固载型TiO2光催化反应器对富营养水体杀藻作用研究

以泡沫镍作为载体，利用电沉积技术将纳米TiO₂负载在泡沫镍上，制成固载型TiO₂光催化反应器。研究表明，经过光催化反应器处理的富营养水体，30 h内叶绿素a由96.2 mg/m³降至2.2mg/m³，下降率达97.6％，而未负载纳米TiO₂普通泡沫镍材料，在同样光强的紫外灯照射下，叶绿素a下降率为74.3％，表明紫外光照射虽然也具有一定的杀藻功能，但是光催化反应才是藻类被杀灭的主要原因。利用9.54 m³景观喷水池进行杀藻中试，光催化反应器也同样表现出优异的杀藻性能，12 d内叶绿素a由18.7 mg/m³降至1.9mg/m³，下降率达到89.8％，水体由浓绿变为清澈见底，这表明光催化反应器具有很强的杀藻能力，通过有效杀灭富营养水体中藻类、控制藻类基数，对应急处理城市景观水、湖泊等富营养水体和突发性藻华，提高生物-生态法处理效率，改善城市水环境具有十分重要的意义。     

Adsorption of arsenate on soils. Part 1: laboratory batch experiments using 16 Chinese soils with different physiochemical properties

Laboratory batch experiments were carried out to study the adsorption of arsenate on 16 Chinese soils with different physicochemical properties. Wide differences in arsenate adsorption were observed, and the Jiangxi and Hubei soils were more effective sorbents for arsenate than other soils. The Langmuir one-surface and two-surface equations were used to model the arsenate adsorption data. Except for the Jiangxi and Hubei soils, the Langmuir one-surface equation gave reasonably good fits to the arsenate adsorption data. However, the Langmuir two-surface equation generally provided a better fit than the Langmuir one-surface equation. For soils with relative high organic matter (OM), dissolved organic carbon (DOC) or extractable phosphate, the Langmuir one-surface and two-surface equations described the adsorption isotherms similarly. In contrast, for soils with relatively low contents of OM, DOC or extractable phosphate, the Langmuir two-surface equation gave the better fit to the arsenate adsorption data.     

Designing monitoring networks to represent outdoor human exposure

Measurements of outdoor human exposure to suspended particulate matter (PM) are always constrained by available resources. An effective network design requires tradeoffs between variables measured, the number of sampling locations, sample duration, and sampling frequency. Sampling sites are needed to represent neighborhood and urban spatial scales with minimal influences from nearby sources. Although most PM measurements for determining compliance with standards are taken over 24-h periods every third to sixth day, outdoor human exposure assessment requires measurements taken continuously throughout the day, preferably over durations of 1 h or less. More detailed particle size and chemistry data are also desirable, as smaller size fractions and specific chemicals may be better indicators of adverse health effects than total mass samples.     

混凝-氧化法处理印染废水

采用混凝 氧化法对印染废水进行处理 ,得出最佳混凝条件及氧化条件。实验结果表明 ,该法可使印染废水的CODCr与色度去除率分别达到 90 .2 %和 99.1%。该方法具有去除率高、操作方便、设备简单、不产生二次污染等优点。     

Performance of three-phase three-dimensional electrode reactor for the reduction of COD in simulated wastewater-containing phenol

The removal of chemical oxygen demand (COD) from wastewater-containing phenol was investigated using three-phase three-dimensional electrode reactor. Special attention was paid to experimentally probe the performance of the reactor in COD removal in the process of repeated batch runs. The experimental results showed that the reactor could remove COD from phenol-containing wastewater much more efficiently than both granulated activated carbon (GAC) adsorption bed and conventional three-dimensional electrode. For 200th batch run, the three-phase three-dimensional electrode reactor with an airflow of 5 l min(-1) and a cell voltage of 30 V could remove 1350 ppm COD from the wastewater in 30 min while conventional three-dimensional electrode reactor with a same cell voltage and GAC adsorption bed with a same airflow only could remove 610 and 1000 ppm, respectively, at the same reaction duration. Although it was found that COD removal decreased with increasing repeated batch runs in our experimental range, due to adsorption saturation of GAC and electrode passivation, the extent of decrease for the three-phase three-dimensional electrode is much less than those for conventional three-dimensional electrodes and GAC adsorption beds. The passivated reactor could be partly re-activated by electrolysis in the presence of MnO2.     

