流态对生物添加强化硝化效果的影响

在15℃、相同氮负荷和添加强度条件下运行SBR和CSTR以对比分析两种典型流态(推流式和完全混合式)对硝化菌添加强化硝化效果的影响.结果表明,添加期间,SBR中氨氧化速率(AUR)和亚硝酸盐氧化速率(NUR)分别为添加前的2.34和2.39倍,停止添加后又分别降为添加前的2.01和1.78倍;添加期间CSTR中AUR和NUR分别为添加前的2.63和2.44倍,停止添加后又分别降为添加前的1.48和1.31倍.荧光原位杂交结果显示,添加期间,SBR中氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)的个数百分比分别为添加前的2.67和2.71倍,添加停止后,又分别降至原来的2.14和1.95倍;CSTR中AOB和NOB分别为添加前的2.91和1.77倍,但在添加停止后CSTR中AOB和NOB分别降至添加前的1.25和1.50倍.因此,硝化菌添加期间,两种流态的添加效果接近,但是在添加停止后,由于流态对硝化菌中K-决策者(Nitrosospira、Nitrospira)和r-决策者(Nitrosomonas europaea、Nitrobacter)的选择作用,添加的硝化菌在完全混合式条件下比推流式条件下更容易被系统淘汰.     

2001-2010年三江源区草地净生态系统生产力估算

三江源区位于青藏高原腹地,是我国长江、黄河、澜沧江三大河流的发源地.为了准确估算该地区草地生态系统的净生态系统生产力,收集整理了2001—2010年青藏高原10个通量观测站点的观测数据,构建了三江源区草地生态系统NEP（net ecosystem production,净生态系统生产力）估算模型,并在站点尺度进行了模型参数化和精度验证;结合区域尺度气象和遥感数据,估算了三江源区草地生态系统NEP.结果表明:① 2001—2010年三江源区草地生态系统多年平均NEP空间分布具有明显的空间异质性,大部分地区表现为碳汇,NEP（以C计）平均值为41.8 g/（m2·a）.② 三江源区草地生态系统NEP呈波动增加趋势,从2001年的20.0 g/（m2·a）增至2010年的82.5 g/（m2·a）;除2002年表现为弱碳源外,其余年份均表现为碳汇,并以2010年碳汇能力为最强.③ 2001—2010年三江源区草地生态系统NEP平均年增长率为5.4 g/m2;NEP年际变化率空间分布显示,大部分地区NEP呈增加趋势,仅有东南部和中部部分区域NEP呈下降趋势.研究显示,2001—2010年三江源区草地生态系统表现为碳汇,并且由于气候的暖湿化趋势,碳汇强度总体表现为增强.      

不同主体功能定位的县域空间功能区划研究

文章通过判别分析法,尝试构建一套针对不同主体功能定位县通用的指标体系,以反映社会经济发展状况、生态环境保护重要性、国土空间开发支撑条件。通过在广西10个不同主体功能定位县的实践应用,将县域空间划分为城镇空间、农业空间和生态空间,重点开发区、农产品主产区、重点生态功能区的城镇空间分别小于30%、20%和10%,农产品主产区的农业空间和重点生态功能区的生态空间均大于50%。研究成果为全省范围推广县域空间功能区划提供了科学依据。     

碳排放影响因子与碳足迹文献综述:基于研究方法视角

从研究方法的角度出发,对近年来国内外碳排放影响因子及碳足迹的相关研究进行文献综述。根据碳排放影响因子的研究方法—情景分析法、因素分解法中的指数分解法以及其他计量模型,介绍了国内外关于碳排放影响因子的研究现状,最后对方法进行归类和对比。根据碳足迹研究方法—投入产出法、生命周期评价法、IPCC法以及其他模型,分析了国内外关于碳足迹的研究进展。最后通过总结,对碳排放和碳足迹的未来研究方向进行了展望。     

广西壮族自治区污水处理厂运行状况及特征分析

基于广西壮族自治区126座污水处理厂2015年运行状况的调查数据,分析广西污水处理厂的工艺特点、污泥处置、出水水质达标情况、运行负荷率和运行费用,评估污水处理厂运行的效率和效果,分析存在的问题,并就污水处理厂的运行和管理提出建议。     

On the effect of Fe(III) on proliferation of Microcystis aeruginosa at high nitrate and low chlorophyll condition

The impact of Fe concentrations on the growth of Microcystisaeruginosa in aquatic systems under high nitrate and low chlorophyll conditions was studied. The responses of cell density, total and cell chlorophyll-a intracellular Fe content and organic elemental composition of M. aeruginosa to different concentration gradients of Fe(III) in the solutions were analysed. The results showed that the proliferation speeds of M. aeruginosa were: (1) decelerated when the Fe(III) concentration was lower than 50 μg/L in the solutions, (2) promoted and positively related to the increase of Fe(III) concentration from 100 to 500 μg/L in the solutions over the experimental period, and (3) promoted in the early stage but decelerated in later stages by excess adsorption of Fe by cells when the Fe(III) concentration was higher than 500 μg/L in the solutions. The maximum cell density, total and cell chlorophyll-a were all observed at 500 μg Fe(III)/L concentration. The organic elemental composition of M. aeruginosa was also affected by the concentration of Fe(III) in the solutions, and the molecular formula of M. aeruginosa should be expressed as C_7–7.5H₁₄O_0.8–1.3N_3.5–5 according to the functions for different Fe(III) concentrations. Cell carbon and oxygen content appeared to increase slightly, while cell nitrogen content appeared to decrease as Fe(III) concentrations increased from 100 to 500 μg/L in the solutions. This was attributed to the competition of photosynthesis and nitrogen adsorption under varying cell Fe content.     

