Nitrate removal under different ecological remediation measures in Taihu Lake: a 15 N mass-balance approach

Ecological remediation is an important measure for the protection of lake water quality in removing nutrients, such as nitrate (NO₃ ^?). In this study, four bioremediation processes (bare sediment, immobilized nitrogen cycling bacteria (INCB) added, Elodea nuttallii added, E. nuttallii-INCB assemblage) were operated at a lab to elucidate the effect of macrophyte appearance and INCB addition on NO₃ ^? removal and achieve the optimal processes for biomediation. ¹⁵?N-NO₃ solution was added to microcosms to identify the key nitrogen transformation processes responsible for NO₃ ^? removal. Results showed that nitrate removal was significantly enhanced after the addition of INCB and E. nuttallii. In the treatments with INCB added, E. nuttallii added, and INCB and E. nuttallii-INCB assemblage, nitrate removal ratio achieved 94.74, 98.76, and 99.15 %, respectively. In contrast, only 23.47 % added nitrate was removed in the control. Plant uptake and denitrification played an important role in nitrogen removal. The water quality was substantially improved by the addition of INCB and macrophyte that can accelerate denitrification and promote nitrogen assimilation of plants. The results indicated that plant uptake and microbial denitrification were key processes for nitrate removal.     

碱熔融活化固硫灰制备地聚合物

采用碱熔融活化法，由固硫灰制备地聚合物。在前期开展的单因素实验的基础上，采用正交实验，考察了NaOH和固硫灰的质量比、煅烧温度、煅烧时间3个因素对固硫灰基地聚合物的抗压强度的影响。采用XRD，SEM，IR等手段分析固硫灰碱熔融活化前后的物相、微观形貌以及硅铝化学键的变化。实验结果表明，以在NaOH与固硫灰的质量比为0.60、煅烧温度为550 ℃、煅烧时间为60 min的条件下制备的碱熔融固硫灰为原料，制备的固硫灰基地聚合物的抗压强度为38.00 MPa。表征结果显示：通过碱熔融活化固硫灰制备的地聚合物的XRD谱图中出现了地聚合物的特征衍射峰;碱熔融固硫灰的结构松散，在颗粒表面及内部存在大量孔隙;经碱熔融处理后固硫灰的硅酸盐和铝酸盐发生了解聚。     

简单式绿色屋顶对雨水径流水质的影响规律研究

绿色屋顶作为海绵城市建设中的重要措施之一,具有良好的环境生态效益。对搭建的5种简单式绿色屋顶装置和混凝土屋面装置进行了天然降雨实测和模拟降雨实验监测比较,分析了各装置出流中总有机碳(TOC)、TN、氨氮、TP和Zn的浓度及负荷,研究了简单式绿色屋顶对屋面雨水径流水质的影响规律。结果表明,简单式绿色屋顶出流中的TOC、TN、氨氮、TP和Zn浓度比混凝土屋面高;简单式绿色屋顶具有径流量截留能力,能够削减部分TN和氨氮负荷,但TOC、TP和Zn浓度较高,导致其污染负荷仍然比混凝土屋面高。种植基质对雨水径流TOC、TN和氨氮浓度有显著影响,对TP和Zn浓度无显著影响;植被对各项污染物浓度均无显著影响;降雨特征对污染物浓度有显著影响。     

纳米二氧化钛对小胶质细胞Notch信号通路及炎症因子分泌水平的影响

由于纳米材料的广泛应用及其可能存在的生物安全性风险,本研究探讨了纳米二氧化钛对小胶质细胞Notch信号通路及炎症因子分泌水平的影响.以不同浓度的纳米二氧化钛染毒小胶质细胞,MTT法测定细胞活力,乳酸脱氢酶(LDH)检测试剂盒测定细胞培养液上清液LDH活性,ELISA法测定细胞培养液上清液肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)的分泌水平,Western Blot法检测Notch-1和Hes-1的蛋白表达水平.结果表明,与对照组相比,纳米二氧化钛40.0 μg·mL-1和50.0μg·mL-1暴露组细胞活力显著降低;纳米二氧化钛20.0、30.0和40.0 μg·mL-1暴露组LDH水平明显升高;纳米二氧化钛15.0,20.0、30.0和40.0 μg·mL-1暴露组TNF-α、IL-1β和IL-6分泌水平升高;纳米二氧化钛20.0、30.0和40.0μg·mL-1暴露组Notch-1及Hes-1蛋白表达水平升高.研究表明,纳米二氧化钛暴露导致细胞活力降低,破坏细胞膜的完整性,炎症因子及Notch信号通路相关蛋白Notch-1和Hes-1的表达水平升高.     

江苏大丰麋鹿国家级自然保护区互花米草对水盐梯度的生态响应

为探究江苏滨海湿地环境因子与互花米草生态特征的关系及水分梯度和盐分梯度对互花米草生态特征的影响,于2020年10月,选取江苏大丰麋鹿国家级自然保护区滨海湿地互花米草为研究对象,测定了互花米草的株高、生物量、密度、盖度及土壤水分、土壤盐分、pH、土壤容重.结果 表明:①土壤水分和土壤盐分是影响互花米草生态特征的重要环境因...     

