活化粉煤灰对垃圾渗滤液的COD吸附作用研究

随着经济的发展和居民生活水平的提高,城市中产生的垃圾越来越多,严重污染城市环境.为此,主要研究了活化粉煤灰对垃圾渗滤液COD的吸附.试验结果表明,活化粉煤灰用量对COD的去除率的影响最大,其次是反应时间、反应温度、垃圾渗滤液的pH值和垃圾渗滤液浓度.在最佳条件下,活化粉煤灰对垃圾渗滤液COD去除率达95.8%.     

UASB反应器酸化后的状态及恢复研究

进行了三组两相厌氧工艺中产甲烧相(UASB)反应器的酸化试验研究，考察了酸化后的状态并采取了三种不同的酸化后恢复手段。结果表明，反应器酸化后表现为COD去除率下降、PH值下降、碱度值下降、产气率减少，同时ORP值上升，菌群组成也发生明显变化；在恢复过程中用贮留的产甲烷相出水快速置换反应器中含有高浓度有机酸的污水，是反应器酸化后的快速恢复手段；工程运行中COD的常规监测有利于防止反应器的酸化；反应器气体产量可作为工程运行的指示性参数。     

Tolerance of limpograss (PI 364344) to excess manganese in acid soil and nutrient solution

Previous studies showed that limpograss, Hemarthria altissima (Poir), Stapf & C. E. Hubb (PI 364344) was tolerant to low temperature and to high concentrations of Al in acid soil, mine spoil and nutrient solution. Additional experiments were conducted to test the tolerance of this limpograss clone to excess Mn, another potential growth‐limiting factor in acid soils.

Cuttings from a single plant were grown in pots of Mn‐toxic Zanesville soil with no lime (pH 5.1) and 1250 ppm CaCO (pH 6.3) and in nutrient solutions containing 0, 4, 8, 16, 32 or 64 ppm Mn at pH 4.0. The grass was highly tolerant to excess Mn in both media. Liming the soil from pH 5.1 to 6.3 did not significantly affect top dry weight of the first harvest and significantly decreased that of the second. In nutrient solutions at pH 4.0 top dry weights were not significantly affected by Mn concentrations up to 64 ppm. Root dry weights were significantly increased by Mn additions of 16, 32 and 64 ppm. Limpograss (PI 364344) was not injured when Mn concentrations were as high as 930 and 9152 ppm in tops and roots, respectively. High Mn tolerance is yet another trait that should enhance the potential use of this grass in revegetating acid mine spoils and other acid sites.     

Changes in Root Cell Wall Chemistry Induced by Manganese Exposure with Two Tobacco Genotypes

Abstract

Induced effects by manganese (Mn) uptake on root cell walls of two tobacco (Nicotiana tabacum L.) genotypes KY 14 (Mn sensitive) and T.I. 1112 (Mn tolerant) were evaluated. The tobacco genotypes were grown in half‐strength Hoagland solutions containing 0 (deficient), 46 (non‐toxic), and 300 µM (toxic) Mn. Root cell walls were isolated and characterized for total polysaccharides, proteins, and individual sugars and amino acids. For both genotypes, the largest and significant difference (P ≤ 0.01) in cell wall polysaccharides and proteins were between Mn levels of 0 and 46 µM. Either deficient or toxic levels of Mn exposure decreased uronic acid, a component of cell wall pectins although the decrease was smaller in T.I. 1112 than in KY 14. Beside uronic acid, significant changes in arabinose, galactose, and rhamnose contents were also observed in cell wall pectins. In addition, toxic level of Mn exposure greatly elevated serine in T.I. 1112 whereas the Mn deficient condition generally reduced serine but increased proline in both genotypes. Serine and hydroxyl‐proline are major amino acid components of extension, a major cell wall structural protein. The results suggest that Mn deficiency and toxicity may affect both metal uptake and mechanical characteristics of tobacco root cell walls. Manganese‐induced changes in root cell wall chemistry appear to differ from the effects of metal stresses of non‐essential elements such as aluminum (Al) and sodium (Na).     

