基于ASM2D模拟的双流态UNITANK改进工艺的设计与实验分析

针对传统UNITANK污泥浓度不稳定、低负荷释磷不充分以及池体容积比例不合理等不足,提出了改进工艺:双流态UNITANK;利用ASM2D模型对改进工艺进行模拟分析,并通过实验对其进行了验证。结果表明,基于ASM2D的模拟是有效的,双流态UNITANK有效克服了传统UNITANK存在的不足。     

Respiratory pigments of Yoldia eightsi, an Antarctic bivalve

Yoldia eightsi, an infaunal protobranch bivalve inhabiting the soft sediments of the Antarctic Sea, contains hemocyanin in its hemolymph and an intracellular hemoglobin in its gills. The concentration of hemocyanin in the hemolymph of Y. eightsi is very low, but the presence of this protein was documented by transmission electron microscopy after negative staining. The structure of Y. eightsi hemocyanin appears to be remarkably similar to that found in Gastropoda. The intracellular gill hemoglobin can be recovered after osmotic shock of the tissue and is isolated as a monomeric form, the molecular weight of which is 15.7 ± 0.4 kDa, as detected by FPLC gel-filtration experiments and SDS-PAGE. Isoelectric focusing experiments suggest the presence of a single native component with pI 6.6. Aggregation products accumulate during exposure to air and are resistant to SDS and β-mercaptoethanol treatment. This process can be avoided by maintaining the sample under a CO atmosphere. The oxygen dissociation curves, determined at pH 7.0 and 7 °C, are slightly sigmoidal, giving a Hill constant value of 1.35, probably related to the formation of aggregation products. The affinity for oxygen is moderately high, half saturation occurring at 3.15 mmHg. Received: 6 May 1997 / Accepted: 22 December 1997     

Polycyclic aromatic hydrocarbons in marine organisms from the Adriatic Sea, Italy

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in bivalves (Mitylus galloprovincialis), cephalopods (Todarodes sagittatus), crustaceans (Nephrops norvegicus) and fish (Mullus barbatus, Scomber scombrus, Micromesistius poutassou, Merluccius merluccius) in several pools coming from the Central Adriatic Sea. These marine organisms were selected because of their multitude, wide distribution and common use in the Italian diet, they were sampled and analyzed during the year 2004. Acenaphthene, benzo(a)pyrene, dibenz(a,h)anthracene, benzo(ghi)perylene and indeno(1,2,3-cd)pyrene showed levels below the instrumental detection limit in all samples. Fluorene, phenanthrene, anthracene, fluoranthene, benz(a)anthracene, benzo(b)fluoranthene and benzo(k)fluoranthene were detected at different concentrations in analyzed samples. Chrysene was detected only in mussels with very low values (average 0.74ngg(-1) wet weight). PAHs composition pattern was dominated by the presence of PAHs with 3-rings (62%) followed from those with 4-rings (37%) and 5-rings (1%). Atlantic mackerel, European hake and blue whiting showed the highest PAH concentrations, ranging from 44.1 to 63.3ngg(-1) wet weight, the group of invertebrate organisms showed a level of contamination about three times lower than those of the vertebrate groups. Mediterranean mussels that did not present very high levels of contamination expressed as sum of PAHs showed one of the highest values of benzo(a)pyrene equivalents (BaPEs). Conversely the latter value was very low in Atlantic mackerel even if this species reported the highest total PAH concentrations. No significant correlation was observed between weight, length and trophic levels and total PAHs.     

Enhanced Cr bioleaching efficiency from tannery sludge with coinoculation of Acidithiobacillus thiooxidans TS6 and Brettanomyces B65 in an air-lift reactor

Bioleaching process has been demonstrated to be an effective technology in removing Cr from tannery sludge, but a large quantity of dissolved organic matter (DOM) present in tannery sludge often exhibits a marked toxicity to chemolithoautotrophic bioleaching bacteria such as Acidithiobacillus thiooxidans. The purpose of the present study was therefore to enhance Cr bioleaching efficiencies through introducing sludge DOM-degrading heterotrophic microorganism into the sulfur-based sludge bioleaching system. An acid-tolerant DOM-degrading yeast strain Brettanomyces B65 was successfully isolated from a local Haining tannery sludge and it could metabolize sludge DOM as a source of energy and carbon for growth. A combined bioleaching experiment (coupling Brettanomyces B65 and A. thiooxidans TS6) performed in an air-lift reactor indicated that the rates of sludge pH reduction and ORP increase were greatly improved, resulting in enhanced Cr solubilization. Compared with the 5 days required for maximum solubilization of Cr for the control (single bioleaching process without inoculation of Brettanomyces B65), the bioleaching period was significantly shorten to 3 days for the combined bioleaching system. Moreover, little nitrogen and phosphorous were lost and the content of Cr was below the permitted levels for land application after 3 days of bioleaching treatment.     

Decontamination of soil containing POPs by the combined action of solid Fenton-like reagents and microwaves

The effect on halogenated aromatics of solid, non-toxic oxidants such as sodium percarbonate and the urea/hydrogen peroxide complex (Fenton-like reagents) was investigated. A microwaves-assisted, solvent-free method for soil decontamination is presented. It marks a considerable advance in the search of more efficient, environment-friendly procedures for the degradative oxidation of persistent organic pollutants. Residual pollutants in treated soil samples were determined by GC/MS analysis after solvent extraction or direct thermal desorption. Results showed that 4-chloronaphthol, 2,4-dichlorophenoxyacetic acid and p-nonylphenol had been degraded completely, 2,4-dibromophenol to a large extent.     

