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.     

Comparing results of cultured and uncultured biological methods used in biological phosphorus removal

Increasing attention has been paid to phosphate-accumulating organisms(PAOs)for their important role in biological phosphorus removal.In this study,microbial communities of PAOs cultivated under different carbon sources(sewage,glucose,and sodium acetate) were investigated and compared through culture-dependent and culture-independent methods,respectively.The results obtained using denaturing gradient gel electrophoresis(DGGE)of polymerase chain reaction-amplified 16S rDNA fragments revealed that the diversity of bacteria in a sewage-fed reactor(1#)was much higher than in a glucose-fed one(2#)and a sodium acetate-fed one(3#);there were common PAOs in three reactors fed by different carbon sources.Five strains were separated from three systems by using a phosphate- rich medium;they were from common bacteria isolated and three isolates could not be found in DGGE profile at all.Two isolates had good phosphorus removal ability.When the microbial diversity was studied,the molecular biological method was better than the culture-dependent one.When phosphorus removal characteristics were investigated,culture-dependent approach was more effective. Thus a combination of two methods is necessary to have a comprehensive view of PAOs.     

提高平菇深层培养木质素降解酶活性和对直接湖蓝5B脱色率的探索性研究

以稻草为主要营养基质对平菇进行深层培养,研究了不同浓度(100、200、400、600、800 mg·L-1)直接湖蓝5B对平菇菌丝体产量的影响,以及平菇对不同浓度(100、150、200、250、300、400 mg·L-1)直接湖蓝5B的脱色率.此外,还研究了平菇分别与3种酵母菌(酿酒酵母、产朊假丝酵母和热带假丝酵母)混菌培养及用不同浓度(50、100、200、300、400 mg·L-1)直接湖蓝5B预适应培养的平菇菌种对木质素降解酶活性和直接湖蓝5B脱色率的影响.结果表明:100~400 mg·L-1的直接湖蓝5B均可显著提高了平菇菌丝体产量,而800 mg·L-1的染料对菌丝体的生长有显著抑制作用;染料浓度越高,平菇对其的脱色率越低,发酵时间越长,脱色效果越好.与平菇单菌发酵相比,平菇分别与酿酒酵母和产朊假丝酵母混菌培养可显著提高发酵体系漆酶的活性,平菇分别与所试3种酵母菌混菌培养时锰过氧化物酶活性均有显著增加,与产朊假丝酵母混菌培养时两种酶活性的增加量最大;用50、100、200 mg·L-1直接湖蓝5B预适应培养的菌种接种可显著提高平菇分泌的漆酶的活性,而50mg·L-1和100 mg·L-1的则显著提高锰过氧化物酶的活性.平菇分别与所试3种酵母混菌培养,以及用50 mg·L-1和100 mg·L-1直接湖蓝5B预培养的平菇菌种接种,发酵体系对直接湖蓝5B的脱色效果有显著促进作用,其中,平菇与产朊假丝酵母混菌培养时脱色率最高,达96.3%.通过比较直接湖蓝5B脱色率与漆酶、锰过氧化物酶活性之间的关系可以看出,漆酶、锰过氧化物酶活性与脱色率间基本呈正相关关系.     

郑州黄河南岸养殖鱼类肌肉中重金属残留特征

以郑州市黄河南岸养殖鱼类为研究对象,分别在巩义、荥阳、惠济和中牟4个渔场内采集鲫鱼、鲤鱼、草鱼和鲢鱼肌肉样品133个,用ICP-MS和LC-AFS方法对Pb、Cr、Cd、Cu、Zn、Hg和As的残留进行了测定,在分析了重金属残留水平的基础上,通过目标危害系数法评估了鱼类的食用安全健康风险.结果表明,郑州黄河南岸4种养殖鱼类肌肉中Pb、Cr、Cd、Cu、Zn、Hg和As的残留均有检出,但仅有Pb、As和Cd 3种元素存在超标样品,超标率分别为13.53%、12.78%和4.51%.7种重金属元素的变异系数在0.13~0.37之间,属中等变异强度,其中以Hg的变异强度最大.Pb、Cr、Cd、Cu、Zn、Hg和As的平均残留水平差异明显,从高到低依次为Zn > Cu > Cr > Pb > As > Hg > Cd,均未超过食品中污染物限量标准.不同鱼类的重金属残留水平也存在较大差异,总体来说鲫鱼和草鱼高于鲤鱼和鲢鱼.相关分析结果显示,养殖鱼类肌肉中7种重金属元素的残留具有相似的来源,并可能以饲料、药物等人为来源为主.健康风险评估表明,儿童面临的鱼类重金属膳食摄入健康风险要高于成人,但日常食用郑州市黄河南岸地区养殖鱼类,重金属对当地居民造成的健康风险并不明显.在7种重金属元素中,As、Hg和Cr是主要风险元素,其污染积累特征及有效防控值得进一步研究.     

