氧化/吸附/混凝协同工艺处理焦化废水生物处理出水的过程及效果分析

针对焦化废水生物处理出水中继续存在多种有机污染物而影响达标及存在安全隐患的现状,基于废水中有机物的物理化学特性,构建了氧化/吸附/混凝的深度处理过程。在NaC lO投加量为40 mg/L,AC投加量为500 mg/L,PFS投加量为300 mg/L,反应时间为0.5 h,以及pH为7.0的最佳条件下,先氧化后吸附混凝,该过程可以实现COD去除率为75%以上,色度去除率80%以上,处理后的水样其COD值与色度值分别下降到60 mg/L及20倍以下;通过GC/MS方法分析处理前后水样中的有机物组分,发现水样中大部分单环芳香族化合物和多环芳香族化合物,部分含氮杂环化学物、有机氯化物以及溴化物被去除,但是,长链烷烃和部分芳香烃继续保留。研究结果证明了氧化/吸附/混凝协同工艺的效果与焦化废水生物出水中有机污染物的分子结构、存在形态形成构效关系,催化作用与氧化作用的协同是获得高效去除率的关键。     

板框压滤机内酒精污泥过滤脱水特性

采用螺杆泵输送和板框过滤机压滤的方法对酒精污泥进行机械脱水,研究了絮凝剂(聚丙烯酰胺PAM)添加量、污泥的进口湿含量、螺杆泵转速、过滤介质和过滤时间对污泥过滤特性的影响,并对滤饼吹气压榨进一步脱水。实验表明,在PAM添加量wPAM=3 kg/(t干污泥),污泥的进口湿含量x0=95%,螺杆泵转速n=180 r/min,过滤时间t=2.5 h并进行吹气压榨可将污泥的湿含量降至69.91%。     

Cesium and strontium sorption by selected tropical and subtropical soils around nuclear facilities

The dynamics of Cs and Sr sorption by soils, especially in the subtropics and tropics, as influenced by soil components are not fully understood. The rates and capacities of Cs and Sr sorption by selected subtropical and tropical soils in Taiwan were investigated to facilitate our understanding of the transformation and dynamics of Cs and Sr in soils developed under highly weathering intensity. The Langmuir isotherms and kinetic rates of Cs and Sr sorption on the Ap1 and Bt1 horizons of the Long-Tan (Lt) and the A and Bt1 horizons of the Kuan-Shan (Kt), Mao-Lin (Tml) and Chi-Lo (Cl) soils were selected for this study. Air-dried soil (<2 mm) samples were reacted with of 7.5 × 10⁻⁵ to 1.88 × 10⁻³ M of CsCl (pH 4.0) or 1.14 × 10⁻⁴ to 2.85 × 10⁻³ M of SrCl₂ (pH 4.0) solutions at 25 °C. The sorption maximum capacity (q_m) of Cs by the Ap1 and Bt1 horizons of the Lt soil (62.24 and 70.70 mmol Cs kg⁻¹ soil) were significantly (p < 0.05) higher than those by the A and Bt1 horizons of the Kt and Cl soils (26.46 and 27.49 mmol Cs kg⁻¹ soil in Kt soil and 34.83 and 29.96 mmol Cs kg⁻¹ soil in Cl soil, respectively), however, the sorption maximum capacity values of the Lt and Tml soils did not show significant differences. The amounts of pyrophosphate extractable Fe (Fe_p) were correlated significantly with the Cs and Sr sorption capacities (for Cs sorption, r² = 0.97, p < 1.0 × 10⁻⁴; for Sr sorption, r² = 0.82, p < 2.0 × 10⁻³). The partition coefficient of radiocesium sorbed on soil showed the following order: Cl soil ? Kt soil > Tml soil > Lt soil. It was due to clay minerals. The second-order kinetic model was applied to the Cs and Sr sorption data. The rate constant of Cs or Sr sorption on the four soils was substantiality increased with increasing temperature. This is attributable to the availability of more energy for bond breaking and bond formation brought about by the higher temperatures. The rate constant of Cs sorption at 308 K was 1.39-2.09 times higher than that at 278 K in the four soils. The activation energy of Cs and Sr sorbed by the four soils ranged from 7.2 to 16.7 kJ mol⁻¹ and from 15.2 to 22.4 kJ mol⁻¹, respectively. Therefore, the limiting step of the Cs⁺ or Sr²⁺ sorption on the soils was diffusion-controlled processes. The reactive components, which are significantly correlated with the Langmuir sorption maxima of Cs and Sr by these soils, substantially influenced their kinetic rates of Cs and Sr sorption. The data indicate that among components of the subtropical and tropical soils studied, short-range ordered sesquioxides especially Al- and Fe-oxides complexed with organics play important roles in influencing their capacity and dynamics of Cs and Sr sorption.     

