污染物需要先从土壤深层迁移至地表,然后挥发至大气,在土壤中迁移的速率较慢,控制着整个挥发过程,可用Ｆｉｃｋ 第二定律来描述。有机污染物在土壤中的非生物降解主要包括氧化－ 还原、光解和水解等反应。土壤中的Ｏ２ 含量、土壤有机质成分和含量、辐射强度、光谱分布、土壤水分含量、温度和ｐＨ 值等都会影响非生物降解过程。其中有些因素通过影响微生物的生物活性,还影响有机污染物的生物降解