畜禽粪肥还田四环素类抗生素(TCs)在土壤-蔬菜系统的分布特征及风险评估

畜禽粪肥还田引起的土壤抗生素污染对蔬菜安全和土壤生态风险的影响应得到足够的重视.四环素类抗生素(TCs)在畜禽粪肥和蔬菜基地土壤中被普遍检出且含量较高.然而,目前针对土壤TCs污染对蔬菜安全和土壤生态风险的研究主要采用盆栽试验和田间调查的研究方法,较少开展田间试验.结合盆栽试验和田间试验的研究方法,调查畜禽粪肥还田引起的TCs在土壤-蔬菜系统中的分布特征,采用日允许摄入量-危害商值法(ADI-HQ法)和物种敏感性分布-风险商值法(SSD-RQ法)分别对蔬菜可食部分TCs污染的人体健康风险和土壤TCs污染的生态风险进行评估.结果表明,盆栽试验和田间试验菜心地上部和地下部TCs含量均以OTC为主;盆栽试验和田间试验菜心地上部(以干重计)ω(OTC)分别高达29.25μg·kg^-1和45.03μg·kg^-1,地下部含量(以干重计)ω(OTC)分别高达87.32μg·kg^-1和135.44μg·kg^-1;且田间试验菜心地上部和地下部3种TCs含量均显著高于盆栽试验.土壤TCs的残留以OTC为主,盆栽试验和田...     

蓝藻厌氧消化产沼气技术研究

为了实现太湖蓝藻的资源化和无害化处置,本文在中温（35℃）条件下对蓝藻与猪粪厌氧发酵产沼气进行了研究。在蓝藻与猪粪发酵最佳接种比例1：2、最佳初始pH7．9、最适发酵液浓度2．9％条件下,通过对所产甲烷的分析,得到回归方程B：4885（1-e-0.034565t）,模型的决定系数R2为0．9819,均方差（RMSE）为123,达到收敛判断标准。蓝藻的生物降解率（BD值）为54．4％。pH的变化范围在6．6～7．9之间,能够较好地反应蓝藻与猪粪混合发酵的水解阶段、产酸阶段和产甲烷阶段。发酵结束后,TS去除率达到22．2％,VS去除率达到25．2％。对发酵过程中COD和氨氮变化的研究表明：反应结束后,COD的去除率达87．44％;高浓度的氨氮对厌氧细菌的生长有一定抑制作用,但是并不影响沼气的组份。各反应器所产生的沼气中甲烷和二氧化碳的含量均能保持在50％和35％左右,最高甲烷含量达到70％。     

The Effect of Rain and Runoff When Assessing Timing of Manure Application and Dissolved Phosphorus Loss in Runoff1

Vadas, Peter A., William E. Jokela, Dory H. Franklin, and Dinku M. Endale, 2011. The Effect of Rain and Runoff When Assessing Timing of Manure Application and Dissolved Phosphorus Loss in Runoff. Journal of the American Water Resources Association (JAWRA) 47(4):877‐886. DOI: 10.1111/j.1752‐1688.2011.00561.x Abstract: A significant pathway of nonpoint source, agricultural phosphorus (P) transport is surface runoff, to which surface‐applied manure can contribute. Increasing the time between manure application and the first rain‐runoff event is proposed as a practice to reduce runoff P loss. Few studies have investigated this aspect of manure P loss in runoff, with mixed results. Studies observing a decrease in runoff P as the time between application and the first rain‐runoff attribute the decrease to adsorption of manure P by soil and manure drying effects, but do not consider the effect of storm hydrology on runoff P. We ran the manure P runoff model SurPhos with data from nine published studies that investigated the effect of time between application and the first rain event on runoff P. SurPhos successfully simulated the experimental conditions in the studies and predicted runoff P loss. Simulation results suggest soil adsorption of manure P is not the dominant mechanism that will significantly decrease manure P availability to runoff. Rather, regardless of when the first rain‐runoff event occurs, storm hydrology will significantly affect manure P loss in runoff. Although model scenarios indicate that increasing the time between manure application and the first rain‐runoff event will typically decrease P loss in runoff, runoff P could be equal to or greater 30 days after application than the day after application if a more intense rain and runoff event occurs at the latter date.     

