Nitrogen removal for low-carbon wastewater in reversed A^2/O process by regulation technology

Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of similar WWTP. When the proposed measures,such as using 0.1% (volume fraction of wastewater) landfill leachate,shortening HRT by 2/3 in the primary sedimentation tank and controlling DO at 0.5 mg/L in the 3rd section of aerobic zone,are applied,15% of the carbon source can be complemented,the favorable property of activated sludge is achieved,and the nitrogen removal effect is significantly improved. The effluent NH3-N is 2 mg/L and the removal rate is 90%. The effluent TN is 17 mg/L and the removal rate is 54%. The up-to-standard discharge of the effluent is achieved. And after the optimization,the unit electricity consumption also reaches 0.21 kW/h and saves 20%.

Research on Technological Process Control Model of Reverse Logistics in Manufacturing System

This paper has found out some important input factors of reverse logistics in manufacturing system throuth analysis and summary,and established four kinds of technological process control models of reverse logistics in manufacturing system according to different processing methods. These models embed each other that form a cubic control system of reverse logistics.

Geometrical Reconstruction and CNC Process of Spurious Tympanic Membrane Based on Reverse Engineering

Perforation of tympanic membrane is one of the main reasons for both deafness and dyssaudia.We could improve and restore audition by restoring or replacing the tympanic membrane.So,whether you can make the spurious tympanic membrane successfully is one of the keys to a successful operation.Utilizing CMM (Coordinate Measuring Machine) measurement equipment, we measured tympanic membrane model precisely and digitally.We also analysed the measured data by point to surface and we have successfully reconstructed the CAD model of the spurious tympanic membrane.Using the model we have got,we schemed out the mold of spurious tympanic membrane.In addition,we utilized MasterCAM compiling CNC (Computerized Numerical Con- trol) code and simulating the course of working.Ultimately,we obtained the mold of spurious tympanic membrane.Our research in this article has great significance to the success of spurious tympanic membrane grafting operation.

Reversible Zn/polymer heterogeneous anode

Commercialization of Zn-metal anodes with low cost and high theoretical capacity is hindered by the poor reversibility caused by dendrites growth,side reactions,and the slow Zn^(2+)-transport and reaction kinetics.Herein,a reversible heterogeneous electrode of Zn-nanocrystallites/polyvinylphosphonic acrylamide(Zn/PPAm)with fast electrochemical kinetics is designed for the first time:phosphonic acid groups with strong polarity and chelation effect ensure structural reversibility and stability of the threedimensional Zn-storage-host PPAm network and the Zn/PPAm hybrid;hydrophobic carbon chains suppress side reactions such as hydrogen evolution and corrosion;weak electron-donating amide groups constitute Zn^(2+)-transport channels and promote“desolvation”and“solvation”effects of Zn^(2+)by dragging the PPAm network on the Zn-metal surface to compress/stretch during Zn plating/stripping,respectively;and the heterostructure and Zn nanocrystallites suppress dendrite growth and enhance electrochemical reactivity,respectively.Thus,the Zn/PPAm electrode shows cycle reversibility of over 6000 h with a hysteresis voltage as low as 31 mV in symmetrical cells and excellent durability and flexibility in fiber-shaped batteries.

Enhanced nitrogen removal at low temperature with mixed anoxic/oxic process

Different hydraulic retention times(HRTs)were tested in a mixed anoxic/oxic(A/O)system at 5C and 10C to investigate the effects of HRT and carrier on nitrogen removal in wastewater at low temperatures.The results showed that the addition of the fillers improved the treatment effect of each index in the system.With an optimal HRT of 7.5 h at 5C,the removal efficiencies of NHþ4-N and total nitrogen(TN)reached 91.2%and 75.6%,respectively.With an HRT of 6 h at 10C,the removal efficiencies of NHþ4-N and TN were 96.7%and 82.9%,respectively.The results of high-throughput sequencing showed that the addition of the suspended carriers in the aerobic zone could improve the treatment efficiency of nitrogen at low temperatures.The microbial analysis indicated that the addition of the suspended carriers enhanced the enrichment of nitrogen removal bacteria.Nitrospira,Nitrotoga,and Nitrosomonas were found to be the bacteria responsible for nitrification,and their relative concentrations on the biofilm at 5C and 10C accounted for 98.11%,92.79%,and 69.98%of all biological samples,respectively.