铈对马尾松离体胚DNA、RNA及蛋白质合成的影响

用含30mgL^-1CeCl3的培养瘁培养马尾松离体胚，采用^3H-T、^3H-U和^3H-Leu标记技术测定：结果表明，CeCl3明显提高马尾松离体胚在培养过程中对DNA、RNA和蛋白质前体的吸收，以及合成这些生物大分子的能力。CeCl3处理在15h开始迅速吸收DNA前体和合成DNA，比CK提前5h。CeCl3处理在10h开始迅速吸收RNA前体和合成RNA，比CK提前5h，CeCl3处理5h,蛋白质合成前体的吸收量和蛋白质合成量明显高于CK。图6参19     

S-phase,apoptosis and peroxisome proliferation in avian hepatocyte cultures following exposure to the phenoxy herbicide 2,4-D

Phenoxyherbicides induce peroxisome proliferation, as do other structurally related or unrelated chemicals which were found to be nongenotoxic carcinogens in rodents. The widespread use of 2,4-dichlorophenoxyacetic acid (2,4-D) raised concerns over the potential to produce cancer, yet results from epidemiological and experimental studies do not provide definitive evidence that 2,4-D is carcinogenic. The objective of the present study was to verify whether 2,4-D might interfere with cell growth similar to other peroxisome proliferators using cultured avian hepatocytes. Primary hepatocyte cultures from 18-day-old chick embryos were exposed to 2,4-D for up to 72 h followed by an assessment of replicative DNA synthesis and apoptosis. Further, peroxisome proliferation was evaluated. Results showed that 2,4-D stimulated DNA synthesis and suppressed spontaneous apoptosis, while the effects on peroxisome proliferation were less evident.     

资源环境约束下的天津市盐渍土农业利用研究

盐渍土作为一种重要的宜耕后备资源,其农业开发利用已成为解决人口、粮食、资源和环境等问题的重要措施。论文通过天津市盐渍土农业利用中面临的水土资源短缺、环境污染与经济效益差等问题进行系统分析后得出：目前天津市盐渍土面积为32.42×10⁴ hm²,其中,重度盐渍土与盐土大多分布在滨海平原地区,这些区域恰恰是补充耕地的主要来源,然而由于其盐渍化程度原本就高,即使改良后很快又会返盐;天津市目前年均缺水量为6×10⁸~9×10⁸ m³,水资源短缺已成为限制农业发展的重要瓶颈问题,若改良这些盐渍土宜耕后备资源并继续采用传统的农业耕作方式,将会进一步加大农业用水缺口,农药、化肥、地膜的过量施用,也加重了环境污染危害;并且,耗费巨大成本改良后的耕地,由于比较效益差、后续利用与管理资金难以维系,面临着无人耕种的困境。随着城市化与社会经济发展结构的变化,农业早已不再是天津市国民经济发展的主导产业。但是为了保障国家粮食安全,天津市也必须承担一定的耕地保有量和基本农田保护任务。鉴于大都市区对蔬菜的巨大需求,综合考虑区域资源、环境与效益因素,在滨海平原的盐渍土上发展设施水培蔬菜,不仅可有效缓解耕地保护压力,保护生态环境、提高经济效益,将北京市的蔬菜基地外迁至滨海平原,也有助于促进京津一体化发展。