污泥施入黄土后重金属Cu、Zn、Cd的淋滤迁移

污泥土地利用是目前国内外污泥处置的主要方式和鼓励方向,在中国西北黄土地区更有前景和意义.污泥富含有机质和营养元素可弥补黄土的贫瘠缺陷,改善黄土肥力、增加植物产量.污泥施入黄土后,灌溉水对污泥重金属的淋滤迁移和污染风险是值得研究的课题之一.研究旨在了解重金属Cu、Zn、Cd在黄土层中的淋滤迁移特征,为黄土地区污泥的土地利用及重金属污染控制提供实验依据.实验选择污泥中含量或毒性大的Cu、Zn、Cd 3种重金属作为研究对象,通过室内模拟土柱对表层堆肥污泥中2种源强的重金属进行1年灌溉用水量的淋滤对比实验,测定淋滤前后土柱中和渗出液的Cu、Zn、Cd总量、有机质及pH值,以期分析重金属在黄土中的淋滤、迁移特征.结果表明,淋滤作用可使堆肥污泥Cu、Zn、Cd发生少量迁移并富集于土柱中、上部,大部分或绝大部分重金属仍滞留于耕作层(0～20 cm);淋滤使堆肥污泥Cd与Cu向下迁移约30 cm,Zn向下迁移约20 cm;渗出液呈弱碱性,其中Cu、Zn、Cd 3种重金属的浓度较入渗水均有增多,但随渗出液从黄土柱中溶出的重金属量极少.实验表明,耕作层重金属源强对Cu、Zn、Cd在土柱剖面中的淋滤、迁移和滞留作用以及溶出量均有不同程度的影响,堆肥污泥土地利用可以明显改善黄土肥力,灌溉对耕作层污泥有机质的淋滤损失量较小.并得出,堆肥污泥在黄土地区的土地利用是可行的.     

茜素绿的微波无极紫外光降解及产物分析

以茜素绿为研究对象,探讨了蒽醌类染料在微波无极紫外灯光辐射下的降解行为。结果表明,茜素绿的脱色反应符合一级反应动力学规律,反应120 min后COD和TOC的去除率分别为65.79%和60.98%;采用荧光色谱仪和电子顺磁共振仪检测到降解过程中羟基自由基和超氧自由基为主要活性物种;利用红外光谱仪、离子色谱仪和电子喷雾质谱仪分析了反应过程中的中间产物;采用电喷雾等技术和离子色谱测定了茜素绿降解的中间产物,并推断了茜素绿微波紫外光降解可能的历程;采用大肠杆菌和锦鲤对溶液进行了生物毒性检测与评价,由于中间产物的产生降解溶液的毒性先升后降。     

Effect of initial pH control on biological phosphorus removal induced by the aerobic/extended-idle regime

Recently, it has been reported that biological phosphorus removal (BPR) can be induced by an aerobic/extended-idle (AEI) regime. This study further investigated the effect of initial pH ranging from 6.6 to 8.2 on BPR in the AEI process, and compared the BPR performance between the AEI and the anaerobic/oxic (A/O) regimes under their optimal initial pH value. Experimental results firstly showed that phosphorus removal linearly increased with initial pH increasing from 6.6 to 7.8, but slightly decreased when initial pH increased from 7.8 to 8.2. The optimal initial pH should be controlled at 7.8, and the phosphorus removal at initial pH 7.8 was approximately 1.7-time than that at initial pH 6.6. The mechanism studies showed that the biomass cultured at initial pH 7.8 contained more polyphosphate accumulating organisms (PAOs), lower glycogen accumulating organisms (GAOs), and had higher activities of exopolyphosphatase and polyphosphate kinase than that cultured at initial pH 6.6. Cyclic studies revealed that initial pH control affected the transformations of intracellular polyhydroxyalkanoates and glycogen, which might thereby influence microbial competition between PAOs and GAOs. Then, BPR performance between the AEI and the A/O regimes by adjusting initial pH at 7.8 was also compared. The results showed the AEI regime could drive a better BPR than the generally accepted A/O regime (98% vs 88%). Finally, controlling initial pH at 7.8 to promote BPR in the AEI process was confirmed for a municipal wastewater.     

