郑州市大气PM2.5中重金属的污染特征、来源及健康风险评估:基于高分辨数据

为了研究城市大气PM_2.5中重金属的污染特征和来源,于2017年的7月和10月及2018年的1月和4月,利用在线金属分析仪对郑州市大气PM_2.5中的21种元素进行在线检测,分析了重金属浓度变化;通过富集因子、主成分分析和潜在源贡献等方法对重金属进行溯源;采用环境健康风险评价模型评估其健康风险.结果表明,K、 Zn、 Mn、 Pb、 Cu、 As、 Cr和Se的浓度随污染等级的提高而增加;富集因子和主成分分析法结果表明,重金属主要来源为地壳源、混合燃烧源、工业源和机动车源;雷达特征图表明,地壳源主导的污染主要发生在春、冬两季,混合燃烧源主导的污染主要发生在冬季;Pb、 As和Ni受汾渭平原、京津冀和河南南部的传输影响较大,Cd受采样点西北部影响较大;As对成年人和儿童均有显著致癌风险,Pb和Sb对儿童存在显著非致癌风险.     

镁铁复合絮凝剂的表征及应用研究

以FeSO4、MgO和H2SO4为原料,制备了新型镁铁复合絮凝剂(PFMS),考察了PFMS的结构和Fe(Ⅲ)分布形态,为了考察自制PFMS、自制聚合硫酸铁(PFS)与工业PFS产品的絮凝性能差别,选择高岭土模拟浊度废水、直接耐晒黑G模拟染料废水和焦化废水生化出水,分别进行了去除浊度、色度和COD的絮凝实验.结果表明,Mg2+未参与聚合过程,但引入Mg2+提高了PFMS的稳定性.PFMS对浊度去除效果略高于自制PFS和工业PFS,余浊<5NTU;在碱性条件下,PFMS的脱色率、COD去除率高于自制PFS和工业PFS.     

A novel biosorbent: characterization of the spent mushroom compost and its application for removal of heavy metals

The spent mushroom compost of Lentinus edodes was used as a biosorbent for adsorbing cadmium, lead and chromium from solutions under batch conditions for the first time. Titration of the biomass revealed that it contained at least three types of functional groups. The Fourier transform infrared spectrometry showed that the carboxyl, phosphoryl, phenolic groups were the main groups. The simulated values of pK, and molar quantity were 5.00 and 0.44 mmol/g, 7.32 and 1.38 mmol/g, 10.45 and 1.44 mmol/g, respectively. The biosorption ability increased with pH in acid condition. When 10 mg/L biomass dosage was added in, there was no significant increment of metal uptake. The maximum uptake estimated with the Langmiur isotherm model were 833.33 mg/g for Cd（ Ⅱ ）, 1000.00 mg/g for Pb（ Ⅱ ） and 44.44 mg/g for Cr（ Ⅲ ）, respectively. All the results showed that vast potential sorption capacity was existed in the biomass for adsorbing these three kinds of metals studied.     

Accelerated ash accumulation method for diesel particulate filter and its characterization: a review

ABSTRACT

It is well known that high-efficiency wall-flow particulate filter is the most commonly used technology that can effectively reduce both particulate matter (PM) and particulate number (PN) to comply with the latest emission legislations. Ash, defined as the noncombustible, non-evaporative residue derived mostly from lubricants, has critical impact on engine backpressure, particulate filter filtration efficiency and durability performance, therefore, the investigation of ash impact on particulate filter is of great importance. Due to cost-saving potential, several published methods from different laboratories for accelerated ash loading under carefully controlled conditions are described in this review, including some characterization methods that have been used for the evaluation of filter performance. In addition, the impact of ash deposit on back pressure and regeneration performance are also discussed in this review.     

2,4-dichlorophenoxyacetic acid (2,4-D) micropollutant herbicide removing from water using granular and powdered activated carbons: a comparison applied for water treatment and health safety

Abstract

Activated carbons are well-known porous materials as an effective adsorbent used for the removal of emerging contaminants, such as herbicides, which are increasingly present in water bodies. Most water treatment plants, specially in Brazil, are unable to completely remove such contaminants by the conventional process and advanced treatment using activated carbons is required. The aim of this paper was to verify the influence of the activated carbons granulometry and specific surface area on the 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide removal efficiency using distilled-deionized water and filtered water collected from a conventional Water Treatment Plant. Commercial activated carbons samples used in this work were obtained from two different manufacturers. Activated carbons were analyzed by the specific surface area, pore size and volume distribution, nuclear magnetic resonance, infrared and x-ray spectroscopy, moisture, volatile matter and ash contents. Batch adsorption isotherms experiments were used and performed by Langmuir and Freundlich models. Granular and powdered activated carbons removed over 99% of 2,4-D in distilled water and near to 99% using filtered water. The activated carbons evaluated in this work presented high performance and played a key role in water treatment by removing 2,4-D herbicide, ensuring the protection of human health and the ecosystem.     

