牛粪堆肥腐殖质的动态变化研究

牛粪堆肥实质是有机物质分解的同时形成腐殖质的过程。本研究通过向牛粪中接种发酵微生物进行堆肥,研究分析了总有机碳含量、总腐殖酸、游离腐殖酸和水溶性腐殖酸等的腐殖质物质含量的动态变化。研究结果表明：在牛粪发酵过程中,总有机碳含量呈明显降低趋势,发酵微生物处理下的下降幅度明显大于不接种发酵微生物的处理;总腐殖酸、游离腐殖酸和水溶性腐殖酸含量在发酵前期呈明显的降低趋势,但至发酵腐熟期又逐渐升高。发酵前期,外源微生物的处理,使其下降幅度明显大于不接种外源微生物的处理,但在发酵腐熟期变化不大。     

堆肥腐熟度的研究进展

评价腐熟度是有关堆肥土地安全利用最重要的问题之一。腐熟度指标可分为三类：物理学指标、化学指标及生物学指标。物理学指标易于检测,常用于描述堆肥过程所处的状态;化学指标得到了广泛研究和应用;堆肥过程是一个生物过程,腐熟度与未腐熟堆肥中植物毒性物质有关,可采用生物学方法进行评价。现在还没有一种公认的堆肥腐熟度指标。采用化学和生物指标综合评价腐熟度是目前最为常用的评价方法。     

荧光光谱技术在堆肥腐熟度评价中的应用

高温好氧堆肥是世界各国资源化利用固体有机废弃物最重要的途径之一,堆肥腐熟度是评价堆肥过程及堆肥产品质量的重要尺度.荧光光谱(FS)技术具有诸多优点,目前已广泛应用于不同来源有机质结构特征的研究,其在堆肥腐熟度评价中具有广阔的应用前景.在分析了FS技术的原理及特点的基础上,从发射光谱、激发光谱、同步FS和三维FS方面详实综述了FS技术在有机固体废弃物堆肥物质转化及腐熟度评价中的应用原理及其国内外进展,并对FS技术在堆肥腐熟度评价中存在的问题及发展前景进行了评述.     

添加不同量的腐殖酸对猪粪堆肥中主要养分变化的影响

腐殖酸是一种可以控制堆肥氮素损失的天然固定剂,通过研究腐殖酸对猪粪堆肥过程中主要养分含量变化的影响,确定了腐殖酸的最佳加入量.结果表明,加入5%含量(占鲜猪粪重)的腐殖酸最有利于发酵反应的进行,能够促进有机质的分解,有效控制氮素损失,可使速效钾含量增加,但对有效磷的转化能力影响不大;与其他处理相比,加入5%含量的腐殖酸...     

水葫芦与厨余垃圾混合好氧堆肥中氮素变化及对腐熟度的影响

通过采用间歇式好氧动态堆肥工艺,对厨余垃圾与添加水葫芦的厨余垃圾进行堆肥实验,探讨堆肥进程中全氮、氨基酸态氮、蛋白质的变化及对腐熟度的影响。结果表明,全氮含量在堆肥后期有所提高,分别由1.76%和2.23%提高到3.64%和2.67%;氨基酸态氮含量与微生物活性显著负相关;添加水葫芦使堆体温度提高,促进了蛋白质的快速降解;堆肥中N素是影响种子发芽的主要因素;添加水葫芦能够促进堆肥的腐熟。     

二丁与连翘药渣联合堆肥腐熟度评价

为了对不同比例的二丁与连翘药渣堆肥腐熟度进行评价,采用条垛式好氧堆肥方式,将二丁和连翘两种药渣按照5种不同的比例进行堆肥处理,通过分析堆肥过程中温度、pH、C/N和发芽指数等指标的变化规律,对堆肥腐熟度进行评价。结果表明:在试验处理条件下及堆肥周期内,单一药渣堆肥的两组处理未能完全腐熟,混合药渣堆肥的3组处理均已达到完全腐熟的标准,说明两种药渣混合后进行堆肥,可以有效促进堆肥的顺利进行,且二丁与连翘比例为2∶1(质量比)时发酵效果最好。3组混合药渣的发酵产物可以作为有机肥或土壤改良剂施用,也可以与化肥配合,制备成有机/无机配方肥。     

