人工湿地填料有机堵塞问题的化学溶脱法室内模拟

用化学溶脱法解决人工湿地填料的有机堵塞,结果表明:用碱类、酸类、强氧化剂和洗涤剂可以使有效孔隙率和渗透系数均有不同程度的增加,以强氧化剂类(次氯酸钠)最为明显,可以使渗透系数恢复到原来的69%;三种溶液都对基质中的微生物类群和基质酶产生了伤害,但是经过7d可以基本恢复,说明解决人工湿地有机堵塞的问题可以借鉴和尝试"溶脱法".     

Mechanical Property and Biodegradability of Cast Films Prepared from Blends of Oppositely Charged Biopolymers

Biodegradable cast films of about 50 m thickness were fabricated by blending oppositely charged biopolymers such as anionic starch–chitosan, and cationic starch–pectin. The tensile strength and elongation at break (%) of films were evaluated as well as their capacity to degrade in compost. Films recovered from soil every 48 h showed consistent degradation (weight loss), diminution of the polymers characteristic peak absorbance in the carbohydrate fingerprint region of the FTIR, and changes in the surface morphology via scanning electron microscopy (SEM). Anionic starch–chitosan films had much superior tensile strength and elongation compared to cationic starch–pectin, suggesting that the ionic bonds formed between anionic-starch and positively charged groups in chitosan polymer were much more stable and stronger. Initially, both films lost about 36% weight within 96 h, which also correlated well with the loss in the characteristic absorption peaks in the region of the infrared spectrum typical of biopolymers. The total mineralization of films by microorganisms in compost soil was also measured using respirometric techniques. Though the rate of mineralization differed for two formulations, total mineralization (extent) for both films were achieved within 45 days.     

氨基酸双子表面活性剂复配增溶PCE性能研究

利用氨基酸双子表面活性剂N,N'-双月桂酰基乙二胺二丙酸钠(DLMC)及其复配体系来提高四氯乙烯(PCE)在地下水中的溶解性,强化去除效果.测定了 DLMC的初级生物降解性并将其与短链醇(异丙醇IPA,乙醇)和传统表面活性剂十二烷基硫酸钠(SDS),辛基苯基聚氧乙烯醚(TX-100)和聚氧乙烯脱水山梨醇单油酸酯(Twe...     

苯并[a]蒽与肺表面活性剂混合磷脂的相互作用

为探究多环芳烃对肺表面活性物质(PS)膜的影响,选取1,2-二棕榈酰-sn-甘油-3-磷酸胆碱(DPPC)和1-棕榈酰-2-油酰-sn-甘油-3-磷酸胆碱(POPC)混合磷脂为PS模型,研究了苯并[a]蒽与DPPC/POPC混合磷脂的界面化学相互作用.结果表明,苯并[a]蒽对DPPC/POPC混合膜的相变影响显著,会削...     

S-TE剩余污泥溶解过程中VSS的变化研究

从土壤中筛选出1株能分泌胞外酶、促进污泥溶解的嗜热脂肪芽孢杆菌Bacillus stearothermophilusAT07-1,将AT07-1培养液接种到不同浓度（TSS约为7.5、14.5、20.5 g/L）的剩余污泥中,于65℃进行嗜热菌溶解试验,并与未接种试验进行对比。结果表明,接种嗜热菌AT07-1促进了污泥中悬浮固体的溶解。60h时接种试验VSS的溶解率分别为61.41%、53.79%、41.86%,比不接种试验同期分别提高了27.57%、25.24%、16.26%。试验条件下VSS溶解过程在初始阶段（t=3d）符合一级反应动力学模型,接种后溶解速率常数Kd显著提高,从0.12 d-1、0.08 d-1、0.09 d^-1分别增加到0.27 d^-1、0.24 d^-1、0.13 d^-1。     

微气泡臭氧强化污泥碳源的释放过程

臭氧处理污泥后释放的碳物质可作为低碳市政污水生物处理的重要碳源补充。为突破传统臭氧处理效率低等问题,研究采用微气泡臭氧技术以强化污泥碳源释放效果。结果表明,在臭氧投加量为200 mg O3·（g SS）-1时,污泥SCOD增长了1 964 mg·L-1,为传统臭氧处理的2.1倍,DDCOD由18.1%上升至41.5%,污泥碳源释放效果显著提高。同时确定了微气泡臭氧处理在臭氧浓度为100.0 mg·L-1,污泥浓度为5 g·L-1,污泥初始pH为9的条件下,污泥碳源矿化损失较小且污泥碳源释放效果较好,在臭氧投加量为160 mg O3·（g SS）-1时污泥SCOD增长了1 923 mg·L-1,DDCOD达到41.2%。与传统臭氧处理相比,微气泡臭氧处理能提高臭氧传质效率与间接反应强度,更有利于污泥碳源的释放。     

