非烃和沥青质热模拟生烃研究

为弄清楚非烃 +沥青质热演化过程中的生烃情况 ,对未熟非烃 +沥青质进行了低温模拟生烃实验 ,实验结果表明非烃 +沥青质在低温条件下 (<2 5 0℃ )生成烃类气体量很少 ,主要以生成液态烃为主 ,液态烃转化率最高可达 388mg/g ,所生成的液态烃表现出明显的奇碳优势 ,为未熟 低熟油。原始母质类型不同的非烃+沥青质模拟产物特征有所不同。非烃 +沥青质对未熟 低熟油的生成有重要意义。     

AHP与模糊评判法在垃圾填埋场选址中的应用对比

以对比研究层次分析法和模糊评判法在垃圾填埋场选址中的应用特征,并探究两者综合应用的可能性为目的,以自然地理、地质环境、工程地质条件及环境保护为评价标准,对广州市4个拟建填埋场进行了适宜性评价。在层次分析法确定的权重值的基础上,利用模糊评判法进行计算,最终确定兴丰填埋场为最佳场地,评价结果与实际应用情况相符。另外,通过对比分析发现,在参数选择与定量化方面,模糊评判法评价结果的准确性更高,而层次分析法的计算工作量较少;在评判结果的适用性方面,层次分析法的评判结果与实际相符性程度更高。研究表明,两种方法结合起来应用于垃圾填埋场的选址是可行的,且可提高评判结果的准确度。     

新生MnO2对水中活性艳红K-2G的脱色作用研究

以化学法合成的新生MnO2作吸附剂，对水中活性艳红K－2G进行吸附脱色研究，探讨了影响吸附的因素和吸附机理，结果表明：新生MnO2对活性艳红K－2G的吸附符合Langmuir吸附等温式，吸附前溶液pH值是影响染料脱色效果的最主要因素，染料浓度，MnO2投加量和温度影响程度较小，在实验条件下可使活性艳红K－2G的脱色率高达96％。     

Effects of surfactants on graphene oxide nanoparticles transport in saturated porous media

Transport behaviors of graphene oxide nanoparticles (GONPs) in saturated porous media were examined as a function of the presence and concentration of anionic surfactant (SDBS) and non-ionic surfactant (Triton X-100) under different ionic strength (IS). The results showed that the GONPs were retained obviously in the sand columns at both IS of 50 and 200 mmol/L, and they were more mobile at lower IS. The presence and concentration of surfactants could enhance the GONP transport, particularly as observed at higher IS. It was interesting to see that the GONP transport was surfactant type dependent, and SDBS was more effective to facilitate GONP transport than Triton X-100 in our experimental conditions. The advection–dispersion–retention numerical modeling followed this trend and depicted the difference quantitatively. Derjaguin–Landau–Verwey–Overbeek (DLVO) interaction calculations also were performed to interpret these effects, indicating that secondary minimum deposition was critical in this study.     

Historical records of polycyclic aromatic hydrocarbon deposition in a shallow eutrophic lake: Impacts of sources and sedimentological conditions

Sediment core samples collected from Lake Chaohu were analyzed for 15 priority polycyclic aromatic hydrocarbons(PAHs)to assess the spatial and temporal distributions of the PAHs during lacustrine sedimentary processes and regional economic development.Assessing the PAH sedimentary records over an approximately 100-year time span,we identified two stages in the PAH inputs and sources(before the 1970 s and after the 1970s)in the eastern lake region near a village,whereas three stages(before the 1950 s,1950s–1990s and after the1990s)were identified in the western lake region near urban and industrial areas.Rapid increases in the PAH depositional fluxes occurred during the second stage due to increased human activities in the Lake Chaohu basin.The composition and isomeric ratios of the PAHs revealed that pyrolysis is the main source of PAHs in this lake.Strong positive relationships between PAH concentration and the total organic carbon concentration,sediment grain size( 4 μm),as well as the local population and Gross Domestic Product indicated that the sedimentary conditions impact the depositional characteristics of the PAHs;simultaneously,socioeconomic activities,such as energy consumption and the levels of urban industrialization and civilization,affect both the composition and abundance of the PAHs.     

污水生物除磷若干影响因素分析

在系统阐述污水生物除磷机理的基础上,深入分析了微生物群体平衡、城市污水水质、环境因子以及工艺运行参数和运行方式等方面对生物除磷效果的影响.分析结果表明:生物除磷系统的溶解氧浓度不宜太高,一般好氧区DO＜2 mg/L,厌氧区DO＜0.2 mg/L;厌氧段存在硝酸盐对生物释磷有负面影响,缺氧段存在一定浓度的硝酸盐有利于生物聚磷;碳源必须充分、易降解;TKN/COD＜0.1的城市污水有利于生物除磷;pH偏碱性可提高生物除磷效率;低温对生物除磷效果影响不明显.     

