Regional carbon cycle responses to 25 years of variation in climate and disturbance in the US Pacific Northwest

Variation in climate, disturbance regime, and forest management strongly influence terrestrial carbon sources and sinks. Spatially distributed, process-based, carbon cycle simulation models provide a means to integrate information on these various influences to estimate carbon pools and flux over large domains. Here we apply the Biome-BGC model over the four-state Northwest US region for the interval from 1986 to 2010. Landsat data were used to characterize disturbances, and forest inventory data were used to parameterize the model. The overall disturbance rate on forest land across the region was 0.8 % year^?1, with 49 % as harvests, 28 % as fire, and 23 % as pest/pathogen. Net ecosystem production (NEP) for the 2006–2010 interval on forestland was predominantly positive (a carbon sink) throughout the region, with maximum values in the Coast Range, intermediate values in the Cascade Mountains, and relatively low values in the Inland Rocky Mountain ecoregions. Localized negative NEPs were mostly associated with recent disturbances. There was large interannual variation in regional NEP, with notably low values across the region in 2003, which was also the warmest year in the interval. The recent (2006–2010) net ecosystem carbon balance (NECB) was positive for the region (14.4 TgC year^?1). Despite a lower area-weighted mean NECB, public forestland contributed a larger proportion to the total NECB because of its larger area. Aggregated forest inventory data and inversion modeling are beginning to provide opportunities for evaluating model-simulated regional carbon stocks and fluxes.     

城市污水处理厂污泥资源化利用技术进展

针对目前污水厂污泥传统处理方法存在的不足与弊端 ,提出污泥资源化利用技术是今后污泥最终处置的根本方式 ,并就目前研究的污泥热解制油技术、制取燃料技术、堆肥土地利用技术和热解制取吸附剂技术等主要的资源化利用技术进行了综述。     

新型滤槽除尘器配套脱硫工艺试验研究

采用半干法脱硫系统与新型滤槽除尘器相结合 ,可有效提高系统的脱硫、除尘效率。研究了影响该技术脱硫效率的主要因素。该技术集脱硫、除尘于一体 ,工艺简单 ,运行成本较低 ,尤其适用于燃煤含硫量≤ 1 .2 %的锅炉烟气的脱硫。     

铝污泥灰改性混凝土水化及耐硫酸腐蚀特性

为探究铝污泥灰改性混凝土水化特性,对煅烧后铝污泥灰按照不同掺量(0%、10%、20%、30%)制备试样并进行XRD、TG、SEM测试,结合耐硫酸腐蚀实验分析其抗腐蚀特性。结果表明：铝污泥灰掺量为10%~20%时,可以提高混凝土的抗折抗压强度,抗硫酸侵蚀性能在掺量为20%时最优。这是由于铝污泥灰的火山灰效应产生水化硅酸钙凝胶 (C-S-H) 充填毛细孔隙所致,微集料效应还可细化混凝土孔隙,提高混凝土微观结构致密化水平;另一方面,铝污泥灰的掺入,降低体系的Ca/Si比,提高Al/Si比,减少了水化产物Ca(OH)₂含量,促进C-A-H等耐酸侵蚀物相的生成,从而降低了侵蚀介质的侵入与腐蚀速度。本研究可为混凝土改性及耐蚀混凝土研发提供参考。     

Impact of the novel neonicotinoid insecticide Paichongding on bacterial communities in yellow loam and Huangshi soils

