Characteristics of penicillin bacterial residue

IMPLICATIONS: During the production of penicillin, a mass of waste bacterial residue is generated. In the past, the bacterial residues have been used for food additives. Unfortunately, doubts of their suitability as a feedstock have been raised because of the small amount of antibiotics and the degradation products remaining in the bacterial residues. So, penicillin bacterial residue is one of the hazardous wastes. Therefore, penicillin bacterial residue should be managed in accordance with the hazardous waste. To get a right method, the penicillin bacterial residue was characterized.     

自燃煤矸石山覆盖材料压缩及压实特性实验

自燃煤矸石山表面构建覆盖层,需要具备一定的低渗透性能以有效阻隔空气,防止煤矸石山内部发生自燃。本研究通过室内实验,测定煤矸石山构建覆盖层涉及的碾压材料包括黄土、粉煤灰及掺有粉煤灰的混合土样的界限含水率、一维压缩特性及压实特性,揭示和分析7种覆盖材料配方的压缩压实特性,表明覆盖材料通过碾压可有效阻隔空气,起到阻燃作用;将粉煤灰掺人到一般黄土材料中,可减缓混合土样击实曲线的陡峭性,从而降低材料在碾压中对含水率的敏感度。实验旨在为进行煤矸石山覆盖层碾压提供科学的实验数据及设计参数。     

Consultant Guide/1986

ABSTRACT

To obtain annual odor emission profiles from intensive swine operations, odor concentrations and emission rates were measured monthly from swine nursery, farrowing, and gestation rooms for a year. Large annual variations in odor concentrations and emissions were found in all the rooms and the impact of the seasonal factor (month) was significant (P < 0.05). Odor concentration was low in summer when ventilation rate was high but high in winter when ventilation rate was low, ranging from 362 (farrowing room in July) to 8934 (nursery room in December) olfactory unit (OU) m^?3. This indicates that the air quality regarding odor was significantly better in summer than that in winter. Odor emission rate did not show obvious seasonal pattern as odor concentration did, ranging from 2 (gestation room in November) to 90 (nursery room in April) OU m^?2 sec^?1; this explains why the odor complaints for swine barns have occurred all year round. The annual geometric mean odor concentration and emission rate of the nursery room was significantly higher than the other rooms (P < 0.05). In order to obtain the representative annual emission rate, measurements have to be taken at least monthly, and then the geometric mean of the monthly values will represent the annual emission rate. Incorporating odor control technologies in the nursery area will be the most efficient in reducing odor emission from the farm considering its emission rate was 2 to 3 times of the other areas. The swine grower-finisher area was the major odor source contributing 53% of odor emission of the farm and should also be targeted for odor control. Relatively positive correlations between odor concentration and both H₂S and CO₂ concentrations (R ² = 0.58) means that high level of these two gases might likely indicate high odor concentration in swine barns.

IMPLICATIONS The emissions of air pollutants including odors, greenhouse gases, and toxic gases have become a major environmental issue facing animal farms in the U.S.A. and Canada. To ensure the air quality in the vicinity of intensive livestock farms, air dispersion models have been used to determine setback distances between livestock facilities and neighboring residences based on certain air quality requirement on odor and gases. Due to the limited odor emission data available, none of the existing models can take account of seasonal variations of odor emissions, which may result in great uncertainties in setback distance calculations. Therefore, the obtained seasonal odor and gas emission rates by this study can be used by the government regulatory organizations and researchers in air dispersion modeling to get improved calculation of setback distances.     