Investigation of magnetization reversal process in pinned CoFeB thin film by in-situ Lorentz TEM

Exchange bias effect has been widely employed for various magnetic devices.The experimentally reported magnitude of exchange bias field is often smaller than that predicted theoretically,which is considered to be due to the partly pinned spins of ferromagnetic layer by antiferromagnetic layer.However,mapping the distribution of pinned spins is challenging.In this work,we directly image the reverse domain nucleation and domain wall movement process in the exchange biased Co Fe B/Ir Mn bilayers by Lorentz transmission electron microscopy.From the in-situ experiments,we obtain the distribution mapping of the pinning strength,showing that only 1/6 of the ferromagnetic layer at the interface is strongly pinned by the antiferromagnetic layer.Our results prove the existence of an inhomogeneous pinning effect in exchange bias systems.

A/A/O与CASS污水处理工艺碳排放评价与碳减排对策

污水处理行业的碳排放定量评估及碳减排潜力挖掘是实现“双碳目标”的迫切需求.文章采用A/A/O工艺(A厂)和CASS工艺(B厂)两种典型工艺的污水处理厂为研究对象,核算框架以《污水处理厂低碳性能评估技术规范》(CAEPI 49—2022)为主要依据,研究结果表明,A厂总碳排放强度(0.43 kgCO_(2)·m^(-3))比B厂(0.30 kgCO_(2)·m^(-3))高0.13 kg CO_(2)·m^(-3);两厂的间接碳排放均为主要贡献,分别占总碳排放强度的55.4%(A厂)、79.2%(B厂),其中,电耗贡献(A厂34.0%、B厂48.6%)均为间接碳排放的最大占比.相较CASS工艺,A/A/O工艺对COD的去除率高11.3%,对TN的去除率低6.8%,但A/A/O工艺总碳排放强度中CH_(4)占比较CASS工艺多29.5%,药耗方面则低6.8%.降低电耗、药耗等间接碳排放是污水处理行业碳减排主要措施.

Magnetization Reversal Process of Single Crystal a-Fe Containing a Nonmagnetic Particle

The magnetization reversal process and hysteresis loops in a single crystal α-iron with nonmagnetic particles are simulated in this work based on the Landau-Lifshitz-Gilbert equation. The evolutions of the magnetic domain morphology are studied, and our analyses show that the magnetization reversal process is affected by the interaction between the moving domain wall and the existing nonmagnetic particles. This interaction strongly depends on the size of the particles, and it is found that particles with a particular size contribute the most to magnetic hardening.

Symmetry Violation of Time Reversal in Third Order Vertex Angle Renormalization Process of Electromagnetic Interaction

According to the current understanding, electromagnetic interaction is invariable under time reversal. However, the proof of time reversal symmetry in quantum theory of field has not considered the effects of high order perturbation normalizations. It is proved in the paper that when the renormalization effect of third order vertex angles process is taken into account, the symmetry of time reversal will be violated in electromagnetic interaction process. Because the magnitude order of symmetry violation is about 10–5, but the precision of current experiments on time reversal in particle physics is about 10–3, this kind of symmetry violation can not be found. The result reveals the micro-origin of asymmetry of time reversal and can be used to solve the famous irreversibility paradox in the evolution processes of macro- material systems.

