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991.
应用生态动力学模型评价上海淀山湖富营养化控制方案 总被引:9,自引:0,他引:9
近年来,由于淀山湖入湖河流和环湖污水排放,淀山湖水质严重富营养化,夏季高温季节蓝藻水华时有发生。基于最近开展的比较系统的大规模水文、水质、生物同步监测和底质氮磷营养盐释放通量实验,进行入湖氮磷营养盐通量计算分析。通过建立淀山湖水动力一生态动力学耦合模型,利用同步实测和历史资料进行水动力模型和生态动力学模型的率定验证,模拟典型风场作用下的淀山湖三维流场特征;利用生态动力学模型系统研究淀山湖氮磷营养盐和藻类的时空变化和演替规律,初步掌握淀山湖的富营养化过程;综合评价了污染负荷削减、水力调度(水体停留时间)等措施对控制淀山湖富营养化的作用,明确磷是淀山湖藻类生长的关键营养盐限制因子。模型预测结果表明,磷负荷削减50%以上才能使淀山湖夏季蓝藻生物量开始下降;削减90%以上的营养盐负荷才能有效抑制蓝藻水华;水体停留时间的长短是藻类是否过度繁殖的重要条件,加大引水流量,减少淀山湖水体停留时间是有效控制蓝藻水华的重要途径;目前阶段,与控制营养盐负荷(50%)相比,增大引水流量可以更有效地降低蓝藻暴发时的生物量。 相似文献
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构建了环境经济投入产出模型,针对淘汰落后产能对经济发展的影响进行了实证研究,定量计算了2006~2007年问淘汰落后产能对于经济社会发展的贡献度和影响.研究表明,虽然淘汰落后产能对于传统的国民经济发展指标有一定负面影响,但对于优化经济增长方式确实起到了积极作用.一是优化了产业结构,第一、二、三产业结构由2005年的12.4%,48.6%,39.0%调整为2006年的12.5%,48.2%和39.3%,2007年调整为12.6%,47.8%和39.6%,第二产业所占比重逐步下降,第三产业所占比重逐步上升;在第二产业内部.造纸、食品、电力、炼焦、金属冶炼、非金属矿物制品业等重污染行业的增加值所占比重持续下降,产业结构逐步得到优化.二是提高了经济效率,从涉及到的造纸、食品、电力、炼焦、金属冶炼、非金属矿物制品业6个产业部门2006年和2007年的COD和SO_2的产污系数看,都比2005年有所降低.2006年和2007年,食品制造业的单位增加值COD排放量比2005年分别下降了6.6%和25.0%;金属冶炼及压延加工业的单位增加值SO_2排放量比2005年分别下降3.5%和6.9%. 相似文献
997.
Using the nematode Caenorhabditis elegans as a model animal for assessing the
toxicity induced by microcystin-LR 总被引:1,自引:0,他引:1
Among more than 75 variants of microcystin(MC),microcystin-LR(MC-LR) is one of the most common toxins.In this study,the feasibility of using Caenorhabditis elegans to evaluate MC-LR toxicity was studied.C.elegans was treated with MC-LR at different concentrations ranging from 0.1 to 80 μg/L.The results showed that MC-LR could reduce lifespan,delay development,lengthen generation time,decrease brood size,suppress locomotion behavior,and decreases hsp-16-2-gfp expression.The endpoints of generation time,brood... 相似文献
998.
Development and application of a two-dimensional water quality model for the
Daqinghe River Mouth of the Dianchi Lake 总被引:1,自引:1,他引:0
Water quality models are important tools to support the optimization of aquatic ecosystem rehabilitation programs and assess their efficiency. Basing on the flow conditions of the Daqinghe River Mouth of the Dianchi Lake, China, two-dimensional water quality model was developed in the research. The hydrodynamics module was numerically solved by the alternating direction iteration (ADI) method. The parameters of the water quality module were obtained through the in situ experiments and the lab analyses that were conducted from 2006 to 2007. The model was calibrated and verified by the observation data in 2007. Among the four modelled key variables that were water level, CODcr, NH3-N and PO4-P, the minimum value of the coefficient of determination (CoD) was 0.69, which mean the model performed reasonably well. The developed model was then applied to simulate the water quality changes at the downstream cross-section assuming that the designed restoration programs were implemented. According to the simulated results, the restoration programs could cut down the loads of CODcr and PO4-P about 15%, however, they would have very little effect on the NH3-N removal. Besides, the water quality at the outlet cross-section would be still in class V (3838-02), indicating more measures should be taken to further reduce the loads. The study demonstrated the capability of water quality models to support aquatic ecosystem restorations. 相似文献
999.
A laboratory scale test was conducted in a combined membrane process (CMP) with a capacity of 2.91 m3/d for 240 d to
treat the mixed wastewater of humidity condensate, hygiene wastewater and urine in submarine cabin during prolonged voyage.
Removal performance of chemical oxygen demand (COD), ammonia nitrogen (NH4
+-N), turbidity and anionic surfactants (LAS)
was investigated under di erent conditions. It was observed that the e uent COD, NH4
+-N, turbidity and LAS flocculated in ranges of
0.19–0.85 mg/L, 0.03–0.18 mg/L, 0.0–0.15 NTU and 0.0–0.05 mg/L, respectively in spite of considerable fluctuation in corresponding
influent of 2120–5350 mg/L, 79.5–129.3 mg/L, 110–181.1NTU and 4.9–5.4 mg/L. The e uent quality of the CMP could meet the
requirements of mechanical water and hygiene water according to the class I water quality standards in China (GB3838-2002). The
removal rates of COD, NH4
+-N, turbidity and LAS removed in the MBR were more than 90%, which indicated that biodegradation
is indispensable and plays a major role in the wastewater treatment and reuse. A model, built on the back propagation neural network
(BPNN) theory, was developed for the simulation of CMP and produced high reliability. The average error of COD and NH4
+-N was
5.14% and 6.20%, respectively, and the root mean squared error of turbidity and LAS was 2.76% and 1.41%, respectively. The results
indicated that the model well fitted the laboratory data, and was able to simulate the removal of COD, NH4
+-N, turbidity and LAS. It
also suggested that the model proposed could reflect and manage the operation of CMP for the treatment of the mixed wastewaters in
submarine. 相似文献
1000.
西藏地区春青稞耗水特征及适宜灌溉制度探讨 总被引:5,自引:0,他引:5
以中科院拉萨高原生态试验站为依托,通过开展春青稞生长与土壤水分定位观测实验,利用SHAW模型实现对春青稞农田蒸散发与土壤水深层渗漏与补给过程模拟,分析了春青稞的耗水特征,并对其适宜的灌溉制度进行了初步探讨:①春青稞生长期间,耗水450 mm左右,其中,分蘖—拔节、拔节—抽穗、抽穗—蜡熟这3个阶段是春青稞的耗水旺期,耗水量占整个生长期的72%。把握住该时期的水分供应,对提高作物产量十分重要。②在春青稞的需水关键期降水量仅能满足作物需水的58%,必须补充人工灌溉;但现行的灌溉制度由于灌溉量较大,不仅加大土壤蒸发,更造成较大的深层渗漏。③在播种—出苗、拔节—抽穗期分别灌溉50 mm,抽穗—蜡熟期灌溉60 mm,共减少灌溉用水125 mm后,深层渗漏减少了81%(131 mm);深层土壤水向上补给量增加了55%(44 mm)。节水灌溉不仅减少了土壤蒸发与深层渗漏也促使深层土壤水向上补给根系层,应该大力推广这一灌溉制度。 相似文献