不同生境条件下苦槠丛枝菌根对根际土壤磷酸酶活性的影响

以浙江千岛湖和宁波天童两个不同区域内的苦储(Castanopsis sclerophytta)为材料,对处于不同生境条件下的苦槠丛枝菌根(AM)进行了研究.结果表明:两地区土壤pH均处于苦储丛枝菌根生长发育的最适范围内,丛枝菌根的侵染率无明显差异;酸性磷酸酶为两区域内的主导磷酸酶,各种磷酸酶活性均是天童地区高于千岛湖地区;AM侵染率与根际土壤磷酸酶活性之间均呈现正相关,其中天童地区为显著相关,说明AM侵染率对根际土壤磷酸酶活性在某种程度上存在有一定的影响.     

超声技术降解酸性红B废水

以酸性红Ｂ染料模拟废水为对象,考察了废水浓度、ｐＨ、超声时间、ＮａＣｌ投加量及曝气等因素对其超声降解效率的影响．实验结果表明：酸性红Ｂ降解率与超声时间基本上成线性关系;初始浓度高,降解率大;ｐＨ值增大,降解率减小;当溶液中ＮａＣｌ投加量从０ 增加到１ｇ／Ｌ,降解率从４３％ 增加到近９０％ ;再增加溶液中ＮａＣｌ的浓度,对其降解率影响不大;水浴温度升高,酸性红Ｂ降解率增大;曝气及Ｈ₂Ｏ₂ 投加量对其降解率的影响不大．     

Ceramic tiles with black pigment made from stainless steel plant dust: Physical properties and long-term leaching behavior of heavy metals

Stainless steel plant dust is a hazardous by-product of the stainless steelmaking industry. It contains large amounts of Fe, Cr, and Ni, and can be potentially recycled as a raw material of inorganic black pigment in the ceramic industry to reduce environmental contamination and produce value-added products. In this paper, ceramic tiles prepared with black pigment through recycling of stainless steel plant dust were characterized in terms of physical properties, such as bulk density, water absorption, apparent porosity, and volume shrinkage ratio, as well as the long-term leaching behavior of heavy metals (Cr, Ni, Pb, Cd, and Zn). The results show that good physical properties of ceramic tiles can be obtained with 8% pigments addition, sample preparation pressure of 25 MPa, and sintering at 1200 ºC for 30 min. The major controlling leaching mechanism for Cr and Pb from the ceramic tiles is initial surface wash-off, while the leaching behavior of Cd, Ni, and Zn from the stabilized product is mainly controlled by matrix diffusion. The reutilization process is safe and effective to immobilize the heavy metals in the stainless steel plant dust.

Implications: Stainless steel plant dust is considered as a hazardous material, and it can be potentially recycled for black pigment preparation in the ceramic industry. This paper provides the characteristics of the ceramic tiles with black pigment through recycling stainless steel plant dust, and the long-term leaching behavior and controlling leaching mechanisms of heavy metals from the ceramic tile. The effectiveness of the treatment process is also evaluated.     

Time series analysis of ambient air pollution effects on daily mortality

Although the growths of ambient pollutants have been attracting public concern, the characteristic of the associations between air pollutants and mortality remains elusive. Time series analysis with a generalized additive model was performed to estimate the associations between ambient air pollutants and mortality outcomes in Shenzhen City for the period of 2012–2014. The results showed that nitrogen dioxide (NO₂)-induced excess risks (ER) of total non-accidental mortality and cardiovascular mortality were significantly increased (6.05% (95% CI 3.38%, 8.78%); 6.88% (95% CI 2.98%, 10.93%), respectively) in interquartile range (IQR) increase analysis. Also, these associations were strengthened after adjusting for other pollutants. Moreover, similar associations were estimated for sulfur dioxide (SO₂), particulate matter with an aerodynamic diameter of <10 μm (PM₁₀), and total non-accidental mortality. There were significant higher ERs of associations between PM₁₀ and mortality for men than women; while there were significant higher ERs of associations between PM₁₀/NO₂ and mortality for elders (65 or elder) than youngers (64 or younger). Season analyses showed that associations between NO₂ and total non-accidental mortality were more pronounced in hot seasons than in warm seasons. Taken together, NO₂ was positively associated with total non-accidental mortality and cardiovascular mortality in Shenzhen even when the concentrations were below the ambient air quality standard. Policy measures should aim at reducing residents’ exposure to anthropogenic NO₂ emissions.     