淮南市平山头水源地水中PAEs污染情况分析

以淮南市平山头水厂水源4种邻苯二甲酸酯类（PAEs）：邻苯二甲酸二甲酯（DMP）、邻苯二甲酸二乙酯（DEP）、邻苯二甲酸丁基苄基酯（BBP）、邻苯二甲酸二丁酯（DBP）为研究对象,研究了水源地水中PAEs的污染情况。研究结果表明：DMP、DEP、BBP、DBP的检出率分别为50％、83．3％、83．3％、100％,DBP的达标率为100％;DMP、DEP、BBP、DBP对∑4PAEs污染的贡献率依次为：5．2％、3．7％、20．1％、71．1％,说明平山头水厂水源地水中PAEs污染主要以DBP为主。水源地各采样点∑4PAEs的含量范围0．632～1．623μg／L,其采样断面平均浓度顺序为：上游〉中游〉下游。     

Bioremediation of strontium (Sr) contaminated aquifer quartz sand based on carbonate precipitation induced by Sr resistant Halomonas sp

Contamination of aquifers or sediments by radioactive strontium (⁹⁰Sr) is a significant environmental problem. In the present study, microbially induced calcite precipitation (MICP) was evaluated for its potential to remediate strontium from aquifer quartz sand. A Sr resistant urease producing Halomonas sp. was characterized for its potential role in bioremediation. The bacterial strain removed 80% of Sr from soluble-exchangeable fraction of aquifer quartz sand. X-ray diffraction detected calcite, vaterite and aragonite along with calcite-strontianite (SrCO₃) solid solution in bioremediated sample with indications that Sr was incorporated into the calcite. Scanning electron micrography coupled with energy-dispersive X-ray further confirmed MICP process in remediation. The study showed that MICP sequesters soluble strontium as biominerals and could play an important role in strontium bioremediation from both ecological and greener point of view.     

Biodegradation of nicosulfuron by the bacterium Serratia marcescens N80

By enrichment culturing of the sludge collected from the industrial wastewater treatment pond, we isolated a highly efficient nicosulfuron degrading bacterium Serratia marcescens N80. In liquid medium, Serratia marcescens N80 grows using nicosulfuron as the sole nitrogen source, and the optimal temperature, pH values, and inoculation for degradation are 30-35°C, 6.0-7.0, and 3.0% (v/v), respectively. With the initial concentration of 10 mg L?1, the degradation rate is 93.6% in 96 hours; as the initial concentrations are higher than 10 mg L?1, the biodegradation rates decrease as the nicosulfuron concentrations increase; when the concentration is 400 mg L?1, the degradation rate is only 53.1%. Degradation follows the pesticide degradation kinetic equation at concentrations between 5 mg L?1 and 50 mg L?1. Identification of the metabolites by the liquid chromatography/mass spectrometry (LC/MS) indicates that the degradation of nicosulfuron is achieved by breaking the sulfonylurea bridge. The strain N80 also degraded some other sulfonylurea herbicides, including ethametsulfuron, tribenuron-methyl, metsulfuron-methyl, chlorimuron-ethyl,and rimsulfuron.     