二丁与连翘药渣联合堆肥腐熟度评价

为了对不同比例的二丁与连翘药渣堆肥腐熟度进行评价,采用条垛式好氧堆肥方式,将二丁和连翘两种药渣按照5种不同的比例进行堆肥处理,通过分析堆肥过程中温度、pH、C/N和发芽指数等指标的变化规律,对堆肥腐熟度进行评价。结果表明:在试验处理条件下及堆肥周期内,单一药渣堆肥的两组处理未能完全腐熟,混合药渣堆肥的3组处理均已达到完全腐熟的标准,说明两种药渣混合后进行堆肥,可以有效促进堆肥的顺利进行,且二丁与连翘比例为2∶1(质量比)时发酵效果最好。3组混合药渣的发酵产物可以作为有机肥或土壤改良剂施用,也可以与化肥配合,制备成有机/无机配方肥。     

接种外源微生物菌剂对香蕉茎秆堆肥的影响

为了研究接种外源微生物菌剂对香蕉茎秆堆肥的影响,本实验采用高温好氧堆肥技术,设计了对照（不接菌）、接种白腐菌及棱盖多孔菌3个处理,探讨了不同处理堆肥过程中堆体温度、水分、pH值、电导率、有机碳、C/N、发芽指数及堆肥质量的变化情况。结果表明,接种微生物菌剂处理的温度均高于对照,且高温期持续时间相对较长,以接种白腐菌处理的高温持续时间最长;接种外源微生物菌剂对堆肥含水率、pH、EC、全碳、C/N变化影响不大;与对照相比,接种白腐菌可增加全氮及全钾的含量,有利于提高堆肥产品质量;接种白腐菌处理在36 d（GI〉50%）就达到腐熟,比对照提前8 d腐熟,明显缩短堆肥腐熟时间;而接种棱盖多孔菌处理比对照推迟10 d腐熟,共需54 d不利于香蕉茎秆堆肥的进行。     

添加腐熟污泥对生活垃圾堆肥氮素转化与损失的影响

研究添加腐熟污泥对垃圾好氧堆肥过程中氮素转化与损失的影响,实验设置生活垃圾与腐熟污泥质量比分别为1∶1、2∶1和4∶1,以单独生活垃圾为对照,主要监测堆肥过程中固相（TN、氨氮、硝态氮和亚硝态氮）和气相（NH3和N2O）中氮素转化规律。结果表明：与单独生活垃圾相比,生活垃圾与腐熟污泥比例为1∶1和4∶1时,有机氮与TN损失明显减少;至堆肥结束4组堆体铵态氮与硝态氮相较于堆肥初期均有不同程度提高,其中4∶1组铵态氮与硝态氮提高最多,分别为32.3%和86.1%;亚硝态氮含量在整个堆肥过程中一直处于下降趋势;腐熟污泥的添加使物料堆肥过程中氨气和N2O的释放量随着腐熟污泥添加量的增加而减小。总体而言,由于腐熟污泥对氨气良好的吸附性能和其含有的大量亚硝酸盐氧化菌,加入堆肥后减少反硝化途径N2O的产生,从而减少生活垃圾堆肥过程中氮素损失和温室气体的释放。     

