Improved biogas production from rice straw by co-digestion with kitchen waste and pig manure

In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37 ± 1 °C) anaerobic digestions were performed at a substrate concentration of 54 g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9–70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4 L/kg VS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others.     

Variations of organochlorine pesticides and polychlorinated biphenyls in atmosphere of the Tibetan Plateau: Role of the monsoon system

Monsoon transport is an important process that influences the global transport of persistent organic pollutants. Only a few studies focused on the influence of monsoon on organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) levels in the Tibetan Plateau. In this study, 19 samples were collected in Lhasa, the capital of Tibet Autonomous Region, using a high-volume air sampler. The average concentrations of α-HCH, γ-HCH, p-p′-DDT, p-p′-DDE, o-p′-DDT, α-endosulfan, β-endosulfan and PCBs (including PCB-28, 101, and 118) were 2.3, 10.3, 3.2, 2.9, 5.8, 6.3, 2.2, and 10.6 pg m^?3, respectively. The weak correlation coefficients between lnp (natural logarithm of partial pressure) and 1/T (reciprocal temperature) were obtained for DDTs and β-endosulfan (r² values ranged from 0.13 to 0.41). However, no significant correlations were obtained for HCHs and PCBs. These results suggested that both local emission and long-range atmospheric transport (monsoon) may influence the distribution of OCPs at Lhasa. In this study, peak concentrations of DDTs, endosulfans and PCBs were found in August, when Eastern Monsoon system occurred. However, the maximum concentrations of HCHs appeared in June (Indian Monsoon is the dominant air circulation pattern). Monthly variation of OCP/PCB levels was likely associated with the different air sources of monsoon system.     

浅谈儿童目动综合症与铅中毒

儿童多动综合症是表现为与同龄儿童相比，有长时间持续的、明显的注意力不集中和活动过度为主要特征的一组行为障碍。国内报道本症患病率为1.3％～15.9％，且以男孩为多见，起病年龄以5～8岁占多数。其临床表现主要为5个方面：(1)注意障碍；(2)活动过度；(3)情绪不稳，任性冲动；(4)认知障碍，学习困难；(5)行为问题，适应困难。本病的病因，迄今仍不清楚，但由于与微量元素关系的研究日渐深入，有人认为血铅增高和低铁与本症密切相关。为此，本文就如何预防儿童铅中毒，减少多动症的发生作一综述。 1 儿童铅中毒的标准 铅是具有导致神经性病症的重金属元素。铅进入人体后，主要从尿中排出，正常人每日由尿排铅约20～80μg。     

浅议中国报废汽车产业现状及发展战略

综述了我国报废汽车回收拆解和再制造行业的相关政策、方针和法律法规,对目前我国报废汽车产业的现状和存在的问题进行研究,结合国内外的相关理论和实际经验,从战略性高度,提出我国报废汽车产业健康发展的政策措施建议.     

关于新国标GB/T 29510-2013的思考

本文对2014年2月刚生效的新国标GB/T29510-2013《个体防护装备配备基本要求》的一些背景情况及内容做了介绍,主要包括PPE配备基本原则和以作业现场职业危害因素辨识与危害水平评估为基础制定PPE配备方案的工作程序,并探讨了新标准的应用价值,即标准在推动用人单位依据作业现场实际情况开展PPE配备和使用管理中所发挥的作用,和帮助职业健康监管部门监督企业选好、用好PPE,进而落实用人单位保护劳动者健康的主体责任过程中可发挥的功能。     

大连水产养殖业抗生素残留风险及其检测方法研究进展

在水产养殖业中,抗生素作为疾病治疗剂和促生长剂被频繁使用,已给环境和人类健康带来隐患。对大连市水产养殖业的调研结果表明,虽然抗生素作为饲料添加剂曾经为水产养殖业的发展做出了重要贡献,但其负面影响已逐渐显现,成为阻碍养殖业继续深入发展的瓶颈问题。本文通过调查抗生素的使用现状、环境来源、管控措施以及分析方法,对其吸附降解行为、毒性效应进行了讨论,最后指出了目前研究中存在的问题,并对未来进行了展望。     

人工湿地应用于富营养化景观水体修复

以某会议中心1号和2号人工湿地为研究对象,研究了人工湿地对富营养化景观水体的净化效果。结果表明:1号和2号人工湿地对COD、TN和TP均具有较好的处理效果,植物的差异对湿地污染物去除效果的影响不明显。TP的去除主要依靠基质的作用。湿地的前段和中段是整个湿地COD和TN去除的主体,且前段的去除率高于中段。     

Assessment of Bisphenol A (BPA) neurotoxicity in vitro with mouse embryonic stem cells

The adverse effects of environmental pollution on our well-being have been intensively studied with many in vitro and in vivo systems. In our group, we focus on stem cell toxicology due to the multitude of embryonic stem cell (ESC) properties which can be exerted in toxicity assays. In fact, ESCs can differentiate in culture to mimic embryonic development in vivo, or specifically to virtually any kind of somatic cells. Here, we used the toxicant Bisphenol A (BPA), a chemical known as a hazard to infants and children, and showed that our stem cell toxicology system was able to efficiently recapitulate most of the toxic effects of BPA previously detected by in vitro system or animal tests. More precisely, we demonstrated that BPA affected the proper specification of germ layers during our in vitro mimicking of the embryonic development, as well as the establishment of neural ectoderm and neural progenitor cells.     

PX项目环境风险分析

系统分析了PX项目的环境风险,结果表明:PX项目装置各单元均不是危险化工工艺单元,安全设施和污染治理水平相较于其它石油化工装置更高,但是基于装置物料的危险性和生产企业的高环境敏感度,PX项目的环境保护工作面临较大挑战。在此基础上,剖析了目前国内PX项目存在的主要环境风险问题,并提出相应的对策建议。     

两种不锈钢在冷却塔冷凝酸液中的耐蚀性能

目的分析304不锈钢和316L不锈钢在电厂冷却塔内海水及烟气形成的模拟冷凝酸液环境中的耐蚀性能。方法利用浸泡试验和电化学试验方法测试两种不锈钢在模拟冷凝酸液中的腐蚀形貌、腐蚀率和极化曲线。结果 304不锈钢在模拟冷凝酸液中的耐蚀性能较差,其腐蚀率及钝态稳定性受冷凝酸液pH值的影响较大;316L不锈钢在模拟冷凝酸液中的耐蚀性能较好,其腐蚀率及钝态稳定性受冷凝酸液pH值的影响较小。结论 316L不锈钢在冷却塔冷凝酸液中的耐蚀性能明显优于304不锈钢。