Subcritical water oxidation of propham by H2O2 using response surface methodology (RSM)

This study was conducted to investigate the degradation of propham, which is a compound that pollutes water and seriously threatens human health, by subcritical water oxidation and using H₂O₂ as an oxidising agent. The maximum total organic carbon removal rate of propham was obtained as 73.65% at 40 min of treatment time and 60 mM of H₂O₂ concentration and 373 K of temperature. In addition, response surface method based on the Box-Behnken design was applied to design the degradation experiments of propham for determination of the combined effects of process variables, namely temperature, concentration of oxidising agent and treatment time. The proposed quadratic model of propham degradation, which was examined with the analysis of variance, was used for navigating the design space. The R² and adjusted R² values of the model were determined as 0.9921 and 0.9819 respectively. It was shown that propham was effectively degraded, thus could be removed from the water by using an environmentally friendly method.     

SBR法处理豆制品废水工艺条件的研究

用SBR法处理豆制品废水的试验表明,该系统具有较好的抗负荷冲击能力,进水COD在300～2000 mg/L之间变化,对系统不造成任何影响;考察了曝气时间、曝气量和污泥浓度等对去除效果的影响,试验结果表明,曝气时间和曝气量对处理效果影响很大,确定该反应系统最佳曝气时间是8 h,适宜的曝气量是800 L/h,而污泥浓度控制在4000 mg/L左右时,处理效率最高,采用进水顶出水的排水方式是可行的,确定系统的最佳排水比是3/5.厌氧段的插入可以减少剩余污泥的产量.     

炼钢废气除尘污水处理的研究

系统地研究了影响石灰中和法处理转炉除尘废水含铜沉降速度的因素.结果表明,在搅拌时间10 min和中等搅拌强度的条件下,pH值控制在8.2～9.0范围内能使废水中铜含量在1 h的沉降时间内降至国家排放标准2 mg/L以下.实验还研究了在石灰中和过程中加入适量絮凝剂的影响因素.结果表明,在搅拌时间3 min和相同pH值范围的条件下,加入絮凝剂能使废水中铜含量在30 min的沉降时间内降至国家排放标准2 mg/L以下.     

Contribution of anthropogenic pollutants to the increase of tropospheric ozone levels in the Oporto Metropolitan Area, Portugal since the 19th century

The main purpose of this study was to evaluate the contribution of anthropogenic pollutants to the increase of tropospheric ozone levels in the Oporto Metropolitan Area (Portugal) since the 19th century. The study was based on pre-industrial and recent data series, the results being analyzed according to the atmospheric chemistry. The treatment of ozone and meteorological data was performed by classical statistics and by time-series analysis. It was concluded that in the 19th century the ozone present in the troposphere was not of photochemical origin, being possible to consider the respective concentrations as reference values. For recent data a cycle of 8h for ozone concentrations could be related to traffic. Compared to the 19th century, the current concentrations were 147% higher (252% higher in May) due to the increased photochemical production associated with the increased anthropogenic emissions.     

富营养化湖泊底泥污染控制技术评估

回顾了我国在富营养化湖泊底泥污染控制技术方面的研究进展,并从富营养化湖泊底泥污染控制技术的运用效果、环境影响、社会影响、经济性、适用性以及与其他技术的相关性等六个方面,全面评估了破坏分层、人工曝气、化学增氧、底泥疏浚和底泥封闭等五类技术.     

黄磷废水处理技术

黄磷废水成分复杂,含P4、F-和CN-等多种有毒有害物质,污染严重,须经过处理达标后方可排放.目前国内黄磷废水处理通常采用物化法,其又可分为沉淀氧化法和闭路循环法.分别就这2种技术方法的处理过程及优缺点进行了探讨,并对其存在问题的解决提供了思路.     

Trace elements and microbiological parameters in farmed Nile tilapia with emphasis on muscle,water, sediment and feed

Fish may bioaccumulate contaminants from the aquatic environment and extend them to the food chain provoking risks to human health. This study evaluated the microbiological parameters of the pond´s water and trace elements concentrations in samples of water, sediment, feed and muscle of farmed Nile tilapia used for human consumption in southern Brazil. A total of 240 fish were collected from 12 tilapia farms. Sediment, tank water and dry ration used in the animals' diet were collected for analysis. Analysis were performed by Energy Dispersion X-ray Fluorescence (EDXRF), Inductively Coupled Plasma Mass Spectrometer (ICP-MS), Induced Coupled Plasma Optical Emission Spectrometer (ICP-OES), and Atomic Absorption Spectrometer (AAS-VGA). In addition, the microbiological analysis of the water was carried out. The concentrations of Se, I, Fe, Cu and Zn in fish muscle were higher than the recommended by the Brazilian legislation, considering the advised daily intake for adults. The arsenic element had concentrations above the limit stipulated by the present Brazilian legislation, observed in all samples of muscle, sediment and tank water highlighting a possible environmental and fish contamination by the toxic element. Moreover, the arsenic concentration in the water presented a positive correlation (ρ?=?0.33) with arsenic in the muscle, suggesting that tilapia is a good environmental bioindicator, once they properly reflect the levels of arsenic in the water. It is suggested to perform an arsenic speciation for quantification of the inorganic form and accurate assessment of the degree of toxicity in the muscle samples and risks it can bring to human health. Regarding the other potentially toxic elements (Hg, Pb and Cd), and microbiological analysis of water it was verified that the consumption of the fish in question does not raise risks, since the values are within a quality benchmark established by law. The concentration of total and fecal coliforms in pond´s water in the facilities was in agreement with the microbiological indexes required by the legislation of CONAMA class II. Western region presented the lowest concentrations of fecal coliforms when compared to the other regions. There was no significant difference in the microbiological counts of total heterotrophic bacteria, Vibrio spp. and Pseudomonas spp. among the regions.     

土壤/沉积物中重金属生物有效性和生物可利用性的研究进展

土壤/沉积物中重金属的污染问题越来越引起重视,而重金属在环境中的生态风险与其生物可利用性和生物有效性密切相关。在总结国内外研究的基础上,明确了重金属生物有效性和生物可利用性的定义;概述了用于研究土壤/沉积物中重金属生物有效性的生物模型(小鼠、猪、兔子等);总结了用于研究土壤/沉积物中重金属生物可利用性的几种体外方法,包括模拟人类肠胃消化(PBET、SBRC、UBM等)和底栖生物消化;分析了土壤/沉积物中重金属生物有效性和生物可利用性的关键影响因素(土壤/沉积物理化性质和分析方法)。提出了未来土壤/沉积物中重金属生物有效性和生物可利用性的研究方向,以期为重金属生态风险的评价和控制提供参考。     

内电解法预处理甲基氯化物生产废水的研究

用内电解法预处理有机磷农药中间体甲基氯化物生产废水，结果表明是可行的，废水CODcr，有机磷，硫化物的去除率分别达到62.43%，60.62%，76.37%，出水的BOD5／CODcr由0.107上升至0.302，为后续的生化处理创造了良好的条件。实验确定的操作条件为铁碳比铁碳比2、废水pH值5.5,反应温度＞50℃，停留时间＞7h，CaO用量200mg/L。     

环境材料及其评价方法

本文综述了环境材料的实质、特点及其与传统材料在主要内涵、研究重点、评价指标体系和材料选择原则的差异 ,并介绍了环境材料的评价体系与方法和设计原则