中国职业安全卫生工作走一体化发展道路的必要性

20世纪80年代以来,我国的经济结构发生了很大变化,现行的管理体制已经不能适应经济发展的要求.一方面,经济多元化所产生的负面影响严重地削弱劳动者享有职业安全健康的权益.另一方面,中国工业化的迅速发展加剧了恶性重大事故频繁发生和职业病居高不下[1].在国内经济发展和国际竞争的巨大压力下,中国职业安全卫生已经走到了一个十字路口.2006年中国安全生产报的一项调查显示,职业安全与职业卫生再次实行一体化统一监管是必然趋势[2].     

Regional medical waste management in China: a case study of Shenyang

Medical waste management is of great importance due to its potential environmental and public health risks, especially in developing countries where both financial and technological resources on medical waste management are still lacking. Although many studies have focused on country-scaled medical waste management, few have paid close attention to regional (city-scale) management, particularly in China. This paper fills such a gap by employing a case study approach. Due to its representative nature, Shenyang was selected as the case study. After a review of China’s medical waste management, an empirical study in Shenyang was conducted in order to analyze the current state as well as identify key challenges on regional medical waste management. Based upon the local realities and aiming to better manage medical wastes, an integrated medical waste management framework is developed. Such a platform encourages the establishment of a specific medical waste management authority, a city scaled capacity building program on improving the general public’s awareness, an information platform, application of state-of-the-art technologies, as well as creation of an effective financial system. The combination of such initiatives can significantly improve the overall eco-efficiency of medical waste management at the regional level and should be promoted to other developing cities.     

Herbicide Roundup® and its main constituents cause oxidative stress and inhibit acetylcholinesterase in liver of Carassius auratus

Roundup® is a glyphosate-based herbicide containing a mixture of surfactants. This paper evaluates the toxic effects of Roundup® and its main constituents on the goldfish, Carassius auratus, after 7 days exposure. Fish were exposed to 0.16, 0.032 and 0.0064 mg/L of Roundup® [containing 41% isopropylamine salt of glyphosate (G.I.S) and 18% polyoxyethylene amine (POEA)], G.I.S, and POEA. Their livers were taken for determining reactive oxygen species (ROS), superoxide dismutase (SOD) activity, malondialdehye (MDA) content and acetylcholinesterase (AChE) activity. Hydroxyl radical (·OH) could be induced by exposing Roundup® at a rate of 43%–111%, G.I.S at 90%–124% and POEA at142%–157%. A decreased SOD activity was observed in fish exposed to G.I.S and POEA. The contents of MDA significantly increased when exposed to Roundup® at all concentrations, 0.16 mg/L G.I.S and 0.032 mg/L POEA. The exposure led to an inhibition of AChE in livers overall during the experimental periods. POEA was more toxic than Roundup® or G.I.S during this experiment. AChE and ·OH are supposed to be sensitive biomarkers of the exposure of Roundup® and its main constituents to C. auratus.     

