畜禽粪便有机肥中重金属在水稻土中生物有效性动态变化

通过土壤淹水培养试验和土壤淹水培养不同时间后同时开始的水稻生物盆栽试验,研究不同畜禽粪便有机肥中Cu、Zn、Cd、Pb在水稻土中生物有效性动态变化以及与等量重金属无机盐的差异,明确不同畜禽粪便有机肥中不同重金属生物有效性差异及动态变化规律.结果表明,水稻土施入畜禽粪便有机肥后30~60 d内,畜禽粪便有机肥处理土壤溶液中重金属含量显著低于等量重金属无机盐处理,重金属无机盐处理土壤溶液中Cu、Zn、Cd、Pb的含量分别是鸡粪处理的2.4倍、3.1倍、3.9倍和327.3倍,分别是猪粪处理的2.0倍、2.2倍、15.6倍和4.0倍.60d后畜禽粪便有机肥处理和对应等量重金属无机盐处理土壤溶液中Cu、Zn、Cd、Pb的含量变的无差异.不同施用时间的畜禽粪粪便有机肥处理水稻体内Cu、Zn、Pb含量均显著低于对应的等量重金属无机盐处理,施用畜禽粪肥处理降低了土壤中Cu的生物有效性.畜禽粪便有机肥中重金属的生物有效性随施用后不同时间的变化呈现先升高后降低再升高规律,在施用后2个月时畜禽粪便有机肥中重金属的生物有效性最低,只相当于对应的等量重金属无机盐的13.0%~30.0%.     

烟气深度余热回收技术对燃气锅炉NOx排放扩散迁移规律的影响研究

运用Fluent计算软件对北京市丰台区某燃气锅炉排放烟气中NOx的转化和扩散过程进行了数值模拟,定量地研究了烟气深度余热回收技术对燃气锅炉排放NOx在大气中的迁移规律产生的影响,并与Screen 3模型模拟的结果进行了对比.研究发现:烟气深度余热回收技术的应用使NOx的最大落地浓度与烟气直排时相比增加了2.5倍,NOx对本地地表的影响面积增大了15750 m2,增加了本地环境污染的风险.结合燃气锅炉的NOx控制技术提出了缓解局部环境风险的解决方案.结果表明,烟气深度余热回收技术与低氮燃烧技术联用,NOx的控制效率达到70%以上时,在有效提升锅炉热效率的同时,可以缓解由于烟温大幅下降造成的本地环境污染恶化的风险.     

济宁市生态文明建设的战略构想与对策

推进生态文明建设、建设美丽中国成为社会主旋律.文章从生态资源、生态空间、生态产业、转型发展等方面分析了济宁生态文明建设的优势,从战略顶层设计角度出发,研究提出了生态文明建设的总体要求、生态功能分区定位和实施步骤,针对近期济宁市生态文明建设存在的问题,从体制创新、制度体系、转型升级、考核监督、大气治理、水污染防治、城乡绿化等方面提出了具体的对策建议.     

Two-step fast microwave-assisted pyrolysis of biomass for bio-oil production using microwave absorbent and HZSM-5 catalyst

A novel technology of two-step fast microwave-assisted pyrolysis(f MAP) of corn stover for bio-oil production was investigated in the presence of microwave absorbent(Si C) and HZSM-5catalyst. Effects of f MAP temperature and catalyst-to-biomass ratio on bio-oil yield and chemical components were examined. The results showed that this technology, employing microwave, microwave absorbent and HZSM-5 catalyst, was effective and promising for biomass fast pyrolysis. The f MAP temperature of 500°C was considered the optimum condition for maximum yield and best quality of bio-oil. Besides, the bio-oil yield decreased linearly and the chemical components in bio-oil were improved sequentially with the increase of catalyst-to-biomass ratio from 1:100 to 1:20. The elemental compositions of bio-char were also determined. Additionally, compared to one-step f MAP process, two-step f MAP could promote the bio-oil quality with a smaller catalyst-to-biomass ratio.     

Enhanced methane production in an anaerobic digestion and microbial electrolysis cell coupled system with co-cultivation of Geobacter and Methanosarcina

The anaerobic digestion(AD)and microbial electrolysis cell(MEC)coupled system has been proved to be a promising process for biomethane production.In this paper,it was found that by co-cultivating Geobacter with Methanosarcina in an AD–MEC coupled system,methane yield was further increased by 24.1%,achieving to 360.2 m L/g-COD,which was comparable to the theoretical methane yield of an anaerobic digester.With the presence of Geobacter,the maximum chemical oxygen demand(COD)removal rate(216.8 mg COD/(L·hr))and current density(304.3 A/m_3)were both increased by 1.3 and 1.8 fold compared to the previous study without Geobacter,resulting in overall energy efficiency reaching up to 74.6%.Community analysis demonstrated that Geobacter and Methanosarcina could coexist together in the biofilm,and the electrochemical activities of both were confirmed by cyclic voltammetry.Our study observed that the carbon dioxide content in total gas generated from the AD reactor with Geobacter was only half of that generated from the same reactor without Geobacter,suggesting that Methanosarcina may obtain the electron transferred from Geobacter for the reduction of carbon dioxide to methane.Taken together,Geobacter not only can improve the performance of the MEC system,but also can enhance methane production.     

