基于饱和沉淀Ca(DBS)2及结合MBFGA1絮凝沉降去除罗丹明b

通过提高溶液中十二烷基苯磺酸钙(Ca(DBS)2)沉淀的析出,结合微生物絮凝剂GA1(MBFGA1)对Ca(DBS)2的絮凝作用,将阳性染料罗丹明b(RB)从溶液中絮凝去除.在整个絮凝过程中,十二烷基苯磺酸钠(SDBS)增溶RB分子,然后在过量Ca^(2+)的影响下,增溶了RB分子的Ca(DBS)2悬浮物充分析出,最后被MBFGA1絮凝沉淀.为了提高RB的去除效率,采用响应面分析法(RSM)对Ca^(2+)、SDBS及MBFGA1初始浓度进行优化.实验结果表明,最优条件下(SDBS:2.67 mmol/L、Ca^(2+):5.61 mmol/L、MBFGA1:4.34 mL/L),RB和SDBS去除率达到99.80%和90.03%,其出水COD值为89.69 mg/L,低于国家工业废水排放标准,无需进行后续处理.同时,采用环境扫描电镜(ESEM)来探讨RB的絮凝去除机理以及SDBS和Ca^(2+)之间的相互作用.当Ca^(2+)初始浓度相对SDBS初始浓度过量时,增溶RB分子的SDBS胶团(SDBSRB胶团)会与Ca^(2+)反应生成被RB分子附着的Ca(DBS)2颗粒(Ca(DBS)2-RB颗粒),最后Ca(DBS)2颗粒被MBFGA1絮凝沉降;而当SDBS初始浓度相对Ca^(2+)初始浓度过量时,Ca(DBS)2颗粒会逐渐复溶并生成大量的附着Ca^(2+)的SDBS胶团.

污泥基吸附剂制备及在污水处理中应用研究进展

叙述了4种污泥吸附剂(SBA)制备的方法和SBA对水体中各种污染物的吸附研究进展,化学活化法能够制备出具有较大比表面积和孔体积的SBA,但也有造价昂贵等缺点。SBA的比表面积、孔隙结构特征和表面化学性质对水体中污染物的吸附起主要作用。SBA的解吸和再生具有回收有用资源、节约成本的优点。目前实验室级别的SBA的制备成本远低于商业活性炭,但鲜有中试级别以上的报道。认为今后的研究方向应为:在制备SBA时必须注意对人体和环境有害的物质;研究经济高效、环境友好型的活化药剂,将活化技术和吸附剂表面改性技术结合起来,制备具有特定表面性质的SBA,提高其对特定污染物的吸附能力;废弃吸附剂的管理需引起足够的重视。

电子束增材与锻造复合制造钛合金性能研究

为了解决大型钛合金结构件整体增材制造成本过高的问题,结合增材制造的快速成型和等材制造的高精度的优点,提出“锻造+增材”的复合制造方法,使用电子束增材制造技术在已有的锻件毛坯上局部成形。通过金相分析、光谱分析等测试分析技术对熔覆体内的组织和化学成分进行表征,对电子束增材复合制造TC11成形试验件的组织和性能进行分析,结果表明:熔覆金属组织为网篮组织,且α板条随熔覆高度的增加长宽比减小;界面处Al元素含量过高;试验件界面力学性能高于锻件工业标准。

基于改进磷虾群算法的水电站频率控制

针对复杂的水电站调速系统难以确立精确数学模型导致传统比例-积分-微分(PID)控制器控制精度低、自适应能力差等问题,提出了一种改进磷虾群算法对其PID控制器参数进行优化。对磷虾群算法引入进化因子α以及优化算子β以增加算法自适应调节能力。首先将频率误差以及频率误差变化率代入到改进的磷虾群算法控制器中,通过算法迭代得到一组使目标函数最小的PID参数,将这组参数赋给PID控制器对系统进行控制。仿真结果表明:经过该算法优化后的控制器相较于传统PID控制器超调量明显减小、调解时间大大缩短。

