长春市西湖灌区土壤砷污染调查与评价

通过对长春市西湖灌区62个样点土壤砷含量的调查,评价该区域砷的污染状况。方法选择灌区稻田地、菜地、玉米地,以未利用土地为对照,采集耕层土壤样品,测定砷的含量,结果与吉林省土壤背景值比较,利用污染累积指数法评价砷的污染程度。结果未利用地砷含量（P〈0．05）与吉林省土壤背景值（8．38mg／kg）没有显著差剐;稻田、菜地、玉米地耕层土壤砷的算术平均值分别为12．79mg·kg^-1、11．96mg·kg^-1、11．19mg·kg^-1,明显高于吉林省土壤砷的背景值;三种土地利用方式下土壤砷的污染累积指数范围在1．90-1．17之间,并且土壤累积指数随着距污灌渠（口）距离的增大而减小。结论长期利用污水灌溉,导致砷在长春市西湖灌区耕层产生累积．土壤受到一定程度的污染。应当引起关注。     

浮动床膜生物反应器去除焦化废水中间甲酚研究

焦化废水属有毒有害、难降解的高浓度有机废水,其中间甲酚等酚类污染物含量较高且用常用水处理方法去除比较困难。因此,研究了将浮动床生物膜反应器与膜生物反应器进行复合去除焦化废水中间甲酚的影响因素,并与普通MBR反应器在相同间甲酚浓度梯度下的处理功效进行比较。结果表明,在相同间甲酚浓度下,生物浮动床膜生物反应器的处理效果优于普通MBR反应器,其毒阈值为1200 mg/L,普通MBR反应器为1000 mg/L。同时,利用扫描电镜对浮动床膜生物反应器填料上微生物进行观察,考察了间甲酚浓度升高对填料上微生物的影响及附着态微生物形态的变化,得出大型微生物随着间甲酚浓度的提高最后破裂死亡;杆菌种类及数量减少,最后转变成丝状菌;球菌的菌胶团解体,形状变成短杆状。     

中国水资源存在的主要问题及合理开发利用新理念

水资源的时空分布不均、污染严重以及不合理的开发利用使得中国水资源相对短缺,供需矛盾日益加剧。本文在剖析中国水资源开发利用中存在问题的基础上,提出了几条中国水资源合理开发利用的新理念,以期能够用于改善目前水资源开发利用中的不合理现象,从而使中国经济长期可持续发展和社会的长治久安。     

超声波降解水溶液中甲醛的研究

研究了超声波场降解水溶液中甲醛的行为,并探讨了反应动力学方程。实验表明,超声波降解甲醛能够达到较高的降解率,但反应速率较低。甲醛的降解率随超声作用时间的延长而直线上升,在频率200kHz、功率200W的超声场作用4h后可达到90％左右。反应体系的最佳温度为30℃。在碱性区域甲醛的降解率出现大幅度的增加。溶液中溶解气体的种类对降解反应有一定的影响,降解速率顺序为O_3>空气>N_2。超声波降解甲醛的反应符合一级反应动力学模式。     

中和混凝与催化氧化法处理高浓度有机废水

以CODCr3000－8000mg/L,色度900－2000倍,pH＜1的难生化降解的有机废水为水样,采用中和混凝沉淀与催化作用为主的组合工艺对其进行处理试验,着重研究了有关的工艺条件与CODCr去除率的关系。结果表明：只要严格控制中和pH及混凝剂投量和催化氧化的药剂投量、氧化pH和时间,可以获得CODCr去除率为95％－96％的良好效果,同时排放水质中pH、SS和色度均达到排放标准。     

Numerical study of the effects of Planetary Boundary Layer structure on the pollutant dispersion within built-up areas