沉水植物与2种不同辅料混合好氧堆肥

沉水植物富含氮、磷和钾等营养元素,通过堆肥实现营养物质的回收和利用是沉水植物资源化的有效途径。但是沉水植物含水率高、碳氮比低,需要对其进行一定的优化才能实现更好的堆肥效果。本研究采用麦秸、树叶分别作为辅料和沉水植物进行混合好氧堆肥实验,沉水植物好氧堆肥作为控制组。通过测定温度、挥发分、耗氧速率、电导率、种子发芽率（GI）、总氮、总磷和总钾等以评价堆肥产品的腐熟度和养分。结果表明,沉水植物好氧堆肥具有一定可行性,堆肥产品总养分含量为6.01%,符合有机肥使用标准（NY525-2012）中对总养分的要求,具有较好腐熟度,但堆肥产品pH值为8.90,大于标准值8.50,氮素损失率为35.11%;通过分别添加麦秸、树叶与沉水植物混合堆肥,堆肥产品pH值分别为8.33和8.24,氮素损失率分别为20.25%和11.21%;由电导率、GI、碳氮比综合分析3组堆肥产品腐熟度从高到低顺序为沉水植物与树叶 > 沉水植物与麦秸 > 沉水植物。通过添加富碳辅料如麦秸、树叶与沉水植物混合堆肥可以提高堆肥产品腐熟度,减少氮素损失提高肥效。     

Sorption and desorption of Cu and Cd by macroalgae and microalgae

The sorption and desorption of Cu and Cd by two species of brown macroalgae and five species of microalgae were studied. The two brown macroalgae, Laminaria japonica and Sargassum kjellmanianum, were found to have high capacities at pHs between 4.0 and 5.0 while for microalgae, optimum pH lay at 6.7. The presence of other cations in solution was found to reduce the sorption of the target cation, suggesting a competition for sorption sites on organisms. Sorption isotherms obeyed the Freundlich equation, suggesting involvement of a multiplicity of mechanisms and sorption sites. For the microalgae tested, Spirulina platensis had the highest capacity for Cd, followed by Nannochloropsis oculata, Phaeodactylum tricornutum, Platymonas cordifolia and Chaetoceros minutissimus. The reversibility of metal sorption by macroalgae was examined and the results show that both HCl and EDTA solutions were very effective in desorbing sorbed metal ions from macroalgae, with up to 99.5% of metals being recovered. The regenerated biomass showed undiminished sorption performance for the two metals studied, suggesting the potential of such material for use in water and wastewater treatment.     

Kinetic and structural relationships of transition monomeric and oligomeric carboxyl- and choline-esterases

The kinetic and structural relationships of eight electrophoretically pure mammalian serum and liver serine carboxylesterases (CE) and cholinesterases (ChE) have been studied. Eight CE's and ChE's, which were fully resolved but only partially purified, provided additional information. Five of the electrophoretically pure esterases were monomeric, and of these, four belonged to a new and widely distributed class. These four monomeric esterases hydrolyzed choline esters, but at widely differing rates. Thus two were termed monomeric butyrylcholinesterases, mBuChE I and II, and two were monomeric CE's (mCE). The rabbit liver mCE was not a subunit of the oligomeric CE (oCE), although the oCE also hydrolyzed choline esters at a very low rate. The complex kinetics of the mCE's, mBuChE's, oCE's, and of the oligomeric BuChE's of horse and human serum could be interpreted according to a single reaction scheme involving an allosteric site and the equation derived from it. Thus activation and inhibition at high substrate concentrations, together with sigmoidal activity versus substrate concentration plots, all of which characterize the reactions of these esterases, could be interpreted by a single scheme and equation. Structural and kinetic comparisons showed a progressive transition of properties from the oCE's through the mCE's to the oBuChE's. One of the purified mCE's was from horse serum, and it exhibited physical and kinetic properties unlike those of the liver mCE's or oCE's.     

