渤海直排海污染源排放特征及管理对策研究

本文根据2011－2020年渤海直排海污染源监测数据,分析了渤海直排海污染源污染物排放特征及变化趋势,总结了2017年以来特别是渤海综合治理攻坚战实施后直排海污染源治理成效,并提出相应的管理对策。研究结果表明:2011－2020年,渤海直排海污染源污水排放量与黄海、东海和南海海区相比一直处于低位,化学需氧量、氨氮、总磷等污染物排放量总体呈先增加后减少的趋势;从2018年渤海综合治理攻坚战实施开始,直排海污染源入海污水总量呈明显上升趋势,但化学需氧量、总磷、总氮等主要污染物总量和浓度比明显下降,直排海污染源达标率呈逐年上升趋势;空间分布上,山东省、辽宁省属于直排海污染源排放量和排放强度高的省份;时间分布上,2018－2020年第四季度化学需氧量、总氮、总磷、氨氮等主要污染物排放量呈明显上升趋势。结合渤海直排海污染源排放特征,建议应健全渤海直排海污染源管控体系,分类推进渤海直排海污染源精准整治,提升渤海直排海污染源监测能力,为深入开展渤海直排海污染源污染治理提供支撑。     

基于力学机制的钢筋混凝土柱抗剪承载力模型∗

为了兼顾钢筋混凝土(RC)柱抗剪承载力分析的计算精度和简便性,研究建立了一种基于力学机制的RC柱抗剪承载力简化模型。首先基于变角桁架-拱模型理论,结合变角桁架模型的力平衡条件以及变角桁架模型和拱模型之间的变形协调条件,建立了RC柱抗剪承载力分析的理论模型;然后利用38组试验数据进行统计分析,分别确定了混凝土、箍筋和拱模型的抗剪承载力贡献系数近似取值,在此基础上建立了R C柱抗剪承载力分析的简化模型;最后通过与试验数据进行对比分析,验证了该模型的计算精度和适用性。分析结果表明,该模型不仅可以合理分析混凝土、箍筋和拱作用的抗剪承载力贡献,具有较高的计算精度,而且计算公式较为简洁。     

北京市北运河水系底栖动物群落与水环境驱动因子的关系及水生态健康评价

底栖动物可反映多种生态威胁对水环境的积累效应,与河流水生态系统健康状态密切相关.本研究以北京市典型流域北运河流域为例,基于2015年夏季野外采样调查34个站点水生态数据,对底栖动物群落特征进行分析,采用典型对应分析筛选得到水质驱动因子,利用临界点指示类群分析方法探究关键影响因子的指示物种及其阈值,并基于底栖动物完整性指...     

青岛市城市资源、基础设施与其经济社会协调发展的定量评价和分析

在分析青岛市城市资源、基础设施条件与其经济社会发展之间关系的基础上．构建了多层次评价指标体系，对城市资源和基础设施这两大因素与青岛市经济社会发展的协调关系进行定量评价。结果表明,2001—2004年期间，青岛市城市盗源、基础设施与其经济社会各年度的协调发展度均大于0．8。其中,经济社会发展水平呈现持续增长的势头，而城市资源和基础设施的发展水平则呈现出波浪型态势。说明后者的发展尚不够稳定；另外．除了2002年城市资源与基础设施的发展超前于经济社会发展水平外。其余年份都是滞后的。今后要进一步加大对青岛市城市资源与基础设旌开发和建设的力度，以满足城市协调可持续发展的要求。     

脱硝钢架表面体型系数及风致响应分析∗

火电厂中的脱硝钢架由于其高度较高、外形不规则,风荷载是其承受的主要荷载之一。为确保该类结构风荷载的正确评估,以某典型脱硝钢架为研究对象,基于流固耦合理论,利用数值风洞方法对脱硝钢架结构表面体型系数及风致响应进行了研究。根据刚度与质量等效的原则,提出了复杂脱硝钢架结构连续体模型的简化方法,模型简化前后的 1 阶自振周期与振型接近,可近似模拟原结构的平动情况。风向角的变化对迎风面及变截面处体型系数的影响较大,可以忽略风向角对侧面及顶面体型系数的影响。在 0°风向角工况下,结构的位移与应力极值均显著大于 90°风向角工况。因此,0°风向对于结构而言为相对较不利风向,在脱销钢架整体结构方向布置时应予以避免。     

