聚醋酸乙烯储罐氮封系统失效原因分析与对策

聚乙烯醇是一种用途相当广泛的水溶性高分子聚合物,某企业采用醋酸乙烯溶液聚合生产聚醋酸乙烯溶液,聚醋酸乙烯溶液再经过醇解反应生产聚乙烯醇。在聚乙烯醇装置醇解罐区共有12个储罐用于储存聚醋酸乙烯,分析储罐氮封系统现状,存在尾气管道积液不畅、呼吸阀频繁开启、供氮阀不按设定值开闭等问题,从本质安全的角度,提出了解决措施,确保储罐安全运行。     

Study of control strategy and simulation in anoxic-oxic nitrogen removal process

The control strategy and simulation of external carbon addition were specially studied in an anoxic-oxic(A/O) process with low carbon: nitrogen(C/N) domestic wastewater. The control strategy aimed to adjust the flow rate of external carbon dosage to the anoxic zone, thus the concentration of nitrate plus nitrite(NOx^- -N) in the anoxic zone was kept closed to the set point. The relationship was studied between the NOx^- -N concentration in the anoxic zone(SNo) and the dosage of external carbon, and the results showed that the removal efficiency of the total nitrogen(TN) could not be largely improved by double dosage of carbon source when SNO reached about 2 mg/L. Through keeping SNO at the level of about 2 mg/L, the demand of effluent quality could be met and the carbon dosage could be optimized. Based on the Activated Sludge Model No. 1 (ASM No. 1), a simplified mathematical model of external carbon dosage was developed, Simulation results showed that PI controller and feed-forward PI controller both had good dynamic response and steady precision. And feed-forward PI controller had better control effects due to its consideration of influent disturbances.     

利用聚磷菌快速内源性反硝化脱氮研究

从部分聚磷菌在缺氧状态下的反硝化吸磷现象出发，探索了利用经过厌氧释磷，菌体内含有大量PHB的聚磷菌进行快速内源性反硝化脱氮的可能性。试验结果表明：聚磷菌在厌氧段充分有效释磷后，在缺氧段初期3—5min内，就能将30—40mg／L的NO^-3；内源性反硝化脱氮去除65％—75％，达到一级排放标准。     

An estimate of the conversion rates of SO2 to SO2-4 and NO2 to HNO3+ NO3- for the evaluation air pollution in Beijing

The conversion rates of SO₂ to SO^2-₄ and NO₂ to HNO₃₊NO₃- are estimated from the field-data obtained in Beijing in summer, 1988. The results show that the conversion rate of NO₂ is about four times as much as that of SO₂; The conversion rates have a diurnal variation in a day. On the average, the rate of SO₂ is estimated to be 4.7% h^-1 during the daytime and 3.4% h^-1 during the nighttime. Similarly, the rate of NO₂ is estimated to be 17.2% h^-1 and 12% h^-1 respectively.     

滇池沉积物间隙水中氮、磷形态及相关性的研究

对滇池40个样点沉积物间隙水中的氮、磷形态与浓度分析研究结果表明，滇池沉积物间隙水中磷的区域分布特征与其在水体中的分布特征相似，滇池南部间隙水中无机磷浓度较高，有机磷的浓度极低，而北部有机磷浓度较高；间隙水中氨氮（NH4^＋ -N），浓度高出硝酸盐氮（NO3^- -N）浓度约2个数量级，间隙水中氮向上覆水的扩散主要以氨氮为主．滇池沉积物间隙水中氮、磷浓度远高于水体中氮磷浓度，有较强的释放趋势．进一步研究间隙水中氮、磷的关系则表明，沉积物间隙水中总磷和总氮未见明显相关性，但间隙水中总磷、有机磷均与硝酸盐态氮呈负相关．     

δ~(15)N和δ~(18)O指标识别环境中N_2O生成机理

δ15N和δ18O指标在识别环境N2 O生成机理中具有重要的作用。本文主要讨论δ15N指标在识别海洋、土壤和污染水体N2 O生成机理中的作用 ;分析硝化和反硝化作用引起的同位素分馏特征 ;并对δ18O指标的应用进行了探讨。     

鸭绿江口的溶解无机氮

本文讨论了１９９６年５月鸭绿江溶解无机氮的含量和分布变化特征，并同其他一些河口作了比较，鸭绿江口ＮＯ３－Ｎ，ＮＯ２－Ｎ，ＮＨ４－Ｎ的平均含量分别为５０．３．０．４５和３．０５μｍｏｌ／Ｌ，而丹东上游鸭绿江支流瑗河下降的溶解无机氮浓度很高，达２０３．４μｍｏｌ／Ｌ，主要由农业施用氮肥大量从耕用地中流失所致。     

外源稀土微肥对土壤氮磷养分的影响

通过小区试验和盆栽试验，研究了施加不同的浓度稀土微肥对土壤中有效氮、有效磷浓度以及土壤脲酶活性的影响。结果表明，施加高浓度稀土微肥将会影响土壤中有效氮和有效磷的浓度。在分析与之相关的土壤酶活性时发现，施加低浓度的稀土微肥（≤１ｍｇ／ｋｇ）促进土壤脲酶活性并增加土壤有效氮浓度，而施加高浓度稀土微肥（≥５ｍｇ／ｋｇ）则明显的抑制土壤脲酶活性并减少土壤有效氮浓度；施加稀土元素浓度与土壤有效磷浓度之间有较     

沈阳区域环境空气中一氧化氮与二氧化氮时空分布规律

以沈阳区域环境空气监测分析结果为依据 ,分析了 1 994～ 1 998年内空气中一氧化氮与二氧化氮时空分布状况及其变化趋势     

碳源循环单级生物脱氮技术研究

开发了一种列管式固定化细胞生物反应器，其特征在于硝化菌和反硝化菌被混合固定于中空的PVA凝胶管的管壁之中，PVA凝胶管平行置于圆柱形筒体内，构成一个类似于列管式换热器的生物脱氮反应器。需要处理的氨氮废水在固定化细胞管的外侧与圆柱形壳体的内侧间流动，而反硝化所需的碳源（乙醇水溶液）则在PVA凝胶管内循环。研究了列管式固定化细胞生物反应器进行单级生物脱氮的可行性和连续运行的效果，并证明了在非纯菌种的固定化细胞单级生物脱氮过程化细胞生物反应器进行单级生物脱氮的可行性和连续运行的效果，并证明了在非纯菌种的固定化细胞单级生物脱氮过程中，存在着NH^ 4→NO^-2→N2的短积生物脱氮。