Control of chlorinated aromatic compounds from a municipal solid waste incinerator using limestone addition

In this study, limestone powder was directly added to synthetic MSW, which was fed into a small‐scale fluidized bed incinerator. The concentration of CBzs and CPs in the flue gas were measured before and after a secondary combustion air injection. Finally, the PCDDs and PCDFs concentrations were also measured in the flue gas after the secondary combustion zone. The CaCO₃ added to synthetic MSW not only controls HCl in the flue gas, but suppresses the formation of chlorinated aromatic compounds like CBzs, CPs, PCDDs, and PCDFs. The main mechanisms to control the formation of chlorinated aromatic compounds was more likely related to the suppression of catalytic capability of flyash than the HCl reduction in the flue gas. However, the NO concentration was increased by catalytic reaction of limestone in the fluidized bed.     

粉末活性炭处理酚类突发性水污染的应用研究

以苯酚和多种氯酚(CPs)为代表的酚类是一类重要的有机污染物。针对饮用水突发性酚类污染物控制,考察了粉末活性炭(PAC)吸附工艺对苯酚及CPs的去除效果,并讨论了主要影响因素。结果表明,对CPs和苯酚的吸附反应可在10~60 min、300 min内完成,吸附速率从快到慢依次为TCP、MCP、DCP、PCP和苯酚。由于酚羟基(Ar—OH)电离作用受到影响,在3~11范围内去除率随pH值升高而降低。少量腐殖酸对吸附影响不大,但TOC质量浓度超过10 mg/L时腐殖酸可产生明显竞争吸附作用。热力学拟合表明,吸附反应符合Freundlich和Langmuir吸附等温式,苯酚/CPs在PAC上的吸附过程以物理吸附为主,且为放热反应,较低温度有利于吸附反应的进行。相比于准一级反应和孔内扩散反应,准二级动力学方程可较好地描述吸附过程。将PAC用于中山市某饮用水源的模拟突发性污染应急处理,投加10 mg/L的PAC即可有效去除原水中超过饮用水标准3~5倍的CPs类污染物,同时水处理成本仅有少量增加。     

Evidence for the Stepwise Behavioral Response Model (SBRM): the effects of Carbamate Pesticides on medaka (Oryzias latipes) in an online monitoring system

The Stepwise Behavioral Response Model (SBRM), which is a conceptual model, postulated that an organism displays a time-dependent sequence of compensatory Stepwise Behavioral Response (SBR) during exposure to pollutants above their respective thresholds of resistance. In order to prove the model, in this study, the behavioral responses (BRs) of medaka (Oryzias latipes) in the exposure of Arprocarb (A), Carbofuran (C) and Methomyl (M) were analyzed in an online monitoring system (OMS). The Self-Organizing Map (SOM) was utilized for patterning the obtained behavioral data in 0.1 TU (Toxic Unit), 1 TU, 2 TU, 5 TU, 10 TU and 20 TU treatments with control. Some differences among different Carbamate Pesticides (CPs) were observed in different concentrations and the profiles of behavior strength (BS) on SOM were variable depending upon levels of concentration. The time of the first significant decrease of BS (SD-BS) was in inverse ratio to the CP concentrations. Movement behavior showed by medaka mainly included No effect, Stimulation, Acclimation, Adjustment (Readjustment) and Toxic effect, which proved SBRM as a time-dependence model based on the time series BS data. Meanwhile, it was found that SBRM showed evident stress-dependence. Therefore, it was concluded that medaka SBR was both stress-dependent and time-dependent, which supported and developed SBRM, and data mining by SOM could be efficiently used to illustrate the behavioral processes and to monitor toxic chemicals in the environment.     

Altitude profiles of total chlorinated paraffins in humus and spruce needles from the Alps (MONARPOP)

Chlorinated paraffins (CPs) are toxic, bioaccumulative, persistent, and ubiquitously present in the environment. CPs were analyzed in humus and needle samples, which were taken within the Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants (MONARPOP) at sampling sites of 7 different altitude profiles in the Alps. Gas chromatography combined with electron ionization tandem mass spectrometry (EI-MS/MS) was used for the determination of total CPs (sum of short, medium and long chain CPs). CPs were found in all samples; the concentrations varied between 7 and 199 ng g⁻¹ dry weight (dw) and within 26 and 460 ng g⁻¹ dw in humus and needle samples, respectively. A clear vertical tendency within the individual altitude profiles could not be ascertained. Within all altitude profiles, elevated concentrations were observed in humus samples taken between 700 and 900 m and between 1300 and 1500 m. In the needle samples no similar correlation could be observed due to higher variation of the data.     

Development of a comprehensive analytical method for the determination of chlorinated paraffins in spruce needles applied in passive air sampling

Conifer needles are used for the monitoring of atmospheric persistent organic pollutants. The objective of the present study was to develop a method for the detection of airborne chlorinated paraffins (CPs) using spruce needles as a passive sampler. The method is based on liquid extraction of the cuticular wax layer followed by chromatographic fractionation and detection of CPs using two different GCMS techniques. Total CP concentrations (sum of short (SCCP), medium (MCCP) and long chain CPs (LCCP)) were determined by EI-MS/MS. SCCP and MCCP levels as well as congener group patterns (n-alkane chain length, chlorine content) could be evaluated using ECNI-LRMS. For the first time, data on environmental airborne CPs on spruce needles taken within the Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants (MONARPOP) are presented providing evidence that spruce needles are a suitable passive sampling system for the monitoring of atmospheric CPs.