锌、锰对棉花吸收氮、磷养分的影响及机理研究

较高或较低浓度的土壤锌、锰影响棉花对氮、磷养分的吸收、而合适的土壤锌、锰浓度能促进棉花根系和地上部对氮、磷的吸收和积累。提高植株及茎、叶、蕾、铃中氮、磷的含量,对棉花的生产发育,产量及产量构成因素都表现出明显的促进作用,通过水培试验研究发明,锌、锰在一定浓度条件下所表现的促进作用,主要是提高了棉花植株的根系活力,增加棉株叶片的叶绿素含量,调节棉株体内的酶活性,从而增加了棉花对营养物质的吸收、运输和代谢、提高了氮、磷的利用率、增加棉花的产量。     

家畜尿样COD测定中稀释倍数的探讨

综合相关研究资料,对利用CODCr法测定家畜尿样中COD值时样本的稀释倍数进行了探讨。通过计算确定适宜稀释倍数范围为30~50倍,并比较不同稀释倍数对家畜尿样中COD含量的影响,结果显示最佳稀释倍数为30倍。另外对测定过程中的不确定因素进行了分析。     

滇池主要入湖河流水质分析

 对滇池流域的4条入湖河流的总磷、总氮、COD污染进行了调查。结果表明，随着流域内旱雨季变化、河流流量变化、河流地段变化，总磷、总氮、COD含量存在明显差异。入湖口水样总磷、总氮、COD含量明显高于同一河流中、上游。雨季河流流量增加，总磷、总氮、COD含量仍明显增高，特别是雨季前期，由于旱季大量有机物在地面堆积，土壤有效P累积，雨后随地表径流进入河道，使COD、TP增加明显，持续降雨后又有下降趋势。     

四种含木质纤维素原料在牛粪液中的酸化

为了有效转化木质纤维素原料,提高其资源化、能源化利用潜力,研究了干稻秸、玉米秸、草坪草、新鲜状态玉米秸和风干玉米秸这4种木质纤维素原料在牛粪液环境中的酸化发酵规律。监测发酵过程,以质量减少率分析了原料降解效率,以溶解性化学需氧量(soluble chemical oxygen demand,SCOD)评价酸化产物的积累。结果表明,4种原料在牛粪液中的降解效果明显,规律不同。草坪草的质量减少最快且最多,质量减少率为73.25%。稻秸在10d时与草坪草质量减少率均达到50%,总质量减少率为72.01%。鲜玉米秸在18d时质量减少率为68.36%,接近草坪草和稻秸,总质量减少率为71.64%。干玉米秸总质量减少率最低,为57.6%;木质纤维素总量的降解效率依次为:稻秸>草坪草>鲜玉米秸>干玉米秸。其成分中,各原料半纤维素的降解效率最好,其次为纤维素和木质素;干、鲜玉米秸产生有机酸种类和数量较多,稻秸、草、鲜玉米秸、干玉米秸的产生挥发性脂肪酸(volatile fatty acid,VFA)总量最大值依次为3.91、0.54、7.16、10.99g/L。将酸化产物作为厌氧发酵原料角度分析,稻秸和草坪草在酸化过程中可实现SCOD积累,对厌氧发酵有利,而干、鲜玉米秸的酸化作用对厌氧发酵不利。     

厌氧流化床净化畜禽废水与产电性能

为实现从畜禽废水处理中回收能源,先后以厌氧沼液、低浓度畜禽原水及高浓度畜禽原水作为进水,利用厌氧流化床双室微生物燃料电池(anaerobic fluidized bed microbial fuel cell,AFB-MFC)进行微生物产电及有机物去除研究,重点考察氨态氮质量浓度及COD(化学需氧量)容积负荷对系统COD去除率及产电性能的影响。结果表明:以稀释后的沼液作为进水时,当氨态氮质量浓度达到387.6mg/L时,氨态氮对产电微生物产生明显的短期抑制,产电量下降7.0%,但经过5d的适应期后,系统产电恢复到原来的水平。以畜禽原水作为进水时,系统COD容积负荷在12d内由2.3kg/(m3·d)提升至14.9kg/(m3·d)时,COD去除率保持在74.5%～88.1%;随着容积负荷的提升,系统产电量上升,但上升幅度较小,最高输出电压为379.3mV,相应的面积功率密度为74.9mW/m2;由于进水pH值的差异,高浓度畜禽原水最高输出电压较低浓度畜禽原水低21.4mV;AFB-MFC系统内阻较低,仅为48.5Ω,此时功率密度为75.6mW/m2。本装置实现了畜禽废水的高效处理,同时获得电能,为其资源化处理提供新途径。