煤矸石制取聚羟基氯化铝的研究

介绍了用煤矸石制取聚羟基氯化铝的方法,研究了酸浸、调整盐基度等过程的最佳工艺过程。     

应用原子力显微镜研究盐度对棕囊藻生长的影响

研究不同盐度梯度下棕囊藻的生长,实验设计了10个盐度梯度,结果表明:在盐度8~32范围内,棕囊藻的生长正常,最佳生长盐度为16,当盐度低于8或高于32时,藻的生长明显受到抑制,细胞数量增长缓慢,最大细胞数远低于16盐度组。研究发现:棕囊藻在盐度为0的环境下仍能缓慢生长,说明海洋中的棕囊藻赤潮在内陆的淡水湖也可能暴发,用原子力显微镜研究比较盐度为0及36的棕囊藻细胞表面形态,发现两者差异较显著,前者藻细胞的直径大于后者,且后者藻细胞表面形成了明显的塌陷。     

洪水入海对养殖环境影响的数值分析

基于三维流体动力学和热力学原始方程 ,采用σ坐标变换技术 ,建立了三维斜压场数值模型。模型采用ADI格式求解连续方程和动量方程 ,采用FS法和TVD格式求解各标量方程 ,从而使模型的精度提高到二阶 ,并且节省运算时间。利用建立的三维斜压场数值模型 ,对鸭绿江洪水期形成的低盐水体的分布进行了数值模拟 ,进而分析了鸭绿江洪水入海对黄海北部海域的海水养殖业的可能影响。鸭绿江特大泄洪形成的超低盐混浊水体入侵 ,是筏养扇贝致死的主要原因。及时预报大洪水影响下的低盐水体分布 ,可有效地防止洪水污损灾害。     

复合污染中Triton X-100在膨润土/水界面上的吸附行为

研究了水溶液中膨润土对非离子表面活性剂Triton X-100(X-100)的吸附,重点探讨了阳离子表面活性剂CPC、阴离子表面活性剂SDBS、中性无机盐NaCl及温度对膨润土吸附TX-100的影响.结果表明,Na基膨润土吸附TX-100的效果好于Ca基膨润土;低浓度CPC对膨润土吸附TX-100具有增强作用,当CPC初始浓度大于l0000 mg·L-1(平衡浓度Ce约为1CMC)时具有抑制作用,当CPC浓度低于3000 mg·L-1(Ce约为0.03CMC)时,TX-100吸附量与CPC浓度成线性正相关.SDBS能显著降低膨润土对TX-100的吸附,原因是溶液中SDBS与TX-100混合胶束的形成能阻止TX-100与膨润土硅氧表面间的氢键作用及在其表面形成胶束.NaCl的存在可以大大提高膨润土对TX-100的吸附,去除率由56%提高到99%以上.膨润土对TX-100的吸附随温度升高吸附量增大,其吸附热为12.68 kJ·mol-1,标准自由能的减小和熵值的增大是TX-100在膨润土上吸附的推动力.实验结果对用膨润土处理含表面活性剂废水具有一定的理论价值.     

Effects of seawater salinity on nitrite accumulation in short-range nitrification to nitrite as end product

The effect of seawater salinity on nitrite accumulation in short-range nitrification to nitrite as the end product was studied by using a SBR. Experimental results indicated that the growth of nitrobacteria was inhibited and very high levels of nitrite accumulation at different salinities were achieved under the conditions of 25--28℃, pH 7.5--8.0, and the influent ammonia nitrogen of 40--70mg/L when seawater flow used to flush toilet was less than 35% (salinity 12393 mg/L, Cl^- 6778mg/L) of total domestic wastewater flow, which is mainly ascribed to much high chlorine concentration of seawater. Results showed that high seawater salinity is available for short-range nitrification to nitrite as the end product. When the seawater flow used to flush toilet accounting for above 70% of the total domestic wastewater flow, the removal efficiency of ammonia was still above 80% despite the removal of organics declined obviously(less than 60% ). It was found that the effect of seawater salinity on the removal of organics was negative rather than positive one as shown for ammonia removal.     

河北省曲周县盐渍土区土壤养分含量的动态变化

对华北盐渍土区河北省曲周县 79个土壤样点 1 980年和 1 999年土壤养分含量进行了分析 ,结果表明 :1 999年与 1 980年相比 ,土壤有机质含量增加了 41 % ,土壤全氮和速效磷含量分别增加了 1 0 2 %和 351 % ,而土壤速效钾含量则下降了 38% ;土壤有机质含量增加的原因是秸秆还田量增加 ,土壤中全氮、速效磷含量增加的直接原因是土壤中氮肥、磷肥投入量增加 ,而土壤速效钾下降的原因则是钾肥的施入量不足。对不同质地土壤养分含量变化分析表明 ,质地可控制养分的空间分配 ,但人为干预促进了土壤养分含量向均一化方向发展。对不同质地土壤有机质含量与表层含盐量进行相关分析表明 ,表层为轻壤时 ,土壤有机质含量与表层含盐量具有明显的负相关性。     