Characteristics of penicillin bacterial residue

A hybrid selective noncatalytic reduction/selective catalytic reduction (SNCR/SCR) system that uses two types of technology, low-temperature SCR process and SNCR process, was designed to develop nitrogen oxide (NO_x) reduction technology. SCR was conducted with space velocity (SV) = 2400 hr^?1 and hybrid SNCR/SCR with SV = 6000 hr^?1, since the study focused on reducing the amount of catalyst and both achieved 98% NO_x reduction efficiency. Characteristics of NO_x reduction by NH₃ were studied for low-temperature SCR system at 150 °C using Mn-V₂O₅/TiO₂ catalyst. Mn-added V₂O₅/TiO₂ catalyst was produced, and selective catalyst reduction of NO_x by NH₃ was experimented. NO_x reduction rate according to added Mn content in Mn-V₂O₅/TiO₂ catalyst was studied with varying conditions of reaction temperature, normalized stoichiometric ratio (NSR), SV, and O₂ concentration. In the catalyst experiment according to V₂O₅ concentration, 1 wt.% V₂O₅ catalyst showed the highest NO_x reduction rate: 98% reduction at temperature window of 200~250 °C. As a promoter of the V₂O₅ catalyst, 5 wt.% Mn was added, and the catalyst showed 47~90% higher efficiency even with low temperatures, 100~200 °C. Mn-V₂O₅/TiO₂ catalyst, prepared by adding 5 wt.% Mn in V₂O₅/TiO₂ catalyst, showed increments of catalyst activation at 150 °C as well as NO_x reduction. Mn-V₂O₅/TiO₂ catalyst showed 8% higher rate for NO_x reduction compared with V₂O₅/TiO₂ catalyst in 150 °C SCR. Thus, (5 wt.%)Mn-(1 wt.%)V₂O₅/TiO₂ catalyst was applied in SCR of hybrid SNCR/SCR system of low temperature at 150 °C. Low-temperature SCR hybrid SNCR/SCR (150 °C) system and hybrid SNCR/SCR (350 °C) showed 91~95% total reduction rate with conditions of SV = 2400~6000 hr^?1 SCR and 850~1050 °C SNCR, NSR = 1.5~2.0, and 5% O₂. Hybrid SNCR/SCR (150 °C) system proved to be more effective than the hybrid SNCR/SCR (350 °C) system at low temperature.

Implications:?NO_x control is very important, since they are the part of greenhouse gases as well as the cause of acid rain and ozone hole. A technology, so-called hybrid SNCR/SCR process, was tested using Mn-V₂O₅/TiO₂ monolithic catalyst for NO_x reduction, and the method is promising. The results of this study would provide some ideas to parties such as policy makers, environmental engineers, and so on.     

文丘里对脉冲喷吹过滤系统清灰的影响

在自建的脉冲喷吹实验台上,利用Y—YD-7044型压电式传感器和MYD-8801加速度传感器,测试0120×2000mm覆PTFE膜无纺布滤袋在不同喷吹压力下,加文丘里与不加文丘里时的最大侧壁压力峰值和最大反向加速度,并对比计算了获得同样清灰强度时的脉冲阀一次喷吹耗气量。结果显示,添加文丘里能显著增大滤袋中下部最大侧壁压力峰值和整条滤袋上的最大反向加速度,即提高脉冲喷吹清灰强度;对应同样的喷吹压力,加文丘里时的平均最大侧壁压力峰值和平均最大反向加速度比不加文丘里时分别平均提高大约70％和50％;加文丘里获得同样清灰强度时的脉冲阀一次喷吹耗气量比不加文丘里时节省40％左右。证实对于脉冲喷吹清灰系统,添加文丘里能有效改善清灰效果以及减小能量？肖耗。     

产酸克雷伯氏菌Klebsiella oxytoca对硝基苯及4-氯硝基苯的降解

硝基苯类化合物生物降解菌的筛选及性能研究,是制药、染料等行业废水达标的重要基础。以浓度梯度升高法筛选到一株硝基苯厌氧降解菌Klebsiella oxytoca NBA-1。考察了该菌对氧气的需求,以及在厌氧条件下,温度、pH值、外加葡萄糖及硝基苯初始浓度等环境因子对菌株降解硝基苯能力的影响,并进一步讨论菌株对氯取代硝基苯类化合物的降解情况。结果表明,该菌在厌氧条件下生长比好氧条件下慢,但降解速度更快;厌氧降解硝基苯的最佳pH值和温度和分别为8.3和30~35℃;加入0.3%~0.5%的葡萄糖可促进降解,且对300 mg/L以下的硝基苯均有降解能力;该菌能将4-氯硝基苯转化为4-氯苯胺,并进一步脱氯为苯胺。研究结果可为硝基苯及含氯硝基苯的处理工艺选择提供相关的参考依据。     