玉米根内和根际土壤溶磷细菌生物学特性研究

从玉米根内和根际土壤中分离筛选到22株溶磷细菌。根据16SrRNA基因序列分析,2株溶磷效果最好的菌株分别被鉴定为伯克霍尔德氏菌(Burkholderia sp.SY9)和泛菌(Pantoea sp.Gym7c)。同时对菌株SY9和Gym7c的溶磷能力和植物促生特性进行了进一步研究。利用磷酸钙和开阳磷矿矿粉研究了菌株释放P、Ca和Fe的效能。液体培养条件下,菌株在在磷酸钙培养基中的生长好于在开阳磷矿粉培养基中的生长,同时菌株能够合成铁载体。菌株SY9从开阳磷矿粉中释放P、Ca,和Fe的能力比菌株Gym7c强。然而菌株Gym7c从磷酸钙中释放P和Ca的能力比菌株SY9强。菌株Gym7c主要是通过合成的有机酸溶解磷酸钙并释放其中的P和Ca,而菌株SY9是通过合成的有机酸和铁载体溶解开阳磷矿粉并释放出其中的P、Ca,和Fe。溶解开阳磷矿粉的有机酸主要是葡萄糖酸而溶解磷酸钙的有机酸主要包括丁二酸、丙酸、苹果酸和酒石酸等。菌株Gym7c能够合成生长素、铁载体和1-氨基环丙烷-1-羧酸脱氨酶。菌株SY9和Gym7c对酸碱、盐和温度均表现出一定的抗性。     

绿脓杆菌S6产表面活性剂对PAHs增溶效果研究

文章以超声取-高效液相色谱法研究铜绿似单细胞S6菌产生物表面活性剂在浓度、pH值、温度及时间下对萘、蒽.芘、苯并蒽的增溶效果,结果表明:一定浓度范围内,表面活性剂浓度越高,萘、蒽、芘、苯并蒽的溶解度越大;固定生物表面活性剂浓度下,在对萘、蒽、苯并蒽及芘进行增溶时,pH值应控制在6～8之间,最好设置pH值为8;在对萘、蒽...     

双子表面活性剂CG_(12-3-12)、鼠李糖脂与TX-100对多环芳烃增溶作用的比较研究

对新季铵盐型Gemini阳离子表面活性剂CG12-3-12、生物表面活性剂鼠李糖脂Rhamnolipid、普通非离子表面活性剂TX-100以及它们的混合体系对多环芳烃菲和芘的增溶效果进行了比较研究.通过计算与比较临界胶束浓度(CMC)、摩尔增溶率(MSR)和增溶的标准自由能ΔG0s,评价了3种不同类型表面活性剂及它们的混合体系对菲和芘的增溶能力.3种表面活性剂对菲和芘的增溶性大小顺序为:CG12-3-12RhamnolipidTX-100.TX-100/CG12-3-12与TX-100/Rhamnolipid混合表面活性剂都较相对应的单一表面活性剂有更好的增溶能力,在降低表面张力效率方面都能够产生协同效应.但是两种混合溶液都不符合理想溶液的性质.TX-100/CG12-3-12系统的CMCexp相对于CMCmi有更大的负偏差.由两混合体系的吉布斯自由能ΔG0m可以看出,TX-100与鼠李糖脂比与CG12-3-12更容易形成混合胶束.TX-100/CG12-3-12与TX-100/Rhamnolipid表现出协同作用.TX-100/Rhamnolipid混合体系对菲和芘的增溶能力的提高大于TX-100/CG12-3-12混合体系.本实验研究结果可为疏水性有机物污染环境修复效果的强化提供科学依据.     

Bioleaching of cadmium and nickel from synthetic sediments by Acidithiobacillus ferrooxidans

The microbial leaching process was evaluated for the treatment of synthetic sediments contaminated with cadmium and nickel sulfides. A series of batch leaching experiments was conducted to compare metal solubilization in sediment inoculated with Acidithiobacillus ferrooxidans -inoculated sediments to that in sterile control sediment. The rate and extent of metal solubilization were significantly higher in A. ferrooxidans -inoculated reactors than in acidified sterile reactors. The efficiency of cadmium (Cd) solubilization (80) in the bioleaching process was higher than that of nickel (Ni) solubilization (60). The performance of leaching reactors containing only culture supernatants was comparable to that of A. ferrooxidans -inoculated reactors, indicating that indirect non-contact leaching by the products of microbial metabolism is the predominant mechanism for metal solubilization rather than direct microbial sulfide oxidation. Moreover, the similar (60–75%) extents of Cd²⁺ leaching with A. ferrooxidans , cell-free filtrate, and Fe³⁺ suggest that abiotic oxidation of CdS by Fe³⁺ controls the overall leaching rate, and the role of A.␣ferrooxidans is most likely not to oxidize CdS mineral directly but to regenerate Fe³⁺ as an oxidant.