施用沼渣和接种丛枝菌根真菌对甘草生长及矿质营养的影响

沼渣是厌氧发酵的残余物,可作为肥料施用,但因其含有一定量的重金属等有害物质可能导致环境污染风险.丛枝菌根(Arbuscular mycorrhiza,AM)真菌作为植物共生真菌,可以促进植物对矿质养分的吸收,同时能够通过不同途径减轻重金属对植物的毒害.本文采用甘草(Glycyrrhiza uralensis Fisch.)为供试植物开展盆栽试验,考察施用沼渣结合接种AM真菌对甘草生长和矿质营养的影响.试验结果表明,施用沼渣显著促进了植物生长,提高了植物生物量、磷含量和叶片叶绿素含量,与此同时提高了土壤有机质和磷、铬、铜、铅含量,并导致植物重金属含量显著升高.另一方面,AM真菌能够和甘草根系形成良好共生关系,但施用沼渣对菌根侵染表现出显著抑制作用.接种AM真菌促进了甘草生长、提高了根系磷含量及叶片叶绿素含量,同时显著降低了植株重金属含量至安全阈值以内.本试验表明,施用沼渣同时接种AM真菌可在促进甘草生长的同时阻控重金属污染风险,因而可作为沼渣安全利用的一种可行技术途径.     

徐州市尾水导流信息化监测平台的设计与应用研究

南水北调徐州市截污导流工程是保障江苏省南水北调出省水质达到Ⅲ类水标准的关键性工程.徐州市尾水导流信息化监测平台,基于地理信息系统,集数据采集与传输、实时监测、历史数据分析、视频监控、预警预报于一体,对工程现场的各种类型的监测数据和工况信息进行采集、分析和展示应用,是南水北调徐州市截污导流工程实现全面信息化管理的重要技术支撑,为东线水资源安全提供有力保障.     

地下储气库泄漏风险定量分析研究

地下储气库系统易受到地质灾害、腐蚀、设备故障等风险因素的不良影响,降低其稳定性和可靠性,因此对地下储气库进行风险识别与分析,并针对地下储气库泄漏风险进行定量研究十分必要。针对国内某地下储气库泄漏问题,首先辨识出地下储气库泄漏风险因子,并采用事故树分析定性确定了各个风险因子的结构重要度,然后采用层次分析定量确定了地下储气库泄漏事故的风险水平,以为地下储气库风险评估及安全运行提供指导。     

中山市旱季霾特征及数值模拟分析

利用观测数据、Hysplit后向轨迹模式以及WRF-CMAQ模式对中山市旱季霾特征进行模拟分析.中山市霾污染的天气形势以大陆高压型为主.当相对湿度在71%~90%时,气溶胶浓度和能见度的负相关性最显著,且当能见度减小到5 km以下时,PM_(2.5)浓度的大幅减小才能使能见度略有好转.最有可能引起中山发生霾天气的两条污染带,一条是沿中山至湖南南部,另一条是沿中山到粤东地区.WRF-CMAQ模式能较好地模拟出2014年1月份中山PM_(2.5)浓度、能见度的变化趋势以及广东省区域内灰霾的污染过程.在气溶胶质量权重及消光贡献中,硫酸盐的比重最高,在高相对湿度下,二次气溶胶的消光权重超过80%.通过中山PM_(2.5)过程分析发现,在霾过程,无冷空气时PM_(2.5)主要来自气溶胶反应、排放源和水平平流,贡献率分别为35%、15%和10%,有冷空气时水平平流的贡献最大,达37%;在清洁过程,无冷空气时气溶胶主要靠水平平流和干沉降清除,贡献率分别为-39%和-14%,有冷空气时清除以水平平流和垂直对流、扩散为主,贡献率分别为-29%和-25%,说明不同天气条件下霾的污染和清洁机制有着明显差别.     

Regeneration of commercial selective catalyst reduction catalysts deactivated by Pb and other inorganic elements

The regeneration of commercial SCR(Selective Catalyst Reduction) catalysts deactivated by Pb and other elements was studied.The deactivated catalyst samples were prepared by chemical impregnation with mixed solution containing K_2SO_4,Na_2SO_4,CaSO_4,Pb(NO_3)_2and NH_4H_2PO_4.A novel method combining Ethylenediaminetetraacetic acid disodium salt(EDTA-2Na) and H_2SO_4solution(viz.catalysts treated by dilute EDTA-2Na and H_2SO_4 solution in sequence) was used to recover the activity of deactivated samples,and the effect was compared with single H_2SO_4,oxalic acid,acetic acid,EDTA or HNO_3 solutions.The surface structure,acidity and reducibility of samples were characterized by N_2adsorption–desorption,inductively coupled plasma optical emission spectrometer(ICP-OES),scanning electron microscopy(SEM),X-ray diffraction(XRD),X-ray fluorescence(XRF),H-2-temperature programmed section(H_2-TPR),NH3-temperature programmed desorption(NH3-TPD) and in situ DRIFTS.Impurities caused a decrease of specific surface area and surface reducibility,as well as Br?nsted acid sites,and therefore led to severe deactivation of the SCR catalyst.The use of an acid solution alone possibly eliminated the impurities on the deactivated catalyst to some extent,and also increased the specific surface area and Br?nsted acid sites and promoted the surface reducibility,thus recovered the activity partially.The combination of EDTA-2Na and H_2SO_4 could remove most of the impurities and improve the activity significantly.The removal of Pb should be an important factor for regeneration.Due to a high removal rate for Pb and other impurities,the combination of EDTA-2Na and H_2SO_4 solutions provided the best efficiency.