Insecticides are widely sprayed in modern agriculture for ensuring the crop yield, which could also lead to contamination and insecticide residue in soils. Paichongding (IPP) is a novel neonicotinoid insecticide and was developed recently in China. Soil bacterial community, diversity, and community composition vary widely depending on environmental factors. As for now, little is known about bacterial species thriving, bacterial community diversity, and structure in IPP-spraying soils. In present study, IPP degradation in yellow loam and Huangshi soils was investigated, and bacterial communities and diversity were examined in soil without IPP spray and with IPP spray through pyrosequencing of 16S ribosomal RNA (rRNA) gene amplicons. The degradation ratio of IPP at 60 days after treatment (DAT) reached 51.22 and 34.01 % in yellow loam and Huangshi soil, respectively. A higher richness of operational taxonomic units (OTUs) was found in yellow loam soil (867 OTUs) and Huangshi soil (762 OTUs) without IPP spray while OUTs were relatively low in IPP-spraying soils. The community composition also differed both in phyla and genus level between these two environmental conditions. Proteobacteria, Firmicutes, Planctomycetes, Chloroflexi, Armatimonadetes, and Chlorobi were stimulated to increase after IPP application, while IPP inhibited the phyla of Bacteroidetes, Actinobacteria, and Acidobacteria.     

脱氮塔中一株异养硝化真菌的分离鉴定及其脱氮特性

在微生物净化燃煤烟气技术研究中,NO、NOx的脱除效率不高,达不到工艺要求。国内外对于微生物法净化燃煤烟气NO、NOx的细菌作用研究较多,而对真菌的作用却研究很少。为了提高微生物法对燃煤烟气NO、NOx的脱除效率,对脱氮塔生物膜中的异养硝化作用真菌进行了分离、纯化及鉴定,通过摇瓶实验研究了真菌对亚硝酸盐（NO2-）的作用特征,在脱氮塔中对NOx的脱除效率进行了实验验证。实验结果：从脱氮塔生物膜中分离纯化的真菌为木霉属的棘孢木霉Trichodema asperellum（简称：1LNL菌株）;该1LNL菌株能直接将NO2-氧化为NO3-,在实验周期为10 d的条件下,细菌对照组硝化率为31.5%、空白对照组硝化率为8.4%,1LNL菌株的硝化率能达到25.0%,实验证明真菌1LNL菌株具有一定的硝化作用;将1LNL纯菌株扩大培养液400 mL投加到脱氮塔中,NO的脱除率平均提高了4.39%,NOx的脱除率平均提高了4.00%,真菌1LNL能显著提高脱氮柱NO、NOx的脱氮效率。在微生物净化烟气中NO、NOx的研究实践中,真菌的作用应加以重视并应展开更加深入、系统的研究。     

氮添加对侵蚀退化红壤化学性质及芒萁叶功能性状的影响

蕨类植物芒萁(Dicranopteris dichotoma)是我国南方红壤侵蚀区重要的水土保持植物,但目前氮添加对芒萁叶功能性状及其基部土壤化学性质以及这二者之间关系的影响尚不清楚.以芒萁作为研究对象,采用盆栽实验,设置CK(0 g m-2 a-1)、N1(1.1 g m-2 a-1)、N2(2.3 g m-2 a-...     

Response of mercury accumulation to anthropogenic pollution in the past 1000 years based on Lake Huguangyan sediments,Southern China

A new ²¹⁰Pb-dated record of Hg accumulation derived from a sediment core from a Hg-enriched area in Huguangyan Lake (HGY) in South China is presented. Based on synthetic analyses of multi-proxy records including chemical composition, total organic matter, and grain-size distribution in surface sediments and nearby soil samples, it is inferred that the influx of Hg into the lake is mainly a result of atmospheric deposition, with no or minor hydroclimate-induced lithogenic input from the catchment and limited adsorption effects of organic matter and clay. Significantly enhanced anthropogenic input of Hg started in the early 1900s. Since then, several anomalies of Hg accumulation have been the results of wars or intensified economic activities in China. HGY sediments provide a rare and reliable natural archive for detecting atmospheric Hg deposition, which is closely related to anthropogenic activities.

     

Study on cultivation of Trichoderma viride using spent mushroom substrate and control effect on soybean root rot

Journal of Material Cycles and Waste Management - The spent mushroom substrate (SMS) was used as a raw material to prepare T. viride to reduce the production cost of T. viride and promote the...