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231.
232.
对北京市通州区H再生水厂采用的A2/O+MBR工艺运行效果与不同环节碳排放特征进行研究.结果表明:2018年该再生水厂对BOD5,CODcr,NH4+-N,TN和TP的平均去除率分别为97.3%,94.1%,98.6%,77.0%,96.2%;全厂碳排放总量和吨水碳排放量呈春夏季节逐渐降低,秋冬季节缓慢升高的特征,全厂综合吨水碳排放量约为2.26kgCO2e/t.碳排放总量中能耗碳排放量占主要地位,CH4,N2O和物耗碳排放量占比较小;统计分析显示CH4,能耗和物耗吨水碳排放量与BOD5,TN进水浓度及BOD5去除率显著相关;N2O吨水碳排放量与TN与BOD5进水浓度显著相关;直接,间接吨水碳排放量与水量无显著相关性. 相似文献
233.
Junling Li Hong Li Xuezhong Wang Weigang Wang Maofa Ge Hao Zhang Xin Zhang Kun Li Yan Chen Zhenhai Wu Fahe Chai Fan Meng Yujing Mu Abdelwahid Mellouki Fang Bi Yujie Zhang Lingyan Wu Yongchun Liu 《环境科学学报(英文版)》2021,33(4):185-197
Understanding the formation mechanisms of secondary air pollution is very important for the formulation of air pollution control countermeasures in China. Thus, a large-scale outdoor atmospheric simulation smog chamber was constructed at Chinese Research Academy of Environmental Sciences (the CRAES Chamber), which was designed for simulating the atmospheric photochemical processes under the conditions close to the real atmospheric environment. The chamber consisted of a 56-m3 fluorinated ethylene propylene (FEP) Teflon film reactor, an electrically-driven stainless steel alloy shield, an auxiliary system, and multiple detection instrumentations. By performing a series of characterization experiments, we obtained basic parameters of the CRAES chamber, such as the mixing ability, the background reactivity, and the wall loss rates of gaseous compounds (propene, NO, NO2, ozone) and aerosols (ammonium sulfate). Oxidation experiments were also performed to study the formation of ozone and secondary organic aerosol (SOA), including α-pinene ozonolysis, propene and 1,3,5-trimethylbenzene photooxidation. Temperature and seed effects on the vapor wall loss and SOA yields were obtained in this work: higher temperature and the presence of seed could reduce the vapor wall loss; SOA yield was found to depend inversely on temperature, and the presence of seed could increase SOA yield. The seed was suggested to be used in the chamber to reduce the interaction between the gas phase and chamber walls. The results above showed that the CRAES chamber was reliable and could meet the demands for investigating tropospheric chemistry. 相似文献
234.
Chen G Lee H Young KL Yue PL Wong A Tao T Choi KK 《Waste management (New York, N.Y.)》2002,22(7):747-753
An innovative approach of using waste glass in cement production was proposed and tested in a laboratory and cement production plant. The laboratory characterization of 32 types of glass show that the chemical composition of glass does not vary significantly with its color or origin but depends on its application. The alkali content of glass, a major concern for cement production varies from 0 to 22%. For the glass bottles mainly found in Hong Kong waste glasses, the alkali content (Na2O) ranges from 10 to 19% with an average around 15%. There is no significant change of the SO2 content in the gas exhaust of the rotary kiln when about 1.8 t/h of glass bottles were loaded along with the 280-290 t/h raw materials. The content of NOx, mainly depends on the temperature of the kiln, does not show significant change either. The SO3 content of the clinker is comparable with that obtained without the loading of glass. The alkaline content shows a slight increase but still within three times the standard deviation obtained from the statistical data of the past year. The detailed analysis of the quality of the cement product shows that there is not any significant impact of glass for the feeding rate tested. 相似文献
235.
Xu Xiaoyang Zhou Jihai Chen Kun Wang Yang Ai Yanmei Zhang Chenyang Zhou Shoubiao 《Environmental science and pollution research international》2022,29(35):52483-52492
Environmental Science and Pollution Research - Cadmium (Cd) pollution has led to a serious deterioration in soil quality, plant growth, and human health. Therefore, restoration of soil quality is... 相似文献
236.