影响钝顶螺旋藻固碳的环境因子优化

为了提高钝顶螺旋藻生长过程中的固碳速率,从CO2浓度、温度和光周期3个主要环境因子进行优化。实验结果表明,钝顶螺旋藻在2 L三角瓶中培养时,最佳培养条件为10%CO2,温度30℃,光周期16/8。最佳培养条件下,钝顶螺旋藻对数生长期内比生长速率与固碳速率均达到峰值0.512 d-1和42.506 mg/(L.h)。此外,钝顶螺旋藻的底物消耗表明培养液中的N、P足量,其初始添加量可以满足藻体的生长需要;生长过程中补加10%CO2一方面补充钝顶螺旋藻可吸收碳源,另一方面有利于缓解培养液pH升高对藻生长的影响。     

焙烧条件对CuO/ZSM-5催化剂脱硫脱硝性能的影响

以ZSM-5分子筛为载体,通过浸渍法制备10％ CuO/ZSM-5(金属氧化物质量占载体质量)催化剂,以CH4为还原气,考察不同焙烧温度和焙烧时间对催化剂脱硫脱硝性能的影响.XRD和TPR的表征结果显示,最佳焙烧条件为550℃下焙烧4h,在此焙烧条件下,10％ CuO/ZSM-5催化剂达到的最高脱硝脱硫率分别为90.6％和98.8％.     

Synthesis of α-Fe2O3 nanofibers for applications in removal and recovery of Cr(VI) from wastewater

Purpose

Nanomaterials such as iron oxides and ferrites have been intensively investigated for water treatment and environmental remediation applications. The purpose of this work is to synthesize α-Fe₂O₃ nanofibers for potential applications in removal and recovery of noxious Cr(VI) from wastewater.

Methods

α-Fe₂O₃ nanofibers were synthesized via a simple hydrothermal route followed by calcination. The crystallographic structure and the morphology of the as-prepared α-Fe₂O₃ nanofibers were characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope. Batch adsorption experiments were conducted, and Fourier transform infrared spectra were recorded before and after adsorption to investigate the Cr(VI) removal performance and adsorption mechanism. Langmuir and Freundlich modes were employed to analyze the adsorption behavior of Cr(VI) on the α-Fe₂O₃ nanofibers.

Results

Very thin and porous α-Fe₂O₃ nanofibers have been successfully synthesized for investigation of Cr(VI) removal capability from synthetic wastewater. Batch experiments revealed that the as-prepared α-Fe₂O₃ nanofibers exhibited excellent Cr(VI) removal performance with a maximum adsorption capacity of 16.17 mg g^?1. Furthermore, the adsorption capacity almost kept unchanged after recycling and reusing. The Cr(VI) adsorption process was found to follow the pseudo-second-order kinetics model, and the corresponding thermodynamic parameters ΔG°, ΔH°, and ΔS° at 298 K were calculated to be ?26.60 kJ?mol^?1, ?3.32 kJ?mol^?1, and 78.12 J?mol^?1 K^?1, respectively.

Conclusions

The as-prepared α-Fe₂O₃ nanofibers can be utilized as efficient low-cost nano-absorbents for removal and recovery of Cr(VI) from wastewater.     

焦化废水处理过程外排污泥中重金属形态特征及其潜在环境风险

焦化废水处理过程所排放污泥中重金属的含量及化学形态是否构成环境风险将直接影响污泥处置方法的选择,为此,实验采用BCR顺序提取法分析了焦化废水处理站外排污泥中重金属(Cd、Hg、Pb、Cr、As、Ni、Zn、Cu和Mn)的形态特征,并采用地累积指数(Igeo)和潜在生态危害指数(RI)评价了重金属对土壤的潜在环境风险。研究结果表明:除Ni主要以可氧化态存在外,焦化废水外排污泥中其他几种重金属元素主要存在于残渣态,重金属元素的含量低于《城镇污水处理厂污染物排放标准(GB18918—2002)》中的控制限值;与城市污泥相比,焦化废水外排污泥具有低Pb、Cr、Zn、Cu含量,而高Cd、Hg、Mn含量的特点;基于Igeo和RI的评价结果,Cd和Hg是外排污泥中具有一定环境风险的元素,需要考虑其下游去向。焦化废水处理外排污泥中主要存在残渣态重金属成分,不表现为很高的环境风险,其处置应重点考虑其中有机污染物特别是POPs。