超临界二氧化碳萃取环境样品中金属离子的研究进展

原位络合的超临界萃取技术开辟了超临界二氧化碳（ＳＣ－ＣＯ２）萃取金属离子的新途径。本文综述国外有关ＳＣ－ＣＯ２萃取环境样品中金属离子的原理、流程、应用及影响因素等方面的研究进展,并相信随着研究工作的不断深入,更加理想的络合剂和ＳＣ－ＣＯ２携带剂的发现,必将使ＳＣ－ＣＯ２萃取金属离子的技术在环境样品中痕量金属离子的前处理和分析以及有害金属离子的处理等方面的应用前景更为广阔     

Current status of municipal wastewater treatment plants in North-east China: implications for reforming and upgrading

● The performance and costs of 20 municipal WWTPs were analyzed. ● Effluent COD and NH₄⁺-N effluent exceed the limits more frequently in winter. ● Nitrification and refractory pollutant removal are limited at low temperatures. ● To meet the national standards, electricity cost must increase by > 42% in winter. ● Anammox, granular sludge, and aerobic denitrification are promising technologies. Climate affects the natural landscape, the economic productivity of societies, and the lifestyles of its inhabitants. It also influences municipal wastewater treatment. Biological processes are widely employed in municipal wastewater treatment plants (WWTPs), and the prolonged cold conditions brought by the winter months each year pose obstacles to meeting the national standards in relatively cold regions. Therefore, both a systematic analysis of existing technical bottlenecks as well as promising novel technologies are urgently needed for these cold regions. Taking North-east China as a case, this review studied and analyzed the main challenges affecting 20 municipal WWTPs. Moreover, we outlined the currently employed strategies and research issues pertaining to low temperature conditions. Low temperatures have been found to reduce the metabolism of microbes by 58% or more, thereby leading to chemical oxygen demand (COD) and NH₄⁺-N levels that have frequently exceeded the national standard during the winter months. Furthermore, the extracellular matrix tends to lead to activated sludge bulking issues. Widely employed strategies to combat these issues include increasing the aeration intensity, reflux volume, and flocculant addition; however, these strategies increase electricity consumption by > 42% in the winter months. Internationally, the processes of anaerobic ammonium oxidation (anammox), granular sludge, and aerobic denitrification have become the focus of research for overcoming low temperature. These have inspired us to review and propose directions for the further development of novel technologies suitable for cold regions, thereby overcoming the issues inherent in traditional processes that have failed to meet the presently reformed WWTP requirements.     

磷矿山清洁生产评价指标权重最优设计研究

如何科学、准确地确定磷矿山清洁生产评价中各评价指标权重对磷矿山清洁生产评价具有极其重要的意义。因此,为了避免评价结果出现误差,本文通过对行业专家咨询调整不同准则层(或可调整的指标层)中指标所占的权重来确定最优化生产成本,实现集约生产,实现磷矿山企业利润最大化。这一设计方案的提出可为中国清洁生产水平进行准确的评价提供参考。     

场地土壤重金属镉和铅复合污染毒性阈值的推导及其应用

镉(Cd)和铅(Pb)是生物体非必要元素,具有毒性大、迁移性强等特点,二者在场地土壤中通常存在复合污染的现象.土壤污染物预测无效应浓度(predicted no effect concentration,PNEC)是污染物自身毒性与不确定性系数共同决定的参数,其中土壤污染物的生物有效性是PNEC值不确定性的重要来源.本研究选择湖南常宁某铜矿冶炼厂和江苏靖江某电镀厂2个不同类型的污染场地及周边土壤,基于土壤理化性质及重金属的有效性浓度,采用经验模型估算出Cd和Pb单一污染对植物根系生长的半效应浓度(median effect concentration,EC50)及其土壤中的PNEC,通过浓度加和(concentration addition,CA)模型,结合外推因子法,估算获得场地土壤实际Cd和Pb复合污染的预测无效应浓度(PNEC面x).结果 表明,2个场地土壤中Cd的平均含量分别为背景值的102倍和37.6倍,Pb平均含量分别为背景值的15.1倍和3.86倍,Cd和Pb复合污染现象明显.由于2个场地土壤性质差异较大,Cd和Pb的EC50存在较大差异,EC50(Cd)分别为19.1 ～36.2 mg·kg-1和20.1 ～ 35.4 mg· kg-1,而EC50(Pb)分别为366～1891 mg·kg-1和682～1575 mg·kg-1.同时由于场地实际污染土壤的理化性质及Pb/Cd含量比不同,所推导的PNECmix也存在明显差异,Cd含量及其在Cd和Pb总量中的占比较高的土壤样点的PNECmix较低,2个场地的PNECmix分别为0.933～37.9 mg·kg-1和32.9 ～ 744 mg· kg-1.2个场地调查样点中Cd和Pb含量的实测值均在一定程度上高于相应的PNECmix,对植物生长存在一定的生态风险.因此,进行复合污染生态风险基准值制定和生态风险评价时,需要考虑影响污染物的生物有效性和关键场地特异性(site-specific)因素,如土壤理化性质及不同污染物浓度比等.