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881.
以硫化钠为硫化剂,机械化学硫化荧光灯管芯柱玻璃中金属铅,实现金属铅向硫化铅快速转化.通过单因素实验,考察了不同机械化学硫化条件,即球磨时间、球磨转速和球料比对硫化率的影响,并通过XRD、SEM和粒度对硫化产物进行表征.结果表明,硫化率随球磨时间和球磨转速的增大而增大,随球料比的增大先增大后减小,当球磨转速为750r/min、球磨时间为120min、球料比为50:1g/g时,荧光灯管芯柱玻璃中金属铅的硫化率可达96.18%.XRD结果表明,荧光灯管芯柱玻璃中金属铅的机械化学硫化产物为PbS、SEM和粒度结果表明,荧光灯管芯柱玻璃的粒径随球磨转速和球磨时间的增加而减小. 相似文献
882.
为探究游离亚硝酸(FNA)对亚硝酸盐氧化细菌中硝化杆菌属(Nitrobacter)活性抑制动力学影响,采用序批式活性污泥(SBR)反应器,在通过改变系统进水FNA浓度达到富集Nitrobacter基础上,以富含Nitrobacter污泥为对象(宏基因组物种注释和丰度分析显示上Nitrobacter占细菌总数40.3%),基于批次试验,考察不同FNA浓度梯度下亚硝酸盐氧化过程比亚硝态氮氧化速率(SNiOR)变化规律,进而拟合FNA抑制Nitrobacter活性抑制动力学模型,并进行统计学分析.结果表明,当FNA≤0.1mg/L时,随着FNA浓度升高,SNiOR迅速升高.当FNA>0.1mg/L时,SNiOR随着FNA浓度升高而降低.尤其当FNA浓度高于0.7mg/L时,SNiOR始终维持在0gN/(gVSS·d),表明Nitrobacter活性统被完全抑制.统计学分析结果显示相对于Haldane、Aiba、Edwards-1#、Edwards-2#、Luong抑制动力学模型,Han-Levenspiel模型最适合描述FNA对Nitrobacter活性的抑制影响.其统计学常数:残差平方和(RSS)为0.02、可决系数(R2)为0.90、拟合方程的方差检验统计量F值为78.1、可信度P值为3.29×10-12,其动力学常数值分别为:最大比亚硝态氮氧化速率(rmax)为1.57gN/(gVSS·d);半饱和常数(KS)为0.01mg/L;临界抑制常数(Sm)为0.66mg/L. 相似文献
883.
为降低污水污泥中药理活性化合物(PhACs)产生的环境风险,利用生物方法强化污泥厌氧消化,提高其去除效果.以CFA(氯贝酸)、TCS(三氯生)、DCF(双氯芬酸)、CBZ(卡马西平)4种典型的PhACs为目标污染物,利用气相色谱-质谱联用仪(GC-MS)定量分析污泥中的目标物,探究外加生物酶联合污泥厌氧消化法强化对PhACs的作用效果.结果表明,随着SRT(污泥停留时间)的增大,目标物的去除率有一定程度的增大,特别是在高温条件下,当SRT由7 d增至20 d时,CFA的去除率增长了45%;木瓜蛋白酶对中高温系统中CBZ的去除效果最佳,分别为63.8%和67.5%,同时对4种目标物总的去除率最高,分别为57.3%和61.8%;添加溶菌酶试验中,4种目标物去除效果差异较大,中温、高温系统中对TCS的去除效果最佳为81.7%和80.9%,去除效果最差的是CBZ,去除率为40.4%和33.5%;纤维素酶处理中,4种目标物的去除率均小于60%.混合生物酶试验中,高温条件下更易去除PhACs.研究显示,生物酶强化污泥厌氧消化能有效去除污水污泥中的PhACs. 相似文献
884.
本文通过计算城市各环境单元的污染指数、综合污染指数及其变化率,用比较直观的数字来表示城市的综合环境质量及其动态变化,从而提高了环境质量统计数据的可比性和可用性。 相似文献
885.
