WETLANDS AS ACCRETING SYSTEMS: NUTRIENT CYCLING IN WETLANDS

SUMMARY

The major concepts involved in nutrient cycling in wetlands are discussed using phosphorus and nitrogen as examples. The differences in nutrient cycling patterns between hydrologically contrasting wetlands, and the significance of fluctuating water levels in wetlands, are stressed. In South Africa, some research into nutrient cycling in submerged aquatic macrophyte communities has been undertaken, but very little information is available on these processes in wetlands dominated by emergent vegetation forms. Generally, the information available on nutrient cycling processes in South African wetlands is of limited applicability to the assessment of nutrient cycling in whole wetland systems. Therefore, rational wetland management strategies require further research on nutrient cycling.     

WETLANDS AS ACCRETING SYSTEMS: INORGANIC SEDIMENTS

SUMMARY

Concepts dealing with factors affecting the origin, transport and deposition of inorganic sediments as well as their role in the functioning of wetland systems are discussed. The lack of quantitative data, particularly for South African systems, is emphasised. Research priorities, which will lead to a better understanding of inorganic sediment: wetland interactions and allow for rational exploitation of wetlands, are proposed.     

固定化微生物细胞技术在废水处理中的应用*

固定化微生物细胞技术是一门新兴的生物技术,中较为全面地介绍了其定义、分类及载体选择。该技术用于处理高浓度有机废水,含氨氮、难降解、重金属废水非常有效,在废水处理领域有着广阔的应用前景。     

生物膜法和SBR法相结合处理难降解制药废水的研究

采用生物膜法和SBR法相结合的废水处理工艺处理含抗生素类等难降解的制药废水 ,对生物膜的耐冲击负荷能力、生物膜对进水可生化性的影响、生物膜对好氧SBR活性污泥性能的影响、pH对系统去除效果的影响等工艺条件进行研究 ,并通过与传统SBR处理工艺的对比试验 ,进一步揭示了生物膜法和SBR法相结合的处理工艺强的耐冲击负荷能力。     

微生物固定化处理甲醇废水的实验研究

将具有降解甲醇能力的微生物固定于颗粒活性炭,组成固定化微生物反应器,考察其对甲醇废水的处理效果,结果表明,微生物固定化生物反应器处理甲醇废水的最佳条件是ｐＨ７－８,温度２０～３０℃,空气曝 气,甲醇去除率在９０％以上。     

两种生物电化学系统原位缓解人工湿地生物堵塞效果

生物电化学系统(Bio-electrochemical Systems, BES)利用附加电场或自产电场可以促进EPS分散、降解和利用,可在一定程度上控制和缓解人工湿地的生物堵塞。为此,研究采用CW-MEC和CW-MFC两种生物电化学系统对不同生物堵塞时期的人工湿地进行干预,通过比较系统直观堵塞指标(孔隙率、出水速率)、净化效果(COD和氮的去除)及垂直方向上分层EPS的含量等来评价不同干预时机,两种BES系统对生物堵塞的缓解能力。结果表明:两种BES系统均能体现较好的堵塞缓解效果。堵塞前干预, CW-MFC系统能很好地维持污染物COD、TN去除效果(91.4%—61.3%和65%—40%)并提高出水速率(变化率为CW组67.6%);堵塞后修复,CW-MEC系统能显著减少上层EPS含量,恢复系统孔隙率,具有更好的缓解堵塞效果。这两种BES系统原位缓解人工湿地生物堵塞方面皆有较好的应用潜力。     

解烃细菌处理油田污水的研究

从油田污水中分离到一组可高效降解石油烃的混合菌群F6。室内模拟实验证明,该菌群适于油田含油污水的净化处理。采用粒状活性炭为载体的生物流化床系统处理辽河油田“兴一联”（辽河油田兴隆台第一联合站）污水,可使含油量由45mg/L降至4.1mg/L、CODcr由 470mg/L降至42mg/L。处理后的石油污水达到国家石油污水一级排放标准。     

利用丝状绿藻处理含汞污水的试验

用刚毛藻科的丝状绿藻为材料,进行了藻类处理含汞(HgCl2)污水的试验。Hg++浓度为0.5,1.0,2.0,5.0和10.0毫克/升,鲜藻与污水的重量之比为1∶100,4小时内,汞的去除率为70%。进行了藻类连续去汞能力的测定,10克鲜藻依次放入4个含汞污水的水样中(水量均为1升,Hg++浓度平均为3.61毫克/升),在每个水样停留时间为6小时,结果汞的去除率分别为76.8,78.4,61.8,53.1%,平均为67.5%,藻类含汞浓度以鲜重计算达到970ppm。利用藻类四级串联处理含汞量为4.0毫克/升的污水,停留时间共计24小时,总去除率达94%。从试验结果看来,藻类对汞的去除,主要是借助于表面吸附与细胞积累作用,与藻类的光合作用无关。但是0.1—10毫克/升的汞,都明显地抑制藻类的光合放氧,这种抑制作用在藻类接触汞4小时以后表现出来。       

SEASONAL SUCCESSION OF ALGAL PERIPHYTON FROM A WASTEWATER TREATMENT FACILITY1

Attached algal populations were sampled at weekly or biweekly to characterize successional changes in the secondary clarifiers of a wastewater treatment plant. Three communities were compared from areas of slow, medium and rapid current velocities. In general, the algae resembled those reported for other hypereutrophic flowing water. Of the twenty-three algae recorded, Stigeoclonium, Oedogonium, Oscillatoria, Lyngbya, and Pleurocapsa were dominant at some point in the 15 month sampling period. Nutrient concentrations were consistently high (N = 1.1–21.4 mg·L⁻¹; P = 0.1–10.4 mg·L⁻¹); therefore, changes in temporal distribution of algae were probably dependent on seasonal changes in light and temperature. Colonization of artificial substrates was also observed. Small unicellular algae were the first autotrophs to attach and these were followed by larger filamentous forms.     

生物滴滤池在处理重油裂解制气废水中的应用

用多孔填料填充废水处理系统缺氧/好氧（A/O）工艺中的缺氧滴滤池,微生物挂摸之后构成三维的生物膜,处理可生化性差的重油裂解制气废水,不但能显提高废水的可生物降解性,BOD5/COD从进水0.16-0.25提高到出水时的0.24-0.45,而且降低废水中的COD和氨氮分别为4.76%-44.21%和1.93%-44.20%,同时能增强缺氧池的抗冲击能力和减毒作用,有利于后续的活性污泥好氧处理。     

上流式厌氧污泥床处理废液及其有关剖析

国内用上流式厌氧污泥床（ＵＡＳＢ）常温处理酵母废液的试验为数不多,本工作旨在启动ＵＡＳＢ装置中培育颗粒污泥,从而提高水处理程度。文中阐述了实验过程,且通过电镜考察污泥的微生物相,发现其间出现的“准颗粒污泥态”,同时还分析了工艺中产生的一种物质的“抑制临界状况”,推测对”完全的颗粒污泥态”的形成造成了阻遏。文中同时分析了发现的其它现象,对探索酵母废液ＵＡＳＢ常温处理深度的进一步提高有所裨益。