螺蚌和沉水植物搭配对微污染水体的净化作用

通过开展单植不同种类沉水植物及"不同种类的沉水植物+螺蚌"组合搭配对微污染水体的净化能力对比研究,寻求系统稳定性最好、水质净化最佳的组合。2013年8月至2014年3月间的水箱小试研究结果表明,"铜锈环棱螺+椭圆背角无齿蚌+轮叶黑藻+篦齿眼子菜"组合的水质净化作用最佳,对CO D、TN、TP去除率分别为58.79%、64.30%和88.57%,对浮游生物的抑制效果最明显,水箱里基本无水绵及浮萍生长,轮叶黑藻长势较篦齿眼子菜好、生长逐渐占优势。2014年5月-8月的中试研究进一步验证水箱小试的结论,COD、TN和TP的平均去除率分别为57.93%、60.12%和49.28%,轮叶黑藻长势更好。     

2种启动方式下CSTR厌氧甲烷发酵系统的运行特性比较

厌氧产甲烷菌生长缓慢,对生境环境尤为敏感,其富集难且慢,所以厌氧反应器的快速启动一直是热点研究问题。为摸清连续流搅拌槽式反应器（CSTR）处理糖蜜废水的适宜启动条件和调控方法,比较了两种启动方式下CSTR厌氧甲烷发酵系统的运行特性。结果显示,以啤酒废水污水处理车间的剩余污泥为种泥,在HRT为18 h、温度35℃条件下,进水COD为4 000 mg·L-1时直接启动CSTR厌氧反应器,系统因挥发酸积累,产甲烷菌群活性受限,难以富集培养,经过近103 d的运行,系统未形成高效的厌氧甲烷发酵微生物菌群结构体系;而当采用保持HRT18 h不变,进水COD阶段性提升至4 000 mg·L-1的启动方式时,产甲烷菌群活性较高,能在较短时间内得到有效富集和培养,CSTR能成功培养具有完整甲烷发酵功能的微生物菌,COD去除率可在65 d内达到56%,反应器成功启动。     

载镧酒糟污泥生物炭对磷的吸附性能及机理

为实现市政污泥的无害化和资源化利用,以酒糟和市政污泥为原料热解制备酒糟污泥生物炭(LBC_Z),采用共沉淀法将镧(La)负载到LBC_Z表面制得La改性酒糟污泥生物炭(La-LBC_Z),探究了改性剂浓度、La-LBC_Z投加量、溶液初始pH和共存离子对La-LBC_Z吸附磷的影响,使用SEM-EDS、BET、XRD、FTIR和XPS等表征手段分析了吸附机理。结果表明：改性剂浓度为0.1 mol·L⁻¹时La-LBC_Z对磷的吸附效果最好(吸附量为68.32 mg·g⁻¹),为改性前的6倍;吸附过程符合准二级动力学模型和Langmuir模型,为单分子层表面的化学吸附。此外,生物炭孔隙结构不发达,La以氢氧化物形态负载到生物炭表面,络合反应是其主要的吸附机理。在吸附-脱附实验中,La-LBC_Z经过5次循环后吸附量为61.2 mg·g⁻¹,吸附率为87.79%,脱附量为52.65 mg·g⁻¹,脱附率为75.52%,说明其具有良好的循环性能和磷回收性能。     

Simultaneous removal of COD and ammonium from landfill leachate using an anaerobic-aerobic moving-bed biofilm reactor system

The performance of a moving-bed biofilm reactor (MBBR) system with an anaerobic-aerobic arrangement was investigated to treat landfill leachate for simultaneous removal of COD and ammonium. It was found that the anaerobic MBBR played a major role in COD removal due to methanogenesis, and the aerobic MBBR acted as COD-polishing and ammonium removal step. The contribution of the anaerobic MBBR to total COD removal efficiency reached 91% at an organic loading rate (OLR) of 4.08 kgCOD/(m3d), and gradually decreased to 86% when feed OLR was increased to 15.70 kgCOD/(m3d). Because of the complementary function of the aerobic reactor, the total COD removal efficiency of the system had a slight decrease from 94% to 92% even though the feed OLR was increased from 4.08 to 15.70 kgCOD/(m3d). Hydraulic retention time (HRT) had a significant effect on NH+4-N removal; more than 97% of the total NH+4-N removal efficiency could be achieved when the HRT of the aerobic MBBR was more than 1.25 days. The anaerobic-aerobic system had a strong tolerance to shock loading. A decrease in COD removal efficiency of only 7% was observed when the OLR was increased by four times and shock duration was 24 h, and the system could recover the original removal efficiency in 3 days. The average sludge yield of the anaerobic reactor was estimated to be 0.0538 gVSS/gCOD rem.     