改性锰砂对废水中锰的吸附特性研究

通过正交实验,研究pH值、反应时间、锰砂投加量和锰砂改性时间等因素对Mn2+吸附效果的影响。结果表明,在25℃,吸附反应体系pH=9,锰砂投加量为15 g/L,吸附时间为30 min,锰砂的高锰酸钾改性时间为36 h时,改性锰砂对锰的吸附去除率最高,达到了99.99%。四因素的影响顺序为:pH>反应时间>锰砂投加量>锰砂改性时间。在单因素实验中,当pH=7,吸附剂投加量为25 g/L时,经60 min可达吸附平衡,锰的去除率为60.04%,其等温吸附符合Freundlich和Langmuir模型,并且与Langmuir模型的拟合程度更高。本研究还对改性锰砂吸附除锰的机理做了初步探讨。     

Mercury emission and plant uptake of trace elements during early stage of soil amendment using flue gas desulfurization materials

A pilot-scale field study was carried out to investigate the distribution of Hg and other selected elements (i.e., As, B, and Se), i.e., emission to ambient air, uptake by surface vegetation, and/or rainfall infiltration, after flue gas desulfurization (FGD) material is applied to soil. Three FGD materials collected from two power plants were used. Our results show Hg released into the air and uptake in grass from all FGD material-treated soils were all higher (P < 0.1) than the amounts observed from untreated soil. Hg in the soil amended with the FGD material collected from a natural oxidation wet scrubber (i.e., SNO) was more readily released to air compared to the other two FGD materials collected from the synthetic gypsum dewatering vacuum belt (i.e., AFO-gypsum) and the waste water treatment plant (i.e., AFO-CPS) of a forced oxidation FGD system. No Hg was detected in the leachates collected during the only 3-hour, 1-inch rainfall event that occurred throughout the 4-week testing period. For every kilogram of FGD material applied to soil, AFO-CPS released the highest amount of Hg, B, and Se, followed by SNO, and AFO gypsum. Based on the same energy production rate, the land application of SNO FGD material from Plant S released higher amounts of Hg and B into ambient air and/or grass than the amounts released when AFO-gypsum from Plant A was used. Using FGD material with lower concentration levels of Hg and other elements of concern does not necessary post a lower environmental risk. In addition, this study demonstrates that considering only the amounts of trace elements uptake in surface vegetation may under estimate the overall release of the trace elements from FGD material-amended soils. It also shows, under the same soil amendment conditions, the mobility of trace elements varies when FGD materials produced from different processes are used.     

几种倒伞型表面曝气机的充氧性能

对安徽某科技公司产自行研究的几种倒伞型表面曝气器的充氧性能进行模拟比较研究,利用合肥某氧化沟装置在清水条件下对各叶轮的氧总转移系数KLa、理论充氧能力qc、理论动力效率E及水体流速v进行了测试,对比分析了叶片安装角度、片数及叶片设计对充氧能力的影响。结果表明,叶片导流辐板斜角设计对充氧效率影响最大,是叶轮性能提升最关键因素。     

钒基活化液增活V2O5-WO3-MoO3/TiO2催化剂的实验研究

基于催化剂在线增活工艺,以火电厂运行条件下的典型钒钛类失活催化剂为原料,采用单因素变量法展开了钒基活化液各成分对失活催化剂增活效果的研究,对活化液增活后的催化剂进行活性评价及SEM、BET、FT-IR和XRD等分析,考察增活前后NO转换率、催化剂表面形貌及结构的变化情况。研究结果表明,在实验条件下,随着4种活性成分含量的增加,催化剂增活后NO转换率均呈现先升高后降低的规律,NO转换率最高达99%,且增活后催化剂表面活性成分增加,Brnsted酸性位增多,比表面积增加,对烟气具有较强适应力。