新安江流域横向生态补偿的经济效应

以新安江流域横向生态补偿试点作为准自然实验,采用2001~2017年中国安徽和浙江省内县域面板数据,利用双重差分方法（DID）定量研究了试点政策对流域上下游地区经济发展的影响及可能机制.结果显示：试点政策对上游地区的经济发展造成了一定程度的抑制影响,表现为相关地区的人均GDP或地区GDP出现了下降,而对流域下游地区经济发展并无显著作用,这一结论在进行多项稳健性检验后仍然成立;新安江试点政策对上游地区经济发展的负面影响呈现出了“先增强后减弱”的动态变化规律;此外,机制分析显示5个试点县内规模以上工业企业个数显著下降,表明“企业退出”是新安江试点政策对上游地区经济发展造成负面影响的重要原因.本研究可为后续制定和实施跨地区水资源保护的利益调配机制提供依据.     

Disinfection byproduct formation from algal organic matters after ozonation or ozone combined with activated carbon treatment with subsequent chlorination

Algal organic matter (AOM), including extracellular organic matter (EOM) and intracellular organic matter (IOM) from algal blooms, is widely accepted as essential precursors of disinfection byproducts (DBPs). This study evaluated the effect of ozonation or ozone combined with activated carbon (O₃-AC) treatment on characteristic alternation and DBP formation with subsequent chlorination of Chlorella sp.. The effects of pH and bromide concentration on DBP formation by ozonation or O₃-AC treatment were also investigated. Results showed that the potential formation of DBPs might be attributed to ozonation, but these DBP precursors could be further removed by activated carbon (AC) treatment. Moreover, the formation of target DBPs was controlled at acidic pH by alleviating the reactions between chlorine and AOM. Besides, the bromide substitution factor (BSF) value of trihalomethanes (THMs) from EOM and IOM remained constant after AC treatment. However, THM precursors could be significantly decreased by AC treatment. The above results indicated that O₃-AC was a feasible treatment method for algal-impacted water.     

Thiocyanate-induced labilization of schwertmannite: Impacts and mechanisms

Schwertmannite is an amorphous iron(III)-oxyhydroxysulfate that forms in acid mine drainage(AMD) environments. The characteristic of high heavy metal adsorption capability makes schwertmannite a potentially useful, environmentally friendly material in wastewater treatment. Unstable schwertmannite is prone to recrystallization.Understanding the mechanisms that induce schwertmannite labilization and affect its capacity to remove heavy metals are of great environmental and geochemical significance.Thiocyanate(SCNˉ) is a hazardous pseudohalide that is also normally found in AMD.However, little is known about the impact of Fe(III)-binding ligand SCNˉ on schwertmannite stability and its subsequent capacity to bind trace elements. Here, we investigated the adsorption of SCNˉ on schwertmannite and subsequent mineral transformation to characterize this little-known process. The appearance of Fe2+indicated that the interactions between schwertmannite and SCNˉ may involve complexation and reduction reactions. Results showed that the majority of the adsorbed-SCNˉ was immobilized on schwertmannite during the 60-days transformation. The transformation rates of schwertmannite increased with increasing concentrations of SCNˉ. Goethite was detected as the dominant transformation product with or without SCNˉ. The mechanisms of SCNˉ-promoted dissolution of schwertmannite can be described as follows:(1) formation of Fe(III)–NCS complexes on the schwertmannite surface and in solution, a process which increases the reactivity of solid phase Fe(III);(2) the extraction of Fe(III) from schwertmannite by SCNˉ and subsequent schwertmannite dissolution; and(3) the formation of secondary minerals from extracted Fe(III). These findings may improve AMD treatment strategies and provide insight into the use and potential reuse of schwertmannite as a trace element sorbent.     

Study on the mechanism of copper–ammonia complex decomposition in struvite formation process and enhanced ammonia and copper removal

Heavy metals and ammonia are difficult to remove from wastewater, as they easily combine into refractory complexes. The struvite formation method (SFM) was applied for the complex decomposition and simultaneous removal of heavy metal and ammonia. The results indicated that ammonia deprivation by SFM was the key factor leading to the decomposition of the copper–ammonia complex ion. Ammonia was separated from solution as crystalline struvite, and the copper mainly co-precipitated as copper hydroxide together with struvite. Hydrogen bonding and electrostatic attraction were considered to be the main surface interactions between struvite and copper hydroxide. Hydrogen bonding was concluded to be the key factor leading to the co-precipitation. In addition, incorporation of copper ions into the struvite crystal also occurred during the treatment process.     

西安市汉城湖浮游植物群落结构与水质状况分析

为探究汉城浮游植物群落结构特点并确定水体营养化程度,于2015年对汉城湖水体浮游植物群落结构和主要理化因子进行了调查与分析。结果表明:共检测出浮游植物7门44属,其中绿藻门19属,蓝藻门10属,硅藻门6属,金藻门3属,隐藻门、甲藻门和裸藻门各2属;浮游植物细胞密度变化范围为1.42×10~4~24.18×10~4个/L,平均值为11.20×10~4个/L;浮游植物主要优势属为鞘丝藻属(Lyngbya)、锥囊藻属(Dinobryon)、隐藻属(Cryptomonas)、蓝隐藻属(Chroomonas)、平裂藻属(Merismopedia)、裸藻属(Euglene)和裸囊藻属(Trachelomonas)等;浮游植物优势种、污染指示种、多样性指数和水体综合营养状态指数TLI(∑)的综合分析显示,汉城湖水体整体处于中-富营养化状态,秋季水质最差,春季水质最好,氮、磷的含量有逐渐增加的趋势,水体从上游至下游逐渐被净化。     

