Investigation of the accumulation of ash,heavy metals,and polycyclic aromatic hydrocarbons to assess the stability of lysis–cryptic growth sludge reduction in sequencing batch reactor

The accumulation of ash, heavy metals, and polycyclic aromatic hydrocarbons (collectively called potential accumulating substances, PAS) was evaluated to ascertain the stability of lysis–cryptic growth sludge reduction process (LSRP) for municipal sludge treatment. One sequencing batch reactor (SBR) incorporated with homogenization was run to test the LSRP and another SBR as a control. The continuous monitoring results for 2 months showed that the ash and heavy metals slightly increased, and the polycyclic aromatic hydrocarbons decreased by 18.0%, indicating that there may be negligible accumulations during the LSRP. Their accumulations met pattern I, as demonstrated by statistical analysis, proving no PAS accumulation for LSRP. This was further confirmed by sludge activity and system performance. Moreover, the mechanism for no PAS accumulation was discussed. It was concluded that the LSRP was stable with no worries about PAS accumulation under the operational conditions.     

辉县市城区环境空气质量现状及污染防治对策

对辉县市城区2006—2011年间环境空气质量监测数据进行了评价,并对城区污染物浓度时空变化进行了分析。结果表明,辉县市城区大气污染主要表现为可吸入颗粒物污染严重,主要是能源结构不合理、锅炉废气污染严重、城区道路保洁方式落后等原因造成的,由此提出了合理规划城市布局、减少结构性污染等对策。     

Heterogeneous photocatalytic degradation of methyl orange in schwertmannite/oxalate suspension under UV irradiation

Introduction

Schwertmannite was synthesized through an oxidation of FeSO₄ by Acidithiobacillus ferrooxidans LX5 cell suspension at an initial pH?2.5 and 28°C for 3?days and characterized using X-ray diffraction spectroscopy and scanning electron microscope. The schwertmannite photocatalytic degradation of methyl orange (MO) by oxalate was investigated at different initial pH values, concentrations of schwertmannite, oxalate, and MO.

Results

The results demonstrated that photodegradation of MO in the presence of schwertmannite or oxalate alone was very weak. However, the removal of MO was significantly enhanced when schwertmannite and oxalate coexisted in the reaction system. Low pH (4 or less) was beneficial to the degradation of MO. The optimal doses of schwertmannite and oxalate were 0.2?g?L^?1 and 2?mM, respectively. Hydroxyl radicals (·OH) and Fe(II), the intermediate products, were also examined during the reaction to explore their correlation with the degradation of MO.

Conclusion

A possible mechanism for the photocatalytic decomposition of MO in the study was proposed. The formation of Fe(III)-oxalate complexes on the surface of schwertmannite was a precursor of H₂O₂ and Fe(II) production, further leading to the yield of ·OH responsible for the decomposition of MO.     

广州市建筑垃圾资源化的必要性分析

摘要：随着广州市城市化进程的不断加快,城市建筑垃圾的排出量也在快速增长,如何应对和处理建筑垃圾所带来的“垃圾围城”困境,已经成为人们不得不面对的重要问题,推进建筑垃圾资源化是开展建筑垃圾综合治理的有效途径。论述了建筑垃圾资源化再生利用的必要性、紧迫性,指出了广州市建筑垃圾资源化过程中存在的问题,为推进广州市建筑垃圾综合处理实践提供了参考。     

铁碳微电解-Fenton法预处理苯胺基乙腈生产废水的动力学研究

通过采用铁碳微电解-Fenton法预处理苯胺基乙腈生产废水的实验研究,分析了处理过程的COD降解动力学;同时研究了单纯活性炭吸附和微电解过程中COD去除率的变化。结果表明,铁碳微电解的初期COD降解过程近似符合一级反应动力学,并且得到微电解与活性炭吸附对铁碳微电解降解COD的关系式;Fenton反应中通过研究有机物浓度和过氧化氢初始浓度与反应进程的关系,建立了反应动力学模型;单纯吸附实验COD去除率在24h内快速下降,而微电解在相应时间内COD去除率波动较小,为实际应用提供了数据经验和理论依据。     

