太阳能干燥污泥的中试研究

设计出一种以热水为干燥介质的整体式太阳能干燥的中试系统,主要研究不同厚度的剩余污泥在不同季节的干燥情况。试验结果表明:夏季湿污泥的含水率从88%降到40%需要6～14 d,w(VSS)/w(TSS)从79%降到69%;梅雨季节含水率从91%降到40%需要9～26 d,w(VSS)/w(TSS)从58%降到46%;春季含水率从88%降到40%需要7～17 d,w(VSS)/w(TSS)从79%降到57%;秋季含水率从88%降到40%需要7～19 d,w(VSS)/w(TSS)从53%降到49%。夏季时最不利干燥厚度为0.29 m,梅雨季节为0.53 m,春季为0.26 m,秋季为0.31 m;在此基础上,与常用的转盘式干燥器相比,这种太阳能干燥装置能收到很好的经济和环境效益。     

节球藻毒素对小鼠肝脏微结构的影响研究

作为新型生物毒素,节球藻毒素(NOD)常见于爆发水华的水体中,是泡沫节球藻分泌的具有高肝毒性的次生代谢产物.由于其毒性高、暴露途径广且不易降解而日趋受到人们的重视.为了阐明NOD的肝毒性机理,本研究以模式生物小鼠为载体,研究亚慢性NOD诱导下小鼠肝脏在形态学、病理学上的微结构变化.结果表明,10 μg·kg-1.D-NOD下暴露21 d可诱导小鼠肝脏出现“草莓状表面”的肉眼可见的形态学改变.在H&E染色下,观察到在NOD暴露21d可诱导小鼠肝脏出现微小结节、细胞嗜酸性病变、炎症细胞浸润、慢性淤胆及脂肪病变等病理学现象.当暴露时间延长到28 d时,嗜酸性病变恶化并出现嗜酸小体在TEM观察下,小鼠肝细胞在NOD的诱导下出现肝细胞核皱缩、染色质凝集或边集、线粒体嵴横纹加深及分布散乱、内质网肿胀、核糖体脱粒等现象,并且在胞质中多有观察到微泡性脂肪变性及吞噬小泡.上述变化充分说明,在亚慢性暴露条件下,NOD依然具有强烈肝毒性.引起NOD慢性肝中毒的主要原因是肝细胞嗜酸性病变及炎症的诱发,并在暴露时间延长后进一步恶化,肝板结构破坏更加严重.     

抗生素和铜联合作用对蚕豆根尖细胞微核率的影响

为确定抗生素与重金属单一及联合作用对细胞遗传物质的损伤程度,以青皮蚕豆根尖细胞为试验材料,研究四环素类抗生素OTC(土霉素)、CTC(金霉素)、TTC(四环素)和重金属Cu单一以及联合作用对蚕豆根尖细胞微核率和微核指数的影响. 结果表明:①抗生素与Cu单独作用,二者c在0~1.6 mmol/L之间时,蚕豆根尖细胞微核率均高于3.33‰,微核指数均大于1.5,与CK(对照处理)相比差异显著(P<0.01);随着c(抗生素)的增大,蚕豆根尖细胞微核率呈先减后增的趋势. ②抗生素与Cu联合作用时,蚕豆根尖细胞微核率和微核指数均小于单独作用时二者之和,交互作用表现为拮抗作用,其中c(抗生素)∶c(Cu)为1∶4时拮抗作用最明显,c(抗生素)∶c(Cu)为1∶1和1∶2时根尖细胞微核率呈减少的趋势,c(抗生素)∶c(Cu)为1∶8和1∶16时根尖细胞微核率呈增加的趋势. 研究显示,四环素类抗生素与Cu单一及联合作用于蚕豆根尖细胞时,均会对植物根尖细胞造成遗传损伤,但是联合作用时,抗生素在溶液中与Cu发生络合反应,从而可以在一定程度上降低对根尖细胞的遗传损伤.      

