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811.
812.
广州地区农田土壤中有机氯农药残留分布特征 总被引:5,自引:0,他引:5
以网格法在农田土壤中均匀布点,采集土壤样品75个,对广州地区农田土壤中有机氯农药含量及分布状况进行了研究。结果表明,试区土壤有机氯农药的检出率为100%,表明广州地区农田土壤中有机氯农药残留现象普遍存在。六六六(HCHs)和滴滴涕(DDTs)的平均含量分别为42.75μg/kg、52.76μg/kg,含量范围分别在1.35—803.72和2.73—1036.90μg/kg。与国内不同区域的同类研究相比,广州地区土壤的有机氯残留水平较高。在不同利用类型土壤中,有机氯残留状况有所差异,六六六在水稻土中残留量最高,而滴滴涕在菜园土中含量最高。 相似文献
813.
采用单因素试验分析了多功能复合微生物制剂MCMP处理垃圾渗滤液的反应条件,结果表明:投加MCMP能促进渗滤液COD、NH3-N、TP的去除,在反应时间72 h,间歇曝气36h,接种量(VMCMP:V水)为1/8000,进水pH值8时处理效果较好,去除率分别达到37.56%、72.74%、51.56%。MCMP技术与生物膜法联合处理垃圾渗滤液的试验表明:同单纯使用MCMP菌处理渗滤液相比,以陶粒为填料的MCMP生物膜系统,对TP的去除效果有明显提高,去除率达到65.23%,对COD和NH3-N去除率影响不显著。 相似文献
814.
突发环境污染事故应急管理系统被认为是应对事故的一种非常有前景的方法。本文讨论了构建该类系统的现实需求,并根据其关键模块所采用的技术,分类别地介绍了现有的突发环境污染事故应惠管理系统的开发情况和服务内容。在此基础上,指出了该领域尚未解决的问题,并对今后的研究前景进行了展望。 相似文献
815.
816.
Coupling of zero valent iron and biobarriers for remediation of
trichloroethylene in groundwater 总被引:1,自引:0,他引:1
This study attempted to construct a three series barrier system to treat high concentrations of trichloroethylene (TCE; 500 mg/L) in
synthetic groundwater. The system consisted of three reactive barriers using iron fillings as an iron-based barrier in the first column,
sugarcane bagasse mixed with anaerobic sludge as an anaerobic barrier in the second column, and a biofilm coated on oxygen carbon
inducer releasing material as an aerobic barrier in the third column. In order to evaluate the extent of removal of TCE and its metabolites
in the aquifer down gradient of the barrier system, a fourth column filled with sand was applied. Residence time of the system was
investigated by a bromide tracer test. The results showed that residence time in the column system of the control set and experimental
set were 23.62 and 29.99 days, respectively. The e ciency of the three series barrier system in removing TCE was approximately
84% in which the removal e ciency of TCE by the iron filling barrier, anaerobic barrier and aerobic barrier were 42%, 16% and 25%,
respectively. cis-Dichloroethylene (cis-DCE), vinyl chloride (VC), ethylene and chloride ions were observed as metabolites following
TCE degradation. The presence of chloride ions in the e uent from the column system indicated the degradation of TCE. However,
cis-DCE and VC were not fully degraded by the proposed barrier system which suggested that another remediation technology after
the barrier treatment such as air sparging and adsorption by activated carbon should be conducted. 相似文献
817.
通过对桉树速生林基地的生态调查及监测,分析得出以前我国桉树速生林普遍存在地力衰退的问题,导致土壤肥力下降及目前桉树人工林地力衰退已经得到根本性的逆转的主要原因。速生林基地种植的桉树林林下植被与林缘、林外植被没有显著不同,特别是与桉树林地块相近的稀疏马尾松林林下植被以及荒坡植被相比,无论从植被覆盖度、植物种类、高度等看都呈现出增高、增多的趋势,而广东雨量丰富,桉树能同绝大部分林下植物共生。 相似文献
818.
819.
Optimizing water quality monitoring networks using continuous longitudinal monitoring data: a case study of Wen-Rui Tang River, Wenzhou, China 总被引:1,自引:0,他引:1
Mei K Zhu Y Liao L Dahlgren R Shang X Zhang M 《Journal of environmental monitoring : JEM》2011,13(10):2755-2762
Identification of representative sampling sites is a critical issue in establishing an effective water quality monitoring program. This is especially important at the urban-agriculture interface where water quality conditions can change rapidly over short distances. The objective of this research was to optimize the spatial allocation of discrete monitoring sites for synoptic water quality monitoring through analysis of continuous longitudinal monitoring data collected by attaching a water quality sonde and GPS to a boat. Sampling was conducted six times from March to October 2009 along a 6.5 km segment of the Wen-Rui Tang River in eastern China that represented an urban-agricultural interface. When travelling at a velocity of ~2.4 km h(-1), this resulted in water quality measurements at ~20 m interval. Ammonia nitrogen (NH(4)(+)-N), electrical conductivity (EC), dissolved oxygen (DO), and turbidity data were collected and analyzed using Cluster Analysis (CA) to identify optimal locations for establishment of long-term monitoring sites. The analysis identified two distinct water quality segments for NH(4)(+)-N and EC and three distinct segments for DO and turbidity. According to our research results, the current fixed-location sampling sites should be adjusted to more effectively capture the distinct differences in the spatial distribution of water quality conditions. In addition, this methodology identified river reaches that require more comprehensive study of the factors leading to the changes in water quality within the identified river segment. The study demonstrates that continuous longitudinal monitoring can be a highly effective method for optimizing monitoring site locations for water quality studies. 相似文献
820.