Characteristics of penicillin bacterial residue

A hybrid selective noncatalytic reduction/selective catalytic reduction (SNCR/SCR) system that uses two types of technology, low-temperature SCR process and SNCR process, was designed to develop nitrogen oxide (NO_x) reduction technology. SCR was conducted with space velocity (SV) = 2400 hr^?1 and hybrid SNCR/SCR with SV = 6000 hr^?1, since the study focused on reducing the amount of catalyst and both achieved 98% NO_x reduction efficiency. Characteristics of NO_x reduction by NH₃ were studied for low-temperature SCR system at 150 °C using Mn-V₂O₅/TiO₂ catalyst. Mn-added V₂O₅/TiO₂ catalyst was produced, and selective catalyst reduction of NO_x by NH₃ was experimented. NO_x reduction rate according to added Mn content in Mn-V₂O₅/TiO₂ catalyst was studied with varying conditions of reaction temperature, normalized stoichiometric ratio (NSR), SV, and O₂ concentration. In the catalyst experiment according to V₂O₅ concentration, 1 wt.% V₂O₅ catalyst showed the highest NO_x reduction rate: 98% reduction at temperature window of 200~250 °C. As a promoter of the V₂O₅ catalyst, 5 wt.% Mn was added, and the catalyst showed 47~90% higher efficiency even with low temperatures, 100~200 °C. Mn-V₂O₅/TiO₂ catalyst, prepared by adding 5 wt.% Mn in V₂O₅/TiO₂ catalyst, showed increments of catalyst activation at 150 °C as well as NO_x reduction. Mn-V₂O₅/TiO₂ catalyst showed 8% higher rate for NO_x reduction compared with V₂O₅/TiO₂ catalyst in 150 °C SCR. Thus, (5 wt.%)Mn-(1 wt.%)V₂O₅/TiO₂ catalyst was applied in SCR of hybrid SNCR/SCR system of low temperature at 150 °C. Low-temperature SCR hybrid SNCR/SCR (150 °C) system and hybrid SNCR/SCR (350 °C) showed 91~95% total reduction rate with conditions of SV = 2400~6000 hr^?1 SCR and 850~1050 °C SNCR, NSR = 1.5~2.0, and 5% O₂. Hybrid SNCR/SCR (150 °C) system proved to be more effective than the hybrid SNCR/SCR (350 °C) system at low temperature.

Implications:?NO_x control is very important, since they are the part of greenhouse gases as well as the cause of acid rain and ozone hole. A technology, so-called hybrid SNCR/SCR process, was tested using Mn-V₂O₅/TiO₂ monolithic catalyst for NO_x reduction, and the method is promising. The results of this study would provide some ideas to parties such as policy makers, environmental engineers, and so on.     

Boron sorption from aqueous solution by hydrotalcite and its preliminary application in geothermal water deboronation

Hydrotalcite and its calcination product were used to treat pure water spiked with various concentrations of boron and geothermal water containing boron as a major undesirable element. The kinetics process of boron sorption by uncalcined hydrotalcite is controlled by the diffusion of boron from bulk solution to sorbent-solution boundary film and its exchange with interlayer chloride of hydrotalcite, whereas the removal rate of boron by calcined hydrotalcite rests with the restoration process of its layered structure. The results of isotherm sorption experiments reveal that calcined hydrotalcite generally has much stronger ability to lower solution boron concentration than uncalcined hydrotalcite. The combination of adsorption of boron on the residue of MgO–Al₂O₃ solid solution and intercalation of boron into the reconstructed hydrotalcite structure due to “structural memory effect” is the basic mechanism based on which the greater boron removal by calcined hydrotalcite was achieved. As 15 geothermal water samples were used to test the deboronation ability of calcined hydrotalcite at 65 °C, much lower boron removal efficiencies were observed. The competitive sorption of the other anions in geothermal water, such as HCO₃ ^?, SO₄ ^2?, and F^?, is the reason why calcined hydrotalcite could not remove boron from geothermal water as effectively as from pure boron solution. However, boron removal percents ranging from 89.3 to 99.0 % could be obtained if 50 times of sorbent were added to the geothermal water samples. Calcined hydrotalcite is a good candidate for deboronation of geothermal water.     

CTMAB／SDS改性沸石对水中痕量邻苯二甲酸酯吸附机制

以季铵盐阳离子表面活性剂CTMAB及阴离子表面活性剂SDS对粉末状天然沸石进行复合改性,制备得到了CTMAB／SDS改性沸石。对改性沸石及天然沸石进行红外吸收光谱及XRD衍射表征,并研究了PAEs在天然沸石和CT-MAB／SDS改性沸石上的吸附机制。结果表明,阴阳离子表面活性剂没有对层状结构的键型造成较大的影响;PAEs在天然沸石和CTMAB／SDS改性沸石上的吸附更符合表面吸附一分配作用复合模型;PAEs的表面吸附和分配作用对吸附作用的贡献主要受吸附剂中有机质含量及吸附物质大小、极性及溶解度的影响。     