冻融处理对不同阴极构型MFC产电及有机物降解的影响

为了研究不同阴极构型的微生物燃料电池(MFC)处理剩余污泥时的产电以及有机物降解情况,构建了铁氰化钾双室MFC以及生物阴极双室MFC两套系统,分析了两套系统处理剩余污泥时电压、功率密度以及有机物变化及降解情况.结果表明,处理冻融污泥时,铁氰化钾双室MFC8h达到稳定电压0.726V,运行6d时SCOD达到峰值3771.4mg/L,此时最大功率密度最高为10.3W/m3,周期结束(20d)TCOD去除率为70.3%;生物阴极双室MFC运行3d达到稳定电压0.76V并持续22d后下降,15~20d时SCOD达到峰值4538.0mg/L,并获得最高的最大功率密度13.7W/m3,周期结束(30d)去除80.6%的TCOD.相对于铁氰化钾双室MFC,生物阴极双室MFC能够更为彻底的促进污泥有机物溶出并利用其产电,对溶解性碳水化合物利用以及有机物的降解得更为彻底,同时更利于MFC系统的长期稳定运行.     

浅池型太阳能光催化反应动力学研究

研究了浅池型太阳能反应器中亚甲基蓝一级降解动力学常数与光辐射强度、反应器A/V值的关系 .当A/V与光照I均为变量时 ,提出了一个修正的动力学方程 :k =1 6 2 7× 10 -5I0 871(A/V) 1 3 57.同时 ,还建立了一个新的表观量子产率模型 :k =5 2 3CI0 871(A/V) 1 3 57.计算表观量子产率值为 0 17%— 0 30 % ,随着A/V、初始浓度的增大或光强的减小 ,表观量子产率增大     

臭氧预氧化对藻细胞及胞外分泌物消毒副产物生成势的影响

以处于对数生长期后期的悦目颤藻为研究对象,研究了藻细胞及胞外分泌物对氯化消毒副产物生成势(DBPFP)的贡献,以及臭氧预氧化对DBPFP的影响规律,即不同臭氧投量及预氧化时间对DBPFP的影响,并探讨臭氧预氧化控制消毒副产物生成势的原因.研究表明,藻细胞和胞外分泌物的三卤甲烷类副产物都主要是氯仿和一溴二氯甲烷,卤乙酸类副产物都主要是二氯乙酸和三氯乙酸.颤藻细胞和其EOM本身及经臭氧预氧化混凝后形成卤乙酸的能力基本都高于形成三卤甲烷的能力,在实际含藻水的处理中,应该更加重视对卤乙酸的控制.臭氧预氧化可以降低胞外分泌物形成氯化消毒副产物(DBP)的能力,且随着反应时间延长,DBPFP降低越多.在本试验条件下,0.975 mg/L臭氧预氧化10min后混凝,可比单纯混凝降低胞外分泌物DBPFP 31%,其中HAAFP降低52.6%,而THMFP却升高12.5%,可见臭氧预氧化控制胞外分泌物DBPFP主要原因是其可以很好地控制卤乙酸生成势.同时臭氧预氧化会使含藻细胞水样的DBPFP大幅度升高,且随着氧化时间延长,各种氯化消毒副产物生成势几乎呈线性增加.在实际水处理中,应在去除藻细胞之后再进行臭氧氧化以控制DBPFP.     