餐厨垃圾渗滤液强化城市污泥消化作用研究

针对城市污水厂污泥热值低、C/N比低,厌氧消化效率低的问题,结合餐厨垃圾渗滤液中有机物含量高、C/N比高的特点,研究了城市污泥、餐厨垃圾渗滤液共消化过程.结果表明:垃圾渗滤液的添加促进了污泥厌氧消化甲烷气的产生,添加生、熟垃圾渗滤液的消化污泥累计产甲烷量分别为542 mL、2102 mL,是未添加渗滤液(参照样)的污泥消化产气量的1.2倍、4.6倍,甲烷单位产量分别为261(参照样)、675.8、971.0L·kg-1(以VS计);同污泥单独厌氧消化相比,添加生、熟垃圾渗滤液能强化污泥VS/TS的去除,其去除率分别为15.3%和26.3%;通过共消化,污泥上清液的SCOD去除率均高于90%,出水COD也基本一致,并未因垃圾渗滤液的添加而发生大的波动.污泥与餐厨垃圾渗滤液的共消化能够促进有机物的去除,强化甲烷气的产生,实现了污泥与渗滤液的稳定化、无害化和资源化.     

BDE-209和PCB153在致大鼠肝细胞DNA蛋白质交联(DPC)上的拮抗作用

多溴联苯醚(PBDEs)和多氯联苯(PCBs)都是为人熟知的持久性有机污染物,也同为室内半挥发性有机物(SVOCs)。由于二者结构类似,通常认为PBDEs具有和PCBs相似的毒性。染毒剂BDE-209和PCB153分别是PBDEs和PCB家族的主要同系物,并且同时存在于环境和人体组织中。实验以DNA蛋白质交联(DPC)为生物标志物研究BDE-209和PCB153单独及联合染毒的遗传毒性。对大鼠肝细胞在37℃下染毒1h。浓度设置如下:BDE-209(0、1、6.5、12μg.mL-1);PCB153(0、1、6.5、12μg.mL-1);BDE-209(3.25μg.mL-1)+PCB153(3.25μg.mL-1)。实验结果显示:与溶剂对照相比,测得DPC水平随BDE-209(或PCB153)浓度增大而显著增高(p<0.01);PCB153比BDE-209引起更高水平的DPC(p<0.05或p<0.01);联合染毒组的DPC水平显著低于PCB153组(p<0.01),但稍高于BDE-209组(p>0.05)。从以上结果可知,BDE-209和PCB153之间存在拮抗作用;BDE-209和PCB153具有遗传毒性,并且就致DPC作用而言,二者之间可能存在拮抗作用。     

Occurrence of selected antibiotics in Jiulongjiang River in various seasons, South China

The concentrations of six sulfonamides (SAs) and three tetracyclines (TCs) were investigated in Jiulongjiang River during the low water season and the high water season. They were monitored in both surface water and sediment. Total concentrations of all these antibiotics varied from 31 to 25,771 ng g(-1) in sediment samples. In water they ranged from 60 to 2607 ng L(-1) during the low water season and from ND (not detected) to 134 ng L(-1) during the high water season. At the sites nearby breeding farms, chlorotetracycline was found to have the highest concentration of 1036 ng L(-1) in water and 14,666 ng g(-1) in sediments. According to the published data, the concentrations of sulfamethazine, sulfameter and TCs at these sites were higher than that in most rivers. The concentrations during the low water season were tens to hundreds of times higher than that in the high water season. The lower concentrations of TCs in the high water season might result from both dilution and photo-degradation, while dilution and bio-degradation might lead to the lower concentrations of SAs. However, further study is needed to clarify the specific reasons. Concerning the relationship between sediment and water samples, the pseudo-partitioning values of TCs were much higher than SAs. It indicates that the TCs are prone to accumulate in the sediment.     

胶束强化超滤处理阿特拉津的研究

常规处理工艺并不能有效去除水中的环境内分泌干扰物质。研究采用十二烷基硫酸钠(SDS)为表面活性剂对阿特拉津进行增溶,并采用聚砜超滤膜和SDS胶束强化超滤处理阿特拉津。考察了SDS浓度、操作压力、无机盐、β-环糊精和烷基多苷(APG)等因素对工艺的影响。结果表明,胶束强化超滤对阿特拉津的去除率可达80%以上,无机盐、β-环糊精、APG和SDS的复配可以提高阿特拉津的去除率。     

急性镉染毒对河南华溪蟹精子质量的影响

采用急性毒性实验方法,研究了镉(Cd2+)对河南华溪蟹(Sinopatamon henanense)精子质量的影响.实验设置了5个Cd2+浓度组(7.25、14.5、29、58和116 mg·L-1)和1个空白对照组,在2个染毒时间(5d和7d)采用特异性的荧光染料和流式细胞术(FCM)对精子成活率、膜完整性、顶体完整性及染色质结构进行了测定.结果显示,随着Cd2+浓度的增加和染毒时间的延长,精子的成活率下降,质膜和顶体缺失率上升,异染色质所占比率上升.在Cd2+浓度为58、116 mg·L-1条件下暴露5d后,精子成活率显著降低(p ＜0.05);Cd2+浓度为116 mg·L-1时,精子质膜完整性和染色质结构均有明显的损伤;而顶体状态在Cd2+浓度为29 mg·L-1时就呈现显著的损伤(p＜0.01).在Cd2+浓度为29、58、116mg·L-1条件下染毒7d后,精子成活率、质膜完整性和顶体完整性降低;在所有的染毒组,DNA结构受到了显著的破坏.结果表明,Cd2+暴露对华溪蟹精子质量有明显的影响.