Persistence and dissipation kinetics of trifloxystrobin and tebuconazole in onion and soil

The persistence and dissipation kinetics of trifloxystrobin and tebuconazole on onion were studied after application of their combination formulation at a standard and double dose of 75 + 150 and 150 + 300 g a.i. ha^?1. The fungicides were extracted with acetone, cleaned-up using activated charcoal (trifloxystrobin) and neutral alumina (tebuconazole). Analysis was carried out by gas chromatograph (GC) and confirmed by gas chromatograph mass spectrometry (GC-MS). The recovery was above 80% and limit of quantification (LOQ) 0.05 mg kg^?1 for both fungicides. Initial residue deposits of trifloxystrobin were 0.68 and 1.01 mg kg^?1 and tebuconazole 0.673 and 1.95 mg kg^?1 from standard and double dose treatments, respectively. Dissipation of the fungicides followed first-order kinetics and the half life of degradation was 6–6.6 days. Matured onion bulb (and field soil) harvested after 30 days was free from fungicide residues. These findings suggest recommended safe pre-harvest interval (PHI) of 14 and 25 days for spring onion consumption after treatment of Nativo 75 WG at the standard and double doses, respectively. Matured onion bulbs at harvest were free from fungicide residues.     

Sorption and Desorption Behavior of Chloroanilines and Chlorophenols on Montmorillonite and Kaolinite

The bioavailability of pollutants, pesticides and/or their degradation products in soil depends on the strength of their sorption by the different soil components, particularly by the clay minerals. This study reports the sorption-desorption behavior of the environmentally hazardous industrial pollutants and certain pesticides degradation products, 3-chloroaniline, 3,4-dichloroaniline, 2,4,6-trichloroaniline, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol on the reference clays kaolinite KGa-1 and Na-montmorillonite SWy-l. In batch studies, 2.0 g of clay were equilibrated with 100.0 mL solutions of each chemical at concentrations ranging from 10.0 to 200.0 mg/L. The uptake of the compounds was deduced from the results of HPLC-UV-Vis analysis. The lipophilic species were best retained by both clay materials. The most lipophilic chemical used in the study, 2,4,6-trichloroaniline, was also the most strongly retained, with sorption of up to 8 mg/g. In desorption experiments, which also relied on HPLC-UV-Vis technique, 2,4,6-trichloroaniline was the least desorbed from montmorillonite. However, on kaolinite all of the compounds under study were irreversibly retained. The experimental data have been modelled according to the Langmuir and Freundlich isotherms. A hypothesis is proposed concerning the sorption mechanism and potential applications of the findings in remediation strategies have been suggested.     

Sorption and desorption behavior of chloroanilines and chlorophenols on montmorillonite and kaolinite

The bioavailability of pollutants, pesticides and/or their degradation products in soil depends on the strength of their sorption by the different soil components, particularly by the clay minerals. This study reports the sorption-desorption behavior of the environmentally hazardous industrial pollutants and certain pesticides degradation products, 3-chloroaniline, 3,4-dichloroaniline, 2,4,6-trichloroaniline, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol on the reference clays kaolinite KGa-1 and Na-montmorillonite SWy-l. In batch studies, 2.0 g of clay were equilibrated with 100.0 mL solutions of each chemical at concentrations ranging from 10.0 to 200.0 mg/L. The uptake of the compounds was deduced from the results of HPLC-UV-Vis analysis. The lipophilic species were best retained by both clay materials. The most lipophilic chemical used in the study, 2,4,6-trichloroaniline, was also the most strongly retained, with sorption of up to 8 mg/g. In desorption experiments, which also relied on HPLC-UV-Vis technique, 2,4,6-trichloroaniline was the least desorbed from montmorillonite. However, on kaolinite all of the compounds under study were irreversibly retained. The experimental data have been modelled according to the Langmuir and Freundlich isotherms. A hypothesis is proposed concerning the sorption mechanism and potential applications of the findings in remediation strategies have been suggested.     

Bacterial and archaeal diversity in oil fields and reservoirs and their potential role in hydrocarbon recovery and bioprospecting

Environmental Science and Pollution Research - Hydrocarbon is a primary source of energy in the current urbanized society. Considering the increasing demand, worldwide oil productions are declining...     

畜禽养殖业污染与循环经济

解决畜禽养殖业的污染问题要以充分利用资源为根本出发点，通过对污染全过程控制及废物综合利用，达到畜禽粪便的减量化、无害化、资源化，走循环经济的发展道路。     

Degradation in soil and water and ecotoxicity of rimsulfuron and its metabolites.

