石油污染对土壤氮素矿化和硝化作用的影响

在实验室中用同位素示踪法,研究了土壤中不同石油污染量对氮矿化及硝化速率的影响。结果表明,石油对土壤中有机氮的矿化没有显著影响,但减缓了硝化反应的进程。土壤经过１０ｄ的培养,在未污染的土壤中硝化细菌数量由１．６×１０３增加到１．６×１０６,而在受石油污染的土壤上,硝化细菌数量仅增加到６．３×１０４;增加试验前土壤硝化菌数量为２．６×１０６,加油培养１０ｄ后,硝化细菌数量下降了近９０％。     

城市生活垃圾填埋产沼的模拟实验

通过城市生活垃圾的填埋降解模拟实验，研究了不同温度、不同垃圾成份对垃圾降解及填埋气产生过程的影响。实验结果表明：增加温度及在填埋垃圾中添加污泥，可加快填埋垃圾的降解与填埋气的产生，实验期间累计产气量分别比对照组提高2．04和3．4倍；以厨余垃圾为主的样品垃圾，其产气过程的显著特征是产气速率衰减较快，这与国外文献报道有较大差异。对我国城市生活垃圾，填埋封场后产气量的快速衰减，是填埋气利用规划设计应该考虑的问题。     

不同水型水稻土施氮磷肥效果及施用技术的研究

通过在湖北省几种主要成土母质上对不同水型水稻土施用氮磷肥效果及施用技术的研究．初步明确了氮肥的施用效果为淹育型水稻土＞潴育型水稻土＞潜育型水稻土．磷肥效果与之相反．从土壤养分状况、氮肥和磷肥的当季利用率、土壤微生物、土壤还原性物质含量和水土温度等方面，初步分析了不同水型水稻土氮磷肥效果差异的原因．提出了不同水型水稻土氮磷肥的施用技术．     

珠江口红树林硫的累积和循环研究

主要研究了珠江口红树林硫的累积和循环特点，并探讨其对土壤中硫累积的影响．结果表明，珠江口五个红树群落硫的贮存量平均为１７０．４２ｋｇ／ｈｍ２；在群落硫元素的生物循环中，年存留量平均为１７．６０１ｋｇ／ｈｍ２，年归还量平均为３５．６０３ｋｇ／ｈｍ２，年吸收量平均为５３．２０４ｋｇ／ｈｍ２，周转期为３－８ａ，富集率均大于１．选定浅海沉积物的平均含硫量作为林下土壤成土母质的本底含硫量，估算红树植物生长后土壤含硫量的变化，并与群落硫的年归还量作比较．红树林对其林下土壤硫的累积作用有两方面，一是对海水硫的生物选择吸收与归还，二是为海水中的ＳＯ４（２－）为黄铁矿提供有机还原剂和嫌气微生物的能源，尤以后者的作用更重要．     

固氮菌J-25利用味精废水产生絮凝剂的研究

考察了微生物絮凝剂产生菌Azotobacter J-25在味精废水中发酵产生絮凝剂的絮凝特性。实验表明，味精废水经预处理后，加入有机碳源对絮凝剂产生菌Azotobaaer J-25进行培养，菌体在生长过程中产生絮凝剂，并将其分泌到细胞外，培养液的絮凝活性最高达98％以上。该絮凝剂在偏碱性的条件下，对高岭土悬浊液的絮凝效果最好．实际废水的净化实验表明，该微生物絮凝剂对多种废水具有良好的净化效果，尤其对石化废水处理效果最好，CODCr，SS，色度的去除率分别为66．7％，98．3％，93．7％。     

自然粒度下渤海沉积物中有机碳的地球化学特征

对渤海三个典型海域6个站位柱状沉积物自然粒度下的有机碳（OC）进行了研究，探讨了有机碳的垂直分布特征及其氧化还原环境（Eh^0,Es^0,Fe^3 /Fe^2 比值）因素对渤海沉积物中有机碳的影响，渤海自然粒度沉积物中的有机碳含量在0.39-0.86%之间，一般在表层-次表层含量变化较剧烈，在下层变化较缓，相关分析说明，在中层，一般沉积物的还原性相比表层有增强，氧化环境与还原环境共存，有机质被氧化，OC浓度变得趋于减小，Fe^3 /Fe^2 也趋于减小，二者有明显的正相关；在下层，还原环境占据了主导地位，导致大量OC不能被氧化，就被保存了下来，而Fe^3 /Fe^2 却明显减小，所以在下层OC-Fe^3 /Fe^2 呈较强的负相关；在表层又掺杂了生物化学与物理扰动等因素，使OC-Fe^3 /Fe^2 的相关性变得复杂，且不规律，表层-次表层OC主要取决于物质来源和物理搅动，变化较复杂；中，下层主要受氧化还原环境影响，矿化作用明显，有机碳含量逐渐降低；下层除C3区和A区外，有机碳含量也逐步降低。有机碳含量不同层次受不同的物质来源，沉积环境，氧化还原进程与不同的生物化学过程共同影响，从C区的断面分布看，表层-次表层呈垂直叠层分布，主要是逐步垂直沉降沉积的结果。25cm以下呈水平推进式梯度分布，可能由于特殊的沉积事件如大洪水冲刷沉积而致。     

