臭氧氧化—包埋菌流化床生物处理组合工艺深度处理煤气化废水

采用臭氧氧化—包埋菌流化床生物处理组合工艺对煤气化废水进行深度处理。实验结果表明：当臭氧的质量浓度20 mg/L、臭氧进气流量1.5 L/min、臭氧通气时间30 min、包埋菌流化床水力停留时间24 h时,臭氧氧化工序的COD去除率达到30.0%~40.0%,总酚去除率达到100.0%;包埋菌流化床工序的COD去除率达到60.0%以上,氨氮的去除率大于95.0%;经组合工艺处理后,出水COD<60 mg/L,ρ（氨氮）<1.0 mg/L,ρ（总酚）未检出,色度小于50倍,达到GB8978—1996《污水综合排放标准》中的一级排放标准。     

Stand-alone wind power system with battery/supercapacitor hybrid energy storage

This paper presents a stand-alone wind power system with battery/supercapacitor hybrid energy storage. A stand-alone wind power system mainly consists of a wind turbine, a permanent magnet synchronous generator, hybrid energy storage devices based on a vanadium redox flow battery and a supercapacitor, an AC/DC converter, two bidirectional DC/DC converters, a DC/AC converter and a variable load. Several control strategies for the stand-alone wind power system are involved such as a maximum power point tracking (MPPT) control, a vanadium redox flow battery charge/discharge control and a supercapacitor charge/discharge control. The proposed MPPT control combines a sliding mode control with an extreme search control to capture maximum wind energy. This strategy avoids the necessity of measuring wind velocity, obtaining models or parameters of the wind turbine and calculating the differentials of the power generated from the wind power system and from the speed of the generator. The battery charge/discharge control maintains a constant DC bus voltage. When the battery charging/discharging current reaches the setting threshold, the charge/discharge control of the supercapacitor is triggered to limit the charging/discharging current of the battery. The simulation results show that the proposed method can rapidly respond to variations in wind velocity and load power.     

Enhanced electrokinetic remediation of lead-contaminated soil by complexing agents and approaching anodes

Optimizing process parameters that affect the remediation time and power consumption can improve the treatment efficiency of the electrokinetic remediation as well as determine the cost of a remediation action. Lab-scale electrokinetic remediation of Pb-contaminated soils was investigated for the effect of complexant ethylenediaminetetraacetic acid (EDTA) and acetic acid and approaching anode on the removal efficiency of Pb. When EDTA was added to the catholyte, EDTA dissolved insoluble Pb in soils to form soluble Pb–EDTA complexes, increasing Pb mobility and accordingly removal efficiency. The removal efficiency was enhanced from 47.8 to 61.5 % when the EDTA concentration was increased from 0.1 to 0.2 M, showing that EDTA played an important role in remediation. And the migration rate of Pb was increased to 72.3 % when both EDTA and acetic acid were used in the catholyte. The “approaching anode electrokinetic remediation” process in the presence of both EDTA and acetic acid had a higher Pb-removal efficiency with an average efficiency of 83.8 %. The efficiency of electrokinetic remediation was closely related to Pb speciation. Exchangeable and carbonate-bounded Pb were likely the forms which could be removed. All results indicate that the approaching anode method in the presence of EDTA and acetic acid is an advisable choice for electrokinetic remediation of Pb-contaminated soil.     

Synergistic toxic effect of nano-Al2O3 and As(V) on Ceriodaphnia dubia

Engineered nanomaterials (ENMs) alone could negatively impact the environment and human health. However, their role in the presence of other toxic substances is not well understood. The toxicity of nano-Al(2)O(3), inorganic As(V), and a combination of both was examined with C. dubia as the model organisms. Bare nano-Al(2)O(3) particles exhibited partial mortality at concentrations of greater than 200mg/L. When As(V) was also present, a significant amount of As(V) was accumulated on the nano-Al(2)O(3) surface, and the calculated LC(50) of As(V) in the presence of nano-Al(2)O(3) was lower than that it was without the nano-Al(2)O(3). The adsorption of As(V) on the nano-Al(2)O(3) surface and the uptake of nano-Al(2)O(3) by C. dubia were both verified. Therefore, the uptake of As(V)-loaded nano-Al(2)O(3) was a major reason for the enhanced toxic effect.     

Occurrence of diarrheagenic Escherichia coli genes in raw water of water treatment plants

Purpose

The high incidences of waterborne diseases are frequently associated with diarrheagenic Escherichia coli (DEC). DEC may pose a health risk to people who contact surface water for recreation or domestic use. However, there is no published report on the monitoring of DEC in drinking water sources in Taiwan. In this study, the occurrence of DEC genes in raw water for water treatment plants in Taiwan was investigated.

Method

Raw water samples were taken from water treatment plants adjacent to the Kaoping River in southern Taiwan. Each water sample was treated with membrane filtration followed by DNA extraction from the concentrate and concentrate enrichment, respectively. The target genes for various DEC strains of genes were identified, including enteroaggregative E. coli (EAEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC).

