The impact of land use on riparian soil dissolved organic matter and on streamwater quality on Chongming Island,China

Riparian wetland controls the transfer of terrestrial dissolved organic matter (DOM) to surface water bodies. However, the effects of land use on riparian soil DOM quality and its contribution to aquatic environment are largely unknown. In this study, the amount and composition of water-extracted soil organic matter (WSOM) in riparian wetlands were determined to evaluate the effect of land uses on spatial patterns of WSOM and streamwater quality on Chongming Island, China. The fluorescent properties of WSOM and fluvial DOM were analyzed using EEM spectra-combining PARAFAC model and accurate MS and MS/MS identification. Our findings showed no differences in the riparian WSOC contents between land use types (agricultural land, natural wetland, commercial land and industrial land). However, the fluorescent WSOM and its humic-like (Comp.1 and Comp.2) and microbial degradation (Comp.4) components significantly varied under different land uses (P < 0.05). Overall, the fluorescent WSOM quantities and its components (Comp.1, Comp.2 and Comp.4) were present at markedly lower concentrations for agricultural land use relative to the other three land uses. The same distribution pattern was observed for carbonyl compounds and fatty acids in the riparian WSOM molecules (P < 0.05), but the distribution patterns of the lipids were different between the four land uses (P < 0.05). Industrial land could result in the input of more organic matter into the riparian wetland. Our results showed that fluvial Comp.1 and Comp.2 were significantly correlated with WSOM Comp.2 and WSOM Comp.4 (P < 0.05). We also observed that the fluvial trophic status was significantly higher when the fluvial DOM components increased (P < 0.05). These results indicated that land uses can alter the composition of riparian WSOM, reshape fluvial DOM compositions and significantly affect fluvial water quality.     

用陶土吸附处理含镍废水的研究

进行了用陶土吸附处理模拟含Ｎｉ＾２＋废水的研究,探讨了陶土用量,吸附时间、废水酸度,废水中Ｎｉ＾２＋的初始浓度及吸附温度对镍去除率的影响,并用实际含镍废水进行了验证。     

铁路隧道地下水环境动态监测体系的探讨与实践

铁路隧道排放地下水对隧道区域生态环境和人居环境的影响日益受到重视。在阐述监测等级、监测范围、监测对象和方法等的基础上,探讨了铁路隧道地下水环境动态监测体系,并在国内某货运铁路进行了系统实践。通过对48座隧道143处监控点位近3个水文年的系统监测,发现了34处隧道施工造成的失水水源点位;以典型隧道为例,总结说明黄土丘陵地区、基岩山区和岩溶地区监测结果,并讨论监测体系应用效果。     

基于模糊综合评判的汶川8.0级地震重灾区滑坡泥石流气候风险评估

用1971-2000年的30年逐日降水量资料,按旬统计汶川地震重灾县5-12月各旬的雨日、中雨日、大雨日、暴雨日的平均日数和气候概率,根据地震重灾区实际地质环境条件,降低强降雨强度条件,基于模糊综合评判法,按照最大隶属度原则对汶川特大地震重灾区的39个县进行地质灾害时空气候风险评估。结果表明:重灾区的地质灾害气候风险指数值存在两个高值期间,一个是5月中旬至7月上旬,另一个是8月下旬至9月下旬。而10月下旬至次年4月,重灾区降雨明显减少,绝大部分地区没有地质灾害气候风险;从地域分布来看,高风险区域主要集中在重灾区的西部和中部,风险等级为3～4级(风险较大或很大),东部地区风险等级为1～2级(中等风险或风险较小),但7月下旬高等级风险区位置集中在重灾区的南部和东部。     

高速泳动床对村镇微污染水体的预处理效果

利用高速泳动床反应器作为预处理装置处理村镇微污染水体,出水进入组合人工湿地。结果表明,实验阶段高速泳动床在HRT为1.2 h时,尽管泳动床进水各污染物浓度较低,但反应器对COD、TN和TP仍具有较明显(P<0.05)的去除效果,平均去除率分别为11.3%、14.6%和25.8%。高速泳动床反应器对氨氮去除效果尤为明显,去除率达到46.9%。此外,高速泳动床反应器内硝化作用较强,出水中硝态氮含量平均增加率为45.5%,弥补了后续人工湿地硝化作用不强、除氨氮效果不佳的缺点。     

The Vegetation Coverage Dynamic Coupling with Climatic Factors in Northeast China Transect

