土壤中苯胺类污染物的液相色谱测定

试验建立了土壤中苯胺类污染物的液相色谱测定方法,优化了试验条件。方法线性关系很好,7种苯胺类成分的检出限在0.1μg/kg~0.5μg/kg之间,空白加标试验的相对标准偏差RSD在1.8%~4.8%之间,基质加标回收率在63.8%~92.7%之间。实际样品的测定结果表明该方法分离效果好,能够满足土壤中苯胺类分析的要求。     

土壤中挥发性芳香烃顶空气相色谱的测定研究

本文采用顶空-气相色谱法测定土壤中的苯、甲苯、乙苯、对二甲苯、间二甲苯、异丙苯、邻二甲苯、苯乙烯8种挥发性芳香烃。结果表明,8种挥发性芳香烃在1.23μg/L~250μg/L范围内线性关系良好,相关系数为0.9 997~0.9 998,方法检出限(LOD,S/N=3)为0.37μg/L~0.52μg/L,回收率为80.18%~114.14%,RSD为0.82%~8.96%。该方法操作简单,检出限低,且适用性强,可用于土壤中挥发性芳香烃的快速定性定量测定。     

固体进样-热解金汞齐-原子吸收光度法测定土壤中的汞

利用利曼HydraⅡC型原子吸收测汞仪,优化了固体进样-热解金汞齐-原子吸收光度法测定土壤中汞的测试条件,建立了土壤汞的全自动原子吸收测定方法,提出了方法注意要点。试验结果表明,在优化的测试条件下,仪器响应稳定;曲线状态良好(线性范围1~190ng,r=0.999),检出限0.009mg/kg(以称样0.100 0g计);测试结果准确,质控土样相对误差0.6%~2.9%,实际土样精密度1.5%~4.7%,加标回收率95.7%~96.8%。     

快速溶剂萃取-水浴氮吹-高效液相色谱法检测土壤16种多环芳烃

建立了快速溶剂萃取-水浴氮吹-高效液相色谱法检测土壤样品中16种多环芳烃（PAHs）的方法。分别对比了快速溶剂萃取与索式抽提、旋转蒸发浓缩与水浴氮吹浓缩、硅酸镁固相萃取柱与硅胶固相萃取柱净 化的预处理效果,经实验对比后,确认优化预处理条件为：快速溶剂萃取温度120℃,静态萃取时间16min,萃取次数两次,水浴氮吹浓缩,氮吹温度40℃,浓缩液经硅酸镁固相萃取柱净化。方法检出限和测定下限分别为0.21～0.47μg/kg和0.84～1.88μg/kg。在优化条件下,加标水平为0.5mg/kg时,目标物加标回收率为72.66％～113.90％,替代物加标回收率为69.25％,108.63％,相对标准偏差（n＝7）为0.69％～11.8％,适合实际土壤样品中PAHs的检测。     

萃取-气质联用测定土壤中多氯联苯

建立快速溶剂萃取-气相色谱质谱法同时测定土壤中18种多氯联苯单体的方法,比较快速溶剂萃取和微波萃取两种前处理方法操作流程、精密度及回收率。结果表明,18种多氯联苯单体在给定范围内线性关系良好,相对响应因子(RF)的相对标准偏差(RSD)均小于15%,方法检出限范围为0.3~0.5μg/kg,不同浓度级别回收率范围为80.5%~125%,相对标准偏差范围为1.5%~10.1%;快速溶剂萃取较微波萃取有更好的重复性和回收率,微波萃取更适用于大批量样品的快速测定。     

全自动石墨消解原子吸收法测定土壤中的Pb

建立了用硝酸-氢氟酸-高氯酸体系全自动石墨原子吸收分光光度法测定土壤中的Pb的分析方法。土壤中Pb的检出限可达0.07 mg/kg,线性相关系数为0.9998,加标回收率为92.8%~98.4%。所建立的方法安全、快速、简单、灵敏度高、重现性好,是同时大批量分析土壤中Pb含量的可靠高效方法。     

桂西北地区木豆的引种试验及生态经济效益

为了使桂西北地区的荒山坡地尽快育林封山,提高其经济和生态效益,文章对引种木豆进行了试验分析和评价,其经济和生态效益表明：木豆产量最高达1980kg/hm^2,最低为1410kg/hm^2;生物量最高达22980kg/hm^2,最低为18020kg/hm^2;随着种植年份的增加,土壤有机质,全氮,全磷和全钾年均分别增加4.15%-6.30%,3.98%-11.72%,8.96%-19.80%和12.28%-46.43%,土壤的侵蚀量和地表水径流量都显著下降,分别为220.2t/hm^2和167.2m^3/hm^2,径流系数仅为0.010。     