Halogenated polycyclic aromatic hydrocarbons in the environment

Halogenated polycyclic aromatic hydrocarbons (HPAHs) have been reported to occur in air, sediment, fly ash, and biota samples. This review summarized current existing data on the environmental occurrence, behavior, physicochemical properties, emission sources, and toxic equivalents of HPAHs. Firstly, the physicochemical properties of HPAHs were summarized. Then, an overview of environmental occurrence of HPAHs in ambient matrices including biological samples was reviewed. Meanwhile, the emission sources and possible formation mechanisms of HPAHs were discussed. Apart from that, the aryl hydrocarbon receptor (AhR)-mediated activities were summarized, which indicated that the position and number of halogen atoms on the parent PAHs molecule were important determinant factors affecting the AhR-mediated activity of individual HPAHs congeners. Finally, some research recommendations on HPAHs were given.     

Temperature influence on biological phosphorus removal induced by aerobic/extended-idle regime

Previous researches have demonstrated that biological phosphorus removal (BPR) from wastewater could be driven by the aerobic/extended-idle (A/EI) regime. This study further investigated temperature effects on phosphorus removal performance in six A/EI sequencing batch reactors (SBRs) operated at temperatures ranging from 5 to 30 °C. The results showed that phosphorus removal efficiency increased with temperature increasing from 5 to 20 °C but slightly decreased when temperature continually increased to 30 °C. The highest phosphorus removal rate of 97.1 % was obtained at 20 °C. The biomass cultured at 20 °C contained more polyphosphate accumulating organisms (PAO) and less glycogen accumulating organisms (GAO) than that cultured at any other temperatures investigated. The mechanism studies revealed that temperature affected the transformations of glycogen and polyhydroxyalkanoates, and the activities of exopolyphosphatase and polyphosphate kinase activities. In addition, phosphorus removal performances of the A/EI and traditional anaerobic/oxic (A/O) SBRs were compared at 5 and 20 °C, respectively. The results showed the A/EI regime drove better phosphorus removal than the A/O regime at both 5 and 20 °C, and more PAO and less GAO abundances in the biomass might be the principal reason for the higher BPR in the A/EI SBRs as compared with the A/O SBRs.     

活性炭纤维吸附模拟废气中的乙醇和乙醚

采用动态吸附法研究了5种活性炭纤维（ACF）对乙醇、乙醚及模拟混合废气中的乙醇和乙醚的吸附性能。实验结果表明：当ACF-1,ACF-2,ACF-3,ACF-4分别吸附乙醇和乙醚时,在室温、乙醇质量浓度12.0 mg/L、乙醚质量浓度13.0 mg/L的条件下,4种ACF对乙醇的穿透吸附量和饱和吸附量分别为60~70 mg/g和339~409 mg/g,对乙醚的穿透吸附量和饱和吸附量分别为50~65 mg/g和301~344 mg/g;在室温、模拟混合废气中乙醇和乙醚的质量浓度均为11.6 mg/L、吸附时间120 min的条件下,具有较大的比表面积和微孔体积的ACF-5对乙醇的吸附量为205 mg/g,对乙醚的吸附量为223 mg/g;在脱附真空度-0.95 Pa、脱附时间20 min的条件下,经17 次使用的ACF-5对模拟混合废气中乙醇和乙醚的穿透吸附量均为87 mg/g,穿透时间均为12 min。     

Levels, compositions, and inventory of polybrominated diphenyl ethers in sewage sludge of Guangdong Province, South China

