牛骨炭对水溶液中Hg（Ⅱ）吸附性的研究

以牛骨为原料,氯化锌为活化剂制备牛骨基炭,通过静态吸附试验研究了牛骨炭对水中Hg（Ⅱ）的吸附效果并确定了影响吸附性能的因素。研究结果表明：牛骨炭对Hg（Ⅱ）的最佳吸附时间约为2h、吸附温度为25℃、pH值为1、投加量为0．1g、吸附溶液的最大初始浓度为600mg／L,其最大吸附容量Q^0为43．1mg／g,吸附行为符合Freundl—ich吸附等温模型;通过BET分析和扫描电镜（SEM）等手段表征了牛骨炭的孔结构参数及形貌特征,经分析,所制备牛骨炭的孔径分布为中孔。     

南京市地铁车站氡浓度水平的初步调查

采用静电收集氡子体法对南京市地铁车站环境中氡浓度进行了调查,初步掌握了南京市地铁站重点区域的氡浓度放射性水平,按照联合国原子辐射效应科学委员会推荐的评价方法估算氡浓度对地铁内工作人员人均年有效照射剂量。对地铁站新建和扩建项目的机械通风设计,为工作人员和公众的内照射剂量水平估算等提供依据。     

Advantages and risks of using steel slag in preparing composts from raw organic waste

It had been reported that iron and manganese oxides in steel slag enhanced the production of humic acid (HA) from low-molecular-weight compounds, such as phenolic acids, amino acids, and saccharides. In the present study, this function of steel slag was applied to the composting of raw organic wastes (ROWs). The degree of humification of HAs is an important factor in evaluating compost quality. Thus, HAs were extracted from the prepared composts and the humification parameters were determined, in terms of elemental compositions, acidic functional group contents, molecular weights, spectroscopic parameters from UV–vis absorption and ¹³C NMR spectra. The timing for adding steel slag affected the degree of humification of HAs in the composts. The weight average molecular weight of a HA when slag was added initially (29 kDa) was significantly higher than when slag was added after elevating the temperature of the compost pile (17–18 kDa). These results show that ROWs are decomposed to low-molecular-weight compounds after the pile temperature is elevated and the presence of slag enhances the polycondensation of these compounds to produce HAs with a higher degree of humification. Because the slag used in the present study contained several-tens ng g^?1 to several μg g^?1 of toxic elements (B, Cu, Cr, and Zn), leaching tests for these elements from the prepared composts were carried out. Levels for leaching boron from composts prepared by adding slag (0.2–0.4 mg L^?1) were obviously higher than the corresponding levels without slag (0.05 mg L^?1).     

Chemical and spectroscopic characterization of organic matter during the anaerobic digestion and successive composting of pig slurry

In this work, anaerobic digestion of pig slurry and successive composting of the digestate after centrifugation were studied by means of chemical analysis, FTIR and fluorescence spectroscopy as excitation–emission matrix (EEM). Chemical analysis highlighted the organic matter transformation occurring during the processes. A decrease of volatile solids and total organic carbon were observed in the digestate with respect to the fresh pig slurry as a consequence of the consumption of sugars, proteins, amino acids and fatty acids used by microorganisms as a C source. Water Extractable Organic Matter (WEOM) was obtained for all samples and fractionated into a hydrophilic and a hydrophobic fraction. The highest WEOM value was found in the pig slurry indicating a high content of labile organic C. The digestate centrifuged and the digestate composted showed lower hydrophilic and higher hydrophobic contents because of the decrease of labile C. Total phenolic content was lower in the digestate with respect to fresh pig slurry sample (36.7%) as a consequence of phenolic compounds degradation. The strong decrease of total reducing sugars in the digestate (76.6%) as compared to pig slurry confirmed that anaerobic process proceed mainly through consumption of sugars which represent a readily available energy source for microbial activity. FTIR spectra of pig slurry showed bands indicative of proteins and carbohydrates. A drop of aliphatic structures and a decrease of polysaccharides was observed after the anaerobic process along with the increase of the peak in the aromatic region. The composted substrate showed an increase of aromatic and a relative decrease of polysaccharides. EEM spectra provided tryptophan:fulvic-like fluorescence ratios which increased from fresh substrate to digestate because of the OM decompostion. Composted substrate presented the lowest ratio due to the humification process.     

