Cytotoxicity and DNA damage of five organophosphorus pesticides mediated by oxidative stress in PC12 cells and protection by vitamin E

Previous studies have demonstrated that pesticides could induce cytotoxicity and genotoxicity in vivo and in vitro, and that oxidative stress may be an important factor involved. However, investigations comparing the capability of different organophosphorous (OP) compounds to induce cytotoxicity, genotoxicity and oxidative stress are limited. Hence, the aim of this paper was to access the cytotoxic and genotoxic effects of five OPs or metabolites, Acephate (ACE), Methamidophos (MET), Chloramidophos (CHL), Malathion (MAT) and Malaoxon (MAO), and to clarify the role of oxidative stress, using PC12 cells. The results demonstrated that MET, MAT and MAO caused significant inhibition of cell viability and increased DNA damage in PC12 cells at 40 mg L^?1. MAO was more toxic than the other OPs. ACE, MET, MAT and MAO increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) at 20 mg L^?1 and 40 mg L^?1 to different degrees. Pre-treatment with vitamin E(600 μM)caused a significant attenuation in the cytotoxic and genotoxic effect; pre-treatment reversed subsequent OP-induced elevation of peroxidation products and the decline of anti-oxidant enzyme activities. These results indicate that oxidative damage is likely to be an initiating event that contributes to the OP-induced cytotoxicity.     

季铵化合物对好氧活性污泥吸附Ni2+的影响研究

以季铵化合物中最具潜在影响力、毒性较大的苄基季铵盐(BAC)为模型物,进行了BAC对好氧活性污泥吸附Ni2+的影响研究.结果表明,当反应液初始pH≤3时,不同浓度的BAC对好氧活性污泥吸附Ni2+的影响较小,当初始pH在3～9时,不同浓度的BAC对Ni2+吸附的抑制影响顺序为100 mg/L＞20 mg/L＞0 mg/...     

城市污水处理厂建设程序中的环境影响评价研究

在介绍污水处理厂的基础建设程序及环境影响评价的发展概况的基础上,以京溪污水处理厂为例,指出城市规划部门在规划制定过程中,应加大环境影响评价工作的深度,以使污水厂的建设程序得以顺利开展。同时指出城市的卫生、地质、规划、国土、环保等职能部门在制定本部门的法规政策过程中,应发挥协调机制,在工程建设的相关方面达成共识,以确保污水处理厂等市政项目的建设顺利开展,促进城市更好的发展。     

用废变压器油吸收废气中的二甲苯

以废变压器油作为吸收剂对二甲苯废气进行吸收处理,考察了影响二甲苯气体去除率的因素。实验结果表明:二甲苯废气流量为350 L/h、废变压器油喷淋量为40 L/h、进口二甲苯废气平日质量浓度为935 mg/m~3、吸收温度为18℃、吸收时间为50 min时,出口二甲苯气体质量浓度为35 mg/m~3,二甲苯去除率高达96.3%,小于GB16297—1996《大气污染物综合排放标准》中二甲苯质量浓度90 mg/m~3的排放标准。     

SO2 inhalation causes synaptic injury in rat hippocampus via its derivatives in vivo

SO₂ remains a common air pollutant, almost half of the world’s population uses coal and biomass fuels for domestic energy. Limited evidence suggests that exposure to SO₂ may be associated with neurotoxicity and increased risk of hospitalization and mortality of many brain disorders. However, our understanding of the mechanisms by which SO₂ causes harmful insults on neurons remains elusive. To explore the molecular mechanism of SO₂-induced neurotoxic effects in hippocampal neurons, we evaluated the synaptic plasticity in rat hippocampus after exposure to SO₂ at various concentrations (3.5 and 7 mg m⁻³, 6 h d⁻¹, for 90 d) in vivo, and in primary cultured hippocampal neurons (DIV7 and DIV14) after the treatment of SO₂ derivatives in vitro. The results showed that SYP, PSD-95, NR-2B, p-ERK1/2 and p-CREB were consistently inhibited by SO₂/SO₂ derivatives in more mature hippocampal neurons in vivo and in vitro, while the effects were opposite in young hippocampal neurons. Our results indicated that in young neurons, SO₂ exposure produced neuronal insult is similar to ischemic injury; while in more mature neurons, SO₂ exposure induced synaptic dysfunctions might participate in cognitive impairment. The results implied that SO₂ inhalation could cause different neuronal injury during brain development, and suggested that the molecular mechanisms might be involved in the changes of synaptic plasticity.     