新疆小城镇生活污水生态利用技术模式研究——以鄯善县生活污水生态利用为例

本研究以吐鲁番地区鄯善县氧化塘处理后出水灌溉生态林为案例,分析新疆小城镇生活污水生态利用可行性。选择3个示范点,分别对0.2 m、0.4 m、0.6 m、0.8 m、1.0 m五个深度生态利用前后土壤中有机碳、氨氮、硝酸盐氮、亚硝酸盐氮、盐分等污染物浓度进行监测,研究土壤生态系统对生活污水处理效果。研究结果表明土壤的p H、全盐量、钠离子、氯离子灌溉区较对照区有均有降低,降幅分别为1.9%~6.0%、71.43%~95.71%、97.70%~99.53%、95.76%~98.99%。土壤中的有机质、全氮、全磷含量均较非灌区有所增加,且随土层深度的增加其含量增加量逐渐减少,并呈现稳定趋势。研究区从2008-11月投入使用至今,区域地下水水质无明显变化。     

超声波萃取-气相色谱法测定土壤中酚类化合物

建立了超声波提取-气相色谱法测定土壤中酚类化合物的方法。采用二氯甲烷/正己烷混合液萃取土壤中的酚类化合物,提取液经净化、浓缩后,经气相色谱进行分离测定。通过提取方式、提取时间、检出限、精密度及准确度的测定,结果表明:间歇式提取2次,效果最佳;酚类化合物含量在1.00～100 mg/L范围内线性良好,相关系数为0.996～0.999。以10g土壤样品计,方法检出限为0.01～0.03 mg/kg,相对标准偏差为1.0%～10.2%,土壤标准样品测定结果均在可接受范围内。     

ASD-ICP-MS联合快速测定《土壤环境质量标准》中的金属元素

采用HNO3-HCl-HF-HClO4体系在全自动消解仪消解土壤样品,以50.0μg/L的Rh作内标,用电感耦合等离子体-质谱仪同时测定《土壤环境质量标准》的7种元素Cd、As、Cu、Pb、Cr、Zn、Ni。结果表明,土壤标样的测定值与标准值吻合,各元素对应的检出限和相对标准偏差分别为:Cd:0.002 mg/kg和3.6%,As:0.05 mg/kg和5.5%,Cu:0.10 mg/kg和2.9%,Pb:0.18 mg/kg和4.7%,Cr:0.25 mg/kg和2.2%,Zn:0.40 mg/kg和3.4%,Ni:0.20 mg/kg和3.8%。该方法简便快捷,灵敏度高,重现性好。     

Management strategy impacts on ammonia volatilization from swine manure

Ammonia emitted from manure can have detrimental effects on health, environmental quality, and fertilizer value. The objective of this study was to measure the potential for reduction in ammonia volatilization from swine (Sus scrofa domestica) manure by temperature control, stirring, addition of nitrogen binder (Mohave yucca, Yucca schidigera Roezl ex Ortgies) or urease inhibitor [N-(n-butyl) thiophosphoric triamide (NBPT)], segregation of urine from feces, and pH modification. Swine manure [total solids (TS) = 7.6-11.2%, total Kjeldahl nitrogen (TKN) = 3.3-6.2 g/L, ammonium nitrogen NH(+)(4)-N = 1.0-3.3 g/L] was stored for 24, 48, 72, or 96 h in 2-L polyvinyl chloride vessels. The manure was analyzed to determine pre- and post-storage concentrations of TS and volatile solids (VS), TKN, and NH(+)(4)-N. The concentration of accumulated ammonia N in the vessel headspace (HSAN), post-storage, was measured using grab sample tubes. Headspace NH(3) concentrations were reduced 99.3% by segregation of urine from feces (P < 0.0001). Stirring and NBPT (152 microL/L) increased HSAN concentration (119 and 140%, respectively). Headspace NH(3) concentration increased by 2.7 mg/m(3) for every 1 degree C increase in temperature over 35 degrees C. Slurry NH(+)(4)-N concentrations were reduced by segregation (78.3%) and acidification to pH 5.3 (9.4%), and increased with stirring (4.8%) and increasing temperature (0.06 g/L per 1 degree C increase in temperature over 35 degrees C). Temperature control, urine-feces segregation, and acidification of swine manure are strategies with potential to reduce or slow NH(+)(4)-N formation and NH(3) volatilization.     

