Significance of dredging on sediment denitrification in Meiliang Bay, China： A year long simulation study

An experiment for studying the effects of sediment dredging on denitrification in sediments was carried out through a one-year incubation of undredged (control) and dredged cores in laboratory. Dredging the upper 30 cm of sediment can significantly affect physico-chemical characteristics of sediments. Less degradation of organic matter in the dredged sediments was found during the experiment. Denitrification rates in the sediments were estimated by the acetylene blockage technique, and ranged from 21.6 to 102.7 nmol N2/(g dry weight (dw)·hr) for the undredged sediment and from 6.9 to 26.9 nmol N2/(g dw·hr) for dredged sediments. The denitrification rates in the undredged sediments were markedly higher (p0.05) than those in the dredged sediments throughout the incubation, with the exception of February 2006. The importance of various environmental factors on denitrification was assessed, which indicated that denitrification was regulated by temperature. Nitrate was probably the key factor limiting denitrification in both undredged and dredged sediments. Organic carbon played some role in determining the denitrification rates in the dredged sediments, but not in the undredged sediments. Sediment dredging influenced the mineralization of organic matter and denitrification in the sediment; and therefore changed the pattern of inherent cycling of nitrogen.     

垃圾渗滤液处理技术

垃圾渗滤液是垃圾填埋过程中产生的高浓度有机废水,是垃圾填埋过程中产生二次污染的主要因素之一,对水体、土壤、大气和生物都有不同程度的影响,是国内外污水处理的一大难题;综述垃圾渗滤液的四大水质特性并总结了近年来在垃圾渗滤液的预处理、主体工艺及深度处理技术上的研究进展,包括普通的物化预处理和常见的生化主体工艺以及近年来发展迅速的高级氧化技术、膜分离等深度处理工艺;最后为垃圾渗滤液处理技术的发展提出建议和未来研究方向。     

台州大桥施工工期的风险研究

施工工期的风险是导致工程延误,造成项目进度、质量和投资目标失控的重要原因之一。本文以台州大桥为分析对象,通过风险核查表对施工风险因素进行辨识,运用网络计划技术分析了施工工期风险的概率,并根据施工工期的风险因素情况给出相应的风险对策,达到降低工程风险损失的目的。     

运用模糊层次分析法评价关键装置要害部位

针对目前关键装置要害部位的安全技术报告中只进行定性评估的不足,运用模糊层次分析法对催化裂化装置进行了评价,评价结果对改进关键装置要害部位安全管理提供了决策依据.     

吹扫捕集-气相色谱-质谱法测定水中环氧氯丙烷的不确定度评定

依照《测量不确定度评定与表示》,对吹扫捕集-气相色谱-质谱法测定水中环氧氯丙烷的结果进行不确定度评定。通过评定可知标准曲线配制过程所引入的相对不确定度最大,吹扫捕集-气相色谱-质谱法测定模拟水样中环氧氯丙烷结果为（78±21）μg/L。     

中国能源煤化工基地循环经济发展研究

能源煤化工基地由煤矿开采、燃煤发电、煤化工和建材四大主导产业组成,各个主导产业之间的产品、原料、能量、废弃物在一定程度上可以在行业内部或基地内部循环利用,达到节能、降耗、低碳、绿色的目的。本文构建了能源煤化工基地的循环经济框架,并针对各主导行业提出了发展循环经济的途径。     

辉光放电等离子体处理印染废水的实验研究

用辉光放电等离子体技术印染废水降解进行了研究,通过测定CODcr、BOD和pH值的变化初步探讨了降解机理。结果表明:在辉光放电降解印染废水的过程中,发现仅是采用辉光放电水处理技术时,因为过氧化氢的生成导致废水CODcr有一定的升高,而废水的BOD几乎没有变化,说明辉光放电对印染废水几乎没有降解效果;而在亚铁离子的加入后,印染废水出现明显的降解效果,当亚铁离子加入量为50 mg时,印染废水的CODcr和BOD的去除率分别为41.2%和46.2%,降解率得到了很大的提高。     

Photocatalytic degradation kinetics and mechanism of pentachlorophenol based on superoxide radicals

Pentachlorophenol could be photocatalytically reduced with superoxide radicals in aqueous solution under simulated sunlight irradiation.     

Atmospheric carbonyls in a heavy ozone pollution episode at a metropolis in Southwest China: Characteristics, health risk assessment, sources analysis

Ambient carbonyls were continuously observed in the field during a heavy ozone pollution episode in Chengdu, China from August 4 to August 19, 2019, and the pollution characteristics, atmospheric photochemical reactivity, human health risk, and sources of carbonyls were analyzed. Fifteen carbonyls were quantified with average total mixing ratios of 20.38 ppbv Formaldehyde(9.86 ppbv), acetone(4.41 ppbv), and acetaldehyde(3.57 ppbv) were the three most abundant carbonyls. During the heavy ozone po...     

改良剂对土壤Sb赋存形态和生物可给性的影响

采用室内土壤培养法研究不同改良剂(骨炭、生物调理剂、沸石、石灰、油菜秸秆、生物炭、堆肥和赤泥)对土壤Sb化学形态转化和生物可给性的影响.结果表明,除堆肥处理外,添加5%的其他7种改良剂均显著地提高了土壤的p H值,其中石灰处理p H最为明显.BCR分级提取表明,土壤Sb主要以残渣态形式存在.添加生石灰、骨炭和生物调理剂显著地提高了土壤Sb的移动性,而添加赤泥、生物炭和堆肥却显著地降低了土壤Sb的移动性.添加不同的改良剂对土壤Sb的生物可给性也有影响,但是受不同培养时间影响较大.培养2个月后,添加5%的堆肥、5%赤泥和5%生物炭处理导致土壤Sb的生物可给性含量分别比对照降低38%、23%和20%;而添加5%的石灰、5%油菜秸秆和5%的生物调理剂处理导致土壤Sb的生物可给性含量分别比对照提高1.07倍、1.06倍和1.11倍.堆肥、赤泥和生物炭是钝化Sb污染土壤的潜力材料.