气态甲醛致雌性小鼠生殖细胞DNA-蛋白质交联的研究

为了研究气态甲醛对雌性小鼠生殖细胞的影响,以昆明雌性小鼠卵巢为实验材料,采取动态吸入式染毒方式,应用KCl-SDS沉淀法检测了气态甲醛染毒后所引起的小鼠卵巢生殖细胞DNA-蛋白质交联(DPC)效应.结果表明,较低浓度的甲醛(0.5mg·m-3),即可导致明显的DPC效应(与对照相比,p<0.05),并且随着染毒浓度的升高(0.5、1.0、3.0mg·m-3),DPC系数也逐渐升高.上述结果表明在实验所设浓度范围内,甲醛对小鼠卵巢生殖细胞的DNA损伤可以引起DNA-蛋白质的交联,并且DPC系数随着染毒浓度的增大而增大.DNA-蛋白质交联是DNA分子的一种严重损伤,气态甲醛对雌性小鼠生殖细胞具有一定的影响.     

17α-甲基睾酮对稀有鮈鲫肝脏脂质代谢的影响

环境内分泌干扰物对环境影响十分严重,绝大部分进入水环境,危害水生生物健康,进而影响人类健康.17α-甲基睾酮(17α-methyltestosterone,MT)是一种常见的环境雄激素,但在鱼体内的作用机制尚不明确.为了探究MT对鱼类肝脏脂质代谢的影响,采用不同浓度的MT(0、25、50和100 ng·L-1)处理864尾稀有鮈鲫(Gobiocypris rarus),分别在7、14和21 d取肝脏样品.用石蜡组织切片(H-E染色)研究MT对稀有鮈鲫肝脏组织的影响;用RT-qPCR检测4个内参基因的稳定性及5个脂质代谢相关基因(acaca、acacb、fasn、gpat1和cpt1α)的mRNA表达;用ELISA法测定肝脏中甘油三酯的含量.结果 表明,MT会对稀有鮈鲫肝脏造成一定程度的影响,50 ng·L-1 MT处理14 d,肝脏组织损伤最明显.25 ng·L-1和50 ng·L-1 MT处理14 d,相关基因的表达均显著变化(P＜0.05).mRNA表达与组织学结果均表明50 ng·L-1 MT对稀有鮈鲫肝脏影响最为显著.100ng·L-1 MT处理21 d,acaca、cpt1α和gpat1基因表达量显著下降(P＜0.05).MT对雌鱼肝脏甘油三酯影响较雄鱼大.综上,MT通过影响肝脏脂质代谢相关基因mRNA的表达,干扰了稀有鮈鲫肝脏脂质代谢过程,进而对肝脏产生不同程度的损伤.由于MT在不同性别鱼体内的代谢途径不同,推测MT在稀有觞鲫体内可能被芳香化为雌激素(ME),从而发挥部分雌激素作用.     

硫酸铜和马度米星铵联合暴露对鲫鱼的毒性和效应标记物研究

为探究硫酸铜和马度米星铵对水产动物的生态毒性,本研究以鲫鱼为模型,从急性毒性、亚急性毒性和遗传毒性3个方面研究硫酸铜和马度米星铵单一与联合暴露对鲫鱼的毒性效应.结果 表明,硫酸铜对鲫鱼96 h的半数致死浓度(50％ lethal concentration,LC50)为3.6 mg·L-1,硫酸铜和马度米星铵联合暴露时,硫酸铜对鲫鱼的96 h-LC50为1.4 mg· L-1,马度米星铵对鲫鱼的96 h-LC50为4.2 mg·L-1,硫酸铜对鲫鱼为高等毒性;硫酸铜和马度米星铵对鲫鱼的联合毒性表现为协同作用.染毒第7天,硫酸铜和马度米星铵均可影响过氧化氢酶(catalase,CAT)和谷胱甘肽过氧化物酶(glutathione peroxidase,GPx)的活性,随着剂量和染毒时间的增加,CAT和GPx的活性逐渐下降.硫酸铜和马度米星铵单一或联合暴露7d或21 d显著下调cat基因表达,对sod和gpx基因表达无显著影响.染毒后期,染毒组谷丙转氨酶(alanine aminotransferase,ALT)、谷草转氨酶(aspartate transaminase,AST)和碱性磷酸酶(alkaline phosphatase,ALP)活性及丙二醛(malondialdehyde,MDA)含量均高于对照组.硫酸铜和马度米星铵单一及联合染毒均能诱导鲫鱼红细胞产生微核,微核数与硫酸铜和马度米星铵的浓度呈正相关;随着硫酸铜和马度米星铵浓度的增加,肝细胞的脱氧核糖核酸(deoxyribonucleic acid,DNA)出现断裂,彗星尾部所占比例逐渐升高;高浓度联合染毒组红细胞微核率和肝细胞尾部DNA百分比显著高于单一染毒组.硫酸铜和马度米星铵联合暴露可导致鲫鱼血液毒性、肝细胞氧化损伤及遗传毒性的加和性,为评估Cu2+与马度米星铵复合污染对鲫鱼的生态毒性提供基础数据和理论依据.     