基于A^(2)/O工艺污水厂改造与提标工程设计

南方某污水厂提标扩建工程,一期A^(2)/O好氧区采用MBBR工艺改造并增大缺氧区容积;二期提标采用高效沉淀池+纤维转盘滤池+紫外消毒工艺,强化脱氮除磷及SS去除,并对全厂进行除臭设计。提标扩建后总规模12×10^(4)m^(3)/d,直接运行成本约0.63元/m^(3),出水均值为COD 17.10 mg/L、BOD55.40 mg/L、SS 5.80 mg/L、NH_(4)^(+)-N 0.90 mg/L、TN 5.90 mg/L、TP 0.30 mg/L。均优于《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准,其经验可供其他污水厂借鉴。

A^(2)O工艺活性污泥黏性膨胀原因及控制措施

污泥黏性膨胀问题一直是A^(2)O工艺运行控制的难点。郑州市某污水处理厂在运行过程中出现污泥黏性膨胀问题,造成污泥沉降性能变差,SVI逐渐提升至240 mL/g左右,二沉池泥位持续升高。从进水水质、水温、曝气量、浮渣等多方面综合分析引起污泥膨胀的原因,及时从剩余污泥排放量、污泥龄、溶解氧、回流比、水力停留时间等工艺参数调整运行工艺,使污泥膨胀问题得到一定程度的缓解。为彻底消除生物池浮泥,又通过在二沉池配水井精准投加40 mg/L的阳离子高分子絮凝剂,经过一段时间的药剂助沉,明显提高了污泥沉降性能,SVI也逐渐下降至120 mL/g左右的正常水平,解决了污泥黏性膨胀问题,消除了生物池浮泥,为解决污泥黏性膨胀提供了思路。

Polymerization of o-Phenylenediamine Catalyzed byHemeproteins Encapsulated in Reversed Micelle

Hemeproteins encapsulated in reversed micelle formulated with di-2-ethylhexyl sulfosuccinate(AOT) was found to catalyze the polymerization of o-phenylenediamine(o-PDA) with hydrogen peroxide, whereas o-PDA catalyzed by hemeproteins dissolved in water could only form its trimers. As the nanostructural environment in reversed micelle acts as a certain orientation surrounding medium, it offers a strong electrostatic field that alters the reductive potential of Fe 3+/Fe 2+(E m7) in the heme of hemeproteins and thus increases the catalytic activity of peroxidase accordingly. According to the results of UV-Vis, 1H NMR and FTIR, the polymer catalyzed by hemoglobin(Hb) in reversed micelle was presumed to be constructed of lines and trapeziforms alternatively.

Mechanisms and Processes Leading to Reverse Zoning in the Andong Granitoid Pluton, Andong Batholith, Korea

The Andong pluton consists of comagmatic granitoid rocks which constitute outstanding examples of reversely zoned granitoids. The pluton has three lithofacies: hornblende biotite tonalite, biotite granodiorite and porphyritic biotite granite. The zoned pattern forms by locating a tonalite core containing high-temperature mafic assemblages in central part,granodiorite rims in marginal part, and a porphyritic granite cap containing more felsic assemblages in topside of the pluton.Mineral abundances as well as bulk compositions of the granitoids indicate that the interior is enriched in mafic minerals and that it shows higher contents of oxides than the margin and topside. The compositional gradients change gradually with continuity between the lithofacies. The regular compositional variations within the pluton support the argument that the pluton behaved as an individual petrochemical system. Model abundances of the granitoids are in agreement with the bulk compositional gradients, suggesting that no significant interaction with country rocks occurred. Remobilization (resurgence) of deeper parts of the system into the more felsic magmas of the chamber explains the reverse zoning. Fractional crystallization was of importance and probably accounts for the selective removal of the settling phases. The Andong pluton is an example of reversely zoned plutons related by remobilization of more mafic but consanguineous magmas. Large-scale upwelling occurred in the pluton leading to the present arrangement of three lithofacies. It is conceivable that remnants of the reverse zoning become more difficult to discern as the plutonic rocks reach the latest stages of their evolution. In this case, the Andong pluton represents an earlier stage in the evolution of a felsic system that is usually represented by the final stages in normally zoned plutons.