Use of constructed wetland systems with Arundo and Sarcocornia for polishing high salinity tannery wastewater

Treatment of tannery wastewater is problematic due to high and variable concentrations of complex pollutants often combined with high salinity levels. Two series of horizontal subsurface flow constructed wetlands (CWs) planted with Arundo donax and Sarcocornia fruticosa were set up after a conventional biological treatment system operating at a tannery site. The aim of the CWs was polishing organics and nitrogen from the high salinity effluent (2.2-6.6?g Cl(-)?L(-1)). Both plant species established and grew well in the CW. Arundo, however, had more vigorous growth and a higher capacity to take up nutrients. The CWs were efficient in removing COD and BOD(5) with removal efficiencies varying between 51 and 80% for COD (inlet: 68-425?mg?L(-1)) and between 53 and 90% for BOD(5) (inlet: 16-220?mg?L(-1)). Mass removal rates were up to 615?kg COD ha(-1)?d(-1) and 363 BOD(5) kg?ha(-1)?d(-1). Removal efficiencies were 40-93% for total P, 31-89% for NH(4)(+) and 41-90% for Total Kjeldahl Nitrogen. CW systems planted with salt tolerant plant species are a promising solution for polishing saline secondary effluent from the tannery industry to levels fulfilling the discharge standards.     

Water quality effects of clearcut harvesting and forest fertilization with best management practices

Nine small (2.5 ha) and four large (70-135 ha) watersheds were instrumented in 1999 to evaluate the effects of silvicultural practices with application of best management practices (BMPs) on stream water quality in East Texas, USA. Two management regimes were implemented in 2002: (i) conventional, with clearcutting, herbicide site preparation, and BMPs and (ii) intensive, which added subsoiling, aerial broadcast fertilization, and an additional herbicide application. Watershed effects were compared with results from a study on the same small watersheds in 1981, in which two combinations of harvesting and mechanical site preparation without BMPs or fertilization were evaluated. Clearcutting with conventional site preparation resulted in increased nitrogen losses on the small watersheds by about 1 additional kg ha(-1) each of total Kjeldahl nitrogen (TKN) and nitrate-nitrogen (NO(3)-N) in 2003. First-year losses were not significantly increased on the large watershed with a conventional site preparation with BMPs. Fertilization resulted in increased runoff losses in 2003 on the intensive small watersheds by an additional 0.77, 2.33, and 0.36 kg ha(-1) for NO(3)-N, TKN, and total phosphorus, respectively. Total loss rates of ammonia nitrogen (NH(4)-N) and NO(3)-N were low overall and accounted for only approximately 7% of the applied N. Mean loss rates from treated watersheds were much lower than rainfall inputs of about 5 kg ha(-1) TKN and NO(3)-N in 2003. Aerial fertilization of the 5-yr-old stand on another large watershed did not increase nutrient losses. Intensive silvicultural practices with BMPs did not significantly impair surface water quality with N and P.     

Effects of Grazing Exclusion on Soil Properties and on Ecosystem Carbon and Nitrogen Storage in a Sandy Rangeland of Inner Mongolia, Northern China

The Horqin sandy rangeland of northern China is a seriously desertified region with a fragile ecology. The sandy alluvial and aeolian sediments have a coarse texture and loose structure and are therefore vulnerable to damage caused by grazing animals and wind erosion. We investigated whether grazing exclusion could enhance ecosystem carbon (C) and nitrogen (N) storage and thereby improve overall soil quality. We compared soil properties, C and N storage in biomass (aboveground and below-ground), and the total and light fraction soil organic matter between adjacent areas with continuous grazing and a 12-year grazing exclosure. The soil silt?+?clay content, organic C, total Kjeldahl N, available N and K, and cation-exchange capacity were significantly (P?相似文献   

MBR工艺处理粮油加工废水的研究

采用MBR(Membrane Bioreactor)工艺对粮油加工废水进行处理发现,污染物的去除是活性污泥和膜截留共同作用的结果,试验中微生物的去除作用占污染物总去除率的62.9%~88.1%,起主要作用。当系统的污泥负荷和容积负荷分别在0.4~0.54 kgCOD/kgMLSS.d之间和3.8~5.0 kgCOD/m3.d之间变化时,系统对COD的去除率在92.5%以上。本试验所用膜的临界膜通量为8~10 L/(m2.h),系统污泥浓度从1~2g/L增加到10~12g/L时,临界膜通量从10~12L/(m2.h)下降到了3~4 L/(m2.h),随着膜面流速从1.0m/s上升到1.8m/s,膜的临界通量也相应的从4~6 L/(m2.h)上升到了16~18 L/(m2.h),呈正相关。     

超声粉碎-TOC/TN仪法直接测定污水处理厂废水中的总氮

污水处理厂废水经超声粉碎后,使用TOC/TN仪直接测定总氮.对仪器条件、进样方式、微波粉碎时间及加标回收率进行了探讨.相对标准偏差＜2.35％,测定结果与国标法一致,相对误差＜±1.3％,回收率为95.3％ ～97.8％.方法简便、快速、准确.     