半胱氨酸改性Fe_3O_4纳米材料对Pb(Ⅱ)的吸附研究

为了解决水体中Pb(Ⅱ)污染问题,利用SiO_2和半胱氨酸(Cys)对Fe_3O_4纳米粒子进行表面修饰,并用于水中Pb(Ⅱ)的去除研究。实验结果表明,Fe_3O_4@SiO_2@Cys的吸附效果明显优于另外两种未修饰Cys的磁性纳米材料(Fe_3O_4和Fe_3O_4@SiO_2)。当Fe_3O_4@SiO_2@Cys投加量为1.0g/L,pH=6.0,Pb(Ⅱ)初始质量浓度为100mg/L,吸附时间为30min时,水中Pb(Ⅱ)去除率可达到95%以上。在Cd(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)共存条件下,Fe_3O_4@SiO_2@Cys对Pb(Ⅱ)的吸附效果明显优于其他3种金属离子。经5次循环使用后,Fe_3O_4@SiO_2@Cys对Pb(Ⅱ)的去除率仍保持在80%左右。

基于SWAT模型的浏阳河流域径流对土地利用和气候变化的协同响应

气候和土地利用同时作用于流域径流,影响着流域水资源的量和质。以浏阳河流域为例,基于SWAT模型和情景分析方法定量评估未来流域内土地利用和气候变化对径流的作用。首先采用元胞自动机-马尔科夫(CA-Markov)模型模拟浏阳河流域2020和2050年的土地利用空间格局,其次在World Clim数据库中获得未来流域内气候变化数据,最后采用SWAT模型定量评估未来不同情境下土地利用和气候变化对径流的影响。研究结果表明:未来浏阳河流域林地比例下降、城市建设用地和耕地比例增加;气候呈暖干趋势; 2020和2050年,土地利用变化时,浏阳河榔梨站模拟径流将分别减少2. 42和0. 96 m^3/s;气候变化时,榔梨站模拟径流将分别减少3. 02和1. 13 m^3;土地利用和气候变化综合影响下,榔梨站模拟径流将分别减少8. 54和4. 27 m^3/s;说明浏阳河流域径流的变化对气候响应更加敏感,土地利用和气候变化对径流的影响呈非线性协同作用。

海藻酸钠改性纳米零价铁对底泥中Cd的稳定化研究

制备了海藻酸钠改性纳米零价铁(SA-nZVI),并对其结构进行表征。用制备的SA-nZVI和未改性的纳米零价铁(nZVI)修复Cd污染的底泥,通过重金属形态、酶活性、细菌群落多样性变化评价稳定化效果。结果表明,0.10%(质量分数)海藻酸钠溶液制备的SA-nZVI对底泥中Cd的稳定效果最好,随稳定化时间的延长,残渣态质量分数升高,弱酸提取态质量分数下降,30d后相比于不添加修复剂的对照组,残渣态质量分数升高了41.79百分点,弱酸提取态质量分数下降了23.18百分点。脲酶和过氧化氢酶的活性以及细菌群落多样性均支持0.10%海藻酸钠溶液制备的SA-nZVI对Cd的稳定化效果最好。从结构上进行解释,0.10%海藻酸钠溶液制备的SA-nZVI与nZVI相比,表面覆盖了一层海藻酸钠,分散性更好,不易被氧化。

Performance of rotating drum biofilter for volatile organic compound removal at high organic loading rates

Uneven distribution of volatile organic compounds （VOCs） and biomass, and excess biomass accumulation in some biofilters hinder the application of biofiltration technology. An innovative multilayer rotating drum biofilter （RDB） was developed to correct these problems. The RDB was operated at an empty bed contact time （EBCT） of 30 s and a rotational rate of 1.0 r/min. Diethyl ether was chosen as the model VOC. Performance of the RDB was evaluated at organic loading rates of 32,1, 64.2, 128, and 256 g ether/（m^3·h） （16.06 g ether/（m^3·h） ≈ 1.0 kg chemical oxygen demand （COD）/（m^3·d））. The EBCT and organic loading rates were recorded on the basis of the medium volume. Results show that the ether removal efficiency decreased with an increased VOC loading rate. Ether removal efficiencies exceeding 99% were achieved without biomass control even at a high VOC loading rate of 128 g ether/（m^3·h）. However, when the VOC loading rate was increased to 256 g ether/（m^3·h）, the average removal efficiency dropped to 43%. Nutrient limitation possibly contributed to the drop in ether removal efficiency. High biomass accumulation rate was also observed in the medium at the two higher ether loading rates, and removal of the excess biomass in the media was necessary to maintain stable performance. This work showed that the RDB is effective in the removal of diethyl ether from waste gas streams even at high organic loading rates. The results might help establish criteria for designing and operating RDBs.