Development of inherent safety and health index for formulated product design

The numerous formulated products which are introduced to the market consist of chemical ingredients that may cause various safety and health hazards to the consumers. Therefore, it is extremely important to practice a systematic methodology to formulate products with acceptable safety and health performances. This work presents an index-based methodology to assess the safety and health hazards of the ingredients during the early formulation stage of product design. Hence, new inherent safety and health sub-indexes are introduced to improve the current safety and health hazards that are needed in formulated product design. The inherent safety and health sub-indexes are assigned with scores based on the degree of potential hazards. A higher score indicates a higher safety risk or severe health effect, and vice versa. The proposed methodology will greatly assist the users to identify the adverse safety and health effects caused by the ingredients. Hence, it is pivotal to eliminate or reduce the safety and health impacts from product usage. A case study on common ingredients used in the formulation of paint is presented on this study to describe the proposed method.     

苯胺降解菌的分离和特性研究

从活性污泥中分离到一株细菌ＡＮ３，能以苯胺为唯一碳源、氮源和能源生长．经鉴定为食酸丛毛胞菌（Ｃｏｍａｍｏｎａｓａｃｉｄｏｖｏｒａｎｓ）．该菌株可以在高达５０００ｍｇ／Ｌ以上的苯胺中生长．当苯胺浓度为２０００ｍｇ／Ｌ左右时，经３天培养即可全部被降解．该菌株还可以利用乙酰苯胺，但不能利用其他取代类苯胺化合物．ＡＮ３菌的生长和降解苯胺的最适温度为３０℃和ｐＨ为７０．９种金属离子对该菌的生长和苯胺的降解均有不同程度抑制作用，尤以Ａｇ＋和Ｈｇ２＋为明显．该菌与苯胺降解代谢有关酶类的测定结果表明，该菌含有的邻苯二酚－２，３加双氧酶是诱导酶．     

A new environmental chamber for evaluation of gas-phase chemical mechanisms and secondary aerosol formation

A new state-of-the-art indoor environmental chamber facility for the study of atmospheric processes leading to the formation of ozone and secondary organic aerosol (SOA) has been constructed and characterized. The chamber is designed for atmospheric chemical mechanism evaluation at low reactant concentrations under well-controlled environmental conditions. It consists of two collapsible 90 m³ FEP Teflon film reactors on pressure-controlled moveable frameworks inside a temperature-controlled enclosure flushed with purified air. Solar radiation is simulated with either a 200 kW Argon arc lamp or multiple blacklamps. Results of initial characterization experiments, all carried out at 300–305 K under dry conditions, concerning NO_x and formaldehyde offgasing, radical sources, particle loss rates, and background PM formation are described. Results of initial single organic–NO_x and simplified ambient surrogate–NO_x experiments to demonstrate the utility of the facility for mechanism evaluation under low NO_x conditions are summarized and compared with the predictions of the SAPRC-99 chemical mechanism. Overall, the results of the initial characterization and evaluation indicate that this new environmental chamber can provide high quality mechanism evaluation data for experiments with NO_x levels as low as 2 ppb, though the results indicate some problems with the gas-phase mechanism that need further study. Initial evaluation experiments for SOA formation, also carried out under dry conditions, indicate that the chamber can provide high quality secondary aerosol formation data at relatively low hydrocarbon concentrations.     

水体溶解性有机物的化学分级表征:原理与方法

综述了水体溶解性有机物(DOM)的化学分级表征法即树脂吸附分级法(RA)的研究与进展,同时基于该方法存在的一些问题结合我国典型水质体系,从树脂的选择、净化、分级的定义、水样过柱流速、水样树脂体积比的确定等方面进行了研究探讨,给出了完整的实验参数和操作方法.     

涕灭威污染体系研究现场土壤生态系统表征

以湖北省卢龙县刘天庄邵时各村农田生态系统为例，阐述了生态系统的表生方法，得出该生态系统利于做复合污染物的研究，且系统中农药的降解有明显的复杂性，与实验室模拟有差异。为进一步研究复合化学污染物在该生态系统中多介质多界面的环境行为提供了依据。