Growth characteristics of algae during early stages of phytoplankton bloom in Lake Taihu, China

Three treatments, sediment plus lake water (S+W), sterilized sediment plus lake water (SS+W), and sediment plus filtered lake water (S+FW), were recruited to investigate the growth characteristics of algae during pre-bloom and the importance of algal inocula in the water column and sediment. The results showed that in the water column, biomass of all algae increased in all treatments when recruitment was initiated, whereas this tendency differed among treatments with further increment of temperature. The process of algal growth consisted of two stages: Stage I, the onset of recruitment and Stage II, the subsequent growth of algae. Compared with S+W, in Stage I, SS+W significantly increased the biomass of cyanophytes by 178.70%, and decreased the biomass of non-cyanophytes by 43.40%; In Stage II, SS+W notably stimulated the growth of all algae, thus incurring the occurrence of phytoplankton bloom. Further analyses revealed that both metabolic activity and photochemical activity of algae were enhanced in SS+W, which resulted from the releasing of nutrients from sediment. These results suggest that algal growth in Stage II and algal inocula in the water column can be important factors for the formation of phytoplankton bloom. In addition, possible mechanisms promoting algal recruitment and subsequent growth of algae were explored.     

无线电干扰系统电磁辐射安全限值的研究

在严格遵循国家有关部门电磁辐射防护规定中的相关标准情况下,进行无线电干扰系统的实验和操作中,发现当系统长时间使用时,按照电磁辐射相关安全标准设置安全间距仍会对人体健康产生不利影响。文章根据实验数据,对电磁辐射相关安全标准进行了深入研究和探讨,在对国家安全标准探讨的基础上提出考虑电磁辐射危害时不能仅仅将人体作为点来考虑,应充分认识到人体作为等效天线的特征以及吸收功率的问题。     

一种钢渣中氯离子的测定方法

利用蒸馏装置蒸出钢渣中的氯离子,使用硝酸汞滴定方法进行滴定,选用两种钢渣,在不同实验室分别进行了分析测定的比较和验证。结果表明:该方法简便易操作,重现性和准确性都比较高,作为钢渣中氯离子的测定是可行的。     

AFS断续流动氢化物原子荧光光度计测定饮用水中汞

介绍断续流动氢化物原子荧光光度计测定饮用水中汞的方法,研究了酸度,硼氢化钾浓度,灯电流,载气流速等对测定汞的影响.在优化的分析条件下,检测限为0.02ug/L,方法应用于水样中汞的测定,样品加标回收率在96.2％-102％之间,相对标准偏差为2.3％.方法具有操作简便,快速,灵敏度高等优点.     

垃圾焚烧电厂排气筒中的氯化氢的测定

直接用离子色谱淋洗液吸收垃圾焚烧电厂排气筒中低浓度的氯化氢,不仅减少了分析中的两次稀释操作,而且还降低方法的检出限,可用于同类污染源低浓度氯化氢的测定。     

走低碳发展之路实现生态文明之梦

低碳发展是一种以低耗能,低污染,低排放为特征的可持续发展模式。本文简述了走低碳发展之路既是可持续发展的要求,也是实现发展与环保双赢的保证。     

因子分析法在天津市主要河流水质污染程度综合评价中的应用

因子分析法作为一种常用的多元统计分析方法,可以有效地分析河流水质的变化趋势,准确地反映水体的污染状况和污染程度。本文将因子分析法应用于天津市主要河流的水质评价中,得出了天津市主要河流水质状况的综合评价结果和污染程度排名,该研究可为水环境管理与决策工作提供依据。     

Distribution of C/N/P stoichiometry in suspended particulate matter and surface sediment in a bay under serious anthropogenic influence: Daya Bay,China

Environmental Science and Pollution Research - The C/N/P stoichiometry of organic matter can provide useful information for better understanding of the effects of human activities on aquatic...     

PCBs降解菌的筛选及其降解特性研究

采用富集培养的方法从多氯联苯(PCBs)污染土壤中筛选到1株高效降解PCBs的细菌,命名为PS-11.经16S rDNA初步鉴定,此菌株属于嗜麦芽寡养单胞菌(Stenotrophomonas maltophilia).结果表明,菌株PS-11能够以PCBs作为唯一碳源生长并且能够降解PCBs,菌株PS-11对2 mg.L-1PCB52 4 d的降解率为31.1%,7 d的降解率可达52.9%;对难降解的高氯代多氯联苯PCB153 7 d的降解率为10.9%.此外,该菌株的环境耐受性比较好,在30℃、pH为7～9、PCB52浓度为2～10 mg.L-1的条件下生长较快、降解效果较好,尤其在pH 7、PCB52浓度为2 mg.L-1时降解率最高;碳源种类不同,菌株PS-11的生长能力也不同,其中在以蔗糖为碳源时PS-11的生长能力最强,以葡萄糖为碳源时PS-11的适应期最短,且蔗糖、葡萄糖和Tween-80均可提高PS-11对PCB52的降解率;同时菌株PS-11还可耐受一定浓度的重金属,其耐受性大小为Pb2+>Cd2+>Zn2+>Cu2+.     

Formation mechanism and control strategy for particulate nitrate in China

Over the past decade, fine particulate matter (PM) pollution in China has been abated significantly, benefiting from strict emission control measures, but particulate nitrate continues to rise. Here, we review the progress in particulate nitrate (pNO₃⁻) pollution characterization, nitrate formation mechanisms, and the proposed control strategies in China. The spatial and temporal distributions of pNO₃⁻ are summarized. The current status of knowledge on the chemical mechanism is updated, and the significance of its formation pathways is assessed by various approaches such as field observation and modelling of nitrate production rate, as well as isotopic analysis. The factors impacting pNO₃⁻ formation and the corresponding pollution regulation strategies are discussed, in which the importance of atmospheric oxidation capacity and ammonia are addressed. Finally, the challenges and open questions in pNO₃⁻ pollution control in China are outlined.