The effects of different Planetary Boundary Layer(PBL) structures on pollutant dispersion processes within two idealized street canyon configurations and a realistic urban area were numerically examined by a Computational Fluid Dynamics(CFD) model. The boundary conditions of different PBL structures/conditions were provided by simulations of the Weather Researching and Forecasting model. The simulated results of the idealized 2D and 3D street canyon experiments showed that the increment of PBL instability favored the downward transport of momentum from the upper flow above the roof to the pedestrian level within the street canyon. As a result, the flow and turbulent fields within the street canyon under the more unstable PBL condition are stronger. Therefore, more pollutants within the street canyon would be removed by the stronger advection and turbulent diffusion processes under the unstable PBL condition. On the contrary, more pollutants would be concentrated in the street canyon under the stable PBL condition. In addition, the simulations of the realistic building cluster experiments showed that the density of buildings was a crucial factor determining the dynamic effects of the PBL structure on the flow patterns. The momentum field within a denser building configuration was mostly transported from the upper flow, and was more sensitive to the PBL structures than that of the sparser building configuration. Finally, it was recommended to use the Mellor–Yamada–Nakanishi–Niino(MYNN) PBL scheme, which can explicitly output the needed turbulent variables, to provide the boundary conditions to the CFD simulation.     

The nitritation performance of biofilm reactor for treating domestic wastewater under high dissolved oxygen

The objective of this study was to investigate the nitritation performance in a biofilm reactor for treating domestic wastewater.The reactor was operated in continuous feed mode from phases 1 to 3.The dissolved oxygen(DO)was controlled at 3.5–7 mg/L throughout the experiment.The biofilm reactor showed excellent nitritation performance after the inoculation of nitrifying sludge,with the hydraulic retention time being reduced from 24 to 7 hr.Above 90%nitrite accumulation ratio(NAR)was maintained in phase 1.Afterwards,nitratation occurred with the low NH_4~+–N concentration in the reactor.The improvement of NH_4~+–N concentration to 20–35 mg/L had a limited effect on the recovery of nitritation.However,nitritation recovered rapidly when sequencing batch feed mode was adopted in phase 4,with the effluent NH_4~+-N concentration above 7 mg/L.The improvement of ammonia oxidizing bacteria(AOB)activity and the combined inhibition effect of free ammonia(FA)and free nitrous acid(FNA)on the nitrite oxidizing bacteria(NOB)were two key factors for the rapid recovery of nitritation.Sludge activity was obtained in batch tests.The results of batch tests had a good relationship with the long term operation performance of the biofilm reactor.     

上海市油气回收治理设施长效管理中若干问题的探讨

上海市目前有加油站700余家,分布在全市各个行政区县。数量多、分布广、相隔距离远,给管理带来一定难度。尤其是油品销售企业在对自身的管理中,缺乏针对环保设施的维护、保养制度。对于完成油气回收治理改造的加油站没有制定详细的对油气回收设施进行操作、维护的措施。正因为没有相应的制度,导致部分加油站的油气回收设施在失效的状态下仍然继续运作,挥发的油气得不到有效回收。本文通过针对上述问题进行客观分析,对环保主管部门在管理上提出几点建议。     

浅谈环境监测实验室前期内部设计过程中应注意的问题

文章结合作者自己站环境监测实验室建设的实际,提出了环境监测实验室建设的原则和理念,明确了实验室建设内部设计过程,并对环境监测实验室初期内部设计应关注的地方进行了阐述,给以后的环境监测实验室建设内部设计提供必要的借鉴。     

一种以人为本的城市绿地评价方法及其应用——以南京市城市绿地质量评价为例

文章基于"以人为本"的理念,构建了从使用者角度对城市绿地质量评价的简明指标体系,采用多边形综合指标法及德尔菲法,兼顾科学性和可操作性,并应用该指标体系尝试分析南京市城市绿地质量。结果表明:南京城市绿地总体质量处于一般水平,其中公园绿地和风景名胜与自然保护区绿地质量较高。在各项评价指标中,南京居民对绿地管理质量满意度较低,视觉效果满意度、空间布局满意度较高。该评价体系从使用者角度展现了城市绿地的整体水平并直观反映出城市绿地所存在的问题,可为城市绿地规划与管理以及综合评价指标的构建提供重要的依据与参考。