Characterization of the monthly variation in (1 → 3)-β-d-glucan concentrations in university laboratories

We characterize the monthly variation in (1 → 3)-β-d-glucan concentration measured over the course of 1 year, and we evaluate the characteristics of size selection using a two-stage cyclone sampler. The (1 → 3)-β-d-glucan concentrations were measured in four bio-related laboratories. A total of 156 samples were collected using a new two-stage cyclone sampler. Analysis of (1 → 3)-β-d-glucan was performed using the kinetic Limulus amebocyte lysate assay. The study showed that airborne (1 → 3)-β-d-glucan concentrations were significantly higher in laboratory D (mean ± SD 1,105?±?1,893 pg/m³) and in the spring (5,458 pg/m³). The highest concentration of (1 → 3)-β-d-glucan occurred in the spring, particularly in May.     

苦土和氧化镁处理氮磷废水的对比研究

分别采用苦土、纯氧化镁为沉淀剂对模拟高浓度氮磷废水(N/P=0.8)进行了脱氮除磷研究,比较了沉淀剂投加量、pH对2种沉淀剂处理氮磷废水的影响,对沉淀产物进行XRD分析,并进行了经济效益比较。结果表明,pH是影响2种沉淀剂处理氮磷废水的主要因素,随着pH的增加,脱氮除磷效果提高,在平衡pH为9～10之间时氮磷处理效果最佳,pH继续增加,由于磷酸镁沉淀的形成使得氨氮去除率降低。此外,处理相同的废水,苦土的最佳投加量要大于纯氧化镁,但是经济效益比较结果表明,以苦土为沉淀剂处理氮磷废水可大大降低处理成本。     

初沉污泥球磨破解后水解酸化研究

采用球磨机对污水处理厂初沉池的污泥进行球磨破解以控制初沉污泥粒径,然后在不同条件下(污泥粒径、系统pH、污泥投配率)考察初沉污泥的水解酸化效果(以溶解性COD(SCOD)变化显示),以确定初沉污泥水解酸化的最佳条件。结果表明,初沉污泥的最佳水解酸化条件为:污泥粒径25μm、系统pH 11、污泥投配率10%、水解酸化时间5d,此时反应后系统SCOD为8 256mg/L,污泥水解转化效率为32.0%。通过球磨破解、水解酸化的方式回收初沉污泥中的碳源具有一定的可行性和较好的开发利用前景。采用球磨机作为污水处理厂初沉污泥预处理的装置,与其他方法如超声波法、热处理法等相比较,具有适应力强、操作可靠、运行简单等优点。     

循环经济下再生资源规范回收行为研究

提出将再生资源回收分为规范回收与非规范回收两种类型,认为回收行为是建立规范循环经济体系规划的数据基础和政策效应的微观基础。以废旧家电为例,设计了包括废旧家电回收再利用形势感知、回收现状、回收再利用态度、回收影响因素、回收行为以及废旧家电生态消费态度、生态消费问题感知、生态消费影响因素、生态消费行为等9类共31个问题,通过对312名在校大学生的调查,分析了样本个体废旧家电回收因素、样本家庭实际回收行为及现状因素、样本个体废旧家电回收方式的影响因素等废旧家电回收问题及行为总体状况,采用单因素分析方法,深入挖掘了样本不同的社会—经济、社会—人口属性及其他相关因素在废旧家电回收行为上的差异性,给出了相应的理论解释。在调查分析的基础上,提出了促进再生资源规范回收的实施对策。     

厌氧消化过程中温度骤降对酸化活动抑制性的研究

对于厌氧消化过程的酸化阶段,反应器内温度的快速下降将对碳水化合物的分解和产酸活动产生明显抑制。当温度依次从30℃下降到25、20和15℃时,反应器内厌氧微生物数量呈缓慢减少趋势,受温度影响不大;但是,厌氧酸化过程却明显表现出受到每一次骤然降温的影响,其碳水化合物的平均去除率随温度骤降从92%依次降低为84%、72%和25%,且最低分别达到78%、52%和10%。研究还表明,随着温度的骤降,厌氧酸化活动将立即受到强烈抑制,并需要一定的时间来恢复以适应发酵温度的改变。