Air pollutants and the characterization of the organic content of aerosol particles in a mixed industrial/semi-rural area in central Italy

Both regulated and unregulated air pollutants were detected during an intensive seasonal sampling campaign in a mixed industrial/semi-rural area on the outskirts of Rome, Italy, at two sites located opposite a hospital waste incinerator, downwind according to the direction of the prevailing local winds. Concentrations of pollutants were significantly lower than in urban atmospheres. The composition of particulate organic material indicated a heavy biogenic impact, accompanied by a lower contribution from petroleum-related processes. Both PAH and nitro-PAH group compositions of particulates were used to assess the nature and relative importance of sources. Both sites showed that different and diffuse sources contributed to local pollution with a significant contribution from traffic, proving that the hospital waste incinerator was not the main pollution source in this area. Among unregulated compounds, a series of positional isomers of nitro-PAHs and other organic compounds associated with particulate matter were investigated. In particular, 1- and 3-nitrophenanthrene identification was carried out, and they proved to be the most abundant nitro-PAHs.     

中国西南部分地区地震灾害恢复力时空变化特征研究

从自然、社会和经济三个维度遴选了12个指标,构建地震灾害恢复力的综合评价指标体系,综合运用熵权法与模糊逻辑等方法,评价西南四省(四川、云南、贵州、重庆)的地震灾害恢复力,并分析其时空变化特征及主要影响因素.结果表明:2006-2016年,西南四省大部分地区地震灾害恢复力呈提升趋势,且恢复力水平总体随城市级别的增大而增大...     

Bi2WO6催化剂的合成和表征及其光催化活性

以Bi（NO3）3和Na2WO4为原料,采用水热法合成了可见光催化剂Bi2WO6,并采用X射线衍射仪和BET法对其进行了表征。考察了合成温度、Bi2WO6加入量、邻氯苯酚（2-CP）浓度、溶液pH等对2-CP光催化降解效果的影响。实验结果表明：在加入140℃下合成的Bi2WO6催化剂1g／L、原始pH（pH=5．85）、可见光光照210min的条件下,对质量浓度为20mg／L的2-CP溶液进行处理,2-CP去除率最高为97．2％;添加少量H2O2对2-CP的降解有促进作用。     

新型复合混凝脱色剂处理印染废水试验研究

针对某印染厂生产废水,以COD和色度为指标,用混凝试验方法研究了新型复合混凝脱色剂SE对印染废水的处理效果,并探讨了SE投加量及pH值、沉淀时间、搅拌强度对其混凝效果的影响,利用SE与 PAC 和PFS进行了对比试验.结果表明,SE可有效地去除印染废水中的COD和色度,当pH为8～10、沉淀时间为30 min、搅拌强度为75 r/min、投药量为155 mg/L时,去除效果最佳,COD和色度的去除率最高可达83%、94%;相对于PAC 和PFS,SE产生的絮体大而密实,沉降速度快,产生污泥量少,药剂用量少,最佳出水水质为：COD为139 mg/L,色度为37.证明SE是印染废水处理高效实用的复合型混凝剂.     

不同涂层电极和抑制剂对电化学氧化降解苯酚的影响

采用热分解法和电沉积法2种工艺制得4个二氧化铅电极,用扫描电镜（SEM）观察了电极表面形貌.以水杨酸(2-HBA)为捕获剂,用高效液相色谱仪测定羟基自由基与水杨酸的羟基化产物2,5-二羟基苯甲酸(2,5-DHBA)的量作为产生的羟基自由基的浓度.通过羟基自由基的浓度的测定和苯酚的降解,研究了不同涂层电极和抑制剂对电化学氧化对苯酚降解的影响.热分解电极、无掺杂电极、掺铋电极和掺镧电极产生羟基自由基的最大浓度分别为0.781、1.048、1.838、2.044 μmol/L,以这4个电极为阳极对苯酚进行电解, 1.5　h苯酚去除率分别为87.30%、93.55%、97.95%、98.70%,5　h　TOC去除率分别为86.75%、94.26%、98.53%、99.60%;以掺镧电极为阳极,加入抑制剂CO^2-₃、PO^3-₄、CH₃ＣＯＯ^-产生的羟基自由基的最大浓度分别为无检出、0.170 μmol/L、0.270 μmol/L,对苯酚进行电解,5 h苯酚去除率分别为99.06%、99.98%、99.79%.电沉积法制得电极对苯酚的降解效果优于热分解法制得的电极,而掺杂的电极优于无掺杂的电极,掺镧电极对苯酚降解效果最好,抑制剂CO^2-₃、PO^3-₄、CH₃ＣＯＯ^-存在时会对苯酚的降解起到阻碍作用,CO^2-₃阻碍作用最强.不同制备方法和掺杂不同添加剂制得的电极的催化性能不同,对苯酚的降解效果也不同;羟基自由基的浓度越大,苯酚的降解效果越好,抑制剂捕获了产生的羟基自由基,不利于苯酚的降解.