脱硫脱硝技术展望

论述了脱硫脱硝技术现状 ,通过分析比较得出 :湿法脱硫投资和运行成本高 ,产生的副产品无法进行再利用 ;电子束烟气脱硫脱硝技术投资和运行比湿法脱硫低20%～30%,但需要严格庞大的放射线防护设施 ,电子加速器昂贵 ,电子能量损失大。笔者提出强电离放电可以将烟气中的SO₂ 氧化 ,然后生成固体微粒 (NH₄)₂SO₄,提高反应速率 ,简化流程 ,有望真正解决我国的SO₂ 和NO_x。      

水污染源总量控制方法研究

以济南市的水污染源为基础,从排污量、废水组成、产污环节、污染物种类等方面对水污染源进行调查与分析,建立了水污染源各要素的多级递阶结构评价体系,采用层次分析法基础上的模糊评判法筛选出22家代表性企业,并对其连续等比例加密监测,研究浓度-时间、排水量-时间和排污负荷-时间之间的变化关系,得出水污染源排放的浓度主导型、水量主导型、混合型、生活污水型4种排污规律,为水污染源实行浓度控制和总量控制双轨制管理、实施污染物总量监测提供技术支持.      

高压电晕与臭氧联用降解对硝基苯酚

利用臭氧的强氧化性和电晕的高能量降解有毒有害大分子为较低毒性的小分子,以提高可生化性.在pH8～9的条件下,高压电晕与臭氧联用处理对硝基苯酚模拟废水30min,对硝基苯酚的降解率为96.8%,TOC的降解率为38.6%.设计了先电晕后臭氧、先臭氧后电晕分别处理和电晕与臭氧联用处理3种实验方案,结果表明:电晕与臭氧联用处理效率要高于分别处理效率,电晕与臭氧联用具有协同作用;对降解含苯环的大分子效率高,对降解直链分子的效率相对较低.     

上海市截流外排工程污水扩散影响数值研究

城市污水截流外排工程是上海市城市水环境整治的重大战略。文章以CODCr为例,数值模拟研究了上海近岸水域东、南、西三大截流外排干线不同排污方案下污染物的输移扩散规律。结果表明,长江口的水动力条件有利于污水的稀释扩散;在现状排污条件下,无论洪枯季,引起的环境水体污染物CODCr浓度增量均不大,能够满足长江口水环境容量的要求;对于规划排放量的污水,预处理和一级处理条件下引起的环境水体污染物CODCr,浓度增量较为显著,对周围敏感目标的影响也比较大;二级处理条件下所引起的污染浓度增量比较小,对水环境的影响相对较小。因此,在规划城市污水外排工程时,建议必须近期和远期相结合,合理充分利用水体自净能力。     

微波无极灯:一种具有前景的高效光催化光源

微波无极灯具有制造容易、价格低廉、能耗小和光强大等优点。作为光催化氧化的光源时,由于微波的协同作用可有效提高光催化活性,并能简化反应器。从发光机理、微波协同作用、优缺点和影响因素等方面,对微波无极灯在光催化领域的研究进行详细阐述。     

金属铁还原脱氯处理有机氯化物的研究进展

本文对金属铁在还原降解六氯乙烷、四氯化碳、氯仿、三氯乙烯、四氯乙烯、二氯乙烯、氯乙烯、五氯酚、多氯联苯等有机氯化物中的应用作了评述 ,讨论了金属铁降解有机氯化物的反应机理及动力学。     

综合评分法筛选水污染物排放控制因子

控制因子筛选是工业水污染物排放标准制定的重要环节。控制因子筛选应从工业原材料主要成分、排放污染物种类分析着手,逐步缩小备选名单范围。对进入初始名单的污染物,通过综合评分法评价其毒性和暴露水平两方面因素,选择潜在危害指数、年排放量和环境检出率三个指标,制定评分标准,根据各污染物得分情况确定其在排放标准中加以控制的必要性,并以此为主要参考依据确定控制因子。     

Estimating Annual Groundwater Evapotranspiration from Phreatophytes in the Great Basin Using Landsat and Flux Tower Measurements

Escalating concerns about water supplies in the Great Basin have prompted numerous water budget studies focused on groundwater recharge and discharge. For many hydrographic areas (HAs) in the Great Basin, most of the recharge is discharged by bare soil evaporation and evapotranspiration (ET) from phreatophyte vegetation. Estimating recharge from precipitation in a given HA is difficult and often has significant uncertainty, therefore it is often quantified by estimating the natural discharge. As such, remote sensing applications for spatially distributing flux tower estimates of ET and groundwater ET (ET_g) across phreatophyte areas are becoming more common. We build on previous studies and develop a transferable empirical relationship with uncertainty bounds between flux tower estimates of ET and a remotely sensed vegetation index, Enhanced Vegetation Index (EVI). Energy balance‐corrected ET measured from 40 flux tower site‐year combinations in the Great Basin was statistically correlated with EVI derived from Landsat imagery (r² = 0.97). Application of the relationship to estimate mean‐annual ET_g from four HAs in western and eastern Nevada is highlighted and results are compared with previous estimates. Uncertainty bounds about the estimated mean ET_g allow investigators to evaluate if independent groundwater discharge estimates are “believable” and will ultimately assist local, state, and federal agencies to evaluate expert witness reports of ET_g, along with providing new first‐order estimates of ET_g.     

Mineralization of aqueous pentachlorophenolate by anodic contact glow discharge electrolysis

Exhaustive mineralization of pentachlorophenolate ion (PCP) in phosphate buffer was carried out using anodic contact glow discharge electrolysis (CGDE), in which plasma was sustained between the electrolyte and anode. During CGDE, PCP degraded smoothly. The amount of total organic carbon decreased significantly, indicating the eventual conversion of the carbon atoms of benzene nucleus to inorganic carbons. Furthermore, chlorine atoms in PCP were liberated as chloride ions. As a primary intermediate product, 2,3,5,6- tetrachloro-1,4-benzoquinone was detected, and oxalate and formate as byproducts were also found. It was revealed that disappearance of PCP obeyed first-order kinetics. The reaction rate was generally unaffected by both O2 and inert gases in the cell, although it decreased by raising initial pH of solution. In addition, a plausible reaction pathway involving hydroxyl radical was proposed.     

非平衡等离子体治理有机含磷气体的实验研究

采用脉冲电晕放电产生的等离子体对沙林毒剂的模拟剂甲基磷酸二甲酯进行消除研究.着重进行了脉冲峰压、脉冲频率、初始质量浓度、气体流量等对消除率的影响实验.结果发现,消除率随脉冲峰压和脉冲频率的增加而提高,随气体流量和初始质量浓度的增大而降低.同时发现产物中含有C02、H2O、丙酸、甲基磷酸甲酯和磷酸(或P2O5)等物质.