鸡粪和猪粪生物发酵过程中抗生素抗性基因的动态变化

畜禽粪便是储存和传播抗生素抗性基因(ARGs)的主要载体.为明确鸡粪和猪粪堆肥过程中ARGs和MGEs相对丰度的变化及影响其消减的关键环境因子,探索减少畜禽粪便堆肥中ARGs含量并降低其污染风险的有效方法,采用实时荧光定量PCR技术和16S rRNA高通量测序技术,测定了鸡粪和猪粪好氧堆肥75 d的过程中,不同阶段10种ARGs和7种可移动遗传元件(MGEs)的丰度变化和细菌群落变化,分析了ARGs和MGEs与细菌群落的相关性和堆体理化性质(温度、含水率、 pH和DOC)变化对ARGs和MGEs丰度的影响.结果表明,猪粪(PM)中ARGs和MGEs丰度显著高于鸡粪(CM).堆肥结束后,两种堆肥中9种ARGs和5种MGEs的相对丰度均显著降低,其中CM中3种ARGs(tetM、tetT和aacA)和4种MGEs(ISEcp1、IS1216、IS613和tnp614)的去除率达到99%; PM中9种ARGs[tetB(P)、tetL、tetM、tetO、tetT、aacA、aadD、aphA3和sat4]及4种MGEs(ISEcp1、IS26、IS1216和tnp614)去除率均达到99%...     

Understanding gaseous reduction in swine manure resulting from nanoparticle treatments under anaerobic storage conditions

Manure is an impending source of carbon(C), sulfur(S) and water(H_2 O). Consequently,microbial populations utilize these constituents to produce methane(CH4), carbon dioxide(CO_2), greenhouse gases(GHGs), and hydrogen sulfide(H_2 S). Application of nanoparticles(NPs) to stored manure is an emerging GHG mitigation technique. In this study, two NPs: nano zinc oxide(nZnO) and nano silver(nAg) were tested in swine manure stored under anaerobic conditions to determine their effectiveness in mitigating gaseous emissions and total gas production. The biological sources of gas production, i.e., microbial populations were characterized via Quantitative Polymerase Chain Reaction(qPCR) analysis. Additionally, pH, redox, and VFAs were determined using standard methods. Each treatment of the experiment was replicated three times and NPs were applied at a dose of 3 g/L of manure. Also, headspace gas from all treatment replicates were analyzed for CH_4 and CO_2 gas concentrations using an SRI-8610 Gas Chromatograph and H_2 S concentrations were measured using a Jerome 631 X meter. Nanoparticles tested in this study reduced the cumulative gas volume by 16%–79% compared to the control. Among the NPs tested, only nZnO consistently reduced GHG concentrations by 37%–97%. Reductions in H_2 S concentrations ranged from 87% to97%. Gaseous reductions were likely due to decreases in the activity and numbers of specific gas producing methanogenic archaea and sulfate reducing bacterial(SRB)species.     

畜禽粪便污染的环境风险与资源化处理技术分析

畜禽养殖业飞速发展大力促进了我国农村经济的繁荣振兴,但同时出现的畜禽粪便排放量大、处理率低和易造成环境污染等问题也日益突出.在总结我国畜禽粪便排放现状的基础上,系统分析了畜禽粪便中主要环境污染物及其在土壤、水和大气等介质中的赋存、迁移转化等污染特征,并以重金属和抗生素为特征污染物对畜禽粪便农用的环境风险评估方法与风险等级进行了阐述;对比分析了国内外常用的畜禽粪便无害化和资源化处理技术,并评估了热化学转化技术和生物技术等在畜禽粪便能源化和肥料化处理方面的发展前景和应用价值.此外,探讨了目前畜禽粪便污染治理工作中存在的常见问题,并展望了畜禽粪便资源化处理技术未来的发展方向.     

