Treatability studies of naphthalene in soil,water and air with persulfate activated by iron(Ⅱ)

Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO₄], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO₄] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.     

Regulated emission characteristics of in-use LNG and diesel semi-trailer towing vehicles under real driving conditions using PEMS

On-road driving emissions of six liquefied natural gas(LNG) and diesel semi-trailer towing vehicles(STTVs) which met China Emission Standard IV and V were tested using Portable Emission Measurement System(PEMS) in northern China.Emission characteristics of these vehicles under real driving conditions were analyzed and proved that on-road emissions of heavy-duty vehicles(HDVs) were underestimated in the past.There were large differences among LNG and diesel vehicles, which also existed between China V vehicles and China IV vehicles.Emission factors showed the highest level under real driving conditions, which probably be caused by frequent acceleration, deceleration, and start-stop.NOx emission factors ranged from 2.855 to 20.939 g/km based on distance-traveled and 6.719–90.557 g/kg based on fuel consumption during whole tests, which were much higher than previous researches on chassis dynamometer.It was inferred from tests that the fuel consumption rate of the test vehicles had a strong correlation with NOx emission, and the exhaust temperature also affected the efficiency of Selected Catalytic Reduction(SCR) aftertreatment system, thus changing the NOx emission greatly.THC emission factors of LNG vehicles were 2.012–10.636 g/km, which were much higher than that of diesel vehicles(0.029–0.185 g/km).Unburned CH_4 may be an important reason for this phenomenon.Further on-road emission tests, especially CH_4 emission test should be carried out in subsequent research.In addition, the Particulate Number(PN) emission factors of diesel vehicles were at a very high level during whole tests, and Diesel Particulate Filter(DPF)should be installed to reduce PN emission.     

高浓度印染废水处理工程工艺条件与实例分析

研究以三相生物流化床作为工程化反应器处理印染废水的工程工艺条件及操作特性，分别测定流化床内的气相含率，兴体循环速度及体积氧传质系数。     

氟化物在包气带中动态吸附模型的试验研究

从质量作用定律出发 ,根据土柱淋滤试验的原理和方法 ,通过对氟化物在包气带地层中的吸附、迁移规律的总结和研究 ,提出了污染的动态吸附模型及吸附参数的确定方法 ,并采用相关系数检验法予以确定     

上海市在用车推行I/M制度中检测方法的研究

对在用车实施I/M制度，采用底盘测功机模拟道路工况检测汽车排放污染物，按美国国家环保局（EPA）推荐的方法有3种：瞬态短工总法（IM240）、稳态加速模拟工况法（ASM）和瞬态短工部简易质量分析检测法（VMAS）。根据上海市的试验结果，对上述3种方法的检测精度、设备投资以及运行维护诸方面进行分析比较，阐明上海市采用VMAS方法的依据和应注意的问题，并对应采用的模拟道路工况提出了看法。     

模拟垃圾填埋场稳定化过程研究

采用垃圾填埋堆体模拟装置，对杭州市城市生活垃圾在１９９８年２月至１９９８年１０月期间稳定化过程中的垃圾渗滤液水质指标变化、堆体内部温度变化、垃圾减量化、沉降高度和产气量进行了研究，装入模拟装置的２２１ｋｇ生活垃圾经８个月的降解后，垃圾减量化显著，总量降至１２７ｋｇ，其中有机组分由９４．８ｋｇ（４２．９％）降至２０．９３ｋｇ（１６．５％），无机组分由７２．７１ｋｇ（３２．９％）降至５３．６５ｋｇ（４     

Graphical strategies for design of evaporation crystallization networks for environmental wastewater applications

This paper introduces graphical strategies for the design of an evaporation/crystallization network for ternary wastewater environmental applications. Sources, sinks and other streams are located on a ternary composition diagram. While a source is any wastewater stream that has the potential to be recycled, a sink is any unit in the process that can accept sources. The proposed methodology is extremely simple to understand and implement, as it only requires basic solid-liquid phase equilibria data and uses lever arm principles to generate alternative process designs. Geometric constructions are carried out on the ternary composition diagram and the respective lever arms are used to determine intermediate flow rates in the evaporation/crystallization network. The relative locations and flow rates of the sources and sinks under consideration, as well as the unique shape of the solid-liquid equilibrium, drive the design of the separation (via evaporation/crystallization) network. Some generic structures are proposed for a typical evaporation and crystallization network. Once the general problem statement has been defined, special cases consisting of a single source-single sink, single source-two sinks and two sources-single sink are described. These special cases are representative of commonly occurring industrial wastewater design problems. Several graphical insights are listed that allow one to represent evaporation and crystallization operations on a ternary triangular composition diagram and avoid mathematical complexity. The possibility of bypassing a part of the initial feed streams is also considered. Certain feasible composition regions are identified on the ternary composition diagram for cases dealing with multiple sources and sinks. The methodology is useful in pre-screening and eliminating certain sources/sinks and is readily applicable to cases with lower number of sources and sinks. A case study involving the ammonium nitrate manufacturing process is included to demonstrate the broad applicability and value of the proposed approach.     

火焰原子吸收法测定水中的总铬

用火焰原子吸收光谱法测定水中总铬,乙炔流量100L/h、燃烧头高度为9mm、狭缝宽度0.2 nm时,灵敏度和重现性最好.1 mg/L铬溶液中盐酸含量5％、氯化铵含量0.5％时,吸光度较高,相对标准偏差最低.该方法操作简便,灵敏度好,精确度和准确度高,便于推广,适合水中总铬的测定.     

地表水和地下水中的砷、硒同时测定

通过利用双道原子荧光法,同时对地表水和地下水样品中砷、硒进行测定,具有操作更加简单、监测分析速度快、节省试剂等优点。     

Hypsographs: Basic tools for lake management and monitoring

Hypsographs are graphic depictions of the vertical distributions of volumes or masses of water in lakes, ponds, or reservoirs. Quantitative limnological science or engineering must use a hypsograph, or a more complex equivalent system, to undertake calculations of water constituent concentration data by mathematical weighting. Construction of the graph is simple and described. Exemplary uses of the hypsograph are presented.