天然沸石及改性沸石去除低浓度氨氮的研究 总被引:15,自引:4,他引:11
研究了天然斜发沸石在不同的酸、碱和盐改性条件下吸附去除氨氮(NH4+-N)的效果.结果表明:沸石吸附NH4+-N动力学曲线符合“快速吸附、缓慢平衡"的特点,且初始ρ(NH4+-N)越高,吸附速率越快;天然沸石及其改性沸石吸附NH4+-N为单分子层吸附过程,其吸附热力学曲线很好地符合Langmuir曲线. 沸石吸附NH4+-N是吸热反应,适当提高温度能够促进NH4+-N的吸附. 盐改性方法对沸石吸附NH4+-N的效果最好,增加了沸石的比表面积和总孔容,同时有利于沸石的再生. 相似文献
237.
城市道路旁小蜡叶片对重金属的富集特征 总被引:2,自引:0,他引:2
通过对合肥市市区交通干线、城郊公路和植物园道路(对照区)的土壤,以及道路绿化灌木小蜡(Ligustrum sinense)叶片中Cu,Zn,Pb,Cd和Cr含量的测定,分析城市交通产生的大气重金属污染物在土壤和植物叶片中的富集特征.结果表明,公路交通和车辆尾气排放产生的重金属污染物能够显著地在土壤和小蜡叶片中富集.公路土壤中富集的Cu,Zn,Pb和Cr之间有着较高的相关性,且富集量与道路车流量有着明显的正相关.小蜡叶片富集的Cu,Zn,Pb,Cd和Cr主要来自于道路交通产生的大气重金属污染物,同土壤中相应重金属元素的相关性较差,而且市区干线的叶片富集量高于城郊公路,城郊公路高于对照点.雨水的冲刷能够减少小蜡叶片表面重金属的含量,同时小蜡叶片对重金属的富集,在4月至7月的富集速度或富集增量高于7月至10月,这与小蜡叶片的生长趋势相一致. 相似文献
238.
Kun‐Yeun Han Sang‐Ho Kim Deg‐Hyo Bae 《Journal of the American Water Resources Association》2001,37(3):695-708
ABSTRACT: This study developed a QUAL2E‐Reliability Analysis (QUAL2E‐RA) model for the stochastic water quality analysis of the downstream reach of the main Han River in Korea. The proposed model is based on the QUAL2E model and incorporates the Advanced First‐Order Second‐Moment (AFOSM) and Mean‐Value First‐Order Second‐Moment (MFOSM) methods. After the hydraulic characteristics from standard step method are identified, the optimal reaction coefficients are then estimated using the Broyden‐Fletcher‐Goldfarb‐Shanno (BFGS) method. Considering variations in river discharges, pollutant loads from tributaries, and reaction coefficients, the violation probabilities of existing water quality standards at several locations in the river were computed from the AFOSM and MFOSM methods, and the results were compared with those from the Monte Carlo method. The statistics of the three uncertainty analysis methods show that the outputs from the AFOSM and MFOSM methods are similar to those from the Monte Carlo method. From a practical model selection perspective, the MFOSM method is more attractive in terms of its computational simplicity and execution time. 相似文献
239.
240.
为评价大气颗粒物污染对人群心血管疾病死亡的急性效应,应用时间分层的病例交叉设计,分析了杭州市2002~2004年间大气可吸入颗粒物(PM10)日平均浓度短期增加与人群每日心血管疾病死亡的关系,同时分析了其他气态污染物(NO2和SO2)的急性健康效应.结果表明,调整气象因素后单污染物模型显示,滞后期为2d,PM10、SO2、NO2日平均浓度每增加10μg/m3与人群心血管疾病死亡的比值比(OR)分别为1.006[95%可信区间(CI):1.003~1.009],1.017(95%CI:1.007~1.028)和1.020(95%CI:1.009~1.032).多污染物模型中,PM10受到SO2影响,效应估计值略有下降,OR值为1.004(95%CI:1.000~1.009).其他污染物效应则无统计学意义. 相似文献