Nitrogen removal in sequencing batch reactor

ＮｉｔｒｏｇｅｎｒｅｍｏｖａｌｉｎｓｅｑｕｅｎｃｉｎｇｂａｔｃｈｒｅａｃｔｏｒＷａｎｇＦｕｚｈｅｎ；ＰｅｎｇＹｏｎｇｚｈｅｎ；ＹｕＥｒｊｉｅ；ＬｉＢａｉｋｕｎ（ＨａｒｂｉｎＡｒｃｈｉｔｅｃｔｕｒａｌａｎｄＣｉｖｉｌＥｎｇｉｎｅｅｒｉｎｇＩｎｓｔｉｔｕ...     

SBBR同步硝化反硝化处理生活污水的影响因素

序批式生物膜反应器SBBR采用塑料鲍尔环填料,在有氧情况下用于处理实际生活污水.该反应器能很好地创造缺氧微环境,载体生物膜具有吸附储碳能力,出现了良好的同步硝化和反硝化现象.反应器中溶解氧浓度在较大的范围内(0.8～4.0 mg·L-1)能有效地实现同步硝化和反硝化.当溶解氧浓度大于4.0 mg·L-1后,TN容积去除率大幅下降,出水TN大幅上升.增加载体生物膜厚度有利于同步硝化和反硝化.进水浓度基本不影响脱氮的效率,但出水TN随进水浓度增加而升高,建议原水浓度高时可增加后续脱氮处理或减少进水量来满足出水要求.优化运行方法和参数后,SBBR连续运行的TN去除率可稳定在74%～82%.     

Impact of triazophos insecticide on paddy soil environment

ＩｎｔｒｏｄｕｃｔｉｏｎＲｉｃｅｉｓｔｈｅｓｔａｐｌｅｄｉｅｔａｒｏｕｎｄ 3 0 %ｏｆｔｈｅｗｏｒｌｄｐｏｐｕｌａｔｉｏｎａｎｄａｒｏｕｎｄ 60 %ｏｆｔｈｅＡｓｉａｎｐｏｐｕｌａｔｉｏｎ .Ｔｈｉｓｃｒｏｐｉｓｐｒｅｆｅｒｅｎｔｉａｌｌｙｏｒｇｅｎｅｒａｌｌｙｃｕｌｔｉｖａｔｅｄｕｎｄｅｒｓｕｂｍｅｒｇｅｄｓｏｉｌｃｏｎｄｉｔｉｏｎｓｆｏｒｒｅａｓｏｎｓｏｆｂｅｔｔｅｒｙｉｅｌｄｓａｎｄｔｏｐｏｇｒａｐｈｉｃａｌｓｉｔｕａｔｉｏｎｓ(Ｒｅｉｃｈａｒｄｔ,1 997) .Ｔｈｅｉｍｐｏｒｔａｎｃｅｏｆｓｏｉｌｍ…     

生物陶粒流化床-污泥滤层脱氮工艺的试验研究

采用生物陶粒流化床-污泥滤层工艺对含氮有机废水处理进行试验研究,研究结果表明:系统内可固着生长不受抑制的硝化菌种群,氨氮去除率可以达到93%￣95%;三相分离区形成稳定的污泥滤层,可使总氮去除率得以显著提高;当HRT为1.5h,曝气量为0.25m3/h,BOD容积负荷为9.2～10.4BOD5/m3.d,总氮容积负荷0.65kgTN/m3.d条件下,可得到BOD5的去除率85%,总氮去除率74%的处理效果。     

饮用水反硝化脱氮方法研究

为去除饮用水中的硝酸盐氮(NO3ˉ-N)，采用上流式厌氧污泥床(UASB)反应器和固定化微生物进行异养反硝化；自制固定化反硝化菌涂层电极和生物电化学脱氮装置，并用于自养反硝化。试验结果表明。若以甲醇为碳源。当碳氮比(C／N)≥1．o时，室温下经UASB处理4h，NO3ˉ-N去除率为97．7％；若以乙酸为碳源。当C／N≥1．0时，30C下经固定化微生物处理6h，N03ˉ-N去除率为98．6％；在无外加碳源的条件下处理东湖现场水样，30C下经60h后。N03ˉ-N去除率达93．5％。生物电化学脱氮装置可迅速建立自养反硝化菌所需的厌氧环境，水样在室温下经72h处理，脱氮率达96．3％。     

