不同酸性气体及相对湿度对海盐氯损耗过程的影响

使用在广州南村站、深圳竹子林站及西涌站的MARGA仪器实测资料,分析了不同酸性气体及相对湿度对海盐氯损耗过程的影响.在分析深圳竹子林站、西涌站的海盐氯损耗中发现,竹子林站氯损耗平均为48.0％,西涌站海盐氯损耗平均为56.9％,氯损耗的峰值一般出现于下午14时.西涌站、竹子林站和广州南村站酸性气体和碱性气体均以HNO2、SO2、NH3为主,但各站点的比例分布不同,西涌站以HNO2最多(42％),SO2(32％)次之;竹子林站以NH3与SO2为主,百分比分别为36％和34％;广州南村站以SO2为主(58％),NH3次之(20％);而三站HNO3所占比例很小,均为7％.另外,分析了HCl的来源,主要关注了海盐粒子中的NaCl与HNO3反应、NH4Cl的挥发及H2SO4与NaCl的反应这3个来源,发现西涌站与竹子林站HCl和HNO3之间的线性关系较好(R2西涌=0.689,R2竹子林=0.594),说明西涌站与竹子林站的HCl主要来源于NaCl与HNO3反应过程中Cl被HNO3置换而成;而广州南村站二者线性关系较差(R2南村=0.295),说明还存在其他的损耗机制.在研究相对湿度对氯损耗的影响中发现,相对湿度低时氯损耗更容易发生.     

珠江三角洲地区亚运期间颗粒物污染特征

为研究2010年广州亚运会期间珠江三角洲地区颗粒物污染特征,2010年11月11日—30日分别在广州市区城市点及下风向鹤山区域点采集24h颗粒物样品,对其主要化学组分(有机碳OC、元素碳EC和水溶性离子)进行测量.结果显示,观测期间广州和鹤山PM2.5平均质量浓度分别为(73.3±16.5)μg·m-3和(98.2±20.8)μg·m-3.鹤山PM10平均浓度高达131.6μg·m-3,且PM2.5占PM10的74%,表明区域PM2.5污染凸显.广州和鹤山PM2.5中二次无机离子(SNA)分别占39%和42%,有机物(OM)分别占31%和26%,EC分别占5%和6%.根据EC示踪法粗略估算,广州和鹤山PM2.5中一次有机碳POC分别占15%和13%,二次有机碳SOC分别占4%和3%.总体上,广州和鹤山PM2.5中二次生成(SNA+SOA)均约占50%,表明珠江三角洲地区PM2.5区域性二次污染的特征.广州市区PM2.5及SNA、Cl-和EC明显低于区域点鹤山浓度水平;与2004年同期研究(PRIDE-PRD2004)结果相比,气象条件相似,而广州市区PM2.5及EC浓度分别显著降低达29.6μg·m-3(29%)和3.5μg·m-3(49%),反映出亚运期间一次排放得到有效控制.     

浊度对混凝-纳滤组合工艺的影响

主要研究了不同浊度对混凝过程中的腐殖酸及高岭土去除率的影响。结果表明:随着高岭土投加浓度提高,混凝出水中腐殖酸去除率逐渐增大,而高岭土去除率降低;利用激光粒度仪对不同浊度条件下形成的絮体尺寸进行测定,结果表明:随着原水中高岭土投加浓度的增加,混凝出水形成的絮体尺寸逐渐增大,相应纳滤过程的出水通量得到明显改善;污染膜片的SEM显示,提高高岭土浓度在膜表面可形成更为疏松的滤饼层,并有效改善混凝出水的纳滤膜出水通量变化。     

Adsorption of heavy metal ions from aqueous solution by carboxylated cellulose nanocrystals

A novel nanoadsorbent for the removal of heavy metal ions is reported.Cotton was first hydrolyzed to obtain cellulose nanocrystals(CNCs).CNCs were then chemically modified with succinic anhydride to obtain SCNCs.The sodic nanoadsorbent(NaSCNCs) was further prepared by treatment of SCNCs with saturated NaHCO 3 aqueous solution.Batch experiments were carried out with SCNCs and NaSCNCs for the removal of Pb 2+ and Cd 2+.The effects of contact time,pH,initial adsorption concentration,coexisting ions and the regeneration performance were investigated.Kinetic studies showed that the adsorption equilibrium time of Pb 2+ and Cd 2+ was reached within 150 min on SCNCs and 5 min on NaSCNCs.The adsorption capacities of Pb 2+ and Cd 2+ on SCNCs and NaSCNCs increased with increasing pH.The adsorption isotherm was well fitted by the Langmuir model.The maximum adsorption capacities of SCNCs and NaSCNCs for Pb 2+ and Cd 2+ were 367.6 mg/g,259.7 mg/g and 465.1 mg/g,344.8 mg/g,respectively.SCNCs and NaSCNCs showed high selectivity and interference resistance from coexisting ions for the adsorption of Pb 2+.NaSCNCs could be efficiently regenerated with a mild saturated NaCl solution with no loss of capacity after two recycles.The adsorption mechanisms of SCNCs and NaSCNCs were discussed.     