An integrated method for the rapid dewatering and solidification/stabilization of dredged contaminated sediment with a high water content

• An integrated method, called PHDVPSS, was proposed for treating DCS. • The PHDVPSS method showed superior performance compared to conventional method. • Using the method, water content (%) of DCS decreased from 300 to<150 in 3 days. • The 56-day UCS from this method is 12‒17 times higher than conventional method. • Relative to PC, GGBS-MgO binder yielded greater reduction in the leachability. To more efficiently treat the dredged contaminated sediment (DCS) with a high water content, this study proposes an integrated method (called PHDVPSS) that uses the solidifying/stabilizing (S/S) agents and prefabricated horizontal drain (PHD) assisted by vacuum pressure (VP). Using this method, dewatering and solidification/stabilization can be carried out simultaneously such that the treatment time can be significantly shortened and the treatment efficacy can be significantly improved. A series of model tests was conducted to investigate the effectiveness of the proposed method. Experimental results indicated that the proposed PHDVPSS method showed superior performance compared to the conventional S/S method that uses Portland cement (PC) directly without prior dewatering. The 56-day unconfined compressive strength of DCS treated by the proposed method with GGBS-MgO as the binder is 12‒17 times higher than that by the conventional S/S method. DCS treated by the PHDVPSS method exhibited continuous decrease in leaching concentration of Zn with increasing curing age. The reduction of Zn leachability is more obvious when using GGBS-MgO as the binder than when using PC, because GGBS-MgO increased the residual fraction and decreased the acid soluble fraction of Zn. The microstructure analysis reveals the formation of hydrotalcite in GGBS-MgO binder, which resulted in higher mechanical strength and higher Zn stabilization efficiency.     

Inhibition character of crotonaldehyde manufacture wastewater on biological acidification

• The inhibition of the main organic pollutions in CMW was demonstrated. • Variations of AK and BK showed a high correlation with the SAA of Ac and n-Bu. • The inhibitory degree was in the order of Ac>n-Bu for individual toxicants. • Biodegradation products of the main toxicants were analyzed. This work aims to investigate the inhibitory effect of crotonaldehyde manufacture wastewater (CMW) on biological acidification. To reveal the inhibitory effect of wastewater to the anaerobic granular sludge (AnGS), variations of the specific acidogenic activity (SAA) and activities of key enzymes were investigated. The results indicated that the dosage of CMW causing a 50% effect concentration (EC₅₀) on the activity of total volatile fatty acids (TVFA) production was 380 mg COD/g VSS. The inhibitory effect of individual toxicants in CMW on the activity of TVFA production were in the order of crotonaldehyde>ethyl sorbate>(E,E)-2,4-hexadienal, and their inhibitory degrees on individual VFA products were acetic acid (Ac)>n-butyric acid (n-Bu), which could correspond to the variations in the activities of acetate kinase (AK) and butyrate kinase (BK). Furthermore, the combined effect of three toxicants on the activity of TVFA production was significantly higher than that of any individual toxicant, and the contribution of the relative toxicity to CMW was 77.27%. Additionally, the biodegradation products of the main toxicants indicated that the removal of crotonaldehyde and (E,E)-2,4-hexadienal was primarily due to the hydrogenation of alkene and aldehyde and the oxidation of aldehyde. Nevertheless, the removal of ethyl sorbate was primarily based on adsorption. In conclusion, biological acidification has a limited ability to treatment CMW, therefore, a further pretreatment technology should be used to remove the main toxicant of wastewater.