接种微生物与人粪便同步连续投加对好氧堆肥效果的影响简

利用新型梨形筒式好氧堆肥反应器,在通风量为3.0 L/min,搅拌频率为5 min/h的条件下,就不接种微生物、接种土著菌种、枯草芽孢杆菌与酵母菌时人粪便连续投加好氧堆肥效果进行了对比。堆制20 d即2个运行周期中各堆体的温度、含水率、COD、总氮、pH值与GI等的变化表明,接种微生物可以显著提高堆体的升温速率与堆体平均温度、COD降解率、GI（P<0.01）,堆肥可迅速达到完全腐熟。接种土著菌种效果最为明显（P<0.01）,其后相继为枯草芽孢杆菌与酵母菌。接种土著菌种可使堆体温度在50℃以上维持18 d,第8天COD降解率达到61.17%、总氮损失率为25.75%,第6天时GI达到108.22%。     

The fate of recombinant plasmids during composting of organic wastes

Composting was investigated as a means for safe disposal of organic waste containing bacteria that carry transgenes in recombinant plasmids. To generate model recombinant plasmids, a mobile IncQ plasmid, RSF1010, and a non-mobile plasmid, pGFP, were genetically modified to carry a DNA segment encoding both green fluorescent protein and kanamycin resistance and were designated as RSF1010-GFPK and pGFPK. Escherichia coli (E. coli) C600 harboring these plasmids were inoculated into chicken manure specimens that were placed in compost at 20 and 60 cm from the bottom of a 1.0-m high compost bin. Control specimens were held at ambient temperature. By day 10, compost temperatures at the lower and upper levels of the bin had reached 45.3 and 61.5°C, respectively, and at both levels the target E. coli had been inactivated and the plasmids had lost their capacity to be transformed or mobilized. Furthermore, based on real time Polymerase chain reaction (PCR), the transgene fragments along with the host chromosomal DNA fragment from specimens at the upper level had been degraded beyond the detection limit. However, at the lower level where temperatures remained below 48°C these fragment persisted to day 21. At ambient temperatures (0–8°C), the E. coli, plasmids and the transgene fragments persisted in manure specimens throughout the 21 day test period. The study showed the potential for composting as a safe procedure for disposal of bacteria carrying transgenes in recombinant plasmids.     

Influences of adding easily degradable organic waste on the minimization and humification of organic matter during straw composting

To find a better composting process with low greenhouse gas emission and high humus production, the effect of adding kitchen waste on reduction and humification of organic matter during straw composting was studied. Three processes were compared, consisting of different ratios of straw and kitchen waste (1:2, 1:1, and 2:1). At four time points over a 62-d incubation, the reduction and humification of compost was evaluated by measuring the total mass, carbon content, and humic material content of the compost. Treatment 1 (straw/kitchen waste ratio of 1:2) reduced the total mass of compost the most. Treatment 2 (straw/kitchen waste ratio of 1:1) reduced the total carbon content the most, reflecting the highest emission of greenhouse gas. Treatment 3 produced the most humic acid material and released the lowest amount of carbon. Hence, from the point of view of reducing greenhouse gas emissions and increasing stable organic matter such as humus and humic acid during composting, treatment #3 was optimal. The three treatments resulted in significant differences in microbial biomass and enzyme activity during composting. The highest amount of active microbial biomass was associated with the largest reduction in compost mass (treatment 1). Higher proportions of straw (treatments 2 and 3), which contains more lignin, were associated with greater β-glycosidase activity, which may generate more humus that can improve soil quality. Dehydrogenase activity seemed to be the most important microbial factor in organic carbon catabolism or humification.     