规模化养鸡场冲洗废水三段式处理达标排放可行性试验研究

以青岛市某规模化养鸡场冲洗废水为研究对象,考察以"A/O生化+混凝沉淀+MBBR(Moving Bed Biofilm Reactor)氧化"三段式处理工艺处理该类废水达标排放的可行性。试验结果表明:A/O生化段可以有效去除废水中有机污染物,COD的去除率可达92.86%,出水COD浓度可以达到DB 37534—2005《山东省畜禽养殖业污染物排放标准》第三阶段要求;对BOD5、SS、氨氮及TP去除效率分别可以达到90.81%、89.04%、68.42%及80.79%,但出水尚达不到排放标准要求。混凝沉淀可以有效去除废水中SS及TP,处理后出水浓度分别为44 mg/L及2.26 mg/L,可以达到排放标准要求;经济有效的混凝剂为聚合硫酸亚铁,最优投加量为15 mg/L。MBBR氧化对BOD5及氨氮有着较好的去除效果,水力停留时间8 h时BOD5及氨氮出水浓度分别为42 mg/L及19.40 mg/L,出水可以达到排放标准要求。     

微波预处理污泥水解产酸特性研究

以进泥不经微波预处理为对照,研究了在进泥浓度为20 g/L、温度为20℃、HRT为6 d、pH为6.0的条件下,污泥经微波预处理(功率280 W,时间480 s)后加入序批式反应器中的水解产酸效果。结果表明:微波预处理后,污泥发酵液中挥发性脂肪酸(VFAs)、溶解性总糖、SCOD、氨氮浓度最大提高率分别为33%、11%、9%、25%,溶解性蛋白质浓度最多降低46%,微波预处理有助于污泥底物释出及产酸量的提高。     

基于零排放浓盐水处理技术的发展

对基于零排放浓盐水处理技术存在的问题进行了简单分析,然后对基于零排放浓盐水处理技术不同工段的处理新技术进行了简单介绍,最后分析了今后基于零排放浓盐水处理技术的发展方向。     

新形势下高速公路环评中的公众参与

公众参与作为环境影响评价的重要内容,不仅可以提高项目环保措施的有效性和合理性,同时也是环境保护行政主管部门对项目科学决策的重要依据.自从2006年原国家环保总局发布《环境影响评价公众参与暂行办法》,规范了环评中的公众参与工作以来,今年环境保护部又相继出台相关政策,要求进一步做好信息公开和征求公众意见等工作,切实保障公众对环境保护的参与权、知情权和监督权.本文结合沿海地区某高速公路项目环评中公众参与的具体做法,从公众参与的程序、内容及代表性等方面分别介绍了新形势下如何在高速公路环评中深入、有效的开展公众参与工作,并从公众意见调查时间、公参形式选取、公众意见统计和反馈等角度提出了建议,为高速公路等线性工程环境影响评价开展公众参与提供参考.     

油田人工岛开发建设风险控制措施分析

针对油田人工岛开发的特点,通过对人工岛开发建设过程的风险分析与对策研究,制定出有效的预防措施,以保证人工岛开发建设的顺利进行.     

Effects of fenvalerate concentrations and its chiral isomers on bacterial community structure in the sediment environment of aquaculture ponds

To investigate the effect of chiral pesticide fenvalerate (FV) on the micro-ecological environment of aquaculture pond sediment, we used an indoor static experiment to observe the effects of FV added at different concentrations with different chiral isomers on the changes in the sediment bacterial community. The 16S rDNA high-throughput sequencing technique was used to conduct sequencing and analysis of the bacterial community structure as well as changes in aquaculture pond sediments after 4 weeks of cultivation. The results showed that the microbial alpha diversity indices (Sobs and Shannon indices) of the treated groups were significantly lower than those of the control group after 4 weeks (P < 0.05), and the values in the high-concentration group were significantly lower than those of the low-concentration group (P < 0.05). In terms of bacterial group composition, the proportion of abundance of Proteobacteria and Acidobacteria in the treated groups were greater than in the control group after 4 weeks, while the proportion of abundance of Bacteroidetes and Verrucomicrobia were lower. In the high-concentration FV treatment group, the proportion of abundance of Bacteroidetes, Acidobacteria, Chloroflexi, Nitrospinae, unclassified_k_norank, Ignavibacteriae, and Nitrospirae were significantly different from those of the other groups (P < 0.05). Principal coordinate analysis (PCoA) and ANONISIM/Adonis analysis showed that the cis-enantiomer had a stronger effect on the bacterial community as the concentration of FV increased. In addition, the linear discriminant analysis effect size (LEfSe) and linear discriminant analysis (LDA) results revealed differences in the level of enrichment of bacterial groups caused by FV at different concentrations and isomer levels. Collectively, this study showed that FV residue has a pronounced effect on bacterial communities in sediment, which becomes more significant with increasing exposure concentration. The effects of the cis- and trans-enantiomers of FV on the sediment environment are different; the cis-enantiomer has a stronger effect on the bacterial community.