A^(2)O-SBR工艺在城镇污水处理厂中的应用

A^(2)O-SBR工艺为A2O工艺与SBR工艺串联组合,为了探究A^(2)O-SBR工艺在城镇污水处理厂的应用效果,分析广西壮族自治区东兴市城东污水处理厂2021年运行情况,结果表明:厂区出水稳定达标排放,A^(2)O-SBR工艺脱氮除磷效果好;COD、NH_(4)^(+)-N、TP平均去除率为87.05%、97.23%、80.86%,最高去除率为97.55%、98.36%、91.21%;出水浓度相对稳定,A^(2)O-SBR工艺对上述三种污染物的去除率也相对稳定,对NH_(4)^(+)-N效果最好,全年去除率稳定达到95%以上;该污水处理厂平均处理成本0.53元/m^(3)。

A^(2)O和MBR组合工艺在寒冷地区污水处理中的应用分析

为进一步探究寒冷地区污水处理效果的提升路径,以一污水处理厂冬季出水水质不达标为研究对象,确定采用A^(2)O (Anaerobic-Anoxic-Oxic,厌氧-缺氧-好氧)工艺与MBR (Membrane Bio-Reactor,膜生物反应器)工艺相结合的方式进行污水处理,在设计整体方案的基础上,对具体的工艺流程及参数等内容进行全面优化设计,以完成工艺设计。从实际运行效果来看,设计的A^(2)O和MBR组合工艺在寒冷地区污水处理中取得相对较优的效果,证明其具有一定的实际应用价值。

H_(2)O分子在五边形BCN上的吸附与解离特性研究

基于密度泛函理论的第一性原理计算方法,研究了H_(2)O分子在五边形BCN上的吸附与解离过程.研究结果表明,五边形BCN结构的B原子是H_(2)O分子的最稳定的活性吸附位点.H_(2)O分子在该活性位点极易解离,其初步解离过程为放热反应且分解势垒仅为0.191 eV,并形成稳定的OH/H产物.深入研究发现,H_(2)O分子初步解离后的五边形BCN表面,可直接分解后续吸附的H_(2)O分子.该研究结果为五边形BCN对H_(2)O分子的吸附解离机制提供理论借鉴.

多级A/O工艺设计及其在应急污水处理工程中的应用

为有效缓解资阳市第二污水处理厂现状处理能力不足导致的污水溢流问题,改善周边水生态环境,新建了规模为5000 m 3/d的应急污水处理工程。该工程采用“多级A/O+磁混凝沉淀”组合工艺,对其中的多级A/O工艺段进行了深化设计,并对本项目的实际运行效果进行了分析。深化设计结果表明,多级A/O反应器级数宜采用2级,流量分配比宜为7∶3,污泥回流比宜为100%。运行期间的监测数据表明,出水指标均满足《四川省岷江、沱江流域水污染物排放标准》(DB51/2311-2016),其中的COD Cr、TP和TN的去除率分别为96.6%、97.6%和87.2%。通过设置初段硝化液回流,充分发挥初级缺氧池的脱氮能力,使多级A/O工艺的脱氮效率得到了强化。该项目采用的组合工艺简单有效,出水效果好,为城市溢流污水的高标准排放提供了一种更优选择。

寒冷地区污水处理厂A^(2)O工艺改良调试与运行效果

为进一步提升寒冷地区A^(2)O污水处理工艺的运行效果,以位于寒冷地区的A污水处理厂为研究案例,研究1种具有多点进水、混合液多点回流特性,且适用于寒冷地区污水处理厂的改良型A^(2)O工艺,并从多个角度着手,确定该工艺的设计要点和运行技术参数等内容。从实际应用效果来看,该改良型A^(2)O工艺在寒冷条件下仍可取得较优的处理效果,可为后续相关工作提供参考。

基于混凝-Fenton-A/O联合工艺的环氧树脂生产废水处理研究

某工业园区的废水原始排放已满足排放标准,但需要满足更严格的纳管要求。为了进一步提高生产废水处理效能,研究采用了混凝-Fenton-A/O联合工艺进行小规模试验。通过对混凝-Fenton-A/O联合工艺处理环氧树脂生产废水指标进行连续检测,出水COD、氨氮、BOD_(5)去除率分别为92.9%、75%、87.7%,出水指标均满足工业废水纳管标准。