超强静磁场对染料脱色菌Escheriehia coli的acpD基因的影响

将大肠杆菌E.coli ATCC8739置于12.0 T超强静磁场(ultra-strong static magnetic field,SMF)中进行处理,获得了磁场处理0.5、1、2、4和8 h的菌株E.coli-SMFn(n=0.5、1、2、4、8)。在37℃、pH 7、静置的条件下,菌株对偶氮染料AR14(I.C.Acid Red 14)的脱色结果指出,当反应进行到4、6和8 h时,E.coli-SMF8的脱色效率分别为18%、55%和96%,远高于E.coli ATCC8739的3%、19%和50%,表明SMF作用显著地增强了菌株的脱色效率。基因组DNA提取、PCR扩增、分子克隆以及基因测序的实验结果进一步表明,全部6例E.coli ATCC8739菌株的偶氮还原酶基因(acpD)序列均与GenBank中报道的完全一致;而E.coli-SMF8菌株的acpD-SMF8核酸序列中缺失了第99位的胞嘧啶。该缺失突变不仅使acpD-SMF8的核酸序列与acpD的存在显著不同,同时得到了具新活性中心的偶氮还原酶AzoR-SMF8。这个新的活性中心具有更强的黄素(FMN)结合能力,因此使该酶与偶氮染料的亲和力大大增加,促进了脱色效率的提高。     

微生物生理群在猪粪秸秆高温堆肥碳氮转化中的作用

在自制的强制通风静态堆肥反应箱中,猪粪与秸秆以鲜重7∶1的比例进行了堆肥化实验,在堆制的23 d里根据堆温变化分阶段采集堆肥样品,利用MPN法测定了堆料中纤维素分解菌和氮素微生物生理群的数量变化,同时测定了相应的碳、氮含量。结果表明,纤维素分解菌在稳定腐熟阶段较多,对于后期有机碳的降解和腐殖质含量的增大起了很大的作用,在堆制的23 d里,腐殖质增加了2.4%。整个堆制过程中,氨化细菌的数量最大且与氨气释放浓度和铵态氮含量呈显著正相关,都在高温期增加,降温期后减少,氨化细菌的数量在高温期的增加率远高于降温期后的减少率,而铵态氮在高温期的增加率远低于在降温后期的减少率,铵态氮总体上减少了74.1%;亚硝化细菌数量与硝态氮呈正相关;反硝化细菌数量在降温期上升幅度较大,堆制结束时为堆制初期的13倍,且与堆肥中硝态氮含量呈正相关;硝态氮含量增加了87.5%;堆肥后期硝态氮的增加可能与堆肥中存在能进行硝化作用的反硝化细菌有关。固氮菌数量在堆制结束时达堆制初期的2.61倍,主要在降温期增加较多,对堆肥中有机氮的形成起很大作用。     

利用城市污泥堆肥及建筑弃土种植麦冬研究

将污泥堆肥产品分别与建筑弃土按0%、10%、20%、30%、40%和50%(湿重)的比例配制营养土,以麦冬为例进行180 d的栽培实验,分析了营养土对麦冬生长特性、植物体内及栽培土壤中营养学指标和重金属含量的变化规律,并通过模糊综合评价方法选择营养土较佳配制方案。实验结果表明:堆肥比例在50%时麦冬生物量增加率、新生芽数及地表部分比重为最大值,在30%时纺锤体肉质数减少率为最大值;随着营养土中堆肥比例增加,麦冬体内养分含量、重金属积累量随之增加,均在50%时达到最大值;栽培土壤养分越多损失量越多,各指残留率越低,同时全磷、全氮及K含量降低率较有效磷、碱解氮小得多,Cr降低率在5.20%～8.34%之间,Zn降低率在3.27%～17.35%之间;堆肥比例在40%以上的营养土对麦冬生长效果好,但较佳配制方案为堆肥产品占20%。