双氯芬酸的吸附去除过程与机制

研究了非甾体抗炎药双氯芬酸的吸附去除过程与机制。对吸附处理效果较好的活性炭与纳米羟基氧化铁（α-FeOOH）进行了比表面积、Zeta电位等表面特性的表征,研究比较了双氯芬酸在活性炭与α—FeOOH2种材料上的吸附去除效果与吸附机制。结果表明,在相同的实验条件下,活性炭与α-FeOOH对双氯芬酸吸附去除率可分别达到97．9％和84．3％;双氯芬酸在活性炭上的吸附主要是由于活性炭较大的比表面积与疏水分配作用,在α-FeOOH上的吸附主要是由于静电引力作用;活性炭与α-FeOOH对双氯芬酸的吸附去除效果均随pH的升高而降低;在pH=6时,活性炭与α-FeOOH对双氯芬酸钠的吸附等温线均符合Langmuir方程,单位饱和吸附量分别为109．98mg／g和58．96mg／g;活性炭对双氯芬酸具有更强的吸附能力。     

Tracer-based source apportionment of polycyclic aromatic hydrocarbons in PM2.5 in Guangzhou, southern China, using positive matrix factorization (PMF)

From 28 November to 23 December 2009, 24-h?PM_2.5 samples were collected simultaneously at six sites in Guangzhou. Concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) together with certain molecular tracers for vehicular emissions (i.e., hopanes and elemental carbon), coal combustion (i.e., picene), and biomass burning (i.e., levoglucosan) were determined. Positive matrix factorization (PMF) receptor model combined with tracer data was applied to explore the source contributions to PAHs. Three sources were identified by both inspecting the dominant tracer(s) in each factor and comparing source profiles derived from PMF with determined profiles in Guangzhou or in the Pearl River Delta region. The three sources identified were vehicular emissions (VE), biomass burning (BB), and coal combustion (CC), accounting for 11?±?2 %, 31?±?4 %, and 58?±?4 % of the total PAHs, respectively. CC replaced VE to become the most important source of PAHs in Guangzhou, reflecting the effective control of VE in recent years. The three sources had different contributions to PAHs with different ring sizes, with higher BB contributions (75?±?3 %) to four-ring PAHs such as pyrene and higher CC contributions (57?±?4 %) to six-ring PAHs such as benzo[ghi]perylene. Temporal variations of VE and CC contributions were probably caused by the change of weather conditions, while temporal variations of BB contributions were additionally influenced by the fluctuation of BB emissions. Source contributions also showed some spatial variations, probably due to the source emission variations near the sampling sites.     

天然锰砂去除水中的砷

天然锰砂是一种廉价、高效的水处理用材料,但尚未用于水中砷的去除。实验研究了反应时间、砷形态、初始砷浓度、温度、溶液初始pH对吸附过程的影响。结果表明,天然锰砂对As(Ⅲ)的吸附能力大于As(Ⅴ)。25℃时,固液比为10 g/L的条件下,天然锰砂对初始浓度为5.0 mg/L的砷溶液吸附过程经72 h基本达到平衡,平衡时对As(Ⅲ)和As(Ⅴ)的去除率分别达到94.5%和85.9%。吸附过程符合Lagergren准一级反应动力学模型和假二级反应动力学模型。相比之下,假二级动力学模型拟合程度更高。对As(Ⅲ)和As(Ⅴ),45℃时的吸附量均大于25℃时。不同温度下,天然锰砂对As(Ⅲ)和As(Ⅴ)的吸附过程更符合Freundlich等温吸附模型。在溶液初始pH为3～10范围内,锰砂对砷的吸附能力受pH的影响较小。实验结果表明,天然锰砂是一种具有实际应用潜力的除砷材料。     

低温喹啉降解菌的筛选及降解性能

从吉林石化污水处理厂的活性污泥中驯化、筛选获得一株降解效率高且生长速率快高效耐冷菌,命名为WS-5.该菌能以喹啉作为惟一的碳源、氮源及能源.结合菌体的形态观察、生理生化特性实验及16S rDNA序列同源性对比分析,鉴定菌株WS-5为恶臭假单胞菌(Pseudomonas putida).不同降解条件下的实验结果表明,菌株WS-5的最佳降解条件是投菌量为15％,pH值范围在8～10,摇床转速为100 r/min.最佳降解环境下对200 mg/L的喹啉在132 h降解率达到了85.3％.菌株WS-5对初始喹啉浓度为50、100、200和300 mg/L的初始喹啉浓度分别在36、72、192和262 h内完全降解.这将为今后在低温条件下处理含喹啉废水提供技术指导.