O3/H2O2降解水中致嗅物质2-MIB的效能与机理

采用O3/H2O2工艺对水中致嗅物质二甲基异莰醇(2-methylisoborneol,2-MIB)的去除效能与机理进行了研究,探讨了H2O2与O2的投加方式、摩尔比以及溶液pH值和水质等因素对2-MIB降解的影响,并通过Gc-MS对2-MIB的氧化降解中间产物进行了分析.实验结果显示,H202能明显促进O3对水中2-MIB的氧化降解.单独臭氧氧化2Omin时2-MIB的降解率为38.7%;在同样体系中加入适量的H202后2.MIB的降解率最大能提高到89.2%,H202与O3最佳投加摩尔比为0.6左右.低浓度(0.5 mg·L-1)腐殖酸对O3/H2O2体系2.MIB的降解速率有比较明显的促进作用,高浓度的腐殖酸则会产生较明显的抑制作用;自由基捕获剂叔丁醇对O3/H2O2体系中2-MIB氧化降解具有明显的抑制作用.鉴定出2-MIB的氧化降解产物有4-羟基-1,7,7-三甲基双环[2,2,1]庚烷-2-酮、1,7,7-三甲基双环[2,2,1]庚烷-2,4-二酮、1,7,7-三甲基双环[2,2,1]庚烷-2-酮等,并对2-MIB氧化机制和降解的可能途径进行了推导.     

粉煤灰对苯酚废水的吸附研究

在静态条件下研究了粉煤灰对苯酚的吸附性能,结果表明:平均粒径29.06μm,孔隙率64.0686%,在吸附时间50min,粉煤灰用量120 g/L,pH=7.45条件下,对75 mL浓度为30 mg/L的苯酚模拟废水,吸附效果最好,可达82.4%。粉煤灰吸附苯酚机理复杂,偏向于单分子层吸附的Langmuir吸附等温线模式:q=0.042Ce/(1+0.095Ce),吸附反应为一级反应,速率方程为lnC=-0.0096t+3.3097(C0=30 mg/L)。     

丹江口水库水环境保护协调机制研究

针对丹江口库区及其上游水环境保护现状和存在问题,探索建立跨地区、多部门、多层次的丹江口水库水环境保护协调机制,逐步形成国家和地方、流域与区域、水利部门与非水利部门间的水资源保护协调机制,以及流域上、下游分工明确、统一协调的水源地及其上游水资源保护管理新格局,以推进跨地区、跨部门的水资源管理,促进南水北调水源地水资源的持续利用。     

Biochar use in forestry and tree-based agro-ecosystems for increasing climate change mitigation and adaptation

This study reviews the potential use of biochar as soil amendment in afforestation, reforestation, agroforestry, fruit tree orchards, and bio-energy plantations. Implementing this practice could sequester large amounts of carbon (C) over the long-term, potentially offsetting anthropogenic emissions of carbon dioxide, and mitigating climate change. On a global scale, this practice could sequester between 2 and 109.2 Pg biochar-C in 1.75 billion ha of degraded and deforested lands and agroforestry systems. An additional considerable amount could be sequestered in the soil of fruit tree orchards and bio-energy plantations. The anticipated improvement in the quality of the biochar-amended soils is expected to enhance resilience to these land uses, increasing their adaptation capacity to climate change. Yet, specific questions still need to be addressed, for example, the impact of biochar on the availability of nitrogen and potassium for plants in acidic soils and under humid conditions, as well as the impact of biochar on soil and trees in alkaline soils and under Mediterranean or drier conditions. Also, a full assessment of health hazards and environmental risks related to the production of biochar and its application in soil is required. Other questions relate to the environmental and economic costs of biochar application. Therefore, life cycle assessments and economic calculations should be conducted on a site-specific basis and include the practices of feedstock collection, transportation, processing, and spreading. International actions should regulate biochar practice as an eligible means for funding under the C finance mechanism. Specifically, payments should be provided to landowners for accomplishing ecosystem services.     