有机物质添加量对污染土壤铜形态及活性的影响

分析了泥炭和堆肥两种有机物质的添加量水平对冶炼厂附近污染土壤中铜形态及其活性的影响。结果表明, 添加土重２ ． ５ ％ 有机物质就对土壤铜化学形态与活性产生显著的影响, 使氧化锰结合态和松结合有机态铜等向紧结合有机态铜转化, 使土壤化学活性铜 （２ ． ５ ％ 醋酸提取） 降低约２０ ％ ; 添加量增加到５ ． ０ ％ , 控制作用有明显加强的趋势; 添加量再增至１０ ． ０ ％ , 单位添加量有机物质的控制作用明显减弱。     

大气氟污染引起植物落叶及生长物质防护效应的初步研究

梅树经氟化氢熏气后,离区纤维素酶活力升高,这可能是某些植物受大气氟污染后产生非正常落叶的原因。熏气前喷洒生长调节物质,可以相对降低纤维素酶活力,有效地抑制大气氟污染产生的落叶效应。     

水旱轮作改良利用潜育化水稻土的研究

潜育化水稻土存在渍、冷、烂、闭（气）、毒及缺素等障碍因素，采取水旱轮作是改良利用潜育化水稻土极其重要的措施．研究表明，水旱轮作可以改善土壤通气透水性能，提高氧化还原电位，减少还原物质，增加土壤微生物数量及提高其活性，增加土壤速效养分，促进作物生长发育，提高作物产量，并能提高土地利用率，获得全年农业增产增收增值．     

某复合化工污染场地不同介质有机物污染特征层次分析

为全面多层次了解污染场地有机物污染特征,本研究选取生产过农药和涂料产品的某复合污染场地为研究对象,分析该场地不同区域环境空气、土壤气以及土壤等3种介质中有机物污染特征,比较了不同区域不同介质中有机物的存在差异,同时对不同深度土壤及土壤气进行了污染特征分析.结果表明,场地有机物成分复杂,环境空气、土壤气和土壤的3种介质中共检出354种物质,土壤中检出物质数量多达177种,环境空气90种物质,土壤气共检出153种物质.从物质种类组成来看,主要为苯系物、含氧有机物、烷烯烃以及含卤有机物（主要是含氯有机物）;该场地环境空气存在较为严重的挥发性有机物污染,场地不同区域环境空气TVOCs浓度高于国内主要城市城区和部分工业区检测值,涂料环境1#VOCs污染最严重,苯系物和含氧有机物是主要的浓度组成物质,多来自于涂料和农药生产中使用的有机溶剂.不同区域不同深度土层土壤气中挥发性有机物污染程度不同,就不同区域而言,原农药区浓度最高(19.27 mg·m^-3),涂料区1#浓度最低(13.41 mg·m^-3);不同土层土壤气VOCs污染程度不同,涂料区两个区域2 ...     

水稻田的甲烷释放特性及其生物学机理

本文报导采用土柱法和田间原位法研究渍水稻田甲烷释放特性的结果。不同生育期的测定表明,早稻以分蘖盛期时释放量最大,以后逐渐减少,晚稻从分蘖始期起逐渐增加,至分蘖盛期、末期时达到最大,随后在孕穗期急剧减少,至生长后期又有所回升。以原位法测定表明,晚间和上午释放的甲烷量较多,中午几乎无甲烷释放,下午又有少量释放。不同施肥区稻田甲烷释放量明显不同,以施猪粪有机肥区为最高,次为施尿素无机氮区,不施肥区最低。但各施肥区水稻不同生育期的甲烷释放趋势完全一致,以分蘖期释放量最大,稻田释放的甲烷主要是稻植株释放的,可占总释放量的85％以上。行株间土壤释放的量不多。田间水释放极少,就植株而言,甲烷释放部位主要是在与土壤密切结合的未扰动的根基和根系部位,水面下茎秆白色部分和水上绿色部分几乎无释放。根系也主要是靠近根基的上半部分,根尖部位甲烷形成活性明显小得多。且研究表明,产甲烷细菌附存于根表而不进入根内组织。根际土壤中产甲烷细菌、厌氧性纤维素分解细菌和甲烷氧化细菌的数量以及总挥发有机酸含量都明显高于和行间土壤。     

Influencing mechanism of high solid concentration on anaerobic mono-digestion of sewage sludge without agitation