不同基质配比对农村生活垃圾厌氧发酵效率及稳定性的影响 总被引:1,自引:0,他引:1
以典型农村生活垃圾餐厨垃圾(Food Waste,FW)与纸类垃圾(Paper Waste,PW)为基质,通过中温(35℃)批次厌氧共发酵试验,探明不同配比的基质在厌氧共发酵4阶段(水解阶段、酸化阶段、乙酸化阶段、产甲烷阶段)的动力学特性,再结合挥发性脂肪酸(Volatile fatty acids,VFAs)在系统运行过程中的变化,确定FW与PW的最佳配比。结果表明,水解阶段是纸类垃圾的主要限速步骤,而VFAs积累限制了餐厨垃圾甲烷化进程的提高,且VFAs积累主要以丙酸与丁酸为主。当w(FW)≥35%时,产甲烷速率随VFAs质量浓度增大而线性减小,过高的VFAs质量浓度抑制了产甲烷菌的活性。FW与PW最佳基质配比为35∶65(质量比),在此条件下反应速率最为突出,系统运行高效,VFAs能及时被产甲烷菌利用,无有机酸积累,系统运行平稳。 相似文献
886.
887.
张敏 《中国安全生产科学技术》2019,15(10):5-11
基于劳动力健康视角,研究近期公开征求意见的《中华人民共和国基本医疗卫生与健康促进法(草案三次审议稿)》,为进一步完善提供技术支撑。依据循证决策的原理,针对法律草案的相关内容,梳理研究涉及劳动力人群和职业健康的国内外法律和实践。研究结果表明:保障劳动力健康的有关表述,在法律草案的总则、基本医疗卫生服务、医疗卫生机构、医疗卫生人员、健康促进5章仍需要强化,为此提出了14条具体建议和修改意见。 相似文献
888.
Rohit Sharma Kushal Kamboj Jyoti Bhardwaj 《International journal of occupational safety and ergonomics》2019,25(1):51-60
This study investigates the safe carrying load limit in relation to gender of workers in the sugar industry. A total of 632 workers (male and female) were interviewed following a physiological and psycho-physiological methodology. All of these workers were in the age groups of 21–30, 31–40 and ≥41 years. In this study, for the physiological methodology, both field and laboratory data were collected, which included heart rate, heart rate variability, energy expenditure and maximum rate of oxygen consumption. Information regarding hemoglobin content, weight, age, lean body weight, etc., was recorded to know the physical health of the workers. In the psycho-physiological evaluation, load-carrying limits were determined by the psychophysical rating of the load by workers from the selected age groups. By considering the physiological stresses and psycho-physiological evaluation, the safe carrying load limit was determined in head and back mode for male and female workers as per their age groups. 相似文献
889.
Rachel Morrow Paula Brough 《International journal of occupational safety and ergonomics》2019,25(3):467-475
Purpose. Person–environment fit asserts that incompatibility between an employee and aspects of their work environment is more likely to lead to occupational stress. The aim of this study was to investigate the impact that varying levels of person–environment fit had on key criterion outcomes including work engagement, work-related wellbeing and turnover intentions in a unique sample of managerial and administrative mining personnel. Method. An online self-report survey was distributed to an Australian mining organization by the company’s Chief Executive Officer. Anonymous survey links were sent to staff, of which 118 participants responded. The survey consisted of previously validated measures. Results. Hierarchical multiple regression analyses revealed significant relationships between abilities–demand fit, needs–supply fit and work engagement. Additionally, work-related wellbeing was significantly associated with increased person–organization fit and needs–supply fit. However, only needs–supply fit had a significant negative relationship with turnover intentions. Needs–supply fit significantly predicted all criterion variables. Conclusions. This study found that personal need fulfilment through work-related activities had the most significant impact on work-related wellbeing and work engagement. Personal need fulfilment through work also produced the most significant negative relationship with turnover intentions. 相似文献
890.
Katarzyna Naylor Anna Torres Robert Gałązkowski Kamil Torres 《International journal of occupational safety and ergonomics》2019,25(4):597-603
Introduction. Paramedics are at risk of occupational blood exposure, increased by the immediacy of provided treatment. However, the issue has not been acknowledged to date by any research in Europe. Methods. This research aimed at assessing occupational blood exposure among paramedics in Poland. Respondents represented 21 Polish medical institutions. Their participation was voluntary and anonymous. Paramedics were provided with a self-directed job-specific questionnaire adapted to Polish conditions from an original US version. Results. 118 paramedics participated in the study from institutions constituting the National Emergency Medical System in Poland; including ambulance crews, Helicopter Emergency Medical Services and emergency department employees. Occupational exposure was reported by 18.64% of respondents and the main route of exposure was needlestick events. Conclusions. There is a further need to improve education among paramedics concerning the threat of being infected with blood-borne pathogens through all existing routes. Our findings point to the problem as being hidden and considered a shameful issue. 相似文献