利用微拟球藻去除污水中氮磷及生产富油生物质

为探讨污水深度处理和同步获取产油微藻的可行性,建立光生物反应器,应用微拟球藻去除污水和中水中的氮磷,并分析不同浓度的Fe3+和Zn2+离子对微藻的生长和油脂积累的影响,从而在净化污水的同时培养微藻获得富油生物质。结果表明,该藻对污水氮磷具有较强的去除能力,可在13 d内,去除水体中96%的氨氮和94%的磷,同时化学需要氧量(COD)的去除率可达72.9%。在生活污水中培养至第16天,微藻的细胞密度可达4.55×106 cell/mL。Fe3+浓度对微拟球藻的生长具有显著影响(P6 cell/mL。该研究以中水和生活污水为基质培养微拟球藻,同时获取微藻油脂,为污水中氮磷的去除和能源的同步获取提供了新途径。     

厌氧流化床微生物燃料电池及其串并联性能

在高650 mm、有效容积1 280 mL的液固厌氧流化床单室无膜空气阴极微生物燃料电池（MFC）中,研究了燃料电池串并联产电和有机污水处理性能,同时考察了电极面积、活性炭装填体积、温度等因素对产电性能的影响。结果表明,将燃料电池串联,总电压等于3个单级电池的电压之和,约为2 100 mV,最大功率为0.12 mW,而单级电池最大功率为0.05 mW。并联时,输出电压为800 mV,和单级电池输出电压大体相当,而电流为单级电流的2倍。阳极面积增加1倍,产电量增大了30%;电压随活性炭装填体积的增大而增大;温度为40℃时,燃料电池的产电性能最好。     

聚丙烯酸钠作为调理剂对好氧堆肥的保氮影响

实验以污泥、锯末、猪粪为原料,以聚丙烯酸钠（PAAS）为调理剂,利用自制好氧堆肥反应器,研究了PAAS在污泥好氧堆肥中的保氮效果。实验显示,PAAS会提高堆体的pH水平,抑制氨氮的生成,从而减少NH3的挥发源,在PAAS对水溶性氨的吸附作用下,堆肥产品的最终氨氮水平依然得到提高;PAAS对硝化反应有一定的促进作用,添加PAAS的堆体在堆肥周期内的硝氮平均增幅可达到未添加PAAS的空白堆体的4.64倍;添加PAAS的堆体在堆肥周期内全氮平均降幅只有空白堆体的52.24%。PAAS做为堆肥调理剂起到了较为明显的保氮效果。     

兰坪铅锌矿区不同污染梯度下优势植物的重金属累积特征

对兰坪铅锌矿区污染程度不同的3个样地(云南松林、魁蒿群落和马桑灌丛)进行植被调查,选择其中9种共有的自然生长的优势草本植物为研究对象,测定了土壤及植物体的重金属含量.结果显示,3个样地土壤Cu、Cd、Pb和Zn等4种重金属含量均表现为马桑灌丛>魁蒿群落>云南松林;植物体内重金属积累呈现出随着土壤污染程度增加而增加的趋势;所选择的9种植物均不符合超富集植物的标准,依据不同的耐性机制将9种植物分为3类,野棉花能较强吸收土壤中重金属,并转移到地上部分,属于富集型植物;西南金丝梅、倒提壶、长籽柳叶菜、魁蒿、翻白叶和四脉金茅吸收的重金属主要积累在根部,属于根部囤积型植物;尼泊尔蓼和中华山蓼体内重金属含量较低,属于规避型植物.讨论了利用这些植物进行矿山治理.     

典型杀虫剂类内分泌干扰物对水生溞类的毒性效应研究进展

内分泌干扰物(endocrine disrupting chemicals, EDCs),尤其是具有内分泌干扰效应的杀虫剂,因能显著影响水生生物的生长发育和生殖系统,其潜在生态毒性效应引起了人们的广泛关注。溞类在水生生态系统食物链中起着重要的连接作用,更易受到水体中残留的杀虫剂类EDCs的影响,其毒性效应在水生生态系统毒理学研究中有着重要的意义。本文重点综述了杀虫剂类EDCs对溞类产生的生长发育毒性和生殖毒性,从酶活性变化角度分析由此产生的氧化应激和神经毒性,并在基因表达水平上揭示其毒性作用机制,发现杀虫剂类EDCs通过扰乱神经系统和内分泌系统发挥作用,并展望了杀虫剂EDCs在联合毒性、多代效应的研究前景,旨在为研究杀虫剂类EDCs对大型溞的毒性作用和生态环境风险评估提供依据。     

金刚石膜电极对有机污染物的电催化特性

研究了化学气相沉积法(CVD)制备得到的掺硼金刚石膜电极的物理性质和电化学性能.用扫描电子显微镜(SEM)法表征了金刚石膜的表面微观结构,采用循环伏安法和交流阻抗法研究了电极的电化学性质.结果表明,金刚石薄膜表面形态为复晶结构,颗粒大小均匀,掺硼后使电极具有良好的导电性能.金刚石膜电极具有很宽的电势窗口,在酸性、中性和碱性3种介质中分别为4.3V、4.0V和3.0V.同时,金刚石膜电极的背景电流非常低,为-9×10^-6～5×10^-7A.在铁氰化钾电解液中,金刚石膜电极表面在反应过程中始终保持良好的活性,在表面进行的电化学反应具有良好的准可逆性,其电极动力学主要是受扩散过程所控制.金刚石膜电极对有机污染物的催化氧化作用具有选择性.与铂电极和石墨电极相比,金刚石膜电极对苯酚、硝基苯等芳香化合物的催化氧化强烈,氧化过程较为简单、彻底.这些性质表明金刚石膜电极是一种非常适用于环保处理的新型电极.     