High-solids anaerobic digestion of sewage sludge was a promising process, but high solid concentration negatively influenced methane production. The influencing mechanism was systematically analyzed in this study through a series of static anaerobic digestion experiments at total solids (TS) contents of 3%–15%. The results showed that TS 6% was the boundary between low-solids and high-solids anaerobic digestion, and the accumulative methane yield decreased exponentially when TS increased from 6% to 15%. The performance of anaerobic digestion was directly determined by the efficiency of mass transfer, and the relation between methane yield and sludge diffusive coefficients was well described by a power function. Thus, the increasing TS resulted in an exponential increase in sludge viscosity but an exponential decrease in diffusive coefficient. The blocked mass transfer led to the accumulation of volatile fatty acids (VFAs) and free ammonia. Acetic metabolism was the main process, whereas butyric and propionic metabolisms occurred at the initial stage of high-solids anaerobic digestion. The concentration of VFAs reached the maximum at the initial stage, which were still lower than the threshold influencing methanogens. The concentration of free ammonia increased gradually, and the methanogenesis was inhibited when free ammonia nitrogen exceeded 50 mg·L⁻¹. Consequently, the deterioration of high-solids anaerobic digestion was related to the blocked mass transfer and the resulting ammonia accumulation.     

木薯皮堆肥过程中酶活性的变化

以木薯皮为原料进行高温堆肥发酵,研究了堆肥化过程中理化性质和酶活性的变化情况.结果表明:在堆肥发酵过程中.温度变化呈先上升后下降趋势,到后期已趋近于初始温度;而含水率在堆肥处理过程中变化不大.各处理的pH值在发酵结束时为7.3～7.5.过氧化氢酶活性初期较高,随后迅速降低,并维持在较低水平.纤维素酶和脲酶活性在堆肥初期增加,之后逐渐降低.由于堆肥原料不同,不同处理的酶活性变化趋势表现出一定的差异.考虑到堆肥腐熟度受多方面因素的影响,判断堆肥腐熟度时应根据多种指标(包括生物学、化学、物理学指标)综合判断.     

几株光合细菌的气体代谢及对产甲烷细菌甲烷生成的影响

三株分别属于光合细菌三个主要类群（紫无硫细菌、紫硫细菌和绿硫细菌）的菌种和两种产甲烷细菌进行了混合培养试验，结果表明，自养生长的光合细菌减少了产甲烷菌有ＣＨ４生成，而异养生长时紫无硫细菌Ｒｈｏｄｏｐｓｅｕｌｏｍｏｕｓ ｐａｌｕｓｔｒｉｓ能利用乙酸放出ＣＯ２供产甲烷菌利用。在光照厌氧条件下，三株光合细菌的生长培养物和静止细胞都能利用有机酸产氢，有时还伴随着ＣＯ２产出。同时试验了不同ｐＨ值、温度和光照     

不同泥龄下活性污泥絮体性状的研究

采用序批式反应器对不同泥龄下污泥絮体的化学性状(胞外聚合物成分及含量)、物理性状(表面电荷)、形态性状(粒度分布、分形维数)等进行了对比研究.结果表明:泥龄对胞外聚合物总量及各组分含量的影响规律并不明显;多糖/蛋白质愈大,污泥絮体表面电负性愈强;污泥絮体的平均粒径随泥龄的延长呈逐渐减小的趋势,且粒度分布愈来愈均匀;不同泥龄下,污泥絮体形态结构亦不相同,泥龄短时,絮体表面粗糙,结构开放疏松;泥龄长时,絮体表面平滑,结构紧凑;随着泥龄的增大,絮体分形维数逐渐增加.由于不同泥龄下所表现出的污泥絮体性状的差异,直接影响了污泥的絮凝和沉降性能.     

水华蓝藻厌氧发酵工艺技术研究

以太湖水华蓝藻为底物,用改进的CSTR(continuous stirred tank reactor)工艺,研究了不同有机负荷条件下蓝藻厌氧发酵相关参数与蓝藻藻毒素的去除效果.结果表明:在(35±1) ℃条件下,逐步提高有机负荷,系统运行稳定,有机负荷最高可达3.53 kg·m-3·d-1,此时最大容积产气率达0.89 m3·m-3·d-1,COD去除率在70%左右,甲烷体积分数达60%以上.不同负荷条件下,出料中藻毒素(MC-RR、MC-LR)检测均为阴性,已达无害化处理要求,表明该工艺可以有效处置水华蓝藻,实现能量回收与无害化处理的目标.     