神经内镜锁孔开颅清除急性外伤性硬膜下血肿的疗效分析

目的探讨神经内镜锁孔开颅治疗急性外伤性硬膜下血肿的有效性和安全性。方法回顾性分析2016年1月至2022年1月福建省立医院南院神经外科手术治疗的40例急性外伤性硬膜下血肿患者的临床资料。其中20例采用神经内镜锁孔开颅血肿清除术(微创组),20例采用传统大骨瓣开颅手术治疗(传统组)。两组患者性别、年龄、术前硬膜下血肿量等基线资料的差异均无统计学意义(均P>0.05),具有可比性。分析比较两组患者的手术情况(包括手术时长及术中出血量等)、术后1 d格拉斯哥昏迷评分(GCS)、术后并发症及术后6个月格拉斯哥预后分级(GOS)。结果两组患者均顺利完成手术,微创组术中无一例扩大手术。与传统组比较,微创组的手术时长较短[分别为(73.8±6.7)min、(138.3±16.8)min,t=15.92]、术中出血量较少[分别为(26.7±4.7)ml、(96.5±13.1)ml,t=22.46]、术后血肿残余量较少[分别为(3.5±1.3)ml、(7.6±2.6)ml,t=6.24]、住院时长较短[分别为(10.3±2.9)d、(13.8±3.2)d,t=3.71],差异均具有统计学意义(均P<0.05)。与术前比较,微创组和传统组的术后1 d GCS均升高,差异均具有统计学意义(配对t值分别为15.70、13.65,均P<0.001)。两组比较,术后1 d GCS以及术后发生癫痫、肺部感染及颅内感染者占比的差异均无统计学意义(均P>0.05)。术后6个月,所有患者的GOS均为Ⅴ级,两组比较差异无统计学意义(P=1.000)。结论与传统大骨瓣开颅手术比较,采用神经内镜锁孔开颅手术治疗急性外伤性硬膜下血肿可缩短手术和住院时长,减少术中出血和血肿残留,而并发症发生比例和预后情况相近,是一种安全、有效、微创的方法。

赣南地区蔬菜产业基本情况调研报告

为了解赣南地区蔬菜产业现状,根据项目的需要,通过实地走访、发放问卷等形式对赣南地区的蔬菜经营主体进行调研,对赣南蔬菜产业生产规模、布局、生产经营情况、品牌建设、农业技术应用情况、经济效益等方面进行调研。结果表明:赣南蔬菜种植面积和产量呈稳步上升趋势;蔬菜产业布局合理,形成了三大供应区;蔬菜种植户的文化水平普遍不高;种植大户较少,蔬菜产业集约化程度低;现代化农业信息技术含量低、应用面积小;品牌建设相对落后,经济效益受不确定因素影响大。同时对蔬菜生产中存在的问题及应对措施进行了分析,以期对蔬菜产业的发展提供参考依据。

生物炭材料及其在水体中污染物去除领域的应用

生物炭是由生物质在无氧或者缺氧条件下热处理得到的固体碳质材料,已广泛应用于土壤改良、土壤修复、水污染处理、作物增产、碳固定等领域。生物质热解碳化后形成的生物炭具有较高含量且稳定的碳,可降低由生物质燃烧和自然降解所产生的碳排放(碳负性).