Shifted power-law relationship between NO2 concentration and the distance from a highway: A new dispersion model based on the wind profile model

In this paper, a shifted power-law model, based on the wind profile model, had been supposed to simulate concentration gradient of nitrogen dioxide (NO₂) with distance from a highway. Field experiments were performed for NO₂ gradients from a highway in Shanghai by using passive samplers. The shifted power-law model was fitted well with experimental results of field experiments both in this study and in the literature. The results not only verified the validity of shifted power-law relationship between NO₂ concentration and the distance from a highway, but also partially demonstrated that there were some significant similarities between wind profile and air pollutants concentration profile near highway. With known concentration of chosen reference point and appropriate value of the parameter k, the model could be practically applied for predicting the NO₂ distributions near a highway. The methods of determining the parameter k were also discussed for further detailed studies.     

污泥酸化速率影响因子的探讨

采用城市污水厂污泥作为嗜酸微生物菌株来源,通过添加一定量的单质硫,使其中的嗜酸硫杆菌群大量增殖,并使污泥pH大幅降低.取得的培养物可用于废旧干电池中重金属沥滤等的处理.由于培养物对重金属沥滤效率和污泥的酸化速率密切相关,为此进行了不同的污泥种类、加硫量、污泥浓度和曝气强度对污泥酸化速率影响的实验.实验表明,初沉泥、二沉泥和混合浓缩污泥都能迅速利用硫产酸;加硫量(以100 mL污泥计)在0.5、1.0、2.0、4.0 g时,快速酸化的趋势相同.0.5 g的加硫量显示出略微慢的酸化速率,最后达到的最低pH在1.2左右,其他三个都降至1.0以下.污泥质量分数在0.5%、1.0%、2.0%、3.0%、4.0%时,也具有相同的酸化趋势,0.5%质量分数的污泥下降速率最快,这与较低浓度下污泥对pH的缓冲能力较小有关;曝气强度在0.45 L/min和0.3 L/min差别较小,5 d内能迅速降低pH,0.2 L/min的酸化速率较慢,足够长的时间(12 d)也能将pH降至2.5左右,0.1 L/min的曝气强度的酸化速率最慢,不能达到预期的酸化效果.     

磷酸钕共沉淀选择性分离富集-原子吸收测定环境水样中痕量铅

研究提出了用磷酸钕(NdPO4)作为共沉淀捕集剂分离富集环境水样中的痕量Pb2 ,用火焰原子吸收光谱(FAAS)测定的方法.共沉淀受pH、NdCl3和H3PO4溶液用量的影响.结果显示,在溶液pH为3.2时,20 mL水样中加入5 mg/L NdCl3 2 mL、0.5 mol/L H3PO4 3 mL条件下,铅的加标回收率为96.6%～104.2%,方法的检测限为5.7×10-3 mg/L,水体中常见碱金属、碱土金属离子及阴离子在一定范围内不影响测定.     

垃圾焚烧过程中水分促燃脱氯效果的研究

分别在转式垃圾焚烧炉和固定床加热炉中，研究了水分对垃圾焚烧及钙基脱氯效果的影响。研究结果表明，垃圾焚烧过程中一定量水分的存在能促进垃圾焚烧效率，提高钙基氯剂的脱氯效率。同时，分析水分促进垃圾焚烧率和脱氯效果提高的原因，这是由于水分能强化焚烧过程的传质传热，能活化脱氯剂，改善脱氯剂的物理和化学性质，这些研究结果将为垃圾焚烧技术在我国的进一步推广提供科学依据。     

复合型除尘器除尘脱硫一体化工艺实验研究

试验研究了专利产品“高压静电滤槽复合型卧式除尘器”的除尘脱硫一体化工艺。试验表明，在布袋前方的末级电场中实行半干法脱硫工艺具有可行性，可达到除尘脱硫一体化目的。试验同时研究了钙硫比、脱硫灰循环率、饱和温距、喷水量和SO2浓度等对脱硫率的影响。该工艺适用于以低硫煤为燃料的锅炉进行除尘脱硫。