GROUND WATER NITRATE REDUCTION IN GIANT CANE AND FOREST RIPARIAN BUFFER ZONES1

ABSTRACT: Ground water contamination by excess nitrate leaching in row‐crop fields is an important issue in intensive agricultural areas of the United States and abroad. Giant cane and forest riparian buffer zones were monitored to determine each cover type's ability to reduce ground water nitrate concentrations. Ground water was sampled at varying distances from the field edge to determine an effective width for maximum nitrate attenuation. Ground water samples were analyzed for nitrate concentrations as well as chloride concentrations, which were used as a conservative ion to assess dilution or concentration effects within the riparian zone. Significant nitrate reductions occurred in both the cane and the forest riparian buffer zones within the first 3.3 m, a relatively narrow width. In this first 3.3 m, the cane and forest buffer reduced ground water nitrate levels by 90 percent and 61 percent, respectively. Approximately 40 percent of the observed 99 percent nitrate reduction over the 10 m cane buffer could be attributed to dilution by upwelling ground water. Neither ground water dilution nor concentration was observed in the forest buffer. The ground water nitrate attenuation capabilities of the cane and forest riparian zones were not statistically different. During the spring, both plant assimilation and denitrification were probably important nitrate loss mechanisms, while in the summer nitrate was more likely lost via denitrification since the water table dropped below the rooting zone.     

SCR反应塔入口段烟气速度场的数值模拟

使用商业计算软件CFX5．7．1，采用标准k-ε湍流模型，模拟了SCR脱硝反应塔入口段烟气速度场，并分析比较了导流板对烟气速度场的影响及均匀SCR反应塔进口处烟气速度场的作用。     

再燃法烟气脱硝技术

综述了再燃法烟气脱硝技术及其主要影响因素。通过对几种脱硝技术的分析比较，认为再燃脱硝是一种很有前景的脱硝技术，其投资和运行费用界于低NO。燃烧器和选择性催化还原技术之间，有喷氨条件下的先进再燃脱硝效率接近于选择性催化还原技术。总结了国内外对先进再燃脱硝技术各种参数影响条件的研究结果，并论述了该技术的应用要点。     

运用批实验研究溶解氧对米酒去除硝酸盐的影响

为了判别不同溶解氧条件下脱氮效果和碳的需求量,在水温为25~30℃条件下,设置了缺氧、微氧和有氧3种输入条件,以及C/N分别为2.0、1.5两种碳源投放量开展实验。研究表明:溶解氧的存在对反硝化作用的启动有延迟作用,但影响较小。溶解氧对于反硝化过程并没有产生明显的抑制作用,但在溶解氧较低的情况下,反硝化速率更为理想。缺氧条件下,C/N的适宜值应低于1.5;微氧条件下的C/N适宜值在1.5~2.0;而在有氧条件下C/N=2.0时可高效去除硝酸盐。该研究可为农村地区家庭自行去除饮用水中硝酸盐的实际应用提供参考。     

铁炭内电解垂直流人工湿地对污水厂尾水深度脱氮效果

针对污水厂尾水总氮(TN)含量偏高、微生物可利用碳源低的问题,构建铁炭内电解垂直流人工湿地(ICIE-VFCW)装置,研究了ICIE-VFCW对尾水的处理效果,并采用紫外-可见光光谱(UV-VIS)、凝胶过滤色谱(GFC),进一步探讨了ICIEVFCW强化脱氮机制.结果表明,ICIE-VFCW可提高系统对尾水中COD的去除,出水COD可稳定在30 mg·L~(-1)以下,全年、暖季、寒季COD平均去除率较普通垂直流人工湿地分别可提高10.16%、9.81%、11.22%.系统出水TN可维持在10 mg·L~(-1)以下,全年、暖季、寒季TN平均去除率较普通垂直流人工湿地分别提高13.72%、12.90%、16.17%.经过人工湿地处理后,污水中有机物的腐殖度、芳香度及相对分子质量(Mr)均有所下降,且ICIE-VFCW中Mr下降更为明显.湿地基质掺杂铁炭可促进尾水中大分子有机物转化为小分子,为微生物提供更多可利用碳源,从而提高脱氮效率.