原子荧光光谱法与波长色散X射线荧光光谱法测定土壤中不同浓度砷的比对分析

用水浴消解原子荧光光谱法与X射线荧光光谱法同时分析土壤成分标准物质GBW07457(GSS-28)样品和某批实际土壤样品。土壤成分分析标准物质GBW07457(GSS-28)样品10次检测结果都在准确度要求范围内;对砷含量为6.00~100 mg/kg的214个样品进行了详细的比对分析,发现两种方法检测结果一致性比较好。经过比对分析后,得出以下建议:当样品中砷含量>60.0 mg/kg时,超出原子荧光光谱法曲线范围,高浓度样品稀释会带来误差,则优先选择X射线荧光光谱法;当样品中砷含量为6.00~60.0 mg/kg时,两种方法都可以使用,考虑到X射线荧光光谱法样品前处理便捷,可以同时测量多参数,测量效率高,推荐使用X射线荧光光谱法。

慢性硬膜下血肿患者钻孔置管引流失败后再次行神经内镜下血肿清除术的疗效分析

目的探讨慢性硬膜下血肿患者行钻孔置管引流术失败的原因以及再次行神经内镜下血肿清除术的补救优势。方法福建省立医院南院神经外科自2015年5月至2019年5月共收治慢性硬膜下血肿患者100例,首次手术均采用钻孔置管引流术治疗,其中15例患者钻孔置管引流失败后再次行神经内镜下血肿清除术,回顾性分析该15例患者的临床资料和疗效。结果首次术后1 d颅脑CT显示引流管位置错误6例,其中引流管置入脑组织2例,引流管位于血肿内膜下3例,引流管位于血肿包膜外1例;引流管位于血肿分隔腔内9例。15例患者首次手术的疗效均为无效,再次手术的疗效均为显效,术后6个月随访显示均无明显复发。2例患者因首次手术时置管伤及脑组织,遗留有一侧肢体乏力;余13例患者格拉斯哥预后量表(GOS)评分显示预后良好。结论钻孔置管引流术治疗硬膜下血肿时操作应规范,确认引流管位于血肿腔内,术中冲洗彻底;对于首次钻孔置管引流术失败患者,神经内镜下血肿清除术为一种有效的补救方案。

Potential Benefits of Biochar in Agricultural Soils:A Review

Soil degradation,characterized by declines in nutrient status and simultaneous accumulation of pesticide residues,is a major problem affecting agricultural ecosystems.Previous studies indicate that biochar application to soil has promise as a practical method to alleviate these pressures:increasing crop yield and enhancing pesticide degradation.Here,we review the roles of biochar in both chemical and biological promotion of pesticide degradation and the potential benefits of biochar relating to the efficiency of fertilizer use,availability of nutrients,and nutrient exchange.Biochar typically has a high surface area featuring many functional groups,a high cation exchange capacity,and high stability.Major factors that impact on the nutrient retention characteristics of biochar(e.g.,feedstock,pyrolysis temperature,and application rate) are also discussed herein.Nonetheless,more studies of the long-term impacts on soil properties from biochar addition are still required before it can be possible to accurately quantify the sustainability of this approach to sequester carbon and restore soil function.

Mechanism studies on nitrogen removal when treating ammonium-rich leachate by sequencing batch biofilm reactor

The nitrogen removal mechanism was studied and analyzed when treating the ammonium-rich landfill leachate by a set of sequencing batch biofilm reactors(SBBRs),which was designed independently.At the liquid temperature of(32P0.4)°C,and after a 58-days domestica-tion period and a 33-days stabilization period,the efficiency of ammonium removal in the SBBR went up to 95%.Highly frequent intermittent aeration suppressed the activity of nitratebacteria,and also eliminated the influence on the activity of anaerobic ammonium oxidation(ANAMMOX)bacteria and nitritebacteria.This influence was caused by the accumulation of nitrous acid and the undulation of pH.During the aeration stage,the concentration of dissolved oxygen was controlled at 1.2-1.4 mg/L.The nitritebacteria became dominant and nitrite accumulated gradually.During the anoxic stage,along with the concentration debasement of the dissolved oxygen,ANAMMOX bacteria became domi-nant;then,the nitrite that was accumulated in the aeration stage was wiped off with ammonium simultaneously.