Polybrominated diphenyl ethers (PBDEs) were measured in sewage sludge samples collected from major wastewater treatment plants in Guangdong Province, South China. Concentrations of ∑₃₉PBDE (all 39 compounds including tri- to hepta- PBDE congeners except for BDE-209) ranged from 3.6 to 428 ng/g dw with a mean value of 67.4 ng/g dw and a median value of 25.9 ng/g dw, and those of BDE-209 ranged from 9.9 to 5,010 ng/g dw (mean 1,024 ng/g dw and median 824 ng/g dw). The PBDE mixtures detected were mainly comprised of penta-, octa-, and deca-BDEs, with deca-BDE as the dominant constituent. The most abundant congeners, excluding BDE-209, were BDE-47, BDE-99, and BDE-183. Good correlations were found among the concentrations of BDE-47, BDE-99, BDE-100, BDE-138, and BDE-154 (r?>?0.8). However, poor correlations were found between the concentrations of BDE-209 and all other congeners (r?<?0.3). This fact suggests that most tri- to hepta-BDEs detected did not originate from decomposition of deca-BDE. The estimated annual emission of ∑_allPBDEs, ∑₃₉PBDEs, penta-BDE, octa-BDE, and deca-BDE to the Pearl River Delta environment (PRD), based on the sludge samples analyzed, amounts to 232, 20.2, 5.5, 1.7, and 212 kg per year, implicating sewage sludge as a significant source of PBDEs to the PRD environment.     

简青霉降解秸秆条件最优化和诱导剂的作用

实验中采用简青霉对稻草秸秆进行降解作用,通过正交实验的极差、三因素三水平作用趋势图和降解选择性分析,对影响简青霉降解稻草秸秆的3种因素进行了优化,得到培养温度40℃、含水率80%、培养pH为8是降解的最佳固态发酵培养条件。并研究了碱木质素对简青霉分泌木质素降解酶的诱导作用,不同浓度的碱木质素对简青霉产酶的诱导作用不同,且对不同酶的诱导效果也不同,最后得到较低浓度0.5和1 g/L是诱导的适宜浓度。对比较适浓度的碱木质素和常用的诱导剂愈创木酚、吐温80的诱导作用,发现在同样的培养条件下,碱木质素的诱导效果比愈创木酚和吐温80效果都好。     

基于生物表面活性剂的柴油微乳体系构建与性能研究

以生物表面活性剂鼠李糖脂（RL）为表面活性剂,中长碳链正构醇（正丁醇、正戊醇、正己醇、正庚醇及正辛醇）为助表面活性剂,采用滴定法制备RL／柴油／正构醇／水柴油微乳体系,并考察了表面活性剂用量（Km）、助表面活性剂醇的种类及用量（δas）及离子强度对柴油微乳体系最大增溶水量（Wo）的影响,并对不同条件下获得的柴油微乳体系的运动粘度（μ）和表面张力（γ）进行了表征。通过荧光法测得RL在柴油中的临界胶束浓度CMC为7g／L。当生物表面活性剂与柴油的质量比Km为0．02,助表面活性剂选用正庚醇且醇与表面活性剂的质量比δgs为0．1,NaOH溶液质量分数为0．06％时,柴油微乳体系的肛和T较低,形。最大,性能较佳。     

聚乙烯醇-海藻酸钠固定铜绿微囊藻对磷的吸附

利用聚乙烯醇与海藻酸钠固定包埋铜绿微囊藻,通过正交实验获得聚乙烯醇溶液浓度、海藻酸钠溶液浓度及铜绿微囊藻液量去除磷的最佳配比,研究溶液起始pH值、反应时间、磷初始浓度对固定化小球吸附磷的影响。结果表明,固定化小球的最佳制备条件为聚乙烯醇质量分数6%,海藻酸钠质量分数0.5%及铜绿微囊藻浓度2×107个/mL;固定化小球吸附磷的最适起始pH值为6～8,吸附达到平衡的时间为9～12 d,初始磷浓度为1.00 mg/L时去除率最高,达到79.19%。