Effects of ferrous and manganese ions on anammox process in sequencing batch biofilm reactors

Ferrous and manganese ions, as essential elements, significantly affect the synthesis of Haem-C, which participates in the energy metabolism and proliferation of anammox bacteria. In this study, two identical sequencing batch biofilm reactors were used to investigate the effects of ferrous and manganese ions on nitrogen removal efficiency and the potential of metal ions serving as electron donor/acceptors in the anammox process. Fluorescence in situ hybridization analysis was applied to investigate the microbial growth. Results showed that the nitrogen removal increased at high concentrations of Fe2＋ and Mn2＋ and the maximum removal efficiency was nearly 95% at Fe2＋ 0.08 mmol/L and Mn2＋ 0.05 mmol/L, which is nearly 15% and 8% higher than at the lowest Fe2＋ and Mn2＋ concentrations （0.04 and 0.0125 mmol/L）. The stabilities of the anammox reactor and the anammox bacterial growth were also enhanced with the elevated Fe2＋ and Mn2＋ concentrations. The Fe2＋ and Mn2＋were consumed by anammox bacteria along with the removal of ammonia and nitrite. Stoichiometry analysis showed Fe2＋ could serve as an electron donor for NO3-N in the anammox process. Nitrate could be reduced with Fe2＋ serving as the electron donor in the anammox system, which causes the value of NO~-N/NH4-N to decrease with the increasing of N-removal efficiency.     

植被对风沙土风蚀作用的影响

以植物模型、风沙土为实验材料，以风洞模拟实验为研究手段得出初步结论：地表粗糙度为植被特征参数的函数，随植被盖度的增加呈幂函数增加；随植被作用区面积蛎呈线性增加；与行状植物的排列方向和主风向夹角的平方根成正比。在盖度相同的条件下，均匀分布较丛状分布可产生较大的粗糙度。风蚀率随植被盖度的减少呈指数增加。植被盖度对风沙土风蚀作用的影响可划分为３种程度类型：大于６０％为轻度风蚀和无风蚀。６０％￣２０％为中     

异养硝化微生物菌剂及其好氧颗粒污泥的脱氮试验

在3个相同的反应器(No.1、No.2、No.3)中,向活性污泥中投加异养硝化微生物菌剂,以批次试验和SBR试验的方式,研究了异养硝化微牛物菌剂对模拟废水的处理效果.结果表明,该菌剂可以大幅度提高活性污泥对氨氮和COD的去除率.批次运行试验中,反应器No.1运行3 d,氨氮去除率大于98.11%,COD去除率大于99%.该投加菌剂的活性污泥每克干污泥的脱氮能力为15.77 mg d-1.以SBR方式运行16 d的试验中,可能是由于功能菌株的流失导致3个反应器的脱氮效果有逐步降低的趋势.采用该异养硝化脱氮微生物菌剂培育出的异养硝化好氧颗粒污泥对模拟废水进行了脱氮试验.在较低运行温度(11～13℃)下以SBR方式运行10 d,反应器处理效果稳定,氨氮去除率70.75%～76.42%,COD去除率在90%以上.该异养硝化好氧颗粒污泥每克干颗粒的脱氮能力为372.00 mg d-1.以上试验都没有发现硝酸氮和亚硝酸氮的积累.图5表1参19     

基于硫酸根自由基(SO4-·)的污泥预处理技术

应用基于硫酸根自由基（SO4-·）的污泥预处理技术对抚顺某市政污水处理厂浓缩池剩余污泥进行预处理,强化污泥的过滤脱水性能。研究了最佳的氧化反应时间、S2O82-与Fe2+的最佳投加浓度与投加方式;并探讨了SO4-·对污泥特性的影响。结果表明,当S2O82-投加浓度为80 mg·g-1（以干物质计）,Fe2+和S2O82-的摩尔比为1:1,Fe2+按时间比10 min:20 min分2段投加时,在反应时间30 min内,污泥的过滤脱水性能达到最佳。此外,Fe2+活化S2O82-产生的SO4-·是强化污泥脱水的关键。同时,影响污泥脱水性能的胞外聚合物（extracellular polymeric substances,EPS）浓度和组成在氧化反应前后发生变化,污泥的脱水和过滤性能得到提高。     