水环境中腐殖酸与镉离子结合作用的影响因素

通过测定不同化学条件下腐殖酸与镉离子作用后的游离态镉离子浓度及其结合率,研究各因素对腐殖酸与镉离子作用的影响。研究结果表明,pH值、离子强度、投加镉离子总浓度、腐殖酸浓度和反应温度均影响腐殖酸与镉离子的结合。pH值在4.5~6.5范围内,随pH值升高,腐殖酸与Cd²⁺的结合率增大,游离态Cd²⁺浓度减少。溶液的离子强度增大对结合反应有抑制作用。投加Cd²⁺总浓度的增大会导致结合态Cd²⁺浓度和游离态Cd²⁺浓度逐渐增加,而其结合率逐渐减小。腐殖酸浓度逐渐增大,使Cd²⁺和腐殖酸的结合率逐渐增大。在20℃~50℃范围内时,随反应温度升高,游离态Cd²⁺浓度逐渐减小,其结合率逐渐增加。     

广州市南沙区水生生态环境现状的调查研究

在广州市南沙区水域采集地表水和水生生物样品,对水质主要理化指标、叶绿素a含量和初级生产力以及水生生物(浮游植物和浮游动物)的种类、数量、多样性和均匀度指数等进行调查,综合评价了南沙区水域水生生态环境质量.结果表明,利用不同指标对南沙区水域进行评价获得的结果基本一致,介于贫营养化至中营养化状态之间,水生生态环境质量状况较好.     

紫外—荧光检测器高效液相色谱法测定PM2.5中16种多环芳烃

建立了一种利用高效液相色谱(HPLC)同时分离和测定大气颗粒物中16种优控多环芳烃(PAHs)的方法。样品经二氯甲烷超声提取,浓缩后经乙腈定容,以乙腈和水作为流动相进行反相HPLC梯度淋洗分离后,由紫外检测器串联程序波长荧光检测器检测。通过实验条件的优化,实现了16种PAHs组分基线完全分离和高灵敏度检测。16种PAHs检测限为0.05～1.20μg/L,回收率在75.0%～106.0%,相对标准偏差在0.27%～7.42%,均符合方法学的要求。将该方法用于测定贵阳市不同功能区PM2.5中PAHs的含量,具有快速简便、准确灵敏、重现性好等优点,适合大批量样品的分析。     

废LCD面板有机材料水热资源化产乙酸

LCD面板主要由附着偏光片及液晶等有机材料的玻璃面板构成。有机材料的去除及资源化利用是废LCD面板处理的第一步。在水热条件下对废LCD面板进行了降解产酸研究。研究考察了反应温度、反应时间、氧化剂用量、水用量及pH值等对水热产乙酸产率及选择性的影响。通过正交实验确定了水热产乙酸的最佳操作条件：反应温度325℃,反应时间5min,氧化剂（30％H2O2）0．6mL,用水量2mL,近中性环境（pH6-6．5去离子水）。此条件下,乙酸产率及选择性分别为68．83％及70．56％。结果表明,以废LCD面板有机材料为原料,采用水热技术进行产乙酸反应,可实现其资源化再利用。     

Effects of landfill leachate effluent and bisphenol A on glutathione and glutathione-related enzymes in the gills and digestive glands of the freshwater snail Bellamya purificata

Environmental contaminants with estrogenic activity have recently attracted attention due to their potential detrimental effects on the reproduction of human and wildlife. The aim of this study was to evaluate the use of endogenous glutathione and glutathione-related enzymes as biomarkers of exposure to landfill leachate effluent and bisphenol A (BPA) in the freshwater snail, Bellamya purificata. Following exposure to 1%, 5% and 10% landfill leachate effluent and 1, 10, 50 and 100mugl(-1) BPA for 0, 2, 7 and 15d, activities of glutathione S-transferase (GST), selenium-dependent glutathione peroxidase (SeGPx) and glutathione reductase (GR) and levels of total glutathione were measured in the gills and digestive glands of the snails. GST and total glutathione were the most sensitive parameters in both exposure scenarios. GST activities increased by about 80%, while total glutathione decreased to 70% and 80% in the gills and digestive glands, respectively. In contrast, SeGPx and GR activities remained at the same levels in all the treatment groups compared with those of controls. The results indicated that among glutathione and glutathione-related enzymes, GST activity and total glutathione level, which showed dose-dependent dynamics, could be used as biomarkers of aquatic ecosystems contaminated with landfill leachate.