德阳市农用地土壤中镉的分布特征及异常来源分析

通过龙门山区域的德阳市6个县市农用地土壤中镉的采样监测,分析了该区域镉的分布特征及区域分异原因,并对其环境生态风险进行了评价。结果表明,德阳市农用地土壤中镉含量总体水平为0.11~4.68 mg/kg,呈现西北到东南逐渐降低的分布特征;西北部绵竹和什邡市农用地土壤中镉出现超标的范围较广,2个城市约62.5%的监测点土壤中镉出现超标,且绵竹市农用地土壤中镉超标程度和生态风险程度最重,绵竹地区约25%的监测点土壤中镉出现了轻中度超标;监测区域土壤中镉出现较重生态风险点共有4个,均出现在绵竹;但较高含量的镉在该区域并非大范围连片存在;区域农用地土壤中镉异常的来源主要为龙门山中段的地质背景和部分以矿石为原料企业的综合影响。     

1994—2010年东亚地区CO2浓度变化特征及成因分析

在东亚地区选取5个大气本底观测站1994年以来观测的 CO2监测资料,分析了各站大气 CO2的时空变化特征,以及 CO2主要人为源的变化及其影响。结果表明,5个本底站大气 CO2年均值均呈明显升高趋势,2010年较1994年增长幅度为8．4％～9．0％;在北半球国家,CO2月均值有明显的季节变化,高值多出现在冬春等寒冷季节,低值多出现在夏季。减少化石燃料消耗量、增加森林覆盖率及农业覆盖率将对大气中 CO2有削减作用。     

离子色谱-串联质谱测定地表水中高氯酸盐

采用离子色谱-串联质谱测定地表水中高氯酸盐,在US EPA相应分析方法的基础上进行了优化,以阴离子交换柱为分析柱,氢氧化钾为淋洗液,经抑制电导检测后通过阀切换将检测液中大量弱保留的阴离子切到废液后再将强保留的高氯酸盐切入质谱,电喷雾负离子模式电离,选择离子反应监测(SIM)高氯酸盐。方法检出限达0.031μg/L,实际样品相对标准偏差为2.26%~4.45%,加标回收率为93.0%~98.0%。四川省内主要河流的高氯酸盐浓度在未检出~68.0μg/L之间,高氯酸盐污染不容忽视。     

电位滴定法测定水中高锰酸盐指数

提出实验室用电位滴定测定水中高锰酸盐指数的方法。在国标法的基础上研究及优化了标定方法和实验方法,用电位滴定仪测定水中高锰酸盐指数,方法的检出限约为0.15mg/L,测定下限为0.60mg/L。实验证明,标准样品测量值均在推荐值范围内,对0.6mg/L,5.0mg/L,8.0mg/L浓度的NaC2O4标准溶液进行5次测定,得到的相对标准偏差分别为1.59%,0.97%,0.73%。在做低浓度的水样时,高锰酸钾溶液的浓度可以选择0.005mol/L。     

水生腐殖酸分子量分布研究——Ⅰ.串联凝胶色谱法测定水生腐殖酸分子量分布

考察了测定水生腐殖酸分子量分布及其平均分子量的串联凝胶色谱法。结果表明,使用Sepbadex G-25和G-100两种凝胶的色谱柱系统的分离范围可从分子量1000左右到数万,几乎包括了水生腐殖酸分子量分布的整个区段。这样的串联凝胶色谱柱的标定曲线为一折线,可用分段函数近似地加以描述。     

Secondary effect of SO2 pollution: enhanced growth of the army worm, Mythimna separata (Walker)

Effects of SO₂ pollution on growth of the army worm, Mythimna separata, were investigated by rearing the larvae for 12 days on the wheat plants being exposed to SO₂ levels ranged from 50 to 200 ppb in the field open-top fumigation devices. Larval period shortened while their mean relative growth rate (MRGR) increased as SO₂ dose elevated. Similar experiment with the insect on the artificial diet excluded the possibility that SO₂ pollution directly stimulated growth of the army worm.The patterns of change in amino acid hydrolysates in the host foliage suggested that contents of methionine, and perhaps, arginine in food material exposed to unpolluted air were at such levels that they could only support sub-optimum growth of the insect, and SO₂ pollution increased concentrations of these limiting amino acids, resulting in better performance of the larvae.     

Secondary effect of SO_2 pollution: enhanced growth of the army worm, Mythimna separata (Walker)

Effects of SO2 pollution on growth of the army worm, Mythimna separata, were investigated by rearing the larvae for 12 days on the wheat plants being exposed to SO2 levels ranged from 50 to 200 ppb in the field open-top fumigation devices. Larval period shortened while their mean relative growth rate (MRGR) increased as SO2 dose elevated. Similar experiment with the insect on the artificial diet excluded the possibility that SO2 pollution directly stimulated growth of the army worm.The patterns of change in amino acid hydrolysates in the host foliage suggested that contents of methionine, and perhaps, arginine in food material exposed to unpolluted air were at such levels that they could only support sub-optimum growth of the insect, and SO2 pollution increased concentrations of these limiting amino acids, resulting in better performance of the larvae.     

利用整群抽样进行地类监测

引言 根据山西省农业区划委员会关于建立农业资源动态监测体系的研究课题,我们从1981年开始经过三年时间对晋南的永济、运城、临猗、闻喜、夏县等五个县(市)的试点研究,基本建成了以进行土地类型面积和农作物产量调查为主要内容的动态监测体系。这是数理统计中抽样推断理论在农业上的应用,它还可以对大范围多内容的农业资源的变化进行动态监测。因此,“农业资源动态监测”被正式列入国家的“七五”计划。而这个体     

修复铬污染地下水的可渗透反应墙介质筛选

通过实验研究筛选出一种经济、高效的用于修复铬污染地下水的可渗透反应墙(PRB)介质。实验以铬污染地下水为研究对象,分别对Fe0、Fe0+石英砂和包覆型零价铁填料进行了筛选实验,选取处理效果好且经济可行的包覆型零价铁材料作为PRB反应介质。结果表明,以包覆型零价铁材料作为PRB反应介质,大大提高了铁粉的利用效率,且缓解了系统堵塞严重的问题。以包覆型零价铁材料作为PRB反应介质修复Cr(VI)污染地下水是可行的。     

Recovery of high purity sulfuric acid from the waste acid in toluene nitration process by rectification

Waste sulfuric acid is a byproduct generated from numerous industrial chemical processes. It is essential to remove the impurities and recover the sulfuric acid from the waste acid. In this study the rectification method was introduced to recover high purity sulfuric acid from the waste acid generated in toluene nitration process by using rectification column. The waste acid quality before and after rectification were evaluated using UV–Vis spectroscopy, GC/MS, HPLC and other physical and chemical analysis. It was shown that five nitro aromatic compounds in the waste acid were substantially removed and high purity sulfuric acid was also recovered in the rectification process at the same time. The COD was removed by 94% and the chrominance was reduced from 1000° to 1°. The recovered sulfuric acid with the concentration reaching 98.2 wt% had a comparable quality with commercial sulfuric acid and could be recycled back into the toluene nitration process, which could avoid waste of resources and reduce the environmental impact and pollution.