Effect and mechanism of carbon sources on phosphorus uptake by microorganisms in sequencing batch reactors with the single-stage oxic process

To investigate the chief reason for phosphorus uptake by microorganisms affected by substrates in sequencing batch reactors with the single-stage oxic process,two typical substrates,glucose (R1) and acetate (R2) were used as the sole carbon source,and the performances of phosphorus removal and the changes of intracellular storage were compared. The experimental results showed that the phenomenon of excess phosphorus uptake was observed in two reactors,but bacteria's capability to take in phosphorus and its intracellular storage were obviously different under the same operational condition. After steady-state operation,total phosphorus (TP) removed per MLVSS in R1 and R2 was 6.7―7.4 and 2.7―3.2 mg/g,respectively. The energy storage of poly-β-hydroxyalkanoates (PHA) was nearly constant in R1 during the whole period,and another aerobic storage of glycogen was accumulated (the max accumulation of glycogen was 3.21 mmol-C/g) when external substrate was consumed,and then was decreased to the initial level. However in R2,PHA and glycogen were both accumulated (2.1 and 0.55 mmol-C/g,respectively) when external substrate was consumed,but they showed different changes after the period of external consumption. Compared to rapid decrease of PHA to the initial level,glycogen continued accumulating to the peak (0.88 mmol-C/g) in 2 h of aeration before decreasing. During the aeration,the accumulations/transformations of internal carbon sources in R1 were higher than those in R2. In addition,obvious TP releases were both observed in R1 and R2 other than PHA and glycogen during the long-term idle period; moreover,the release content of phosphorus in R1 was also higher than that in R2. The researches indicated that different aerobic metabolism of substrate occurred in R1 and R2 due to the different carbon sources in influent,resulting in different types and contents of aerobic storage accumulated/translated in bacteria of R1 and R2. As a result,ATP content provided for phosphorus uptake was different in R1 and R2,and the capability to take up phosphorus was also different from each other.

Short-term prediction of the influent quantity time series of wastewater treatment plant based on a chaos neural network model

By predicting influent quantity,a wastewater treatment plant(WWTP)can be well controlled.The non-linear dynamic characteristic of WWTP influent quantity time series was analyzed,with the assumption that the series was predictable.Based on this,a short-term forecasting chaos neural network model of WWTP influent quantity was built by phase space reconstruction.Reasonable forecasting results were achieved using this method.

Method of determining grid sizes of finite element method of water quality models for geometrically complex river course

The method of determining grid sizes of finite element method of water quality models is presented on the basis of characteristics of pollutant distributed in the just downstream grid of discharge. A given length of the grid is applied to calculate the minimum distance for the pollutant to complete mixing in the lateral direction in the just downstream grid of the discharge, and the minimum distance is regarded as the maximum width of the grid. Application of the maximum width of the grid and flow rate per unit width of the river results in the number of flow zones in the lateral direction of the river. Consequently division of grids and numerical calculation of water quality with finite element method can be carried out on the basis of available method and topographic map of the river course. Analysis of sensitivity shows that the effect of the width of the river and the effect of the length of the grids on the minimum number of flow zones in the lateral direction is relatively small, and that the effect of the given lateral mixing degree of the pollutants on the minimum number of flow zones is acceptable, which indicates that the method presented is relatively stable. The method can avoid the blindness and randomness in determining the number of flow zones, and can decrease the amount of computation under the condition that the accuracy requirement is met. The problem that determining the sizes of the grids must rely on empirical knowledge has been solved.

Cherry Blossom Yet to Bloom——Notes on 2013 Chinese University Student Delegation’s Visit to Japan

Words such as soft, gentle and elegant are used to describe Japanese cherry blossoms. When tens of thousands of flowers are in full bloom and their pedals shower down, it not only shows the flourishing of Spring but also the vanishing of a momentary beauty. China and Japan have experienced ups and downs in their relationship since the two countries

Old friend from Japan visits China amid fragrance of acacia flower

He is a rigorous,pragmatic,wiseand rational Japanese senior.He is both a veteran politician in Japan and'an old friend of Chinese people',as Chinese President Xi Jinping called him,who has been committed to China-Japan friendly exchanges and cooperation for years.He is Toshihiro Nikai,the current secretary-general of the Liberal Democratic Party of Japan.