Reduced biodegradation of benzonitrile in soil containing wheat-residue-derived ash

Burning of crop residues is a common agricultural practice that incorporates the resulting particulate matter (ash) of high adsorptivity into soils. To investigate the effect of ash on the biodegradation of pesticides in soils, we measured the sorption, desorption, and biodegradation of benzonitrile in a silt loam in the presence and absence of an ash resulting from burning of wheat (Triticum aestivum L.) residue. Biodegradation experiments were conducted by inoculating sorbent slurries with a pure culture of benzonitrile-degrading bacteria (Nocardia sp.). Both liquid- and sorbed-phase benzonitrile concentrations were quantified over time. The ash was approximately 2000 times more effective per unit mass than the soil in sorbing benzonitrile. Amendment of the soil with 1% ash (by weight) resulted in a 10-fold increase in sorption. Sorption of benzonitrile by the ash significantly decreased the solution-phase concentration in the slurries of ash and ash-amended soil. Desorption of benzonitrile from the ash required approximately 60 min to complete, whereas approximately 20 min were required for desorption from the soil. Benzonitrile in the extracts of various sorbents and soil slurry was completely degraded within 500 min. However, the degradation was substantially reduced in the presence of the ash. At 2000 min, only 20% of benzonitrile in ash slurry and only 44% in ash-amended soil slurry were degraded. An acclimation period of approximately 100 min was observed in extracts and slurries containing the ash. Substantial reduction in the biodegradation of benzonitrile in the presence of wheat ash was apparently due to sorption of benzonitrile by the ash, slow desorption from the ash, and the increased acclimation period. Our results suggest that the presence of crop-residue-derived ash may increase the persistence of pesticides in agricultural soils.     

天津市近岸海域秋季浮游动物群落结构与环境因子相关性

浮游动物对海洋生态系统结构平衡起着重要的调节作用。为研究天津市近岸海域浮游动物分布及其与环境因子的关系,于2020年9月在天津市近岸海域设置16个采样点开展调查,采用生物多样性指数评价方法对浮游动物多样性进行评价,利用冗余分析法（RDA）和主成分分析法（PCA）分别对浮游动物多样性与水环境因子之间的关系以及天津市近岸海域主要水环境影响因子进行分析。结果表明：天津市近岸海域共监测到浮游动物18种,桡足类为主要类群,占浮游动物类群总量的50%;物种数量占比较多的为桡足类幼体（Copepodite larva）、近缘大眼剑水蚤（Corycaeus affinis）和桡足类无节幼虫〔Nauplius larva （Copepoda）〕;浮游动物Margalef丰富度指数（D）、Pielou均匀度指数（J）、Simpson优势度指数（C）和Shannon-Wiener多样性指数（H′）分别为1.37、0.71、0.36和1.31;RDA分析表明,悬浮物（SS）浓度与总生物量、D、J、H′均呈负相关,活性磷酸盐浓度与J、H'呈正相关,pH、盐度与C呈负相关,Chla、NH₄ ⁺-N浓度与C、J呈正相关,DO浓度与C、总生物量呈负相关,石油类浓度与C呈负相关;PCA分析显示,SS、Chla和NH₄ ⁺-N浓度是影响浮游动物多样性分布的主要因子。

     

Polybrominated diphenyl ethers in surface sediments of the Yangtze River Delta: Levels, distribution and potential hydrodynamic influence

A total of 32 surface sediments collected from the Yangtze River Estuary, Hangzhou Bay and the Qiantang River were analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of summation operatorPBDEs (sum of 12 PBDE congeners without BDE 209) and BDE 209 varied from n.d. to 0.55 and from 0.16 to 94.6 ng/g, respectively. The spatial variability of summation operatorPBDEs concentrations indicated that waste discharge from the urban areas might been the main source of PBDEs in the Yangtze River Delta. BDE 209 was the predominant congener (approximately 90-100%) detected among the 13 congeners, consistent with the fact that technical deca-BDE mixtures are presently the dominant technical PBDE mixtures used in China. Compared to published data acquired from other locales, PBDE congeners with less than four bromines were more abundant in the present study area. The hydrodynamic conditions may likely be a significant factor in dictating the observed levels and congener distribution patterns of PBDEs.     

安徽地震活动期的划分与地震活动趋势的研究

20世纪以来安徽与中国大陆地震活动呈同步活跃关系。本文对安徽的地震活动周期进行了划分 ,并用综合统计分析方法进行安徽未来地震活动趋势研究 ,结果表明 :安徽目前正处在一个相对较弱的地震活动期 ,该活动期约在 2 0 0 6年前后结束 ,估计发生地震的最大震级为 5级左右 ,可能主要是 4～ 5级地震活动。     

丹江口水源区水生态功能一二级分区研究

水生态功能分区是实现流域水环境"分区、分级、分类、分期"管理的基础。以高程、干燥度及年均径流深为一级分区指标,土地利用、土壤类型、坡度、人均GDP为二级分区指标,将丹江口水源区分为6个一级水生态功能区和19个二级水生态功能区。比较不同分区的水生境状况及底栖动物种群结构特征,发现一级分区间的水生境状况与底栖动物种群结构均存在差异,二级分区之间虽然有部分生境指标较为接近,但底栖动物种群结构差异明显,证明了分区方案的科学性和合理性,为水源区的生态系统保护和水资源管理提供了依据。     

生态补偿的理论探讨

本文深入探讨了生态补偿的概念和内涵，认为生态补偿是一种使外部成本内部化的环境经济手段，其核心问题包括：谁补偿谁，即补偿支付者和接受者的问题，补偿多少，即补偿强度的问题，以及如何补偿，即补偿渠道的问题，本文认为，生态补偿的实施应以产权的明晰为基础，补偿额度须以资源产权让渡的机会成本为标准，进而对生态补偿机制设计了进行了探讨。