施用畜禽粪便堆肥品的蔬菜地CH4、N2O和NH3排放特征

农田是重要的温室气体排放来源之一,其中蔬菜地的温室气体排放日益受到人们关注.以北京市郊某温室种植的油麦菜地为研究对象,通过大棚试验,考察和比较了油麦菜地施用不同类型畜禽粪便堆肥产品的CH4、N2O和NH3排放特征及其影响因素.结果表明,油麦菜地NRM、RM、CF处理的CH4排放系数分别为0.2%、0.027%、0.004%;N2O排放系数分别为0.18%、0.63%、0.74%;NH3排放系数分别为2.00%、3.98%、2.53%.CH4排放通量与土壤温度和地表湿度相关,N2O排放通量与土壤温度、地表温度和湿度相关,CH4、N2O和NH3排放通量均受土壤含水率影响,而温室中的气温不是影响CH4、N2O和NH3排放的主要因素.     

鸡粪堆肥有机物演化对重金属生物有效性影响研究

采用离子色谱、三维荧光光谱、紫外-可见吸收光谱和多元统计分析,研究了鸡粪堆肥水溶性有机物(DOM)和重金属组成与演化特性,探究了有机物演化对重金属生物有效性的影响及其机理.结果显示,堆肥升温期和高温期有机物降解最为剧烈,产生了大量苹果酸、酒石酸、乙酸和草酸,其浓度分别在2097.55~2155.61、39.24~51.58、12.52~12.90及1.68~2.31 mg·L-1之间;堆肥降温期和二次发酵过程,蛋白类物质降解,腐殖质类物质合成,DOM的腐殖化率和缩合度增大,稳定性增强.堆肥过程中水溶态重金属中Fe的浓度(1.069~7.106 mg·L-1)最高,Al、As、Cr、Cu和Mn的浓度(0.1~1.008mg·L-1)其次,Pb的浓度(0.003~0.02 mg·L-1)最低,随着堆肥的进行水溶态重金属含量呈下降趋势(Al除外),相关性分析显示,水溶态重金属主要结合在腐殖质类物质上,生物可利用性低.分析结果表明,堆肥可通过降低水溶态重金属的含量和将水溶态重金属络合在腐殖质类物质上降低产品中重金属的生物有效性.     

畜禽养殖污染物资源化利用技术及模式研究

中国畜禽养殖业污染十分严重。结合中国传统农业"万物并育"思想,论述了畜禽养殖污染物的资源化利用技术及模式,主要有肥料化(牧-肥-草模式、农业废弃物-畜禽粪便堆肥模式、发酵床模式)、能源化(以沼气为核心的利用模式、畜禽粪便-农业废弃物联合发酵制氢模式)、基料化(农林副产物-食用菌模式、以食用菌为中心的循环经济模式、针叶树类木屑-发酵床养猪-食用菌利用模式)、饲料化四种方式。这些利用方式为防治畜禽养殖业污染发挥着重要作用。     

Investigation of physico-chemical properties and microbial community during poultry manure cocomposting process

Co-composting of poultry manure and rubber wood sawdust was performed with the ratio of 2:1 (V/V) for a period of 60 days. An investigation was carried out to study the extracellular enzymatic activities and structural degradation utilizing Fourier transform infrared spectroscopy (FT-IR), thermogravimetry and differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM). The microbial succession was also determined by using denaturing gel gradient electrophoresis (DGGE). The compost was able to reach its highest temperature of 71 ℃ at day 3 and stabilized between 30 and 40 ℃ for 8 weeks. CMCase, FPase and β-glucosidase acted synergistically in order to degrade the cellulosic substrate. The xylanase activities increased gradually during the composting and reached the peak value of 11.637 U/g on day 35, followed by a sharp decline. Both LiP and MnP activities reached their peak values on day 35 with 0.431 and 0.132 U/g respectively. The FT-IR spectra revealed an increase in aromaticity and a decrease in aliphatic compounds such as carbohydrates as decomposition proceeded. TGA/DTG data exhibited significant changes in weight loss in compost samples, indicating degradation of organic matter. SEM micrographs showed higher amounts of parenchyma exposed on the surface of rubber wood sawdust at day 60, showing significant degradation. DGGE and 16S rDNA analyses showed that Burkholderia sp., Pandoraea sp., and Pseudomonas sp. were present throughout the composting process. Ornithinibacillus sp. and Castellaniella ginsengisoli were only found in the initial stage of the composting, while different strains of Burkholderia sp. also occurred in the later stage of composting.