Effects of Cu2+ and humic acids on degradation and fate of TBBPA in pure culture of Pseudomonas sp. strain CDT

Soil contamination with tetrabromobisphenol A(TBBPA) has caused great concerns;however, the presence of heavy metals and soil organic matter on the biodegradation of TBBPA is still unclear. We isolated Pseudomonas sp. strain CDT, a TBBPA-degrading bacterium, from activated sludge and incubated it with ~(14)C-labeled TBBPA for 87 days in the absence and presence of Cu~(2+)and humic acids(HA). TBBPA was degraded to organic-solvent extractable(59.4% ± 2.2%) and non-extractable(25.1% ± 1.3%) metabolites,mineralized to CO_2(4.8% ± 0.8%), and assimilated into cells(10.6% ± 0.9%) at the end of incubation. When Cu~(2+)was present, the transformation of extractable metabolites into non-extractable metabolites and mineralization were inhibited, possibly due to the toxicity of Cu~(2+)to cells. HA significantly inhibited both dissipation and mineralization of TBBPA and altered the fate of TBBPA in the culture by formation of HA-bound residues that amounted to 22.1% ± 3.7% of the transformed TBBPA. The inhibition from HA was attributed to adsorption of TBBPA and formation of bound residues with HA via reaction of reactive metabolites with HA molecules, which decreased bioavailability of TBBPA and metabolites in the culture. When Cu~(2+)and HA were both present, Cu~(2+)significantly promoted the HA inhibition on TBBPA dissipation but not on metabolite degradation. The results provide insights into individual and interactive effects of Cu~(2+)and soil organic matter on the biotransformation of TBBPA and indicate that soil organic matter plays an essential role in determining the fate of organic pollutants in soil and mitigating heavy metal toxicity.     

异烟酸-吡唑啉酮比色法测定海水氰化物实验条件的选择

对异烟酸-吡唑啉酮比色法中氰化物水样保存时间、氯胺T含量、水浴时间和水浴温度进行显色反应条件选择。结果表明:（1）浓度范围为0.5~5 μg/L的氰化物密封水样在pH为12左右的有效保存时间达24 h,在（24~30）h内的氰化物损失率与其氰化物含量呈明显的二次方程拟合关系;（2）在氰化物含量低于4 μg下,氯胺T最佳量为2 mg,且氯胺T增量（即超过最佳量的量）与吸光值降低值呈明显的正相关线性关系;（3）含量低于4 μg的氰化物水样中显色稳定的水浴时间均在20 min之内;（4）含量低于4 μg的氰化物水样中显色灵敏度最高时的水浴温度均在40℃左右。     

广西"十三五"环境保护和生态建设规划指标体系研究

生态环境保护目标指标是环境保护和生态建设规划中的核心内容,制定科学合理的规划指标体系,能够确保规划各项重点任务顺利实施.通过回顾分析"十一五"、"十二五"环境保护和生态建设规划指标体系,结合广西环境现状和发展趋势,在与国家和广西同期规划、计划、方案等衔接基础上,研究提出广西"十三五"环境保护和生态建设规划指标体系,设置了环境质量改善、总量控制、污染治理、风险防范、生态保护和生态公共服务等6个方面共29个指标,以期更好地指导"十三五"环境保护和生态建设工作.     

太湖贡湖湾水域抗生素污染特征分析与生态风险评价

为评估太湖贡湖湾水域抗生素污染程度与生态风险,利用高效液相色谱-串联质谱检测分析了4类抗生素(四环素类、喹诺酮类、磺胺类、大环内酯类)在贡湖湾表层水的污染特征.结果表明,16种目标抗生素中,有13种在贡湖湾水体中检出,质量浓度范围为0.005~4.720μg·L-1,其中土霉素(oxytetracycline,OTC)检出浓度最高.抗生素在南北两湖湾的检出水平也互有高低,其中四环素类抗生素北部湾要高于南部湾,而喹诺酮类和磺胺类抗生素的检出量南部湾要高于北部湾.采用风险商值法进行风险评估,初步评估结果为贡湖湾水域中检出的抗生素中,处于高风险的有5种:四环素类土霉素(OTC)及喹诺酮类诺氟沙星(norfloxacin,NOR)、氧氟沙星(ofloxacin,OFL)、环丙沙星(ciprofloxacin,CIP)和恩诺沙星(enrofloxacin,ENR),占检出种类38.5%;中风险有4种:四环素(tetracycline,TC)、金霉素(chlortetracycline,CTC)、罗红霉素(roxithromycin,ROX)和磺胺甲基异噁唑(sulfamethoxazole,SMX),占检出种类30.8%;其余4种磺胺甲基嘧啶(sulfamerazine,SMR)、磺胺甲氧哒嗪(sulfamethoxypyridazine,SMP)、磺胺喹噁啉(sulfaquinoxaline,SQX)和甲氧苄氨嘧啶(trimethoprim,TMP)为低风险.评估结果表明贡湖水域抗生素存在一定生态风险,其中四环素类和喹诺酮类尤为突出,应引起足够的注意,并采取相应防范措施.