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361.
西辽河流域沙土的氨氮解吸行为研究 总被引:1,自引:0,他引:1
采用小型回填式土柱淋溶实验方法研究了西辽河流域沙土的氨氮解吸行为。结果表明,西辽河流域沙土的氨氮解吸行为符合Langmuir和Freundlich解吸等温式;沙土氨氮解吸比率Dr在0.44~0.99之间,平均为0.75,解吸迟滞性指数TⅡ在0.05~0.65之间,平均为0.29,沙土对氨氮的解吸迟滞性较强,解吸可逆性较弱。被吸附的氨氮解吸淋失的环境风险较小;沙土氨氮解吸比率Dr与土壤有机质含量、粘粒含量和粗粘粒含量呈极显著负相关,影响程度顺序为:有机质含量>粗粘粒含量>粘粒含量;解吸分配系数k和解吸迟滞性指数与土壤有机质含量分别呈极显著和显著正相关,与粘粒含量和粗粘粒含量没有相关性;草地、农田和林地结构由于土壤有机质和团聚体含量较高,氨氮解吸迟滞性较强,氨氮流失的环境风险较小,沙荒地结构氨氮流失的环境风险较大。 相似文献
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近年来,随着环境监测技术规范化建设的不断发展,国家环保部相继出台了包括火力发电、水泥制造、汽车制造、造纸工业在内的12个不同行业类型的建设项目竣工验收技术规范。然而,造纸污泥综合利用热电项目验收监测尚未列入规范编制日程,其中工程调查、标准制定、点位布设和报告编制等环节仍存在一定误区和难点。文章例从上述薄弱环节入手,对常见难点问题提出了相应的解决办法,可供广大环境监测工作者参考和借鉴。 相似文献
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介绍了由PLC和触摸屏组成的控制系统的特点和功能,以及PLC和上位机构成的控制系统可实现污水处理整个过程的实时监测和控制。 相似文献
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Photocatalytic ozonation of phenol and oxalic acid (OA) was conducted with a Ag^+/TiO2 catalyst and different pathways were found for the degradation of different compounds. Ag^+ greatly promoted the photocatalytic degradation of contaminants due to its role as an electron scavenger. It also accelerated the removal rate of OA in ozonation and the simultaneous process for its complex reaction with oxalate. Phenol could be degraded both in direct ozonation and photolysis, but the TOC removal rates were much higher in the simultaneous processes due to the oxidation of hydroxyl radicals resulting from synergetic effects. The sequence of photo-illumination and ozone exposure in the combined process showed quite different effects in phenol degradation and TOC removal. The synergetic effects in different combined processes were found to be highly related to the properties of the target pollutants. The color change of the solution and TEM result confirmed that Ag+ was easily reduced and deposited on the surface of Tit2 under photo-illumination, and dissolved again into solution in the presence of ozone. This simple cycle of enrichment and distribution of Ag^+ can greatly benefit the design of advanced oxidation processes, in which the sequences of ozone and photo-illumination can be varied according to the needs for catalyst recycling and the different properties of pollutants. 相似文献
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Plastics such as polyvinyl chlorides (PVC) are widely used in many indoor constructed environments; however, their unbound chemicals, such as di-(2-ethylhexyl) phthalates (DEHP), can leach into the surrounding environment. This study focused on DEHP's effect on the central nervous system by determining the precise DEHP content in mice brain tissue after exposure to the chemical, to evaluate the specific exposure range. Primary neuronal-astrocyte co-culture systems were used as in vitro models for chemical hazard identification of DEHP. Oxidative stress was hypothesized as a probable mechanism involved, and therefore the total reactive oxygen species (ROS) concentration was determined as a biomarker of oxidative stress. In addition, NeuriteTracer, a neurite tracing plugin with ImageJ, was used to develop an assay for neurotoxicity to provide quantitative measurements of neurological parameters, such as neuronal number, neuron count and neurite length, all of which could indicate neurotoxic effects. The results showed that with 1 nmol/L DEHP exposure, there was a significant increase in ROS concentrations, indicating that the neuronal-astrocyte cultures were injured due to exposure to DEHP. In response, astrocyte proliferation (gliosis) was initiated, serving as a mechanism to maintain a homeostatic environment for neurons and protect neurons from toxic chemicals. There is a need to assess the cumulative effects of DEHP in animals to evaluate the possible uotake and effects on the human neuronal system from exoosure to DEHP in the indoor environment. 相似文献