泡沫镍负载Pr-N共掺杂TiO2的制备及其光催化性能

以泡沫镍为载体,钛酸丁酯为原料,采用溶胶-凝胶法制备Pr-N共掺杂TiO2光催化剂。利用X射线衍射(XRD)、紫外-可见漫反射光谱(DRS)、扫描电镜(SEM)对催化剂进行表征,结果表明,Pr和N的掺杂抑制了TiO2从锐钛矿晶型向金红石晶型的转变,提高了催化剂在可见光区的吸收能力。以孔雀石绿为目标模型化合物,利用正交实验得出当n(Pr)∶n(N)∶n(Ti)为0.0020∶0.2∶1、焙烧温度为400℃时制得的催化剂活性最高。同时,考察了Pr-N共掺杂、Pr掺杂、N掺杂及TiO2对孔雀石绿降解并利用傅立叶红外光谱对降解产物进行分析,实验表明,Pr-N共掺杂之后催化剂对孔雀石绿的降解率较改性之前提高了1.6倍。     

Laboratory assessment of uptake and toxicity of lanthanum (La) in the leaves of Hydrocharis dubia (Bl.) Backer

Increasing amounts of lanthanum (La) is released into aquatic environments. However, little information is available on the influence of La on aquatic plants. In this study, physiological and ultrastructural responses of Hydrocharis dubia (Bl.) Backer leaves to elevated concentrations of La (up to 160???M) were investigated. The accumulation of La was found to be increased in a concentration-dependent manner. La disturbed the intrinsic balance of nutrient elements (P, Mg, Ca, Fe, K, and Zn). Pigment content decreased with the rise of the La concentrations and the EC₅₀ value for chlorophyll was 20???M on day?7. The antioxidants (superoxide dismutase, peroxidase, catalase, reduced ascorbate, and reduced glutathione) exhibited varied response to the La treatments. Malondialdehyde content enhanced gradually at all La concentrations. The enhancement in proline content was found in a concentration-dependent manner. The amounts of three polypeptides with apparent molecular weights of 61.9, 51.5, and 16.7?kDa, respectively, were gradually diminished, as well as one existing polypeptides with apparent molecular weight of 22.3?kDa, elevating in response to increasing La concentrations. Significant damage to the chloroplast, mitochondrion, and nucleus was imposed by La indicated a general disarray in the cellular functions. The negative effects of La on H. dubia unequivocally indicate that La could exert an adverse influence on aquatic ecosystem and should lead to a more careful discharge of such elements into water environment.     

热处理对脱水污泥溶解特性及厌氧消化性能的影响

分别对脱水污泥在100、130和170℃条件下进行热处理,研究热处理对脱水污泥溶解特性的影响。此外,在半连续式完全混合反应器中进行厌氧消化实验研究不同热处理污泥的厌氧消化性能。实验结果表明,在100、130和170℃条件下,污泥COD溶解率由处理前的5.23%分别提高至20.08%、22.50%和27.20%,脱水污泥热处理规律和效果与高含水率污泥(总固体含量<5%)基本一致。经130℃2 h和170℃30 min高温热处理后污泥甲烷产率显著提高,较原泥分别提高24.64%和38.61%,沼气中甲烷含量稍有降低。     

生物过滤塔处理实验室废气

研究了生物过滤塔处理实验室排放的模拟混合废气,考察了反应器对苯、甲苯、二甲苯、乙醇、丙酮、乙酸乙酯和甲烷等废气的去除效果。运行结果表明,在设备稳定运行期间,进气中总挥发性有机物(TVOCs)的浓度为124～380 mg/m3,而出气浓度在10～40 mg/m3,去除效率保持在85%以上。实验室废气中的多种污染物在生物过滤塔中去除机理不同,亲水性污染物的去除效率高于疏水性污染物。通过系统关停后重启,污染物的去除效果在第2天就能恢复,这为生物过滤塔处理实验室废气过程的停运检修或者系统闲置提供了可行性。     

壳聚糖络合-陶瓷膜耦合技术处理低浓度含铜废水

采用孔径为200 nm的陶瓷膜,以壳聚糖为络合剂,研究了络合-陶瓷膜耦合技术处理低浓度含铜废水过程。考察了溶液pH、壳聚糖/ Cu2+质量浓度比、络合剂浓度、离子强度、操作压力及体积浓缩因子等对处理效果的影响。结果表明,壳聚糖投加量与pH是影响处理效果的关键因素,当壳聚糖/Cu2+质量浓度比≥10、pH=6时,Cu2+截留率接近100%,膜通量趋于稳定;在较高浓度外加盐(NaCl和Na2SO4)存在时,Cu2+截留率仍可达到99%以上。将壳聚糖-铜络合物浓缩液酸化解络后通过陶瓷膜过滤分离壳聚糖和游离态的Cu2+,可实现壳聚糖的循环回用;采用回用的壳聚糖处理含铜废水时,Cu2+截留率可达到95.8%。