Phosphatase activity and culture conditions of the yeast Candida mycoderma sp. and analysis of organic phosphorus hydrolysis ability

Orthophosphate is an essential but limiting macronutrient for plant growth. About 67% cropland in China lacks sufficient phosphorus, especially that with red soil. Extensive soil phosphorus reserves exist in the form of organic phosphorus, which is unavailable for root uptake unless hydrolyzed by secretory acid phosphatases. Thus, many microorganisms with the ability to produce phosphatase have been exploited. In this work, the activity of an extracellular acid phosphatase and yeast biomass from Candida mycoderma was measured under different culture conditions, such as pH, temperature, and carbon source. A maximal phosphatase activity of 8.47 × 10^5±0.11× 10^5 U/g was achieved by C. Mycoderma in 36 hr under the optimal conditions. The extracellular acid phosphatase has high activity over a wide pH tolerance range from 2.5 to S.0 （optimum pH 3.5）. The effects of different phosphorus compounds on the acid phosphatase production were also studied. The presence of phytin, lecithin or calcium phosphate reduced the phosphatase activity and biomass yield significantly. In addition, the pH of the culture medium was reduced significantly by lecithin. The efficiency of the strain in releasing orthophosphate from organic phosphorus was studied in red soil （used in planting trees） and rice soil （originating as red soil）. The available phosphorus content was increased by 230% after inoculating 20 days in rice soil and decreased by 50% after inoculating 10 days in red soil. This work indicates that the yeast strain C. mycoderma has potential application for enhancing phosphorus utilization in plants that grow in rice soil.     

Microbial response to CaCO3 application in an acid soil in southern China

Calcium carbonate (CaCO₃) application is widely used to ameliorate soil acidification. To counteract soil and bacterial community response to CaCO₃ application in an acidic paddy soil in southern China, a field experiment was conducted with four different dosages of CaCO₃ addition, 0, 2.25, 4.5 and 7.5?tons/ha, respectively. After one seasonal growth of rice, soil physicochemical properties, soil respiration and bacterial communities were investigated. Results showed that soil pH increased accordingly with increasing dose of CaCO₃ addition, and 7.5?tons/ha addition increased soil pH to neutral condition. Moderate dose of CaCO₃ application (4.5?tons/ha) significantly increased soil dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) content, enhanced soil respiration, while the excessive CaCO₃ application (7.5?tons/ha) decreased these soil properties. High-throughput sequencing results illustrated that moderate dose of CaCO₃ application increased the richness and alpha diversity of soil bacterial community. Compared with control, the relative abundance of Anaerolineaceae family belonging to Chloroflexi phylum increased by 38.7%, 35.4% and 24.5% under 2.25, 4.5 and 7.5?tons/ha treatments, respectively. Redundancy analysis (RDA) showed that soil pH was the most important factor shaping soil bacterial community. The results of this study suggest that proper dose of CaCO₃ additions to acid paddy soil in southern China could have positive effects on soil properties and bacterial community.     

太原市城市化发展对城市气温变化影响的定量化研究

采用位于同一纬度的太原气象站与远郊区农村气象站获取的1957年-2014年的气象数据,用皮尔卡森相关系数、一元线性回归、城市化影响分析等方法研究了在全球气候变暖背景下城市地区气温变化趋势以及城市化影响.结果表明:城市年平均气温升高趋势明显高于农村;城市年极端高温与农村极端高温升高趋势差异不明显;城市年极端低温升高趋势显著高于农村.就城市化影响而言,城市化对年平均气温、年极端低温趋势影响明显,但对年极端高温趋势影响微弱.     

厦门石兜-坂头水库水体营养状态综合评价及变化趋势分析

以水质监测资料为基础,采用综合营养状态指数法（TLI法）和线性插值评分法（SCO法）2种模式,相互印证并综合评价2008．5—2011．6厦门石兜-坂头水库库区水体营养状态。应用Daniel的趋势检验,对评价时段内水库水体营养状态和水质参数（总氮、总磷以及氮磷浓度比）变化趋势进行分析。结果表明：2008年5月-2011年6月期间,石兜-坂头水库水体营养状态为中营养至轻-中度富营养;在此评价期内,总磷、总氮、氮磷比值趋势变化不显著;水体营养状态变化趋势也没有显著意义,始终在中营养至（轻-中度）富营养状态区间波动。水库周边环境及水质的监管措施能否及时到位是影响库区水体营养状态变化的关键。