Comparison of metabolic nitramine degradation by denitrifying species

The biodegradation of two popular nitramine energetics were investigated. The HMX (octa‐hydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine) was mineralized by anaerobic mixed denitrifiers in digested sewage sludge culture. An initial HMX concentration of 120 mg/L decreased to a non‐detectable level (> 99% removal efficiency) in 8 days of incubation under strict anaerobic conditions. It was, however, not effectively metabolized by single denitrifying species, P. aeruginosa, B. subtilis in a nitrogen limiting condition under their optimum growth conditions. The other nitramine energetic, ADN (ammonium dinitramide), was mineralized well in the anaerobic mixed culture. The initial ADN concentration of 250 mg/L was reduced to non‐detectable levels (> 99% removal efficiency) in 5 days of incubation under anaerobic conditions. These results show that the anaerobic mixed culture, compared to the pure monoculture, is superior in the degradation of nitramine energetics.     

Characterization of the dissolved organic matter in sewage effluent of sequence batch reactor: the impact of carbon source

Dissolved organic matter (DOM) transformation in sequence batch reactor (SBR) fed with carbon sources of different biodegradability was investigated. During the biologic degradation process, the low molecular weight (MW) fraction (< 1 kDa) gradually decreased, while the refractory compounds with higher aromaticity were aggregated. Size exclusion chromatography (SEC) and fluorescence of excitation emission matrices (EEM) demonstrated that more biopolymers (polysaccharides or proteins) and humic-like substances were presented in the extracellular polymeric substance (EPS) extracted from the SBR fed with sodium acetate or glucose, while the EPS from SBR fed with slowly biodegradable dissolved organic carbon (DOC) substratestarch had relatively less biopolymers. Comparing the EfOM in sewage effluent of three SBRs, the effluent from SBR fed with starch is more aromatic. Organic carbon with MW>1 kDa as well as the hydrophobic fraction in DOM gradually increased with the carbon sources changing from sodium acetate to glucose and starch. The DOC fractionation and the EEM all demonstrated that EfOM from the effluent of the SBR fed with starch contained more fulvic acid-like substances comparing with the SBR fed with sodium acetate and glucose.     

森林凋落物分解研究进展

森林凋落物是指森林生态系统内由生物组分产生,然后归还到林地表面的所有有机物质的总称。森林凋落物在促进森林生态系统正常的物质循环和养分平衡,维持生态系统功能中具有重要作用,其分解受多因素影响,且各因素之间相互交错。不同情况下,各因子的重要性可能不同。温度和湿度被认为是影响凋落物分解主要的气候因子。凋落物随着温度升高分解速率加快,增加土壤湿度对凋落物分解有积极作用。凋落物的化学性质中,C、N比和木质素含量被认为是最重要的指标。凋落物分解前期的分解速率受到养分含量、水溶性碳化合物和结构碳化合物含量的强烈影响,而后期则更多地受到木质索及纤维素／木质素比值的支配。土壤动物可以粉碎凋落物,土壤微生物也是促进凋落物分解的重要因素,人为活动也影响凋落物分解。N沉降、全球变暖和臭氧层破坏等全球变化对森林凋落物分解的影响已逐渐成为研究热点。未来凋落物分解的研究方向是统一研究方法,开展长期定位监测,加强对分解过程中有机碳含量和释放量的研究,以及N沉降对凋落物分解作用机理的研究。     

Light-induced variation in environmentally persistent free radicals and the generation of reactive radical species in humic substances

• Light irradiation increased the concentration of free radicals on HS. • The increased spin densities on HS readily returned back to the original value. • The “unstable” free radicals induced the formation of reactive radical species. • Reactive radicals’ concentration correlated strongly with EPFRs’ concentration. Environmentally persistent free radicals (EPFRs) in humic substances play an essential role in soil geochemical processes. Light is known to induce EPFRs formation for dissolved organic matter in aquatic environments; however, the impacts of light irradiation on the variation of EPFRs in soil humic substances remain unclear. In this study, humic acid, fulvic acid, and humin were extracted from peat soil and then in situ irradiated using simulated sunlight. Electron paramagnetic resonance spectroscopy results showed that with the increasing irradiation time, the spin densities and g-factors of humic substances rapidly increased during the initial 20 min and then gradually reached a plateau. After irradiation for 2h, the maximum spin density levels were up to 1.63 × 10¹⁷, 2.06 × 10¹⁷, and 1.77 × 10¹⁷ spins/g for the humic acid, fulvic acid, and humin, respectively. And the superoxide radicals increased to 1.05 × 10¹⁴–1.46 × 10¹⁴ spins/g while the alkyl radicals increased to 0.47 × 10¹⁴–1.76 × 10¹⁴ spins/g. The light-induced EPFRs were relatively unstable and readily returned back to their original state under dark and oxic conditions. Significant positive correlations were observed between the concentrations of EPFRs and reactive radical species (R² = 0.65–0.98, p<0.05), which suggested that the newly produced EPFRs contributed to the formation of reactive radical species. Our findings indicate that under the irradiation humic substances are likely to be more toxic and reactive in soil due to the formation of EPFRs.