管式反应器处理生活污水的效能

研发了一种基于射流曝气的管式反应设备,考察了负荷和DO对反应器处理效能的影响。实验结果表明,在温度为15℃、DO 6.0 mg/L、有机负荷为1.0 kg COD/(m3.d)、氮负荷为0.30 kg TN/(m3.d)、HRT为8 h的条件下,管式反应器可使生活污水的COD、NH4+-N及TN分别从335 mg/L、105 mg/L及110 mg/L降至43 mg/L、14 mg/L及18 mg/L,去除率分别为87%、86%和83%。DO对反应器脱氮效能影响显著,DO为6 mg/L时,能构建出同步硝化反硝化系统,NH4+-N和TN的去除率分别为96.6%和86.7%。     

建筑垃圾再生利用分析

以循环经济思想为指导,对建筑垃圾分类及再生利用技术进行分析,建议从源头控制建筑垃圾的产生量,强化全社会对建筑垃圾再生利用的环保意识.提高全社会对再生资源的认识.     

基于GT-Power柴油机颗粒捕集器捕集性能的仿真研究

利用GT-Power软件建立了柴油机颗粒捕集器(DPF)仿真模型,进行了仿真计算。研究了颗粒捕集器本身结构参数对其捕集效率与压降的影响。结果表明,影响颗粒捕集器捕集效率的主要参数有通道密度(CPSI)、过滤体孔隙率、过滤体微孔直径以及过滤壁厚度;影响颗粒物压降的主要参数有通道密度、过滤体渗透率、过滤体孔隙率以及过滤壁厚度。     

Disruption of zebrafish (Danio rerio) reproduction upon chronic exposure to TiO₂ nanoparticles

As common engineered nanomaterials, TiO(2) nanoparticles (nTiO(2)) are usually perceived as non-toxic, and have already been widely used in many products and applications. Such a perception might have been shaped by some short-term studies that revealed no/low toxicity of nTiO(2) to cells and eco-relevant organisms. However, given the ultimate release of nTiO(2) into the aquatic environment, which can act as a sink for engineered nanoparticles, their long-term impact on the environment and human health is still a concern and deserves more research efforts. Here, for the first time, we demonstrate that chronic exposure of zebrafish to 0.1 mg L(-1) nTiO(2), can significantly impair zebrafish reproduction. For instance, there was a 29.5% reduction in the cumulative number of zebrafish eggs after 13 weeks of nTiO(2) exposure. Thus, we provided timely information on indicating a serious risk of reproductive impairment of environments contaminated with low levels of nTiO(2) on aquatic organisms, leading to alterations in population dynamics and aquatic ecosystem balance, and thus warrants a careful scrutiny on toxicity assessment of nTiO(2), especially their long-term impact.     

渗滤液污染地下氧化还原环境与污染物衰减研究

通过土柱实验研究垃圾渗滤液污染地下氧化还原环境的分带现象与污染物的衰减规律.实验结果表明:垃圾渗滤液污染晕中出现了3个顺序氧化还原带,依次为铁还原带、硝酸盐还原带和氧还原带,各带标志性物质Fe3 、NO-2和O2的最高质量浓度分别为14.81、1.41、5.8 mg/L;COD与NH 4-N在监测区间内呈现出相似的衰减规律,随距离的增加浓度降低,随时间的推移浓度升高,COD初期最高去除率达76.8%,后期降到50.0%;NH 4-N初期最高去除率达98.1%,后期降到90.2%.     

孔雀石绿电极催化电位法测定水样中亚硝酸根

根据稀磷酸介质中,亚硝酸根催化溴酸钾氧化孔雀石绿的反应,对用孔雀石绿选择性电极催化电位法测定痕量亚硝酸根进行了研究。实验表明该方法灵敏度高,选择性好,由于室温下进行操作尤为方便。测定线性范围为０－６μｇＮＯ２－／５０ｍｌ。方法检出限为１．９×－９ｇ／ｍｌＮＯ２－。应用该方法测定几种环境水样中亚硝酸根含量,结果满意。本法测得值与标准法测得值对照基本一致。变异系数ＲＳＤ＜４．３％。样品加标平均回收率为９９．７％。