Based on SPOT-VGT images and meteorological data, this paper applied an integrated method to investigate the vegetation dynamic and its response to climate factors during 1998-2008 in Northeast China Transect, one of 15 ecological transects listed in the International Geosphere-Biosphere Programme. The main findings are as follows: (1) The NDVI time series presented nonlinear patterns that vary with timescales. The series fluctuated greatly at the smallest timescale (20?days), showing no salient trend, whereas a trend manifested itself more and more with the increase of time scale and finally stabilized at the 320-day scale. Little difference was found between vegetation types about the NDVI periodicity, as they occurred on either a 280-day or a 290-day cycle. (2) NDVI exhibited a significant correlation with temperature, precipitation, and sunshine hours. Overall, the correlation between NDVI and temperature was the highest, followed by precipitation, sunshine hours, and relative humidity. For different vegetation types, the correlations between NDVI and climate variables diversified, increasing from desert steppe to typical steppe, meadow steppe, and forest. (3) The periodicity of temperature and precipitation occurred in either a 280-day or 290-day cycle, which was approximately coincident with that of NDVI. This further supported the significant relationship between NDVI and these two climate factors. (4) At all the time scales under examination, NDVI and temperature and precipitation are significantly, positively correlated, especially at the 160-day scale, which can be regarded as the most suitable time scale for investigating the responses of vegetation dynamics to climate factors at most stations.     

热等离子体喷枪在垃圾焚烧飞灰处理中的应用

采用了一种自行设计的具有二路进气双阳极特殊结构的热等离子体喷枪作为等离子体发生装置,通过等离子体电弧电压电流诊断系统测量直流氩等离子体射流的工作情况,对其工作特性进行了分析,并探讨了电弧电压在不同工作模式下随工作气体流量变化的趋势及机制。对二路进气下电弧电压信号进行傅里叶变换,发现高频脉动基本消失,而给阳极Ⅱ供电的电源Ⅱ可能存在150 Hz的固有波动。采用热等离子体喷枪对当地垃圾电厂的飞灰进行处理,其熔渣的微观结构紧密光滑且无空隙,这与熔融前的飞灰区别明显。该熔渣对重金属有很好的固定效果,经熔融处理后,Cd、Cr、Ni、Pb浸出浓度已无法检出。Cu、Zn在熔渣中浸出质量浓度为0.13、0.30 mg/L,其重金属浸出浓度远远低于熔融前。结果显示,该热等离子技术是一种处理垃圾焚烧飞灰的有效手段。     

聚丙烯酰胺-锂藻土复合水凝胶吸附处理模拟印染废水

通过自由基原位聚合方法制备了聚丙烯酰胺(PAM)-锂藻土(XLG)复合水凝胶。将此复合水凝胶用于处理碱性品红印染废水,吸附脱色效果良好。实验结果表明:蒸馏水加入量为8.5mL的条件下,XLG和AM的最佳加入量分别为0.6g和1.0g;在废水质量浓度为25m g/L的条件下,废水pH由7.5降至3.0时,PAM-XLG复合水凝胶对碱性品红染料的吸附量由23.77m g/g降至12.67m g/g;废水温度由30℃升高至60℃时,PAM-XLG复合水凝胶对碱性品红染料的吸附量由20.76m g/g增至22.60m g/g。     

高速泳动床对村镇微污染水体的预处理效果

利用高速泳动床反应器作为预处理装置处理村镇微污染水体,出水进入组合人工湿地。结果表明,实验阶段高速泳动床在HRT为1.2 h时,尽管泳动床进水各污染物浓度较低,但反应器对COD、TN和TP仍具有较明显（P〈0.05）的去除效果,平均去除率分别为11.3%、14.6%和25.8%。高速泳动床反应器对氨氮去除效果尤为明显,去除率达到46.9%。此外,高速泳动床反应器内硝化作用较强,出水中硝态氮含量平均增加率为45.5%,弥补了后续人工湿地硝化作用不强、除氨氮效果不佳的缺点。     

复合混凝法处理高浓度聚丙烯酰胺生产废水

采用聚合氯化铝(PAC)混凝和活性炭吸附的复合混凝法处理高浓度聚丙烯酰胺(PAM)生产废水.实验结果表明,最佳处理条件为:废水 pH 6.5,废水温度 35℃,先加入 PAC 混凝后再加入活性炭,PAC 加入量250 mg/L,活性炭加入量 200 mg/L.在此最佳条件下,废水 COD 去除率达 52.0%.该复合混...