Results

Among 55 water samples analyzed, DEC genes were detected in 16 (29.1%) samples. Strain-specific genes for EAEC, EHEC, EIEC, and EPEC were found in the percentages of 3.6%, 10.9%, 9.1%, and 9.1%, respectively. The specific gene for ETEC is not detected in the study. By looking at the presence/absence of specific genes and water sample characteristics, water temperature was found to differ significantly between samples with and without EHEC gene. In addition, pH levels differed significantly for EHEC and EPEC presence/absence genes, and turbidity was significantly different for water with and without EPEC genes.

Conclusion

DEC genes were detected in 29.1% of the raw water samples in the study location. The potential health threat may be increased if the treatment efficiencies are not properly maintained. Routine monitoring of DEC in drinking water sources should be considered.     

膜生物反应器(MBR)-反渗透(RO)工艺深度处理印染废水的实验研究

采用膜生物反应器（MBR）-反渗透（RO）工艺对印染废水进行了深度处理实验。原水经MBR系统处理后,COD去除率、ss去除率和色度去除率分别达89．9％、100％和87．5％。MBR系统处理出水进入反渗透（RO）系统进行处理,硬度去除率和除盐率分别达99．62％和99．64％,同时可进一步除去剩余的COD、色度。系统出水水质满足生产回用的要求。     

Health risk assessment of heavy metals in Cyprinus carpio (Cyprinidae) from the upper Mekong River

The purposes of this research are to quantify the concentration of heavy metals (Zn, Cu, As, Pb, Cd, and Hg) in the water and fish tissues of common carp (Cyprinus carpio) in the upper Mekong River and to thereby elucidate the potential dietary health risks from fish consumption of local residents. Surface water and fish tissues (gill, muscle, liver, and intestine) from four representative sample areas (influence by a cascade of four dams) along the river were analyzed for heavy metal concentrations. Results revealed that the levels of heavy metals in fish were tissue-dependent. The highest Cu and As levels were found in the liver; the highest Zn and Pb levels occurred in the intestine, and the highest Hg level was found in the muscle. The total target hazard quotient (THQ) value for residents is > 1 for long-term fish consumption, and local residents are, therefore, exposed to a significant health risk. Results from the current study provide an overall understanding of the spatial and tissue distribution of heavy metals in water and fish body along the upper Mekong River under the influence of cascade dams and highlight the potential health risk of As for the local residents of long-term fish consumption.

     

浸提分离法提取皂素清洁工艺研究

提出一种通过溶剂提取将游离皂苷与淀粉、纤维等成分分离,从源头上减少用水量、耗酸量和污染物排放量的皂素清洁生产工艺。首先对溶剂提取条件进行优化,得出最佳工艺条件为：90%（体积比）乙醇溶液,料液比1∶7,沸腾回流提取3 h,重复提取3次。然后通过气质联用（GC/MS）分析了皂素废水的有机物组成。研究结果表明,清洁工艺皂素产率为1.51%（降低3.82%）,用酸量比传统工艺减少了71%,头道液COD浓度降低了46%,每100 g原料排放的COD总量下降了84%;皂素废水的有机物污染物主要为糠醛及其衍生物,清洁工艺废水的有机物含量更低,更易降解。     

3株反硝化聚磷菌的分离与鉴定

通过烛缸法培养富集、分离,结合除磷试验、硝酸盐还原产气试验及异染颗粒和PHB颗粒染色辅助检验相结合的方法筛选,得到3株具有较高脱氮除磷效率的反硝化聚磷菌DNPA8, DNPA9和DNPA10。在富氮富磷培养基中培养48 h,各菌株的脱氮率均大于75%,除磷率均大于78%。采用多相分类的方法确定了3株反硝化聚磷菌的分类地位,DNPA8为嗜麦芽寡养单胞菌,DNPA9为水生丛毛单胞菌属首次发现的反硝化聚磷菌;DNPA10为约翰逊氏不动杆菌。该研究结果为富营养化水体的治理提供了有效的菌种资源。     

垃圾填埋场微生物气溶胶粒径分布研究

为了了解垃圾填埋场微生物气溶胶粒径分布规律,在北京市某垃圾卫生填埋场填埋区、渗滤液处理区、生活区分别选定监测点,利用安德森六级微生物采样器,对填埋场空气微生物进行了系统的定点取样、测定和分析。研究结果表明,空气细菌粒径分布均为第Ⅰ级(>8.2 μm)最高,填埋区空气细菌粒径呈偏态分布,渗滤液处理区、生活区分别在第Ⅳ级和第Ⅲ级出现第2个峰值。携带细菌的可吸入微粒在渗滤液处理区比例最大。空气真菌与放线菌均在第Ⅳ级分布最高,携带真菌和放线菌的可吸入粒子的比例显著大于细菌(P<0.05)。填埋区不同作业时段空气微生物粒径在各级分布比例基本一致。填埋区细菌气溶胶中值直径为5.7 μm,渗滤液处理区为3.7 μm,生活区为5.3 μm,显著大于真菌气溶胶和放线菌气溶胶的中值直径(P<0.05)。