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  • 规则波作用下簇状沉水植物群消浪特性实验

    彭浩,陈杰,蒋昌波,何飞,隆院男,屈科,邓斌,伍志元

    在理论分析的基础上通过物理模型实验探究了规则波与簇状沉水植物群的相互作用。结果表明,植物群沿程波高衰减规律在多数情况下与Kobayashi指数形式和Darlymple幂函数形式波高衰减理论模型吻合较好,少数情况下波高衰减集中在植物群后半部分,与上述理论模型并不一致。在植物淹没度等于0.40条件下,植物群沿程波高出现较多壅高现象,且相对壅高值随入射波高的增大而减小;植物群的规则波透射系数变化情况与入射波周期、相对波高、植物淹没度以及植物分布密度等因素相关。当入射波周期等于1.0 s时,透射系数随相对波高的增大而减小,周期大于1.0 s时,透射系数随相对波高的增大出现较强的波动性。本文提出了规则波透射系数与水动力因素及植物因素之间的关系式,得到了近岸簇状沉水植物群消浪特性的基本认识,为采用近岸植物消波护岸提供一定的理论依据。

    年期 [查看摘要][在线阅读][下载 1499K]
  • 菲与纳米银对胶州湾表层沉积物反硝化作用的复合毒性效应评价

    孙鹏飞1 ,白洁1,2,李岿然3**,白晓岩3,田延昭1,赵阳国1,2

    摘要:多环芳烃(PAHs)与纳米材料污染已对沉积物生态系统和人类生存环境构成严重威胁,其复合污染的毒性效应环境危害可能更大。为了深入探讨PAHs与纳米材料对近岸表层沉积物反硝化作用的复合毒性效应,本文选取位于胶州湾(JZB)的大沽河河口区(DRE)E站和湾内S站,分别以菲和纳米银代表PAHs和纳米材料,通过测定不同剂量单一及复合污染下沉积物反硝化潜势(PDA)的变化,结合浓度相加模型(CA)、独立作用模型(IA)和中效/联合指数等效图法(CI)三种复合毒性评价方法,评价菲和纳米银对沉积物反硝化潜势的复合毒性效应,并对评价方法进行了优选。结果表明,两种污染物浓度越高,对研究区域反硝化潜势的抑制作用越大。菲、纳米银单一及复合作用下对河口区沉积物反硝化潜势的EC50值分别为44.62、112.49和64.86 mg·kg-1,对湾内分别为61.79、147.05和96.18 mg·kg-1。菲单一作用对反硝化潜势的抑制效应强于纳米银,但复合污染的抑制效应更强。两种污染物对河口区的沉积物反硝化潜势抑制效应强于湾内,可能与河口区具有较高Eh和沉积物颗粒度及较低的pH、盐度和有机质含量有关。三种毒性效应评价方法的结果表明,菲和纳米银的复合污染对2个站位反硝化潜势的毒性效应均为协同作用,且对大沽河河口区的协同作用更强。此外,CI法对复合效应的预测结果比CA和IA法更为接近实际观测值,且CI不需要考虑污染物作用模式的限制,因此认为CI法更适用于评价混合污染对沉积物反硝化作用复合影响的效果。本研究结果表明,菲和纳米银会增强彼此对反硝化菌及反硝化功能的毒性效应,由此推断,PAHs和纳米材料在环境中同时存在时比其单独存在对沉积环境的危害更大。Abstract: The pollution of PAHs and nanometer materials had posed a serious threat to sediment ecology and human living environment. The environmental effects of combined pollution of PAHs and nanometer materials are worth for paying attention. To explore combined toxicity of PAHs and nanometer materials on denitrification of surface sediment from the coastal area, station E and S from DRE and JZB was selected. Besides, Phenanthrene and AgNPs were chosen as the representatives of PAHs and nanomaterials. The effects of both single and combined pollution of phenanthrene (Phe) and AgNPs in different concentrations on PDA of sediment were measured, and then the combined toxicity of Phe and AgNPs were analyzed by using the methods concentration addition model (CA), independence model (IA) and median-effect equation/ combination index (CI), and the evaluation method was optimized. The results showed that PDA was decreased with the increasing of pollutant concentration. The EC50 of both single and combined pollution of Phe and AgNPs on PDA of DRE and JZB was 44.62, 112.49, 64.86 and 61.79, 147.05, 96.18 mg·kg-1 respectively. The inhibition effect of Phe on PDA was stronger than that of AgNPs, and their combined pollution was strongest. The inhibition effect of pollutant on PDA of DRE was stronger than that of JZB, as DRE has higher Eh, sediment grain size and lower pH, salinity and OM. The three evaluation methods had a good consistency result in the evaluation of combined toxicity effect of Phe and AgNPs, which showed a synergistic effect on PDA of both stations. The synergistic effect of DRE was stronger. In addition, the prediction results of combined effect by CI method were closer to the actual observation values than those by CA and IA methods. Since CI method need not to consider the limitation of action mode of pollutant, CI method was more effective and stronger to predict effects of combined pollution on sediment denitrification. Therefore, the combined exposure of Phe and AgNPs strengthen toxicity effects on denitrifiers and denitrification. It can be concluded that the co-exist of PAHs and nanomaterials in the environment could be more harmful to the sedimentary environment.

    年期 [查看摘要][在线阅读][下载 1321K]
  • 农作物秸秆生物炭技术的经济、固碳和农业效益分析---以威海地区为例

    崔福君,郑浩,陈丕伟,王震宇

    摘 要:农作物秸秆生物炭技术是一项新兴技术,本文以建设农作物秸秆生物炭生产企业为例,假设农作物均匀分布在生产企业周围,以盈亏平衡分析方法,通过农作物秸秆收购半径数学模型,计算威海地区农作物秸秆收购最优半径为36.3km;在最优半径内建设农作物秸秆生物炭生产企业,当农作物秸秆面密度ρ为271.9t/km2时,生产企业经济效益约为6000万,施入土壤后碳封存产生的固炭效益约为4600万元,带来的农业效益约为1.85亿元。同时,提出政府作为环境责任主体,对固碳效益进行分配调节,有利于农作物秸秆生物炭技术的应用推广,实现节能减排、增产增收。Abstract: According the parameters about the biochar price, straw purchase price, transportation costs and others, We calculated bythe mathematical model of the straw acquisition radius to obtain that, when the straw acquisition radius is about 36.3km,the economic benefit is the largest.The straw acquisition radius(36.3km) is almost the same value in our main agricultural areas.As the research object about the straw of the wheat-corn- peanut rotation in two years,when straw areal density is 271.9t/km2 and the straw acquisition radius is 36.3km, the biochar plant benefits about straw biochar sale, carbensequestration,and agricultural increaseproduction,respectively is 60 million yuan,46 million yuan,185 million yuan. Simultaneously,we put forward the interests deploymentrecommendations between the government,business and farmers (farm) about the biochar plant benefits.

    年期 [查看摘要][在线阅读][下载 680K]