秸秆还田下氮肥用量对玉米产量及土壤无机氮的影响

研究连续2年秸秆还田下氮肥用量对玉米产量、氮肥利用率及土壤硝态氮的影响,结果表明,玉米产量随着施氮量的增加逐渐增加,施氮量达到216 kg·hm^-2时,产量最高,施氮量超过216 kg·hm^-2时产量有降低的趋势。相同施氮处理玉米产量年际变化明显,2010年较2009年产量提高0.69％~4.75％。氮肥利用率、氮肥农学利用率和氮收获指数随着秸秆还田年限的增加,均有不同程度的增加。2年0~100 cm土层土壤硝态氮含量均以施氮240 kg·hm^-2最高,且有向土壤深层迁移的趋势,对浅层地下水构成潜在的威胁。与施氮240 kg·hm^-2相比,施氮168、192 kg·hm^-2和216 kg·hm^-2处理0~100 cm土壤无机氮残留量2年平均减少39.87％、35.84％和29.38％。相同施氮处理,0~100 cm土壤无机氮累积量2010年较2009年略有降低。综合考虑玉米产量、氮肥利用率与生态环境效益,该地区最适施氮量200 kg·hm^-2左右。     

Regional inventory of soil surface nitrogen balances in Indian agriculture (2000-2001)

Nitrogen regulates several ecological and biogeochemical processes and excess reactive nitrogen in the environment can lead to pollution problems, including the deterioration of air quality, disruption of forest processes, acidification of lakes and streams, and degradation of coastal waters. Much of the excess nitrogen inputs are related to food and energy production. An important step to understanding the sources of nitrogen and ultimately defining solutions to excess nitrogen is to describe the geographic distribution of agricultural nitrogen contributions from different regions. In this study, soil surface nitrogen loads were quantified for different states of India for the period 2000-2001. Nearly 35.4 Tg of nitrogen has been estimated as inputs from different sources, with output nitrogen from harvested crops of about 21.20 Tg. The soil surface nitrogen balance, estimated as inputs minus outputs, is found to be about 14.4 Tg surplus from the agricultural land of India. Livestock manure constituted a major percentage of total inputs (44.06%), followed by inorganic fertilizer (32.48%), atmospheric deposition (11.86%) and nitrogen fixation (11.58%). Nitrogen balance varied from deficit to surplus for different states. The highest nitrogen surplus was found in Uttar Pradesh (2.50 Tg) followed by Madhya Pradesh (1.83 Tg), Andhra Pradesh (1.79 Tg), etc. A negative nitrogen balance was found in Orissa (-0.01 Tg), Andaman Nicobar Islands (-0.32 Tg) and for some of the northeastern states. Major fertilizer consumption states were found to be Tamilnadu (204 kg/ha), Haryana (132 kg/ha), Punjab (148 kg/ha), followed by others. Similarly, nitrogen inputs from total livestock excretions were found to be high for Kerala (616 kg/ha), Jammu and Kashmir (389 kg/ha), Tamil Nadu (338 kg/ha), etc. The average nitrogen surplus of about 54 kg/ha observed for the agricultural land of the entire country of India is comparatively higher than the average surplus of about 31 kg/ha reported for European countries. These results, obtained from nutrient mass balance calculations, will be useful to formulate nutrient management plans relating to fertilizer usage, livestock management and for adopting some best management strategies at a state level in India.     

真空采血管顶空气相色谱法检测水中三氯甲烷、四氯化碳

采用真空采血管顶空填充柱气相色谱法测定水中三氯甲烷和四氯化碳,结果表明,三氯甲烷在10.0～50.0μg/L,四氯化碳在0.5～4.0μg/L浓度范围内呈良好线性关系,其r值分别为0.9994和0.9998;三氯甲烷和四氯化碳RSD分别在1.64%~2.27%和1.45%~2.40%之间;加标回收率分别在97.0%~103.5%和94.0%~103.2%之间。该方法操作简单,具有较好的灵敏度和准确度,适用于水中三氯甲烷和四氯化碳的检测。