外源亚精胺对盐胁迫下黄瓜根系多胺含量和抗氧化系统的影响

采用营养液栽培,研究了外源亚精胺(Spd)对盐胁迫下抗盐能力不同的2个黄瓜品种"长春密刺"和"津春2号"幼苗根系生长以及根系中多胺(PAs)含量和抗氧化系统的影响.结果表明,外源Spd提高了盐胁迫下黄瓜根系游离态Spd和精胺(Spm)、酸可溶性结合态和酸不溶性结合态腐胺(Put)、Spd和Spm含量,降低了游离态Put含量;同时提高了超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,降低了超氧阴离子(O2(-/.))产生速率、过氧化氢(H2O2)和丙二醛(MDA)含量及电解质渗透率,明显促进了幼苗根系生长;根系中酸不溶性结合态Spd含量与抗氧化酶活性间呈正相关性.表明黄瓜幼苗根系中较高的游离态Spd和Spm、酸可溶性结合态和酸不溶性结合态PAs尤其是酸不溶性结合态Spd含量有利于提高植株抗氧化酶活性,降低O2(-/.)产生速率和膜脂伤害,增强植株抗盐性.     

外生菌根真菌接种和施磷对油松苗抗盐性的影响

采用3种不同的外生菌根真菌Boletus edulis、Xerocomus chrysenteron和Gomphidius viscidus，在山东东营盐渍土环境胁迫下，研究外生菌根真菌接种和施磷对油松(Pinus tabulaeformis)生长的影响及其可能机理。结果表明，接种和施磷都增加了油松植株的干质量，但施磷不如接种对植物生长的促进作用明显；接种外生菌根后，油松体内的K元素含量显著增加，而Na元素的含量没有明显变化，使得w(K)／w(Na)增加，从而改变了植株体内的离子平衡，减轻离子的毒害作用。而不是通过直接减少植物对Na的吸收来增加植物的抗盐性；同时，接种后外生菌根增加了油松对P的吸收，改善了盐渍土壤导致的植物营养亏缺，促进了植物在盐渍环境下的生长。     

Land Evaluation in a Salt-Affected Irrigated District Using an Index of Productive Potential

2 semiarid irrigated area with salt-affected soils. The available soil map is at 1:100,000 scale and its mapping units are used for the land evaluation with the FAO framework. These data are then elaborated using the index value method. This procedure gives a map of land evaluation units and a table that rates the productive potential of these units for six crops: alfalfa, barley, maize, rice, sunflower, and wheat.     

Growth of Plants on TBT-contaminated Harbour Sludge and Effect on TBT Removal (10 pp)

Background Worldwide, large amounts of sediments have to be dredged annually from waterways and harbours. These sediments are sometimes polluted with a variety of toxic compounds. In some countries, including Belgium, the load with the biocide tributyltin (TBT) from ship coatings prohibits the dumping of harbour sludge into the sea. Land-based dumping is a commonly used alternative. Objective This research investigated the feasibility to use land-deposited harbour sludge for plant production. In a field trial, the growth of 38 more or less salt-tolerant plant species on low and high TBT-contaminated sediments was studied. The elimination of TBT from sludge with and without vegetation was compared. The uptake of TBT and its degradation products di- and monobutyltin (DBT and MBT) into harvest products under field conditions was determined. - Experimental Set-up. Sediments dredged in May 2003 from the brackish waters of the port of Antwerp were analysed in the laboratory for soil texture, pH, electroconductivity, sodium, magnesium, potassium, calcium, ammonium, nitrate, total nitrogen, chloride, sulphur and the organotins TBT, DBT and MBT. The sediments were lagooned for one year to dewater, desalinate and improve their structure. Salt-tolerant domestic and wild plants were selected and sown in May 2004. In August 2004, plants were harvested and the produced biomass was determined. Samples were taken from vegetated and non-vegetated top and bottom sediments and from plants growing above soil and analysed for TBT, DBT and MBT. Results The fresh sediments showed a good supply with nutrients and a neutral pH, but were rather saline (EC 14 mS cm-1 of the saturated paste extract). The salinity decreased to 3.7 mS cm-1 during lagoonation. The high and the low contaminated sediment had initially 43 and 1.6 mg TBT kg-1 dry weight, respectively. Besides TBT, several other contaminants were present in the sediments at critical levels. The biomass production of the plant species from the field trial ranged from 0.2 to 13 tons dry mass per hectare. Plants performing excellently were barley, sorghum, rape seed, a clover/grass mix and reed. If at all, a positive influence of TBT on plant growth was seen. TBT was degraded significantly faster (>40%) below barley. The uptake of TBT, DBT and MBT into stem and leaves of reed, grass and clover was very low, but measurable and not related to concentrations in soil. No uptake of TBT or its metabolites into corn of barley was found. Discussion This study confirmed former results: the toxicity of TBT to higher plants is low, and even high levels in soils would not be a hindrance for crop production. The removal of TBT seemed to be increased by both lagooning and plant growth, although the target values for sea dumping in use in certain European countries were not reached. A plausible explanation for the faster degradation of TBT under vegetation is that oxygen is a limiting factor, and plants dewater the soil, thus aerating it. The uptake of the organotins TBT, DBT and MBT into harvest products is probably due to attached soil particles. Conclusions To summarize, barley was the optimal species: it grew very well despite the salinity of the dredged sediments, it had a significantly positive effect on TBT removal; it showed no measurable uptake of TBT or the other butyltins into the harvested product; and it is a cash crop well established in European agriculture. Outlook The amounts of dredged sediments are high, and good soils are becoming increasingly rare. The feasibility of using dredged sediments for non-food production, such as energy crops, should be investigated by a critical risk assessment.