哀牢山山区降水时空分布的影响因素及插值方法比较

为了研究哀牢山山区降水的影响主要因素并探索适于山区降水的空间插值方法,本文利用研究区内30个地面测站10年(2005~2014)的降雨实测数据,根据降雨的时间分布特征,将研究时段划分为年季、干季和湿季,并对影响降水的因素进行空间自相关分析,确定并组合得到影响降水的主要因子,使用留一法交叉检验插值精度,通过分析验证,寻求最优的降雨插值方法。研究结果表明,1)影响降水的主要因子为高程、纬度、坡度、坡向和主风向效应指数(PWEI);2)影响年季降水变化的主要因子为高程、纬度、坡度和坡向;影响湿季降水的主要因子为高程、纬度、坡度和PWEI;影响干季降水的主要因子为高程、坡度、纬度和坡向;3)插值过程中结合环境特征引入影响降水的因子,很大程度上提高了插值结果的精确性。由此可见,降雨插值精度不仅和插值方法本身的结构有关,更重要的是在降水特征的基础上合理筛选及引入主要环境影响因子。     

有序介孔材料过滤脱除纳米颗粒物

多孔材料过滤去除环境纳米颗粒物(nanoparticles,NPs)是空气净化治理的重要方法之一.本文采用介孔分子筛(MCM-41、SBA-15)和有序介孔碳(CMK-3)这3种典型介孔材料对2~20 nm的NPs进行过滤脱除研究,旨在探索介孔材料在NPs过滤方面的应用可行性与相关理论基础.基于3种介孔材料的物理化学性质表征结果,通过本实验发现介孔材料孔道的最可几孔径以及一定量的介孔孔容是吸附NPs的关键,而微孔分布对去除NPs贡献不大.进一步对SBA-15在不同流量及不同颗粒床厚度下对NPs的去除进行了分析,发现纳米颗粒物的最易穿透粒径(most penetrating particle size,MPPS)随着流量的增大而减小,同时MPPS颗粒物的去除效率随之降低,且MPPS基本不受颗粒床厚度变化的影响.本研究为介孔材料过滤脱除NPs提供了技术依据.     

地下水主要组分水化学异常识别方法对比：以柳江盆地为例

地下水化学组分的异常识别是构建水化学背景值及开展人类活动影响程度识别量化的重要基础.以往提出的基于5种水化学图的主要组分异常识别方法取得了良好效果,但是该方法考虑的水化学图种类过多,计算复杂.为简化水化学图法,本文以柳江盆地为例,尝试采用Durov图替代5种水化学图,对地下水主要组分进行异常识别.为此,分别对比分析了水化学图与数理统计法组合出的7种异常识别方法的剔除效果,并进行方法可靠性检验.结果表明,数理统计法与水化学图法结合识别地下水异常相对于两者单独使用可以取得更好的识别效果;其中3σ准则+5种水化学图法和3σ准则+Durov图法对地下水主要组分异常识别效果最好;并证实采用Durov图可以有效替代5种水化学图进行地下水主要组分的异常识别,既保留了水化学识别异常的科学性,又大大简化了异常识别计算的过程.     

不同离子条件对提取沉积物中水溶性有机质光谱特性的影响

水溶性有机质(WSOM)是环境中溶解性有机质(DOM)的重要组成部分,对WSOM化学特性的研究有助于了解环境中DOM对污染物环境归趋的作用.本文利用紫外-可见吸收光谱法(UV-vis)及三维荧光光谱法(3D-EEM)分析了3种不同来源沉积物的WSOM在不同种类及浓度离子浸提液中的光谱特性差异,以揭示天然水化学离子种类及浓度对提取沉积物中WSOM光谱特性的影响.UV-vis光谱分析结果表明:①WSOM在SO■及K~+浸提液中的溶解性有机碳(DOC)含量及其芳香度较高,在Cl~-及K~+浸提液中的有色溶解性有机质(CDOM)丰度高,在NO~-_3、Na~+浸提液中的富里酸含量较高、分子量较小;②浸提液中WSOM的DOC含量及其芳香度、CDOM丰度随离子浓度增加呈先增后减的趋势,同时大颗粒WSOM比例逐渐增加.通过3D-EEM光谱数据结合平行因子分析法发现,沉积物(城市内湖)中WSOM主要由4种荧光组分组成,即可见腐殖酸(C1)、土壤富里酸(C2和C3)、微生物源类腐殖质(C4).4种荧光组分在SO■、K~+浸提液中的荧光强度较高,且随离子浓度增加WSOM的荧光强度、类蛋白物质及类腐殖物质浓度均表现为高浓度受抑制的现象,这一点与吸收光谱数据一致.     

钢铁烧结烟气脱硫灰制备蒸养砖的实验研究

我国钢厂每年的脱硫灰产生量巨大,但由于脱硫灰性状不稳,难以被利用.为缓解这一情况,本文通过对武钢三烧脱硫灰物理、化学、物相等因素的分析,提出应用脱硫灰制备蒸养砖的思路,并通过正交实验得到各种因素对于蒸养砖强度的影响顺序为:水泥熟料添加量＞粉煤灰添加量＞脱硫灰添加量,蒸养砖在最佳配比时抗压强度可达14.05 MPa.