The degradation and ecotoxicity of sulfonylurea herbicide rimsulfuron and its major metabolites were examined in batch samples of an alluvial sandy loam and in freshwater. An HPLC-DAD method was adapted to simultaneously identify and quantify rimsulfuron and its metabolites, which was successfully validated by GC-MS analysis. In aqueous solutions, pure rimsulfuron was rapidly hydrolyzed into metabolite 1 (N-(4,6-dimethoxypyrimidin-2-yl)-N-(3-(ethylsulfonyl)-2-pyridinylurea)), which itself was transformed into the more stable metabolite 2 (N-((3-(ethylsulfonyl)-2-pyridinyl)-4,6-dimethoxy-2-pyrimidineamine)), with half-life (t(1/2)) values of 2 and 2.5 days, respectively. Hydrolysis was instantaneous under alkaline conditions (pH = 10). In aqueous suspensions of the alluvial soil (pH = 8), formulated rimsulfuron had a half-life of 7 days, whereas that of metabolite 1 was similar to that in water (about 3.5 days). The degradation of the two major metabolites was also studied in soil suspensions with the pure compounds at concentrations ranging from 1 to 10 mg l(-1). The half-life of metabolite 1 ranged from 3.9 to 5 days, close to the previous values. Metabolite 2 was more persistent and its degradation is strongly dependent on the initial concentration (C0): half-life values ranged from 8.1 to 55 days at 2-10 mg l(-1), respectively. These values are higher than those determined from the kinetics of metabolite 1 transformation into metabolite 2 (t(1/2) = 8-19 days). The ecotoxicity of the three chemicals was evaluated through their effect on Daphnia magna and Vibrio fischeri (Microtox bioassay). No effect was observed on D. magna with 24 and 48 h acute toxicity tests. Similarly, no toxic effect was observed with the Microtox test for the three chemicals in the range of concentrations tested that included the field application dose. Thus, being of low persistence and lacking acute toxicity, these chemicals present a low environmental risk. However, chronic effects should be studied in order to confirm the safety of rimsulfuron and its major metabolites.     

Isocyanatocyclohexane and isothiocyanatocyclohexane levels in urban and industrial areas and possible emission-related activities

Isocyanatocyclohexane and isothiocyanatocyclohexane are becoming relevant compounds in urban and industrial air, as they are used in important amounts in automobile industry and building insulation, as well as in the manufacture of foams, rubber, paints and varnishes. Glass multi-sorbent tubes (Carbotrap, Carbopack, Carboxen) were connected to LCMA-UPC pump samplers for the retention of iso- and isothiocyanatocyclohexanes. The analysis was performed by automatic thermal desorption (ATD) coupled with capillary gas chromatography (GC)/mass spectrometry detector (MSD). TD-GC/MS was chosen as analytical method due to its versatility and the possibility of analysis of a wide range of volatility and polarity VOC in air samples. The method was satisfactory sensitive, selective and reproducible for the studied compounds. The concentrations of iso- and isothioisocyanatocyclohexanes were evaluated in different urban, residential and industrial locations from extensive VOC air quality and odour episode studies in several cities in the Northeastern edge of Spain. Around 200–300 VOC were determined qualitatively in each sample. Higher values of iso- and isothiocyanatocyclohexane were found in industrial areas than in urban or residential locations. The concentrations ranged between n.d.−246 and n.d.−29 μg m⁻³ for isocyanatocyclohexane and isothiocyanatocyclohexane, respectively, for industrial areas. On the other hand, urban and residential locations showed concentrations ranging between n.d.−164 and n.d.−29 μg m⁻³ for isocyanatocyclohexane and isothiocyanatocyclohexane, respectively. The site location (urban or industrial), the kind and nearness of possible iso- and isothiocyanatocyclohexane emission activities (industrial or building construction) and the changes of wind regimes throughout the year have been found the most important factors influencing the concentrations of these compounds in the different places.