Mechanism of dichloromethane disproportionation over mesoporous TiO2 under low temperature

• Mechanism of DCM disproportionation over mesoporous TiO₂ was studied. • DCM was completely eliminated at 350℃ under 1 vol.% humidity. • Anatase (001) was the key for disproportionation. • A competitive oxidation route co-existed with disproportionation. • Disproportionation was favored at low temperature. Mesoporous TiO₂ was synthesized via nonhydrolytic template-mediated sol-gel route. Catalytic degradation performance upon dichloromethane over as-prepared mesoporous TiO₂, pure anatase and rutile were investigated respectively. Disproportionation took place over as-made mesoporous TiO₂ and pure anatase under the presence of water. The mechanism of disproportionation was studied by in situ FTIR. The interaction between chloromethoxy species and bridge coordinated methylenes was the key step of disproportionation. Formate species and methoxy groups would be formed and further turned into carbon monoxide and methyl chloride. Anatase (001) played an important role for disproportionation in that water could be dissociated into surface hydroxyl groups on such structure. As a result, the consumed hydroxyl groups would be replenished. In addition, there was another competitive oxidation route governed by free hydroxyl radicals. In this route, chloromethoxy groups would be oxidized into formate species by hydroxyl radicals transfering from the surface of TiO₂. The latter route would be more favorable at higher temperature.     

A review on anammox process for the treatment of antibiotic-containing wastewater: Linking effects with corresponding mechanisms

• Anammox is promising for nitrogen removal from antibiotic-containing wastewater. • Most antibiotics could inhibit the anammox performance and activity. • Antibiotic pressure promoted the increase in antibiotic resistance genes (ARGs). • Antibiotic-resistance mechanisms of anammox bacteria are speculated. Antibiotic is widely present in the effluent from livestock husbandry and the pharmaceutical industry. Antibiotics in wastewater usually have high biological toxicity and even promote the occurrence and transmission of antibiotic resistant bacteria and antibiotic resistance genes. Moreover, most antibiotic-containing wastewater contains high concentration of ammonia nitrogen. Improper treatment will lead to high risk to the surrounding environment and even human health. The anaerobic ammonium oxidation (anammox) with great economic benefit and good treatment effect is a promising process to remove nitrogen from antibiotic-containing wastewater. However, antibiotic inhibition has been observed in anammox applications. Therefore, a comprehensive overview of the single and combined effects of various antibiotics on the anammox system is conducted in this review with a focus on nitrogen removal performance, sludge properties, microbial community, antibiotic resistance genes and anammox-involved functional genes. Additionally, the influencing mechanism of antibiotics on anammox consortia is summarized. Remaining problems and future research needs are also proposed based on the presented summary. This review provides a better understanding of the influences of antibiotics on anammox and offers a direction to remove nitrogen from antibiotic-containing wastewater by the anammox process.     

接枝羧基淀粉对贵金属离子吸附性能研究

研究了接枝羧基淀粉（ＩＳＣ）对贵金属离子Ａｇ（Ⅰ）,Ｐｄ（Ⅱ）、Ｐｔ（Ⅳ）的静态吸附性能和选择性及介质的ＰＨ对其吸附性能的影响,利用接枝羧基淀粉与Ａｇ（Ⅰ）形成螯合物的红外光谱和Ｘ－射线光电子能谱数据（ＸＰＳ）探讨了其吸附作用机理。     

环境影响评价中公众参与机制和方法探讨

环境影响评价中的公众参与最早开始于发达国家。我国环境影响评价中公众参与借鉴了西方发达国家和国际金融组织的成功经验,同时又充分考虑了我国的国情。笔者探讨了环境影响评价公众参与的概念和内容,提出了我国公众参与的基本方法和机制。      

铁内电解法处理硝基苯类废水的机理与展望

硝基苯类化合物是广泛应用的化工原料 ,目前它们已造成了严重的环境污染 ,并危及人体的健康。利用内电解法处理环境污染物的方法目前倍受青睐 ,本文介绍了内电解法处理硝基苯类废水的作用机理、硝基苯类化合物的转化途径 ,概述了内电解法去污的影响因素 ,探讨了其发展动向。     

废水处理中的几种廉价吸附剂

介绍了废水处理中具有良好实际应用价值的几种性能良好的廉价吸附（粉煤灰、混炭和膨润土等），对它们的作用机理、处理效能及应用前景进行了分析。