中国陆地生态信息空间化技术研究(Ⅱ)——太阳辐射要素

论文以MTCLIM模型为基础,根据中国的实际情况,对模型的参数进行了优化与调整,建立了适合我国的基于温度、降水和相对湿度等因子的太阳总辐射计算模式。提出了太阳总辐射空间化的模式,即先参数化,然后采用合适的空间插值方法(论文中采用地统计学方法)实现空间化。同时鉴于逐日太阳总辐射空间化工作量庞大,提出了在计算月均日结果的基础之上,采用线性插值技术快速得到逐日太阳辐射值。从而得到了中国太阳总辐射的空间分布结果。     

Toxicity Assessment of Treated Wastewater Using Cultured Human Cell Lines

Bioassay using cultured human cell lines was applied to an effluent of a wastewater treatment plant (WWTP) in Sapporo to assess their toxicity, and in order to investigate the fate of toxicity in the WWTP, bioassay of the water samples from several points in WWTP (influent, effluent, return flow from thickener, from dewatering process and from incineration process) was performed. We also applied bioassay to the mixture of the activated sludge from the investigated plant and artificial sewage. These results showed that the toxicity of the effluent was more intensive than the influent, and organic matter released from activated sludge bacteria during their decay process contributed to the increase of toxicity in the effluent.     

Neural stem cell-based in vitro bioassay for the assessment of neurotoxic potential of water samples

Intensive agriculture activities, industrialization and growing numbers of wastewater treatment plants along river banks collectively contribute to the elevated levels of neurotoxic pollutants in natural water reservoirs across Europe. We established an in vitro bioassay based upon neural stem cells isolated from the subventricular zone of the postnatal mouse to evaluate the neurotoxic potential of raw wastewater, treated sewage effluent, groundwater and drinking water. The toxic potential of water samples was evaluated employing viability, proliferation, differentiation and migration assays. We found that raw wastewater could reduce the viability and proliferation of neural stem cells, and decreased the neuronal and astrocyte differentiation, neuronal neurite growth, astrocyte growth and cell migration. Treated sewage water also showed inhibitory effects on cell proliferation and migration. Our results indicated that relatively high concentrations of nitrogenous substances, pesticides, mercuric compounds, bisphenol-A, and phthalates, along with some other pollutants in raw wastewater and treated sewage water, might be the reason for the neuroinhibitory effects of these water samples. Our model successfully predicted the neurotoxicity of water samples collected from different sources and also revealed that the incomplete removal of contaminants from wastewater can be problematic for the developing nervous system. The presented data also provides strong evidence that more effective treatments should be used to minimize the contamination of water before release into major water bodies which may be considered as water reservoirs for human usage in the future.     

One-step ball milling-prepared nano Fe2O3 and nitrogen-doped graphene with high oxygen reduction activity and its application in microbial fuel cells

• Nano Fe₂O₃ and N-doped graphene was prepared via a one-step ball milling method. • The maximum power density of Fe-N-G in MFC was 390% of that of pristine graphite. • Active sites like nano Fe₂O₃, pyridinic N and Fe-N groups were formed in Fe-N-G. • The improvement of Fe-N-G was due to full exposure of active sites on graphene. Developing high activity, low-cost and long durability catalysts for oxygen reduction reaction is of great significance for the practical application of microbial fuel cells. The full exposure of active sites in catalysts can enhance catalytic activity dramatically. Here, novel Fe-N-doped graphene is successfully synthesized via a one-step in situ ball milling method. Pristine graphite, ball milling graphene, N-doped graphene and Fe-N-doped graphene are applied in air cathodes, and enhanced performance is observed in microbial fuel cells with graphene-based catalysts. Particularly, Fe-N-doped graphene achieves the highest oxygen reduction reaction activity, with a maximum power density of 1380±20 mW/m² in microbial fuel cells and a current density of 23.8 A/m² at –0.16 V in electrochemical tests, which are comparable to commercial Pt and 390% and 640% of those of pristine graphite. An investigation of the material characteristics reveals that the superior performance of Fe-N-doped graphene results from the full exposure of Fe₂O₃ nanoparticles, pyrrolic N, pyridinic N and excellent Fe-N-G active sites on the graphene matrix. This work not only suggests the strategy of maximally exposing active sites to optimize the potential of catalysts but also provides promising catalysts for the use of microbial fuel cells in sustainable energy generation.