Study Progress Analysis of Effluent Quality Prediction in Activated Sludge Process Based on CiteSpace

In this paper, CiteSpace, a bibliometrics software, was adopted to collect research papers published on the Web of Science, which are relevant to biological model and effluent quality prediction in activated sludge process in the wastewater treatment. By the way of trend map, keyword knowledge map, and co-cited knowledge map, specific visualization analysis and identification of the authors, institutions and regions were concluded. Furthermore, the topics and hotspots of water quality prediction in activated sludge process through the literature-co-citation-based cluster analysis and literature citation burst analysis were also determined, which not only reflected the historical evolution progress to a certain extent, but also provided the direction and insight of the knowledge structure of water quality prediction and activated sludge process for future research.

Effects of Effluent from a Dumpsite on the Physicochemical Properties of River Achichum in Bamendakwe, Northwest Cameroon

This study was aimed to assess the effects of effluent from a dumpsite on the physicochemical properties of river Achichum in Bamendakwe in the Bamenda I municipality, Northwest Region of Cameroon. The quality of water used for domestic purposes by the population of this area is mostly appreciated through its organoleptic assessment while no attention is paid to the physicochemical and microbiological properties. Samples (upstream, effluent, and downstream) were collected in the months of September 2022 and February 2023 and examined for organoleptic, physicochemical and bacteriological characteristics using standard methods. The river was contaminated to different extents by nitrates (28.56 - 149.91 mg/L), sulphates (246.89 - 725.42 mg/L) and heavy metals (0.01 - 0.04 mg/L for lead and 0.98 - 2.15 mg/L for aluminum). This contamination could be due to an inflow of the untreated effluent into the river. The river contained a high pollution level of lead and aluminum. Bacteriological investigations revealed that all the analyzed samples from the river contained indicators of faecal pollution such as Enterobacteria spp., E. coli, Streptococcus spp., Salmonella spp., Shigella spp., Staphylococcus spp. and Vibrio spp. Consequently, its utilization exposes consumers to health risks. Thus, water from the river should be treated prior to consumption.

Analysis of Effluent Outfall Problems and Their Classification and Regulation Countermeasures

Effluent outfalls are an important exit for pollutants discharged from the source flowing into environmental water bodies,as well as an important guarantee for the ecological environment of natural water bodies.In response to main problems of large and diverse effluent outfalls,as well as their monitoring analysis,tracing and regulation in China,classification and regulation countermeasures were proposed based on the characteristics of effluent outfalls.It is suggested that a comprehensive management and control system should be built by improving the management and control system,upgrading monitoring techniques and strengthening social supervision and public education,so as to provide a scientific basis for the supervision and management of effluent outfalls in China and help promote the improvement of water quality and the sustainable development and utilization of water resources.

A Reduced Mechanism for Flame Inhibition by Phosphorus-containing Compounds Based on Level of Importance Analysis

A reduced mechanism for propane/air combustion and its flame inhibition by phosphorus-containing compounds (PCCs) is constructed with the level of importance (LOI) method. The analysis is performed on solutions of freely propagating premixed flames with detailed chemical kinetics involving 121 species and 682 reactions proposed by Jayaweera et al. For the non-homogeneous reaction-diffusion system, the chemical lifetime of each species is weighted by its diffusion timescale, and the characteristic flame timescale is used to normalize the chemical lifetime. The definition of sensitivity in LOI is extended so that multi-parameters can be used as sensitivity targets. Propane, oxygen, dimethyl methylphosphonate (DMMP), and flame speed are selected to be perturbed for sensitivity analysis, the species with low LOI index are removed, and reactions involving the redundant species are excluded from the mechanism. A skeletal mechanism is obtained, which consists of 57 species and 268 elementary reactions. Calculations for laminar flame speeds, key flame radicals and catalytic cycles using the skeletal mechanism are in good agreement with those by using the detailed mechanism over a wide range of equivalence ratio undoped and doped with DMMP.

^(31)P NMR Study on Some Phosphorus-Containing Compounds

31P NMR has become a widely applied spectroscopic probe of the structure of phosphorus-containing compounds. Meanwhile, the application of 31P NMR has been rapidly expanded to biochemistry and medicinal chemistry of phosphorus-containing compounds because the growing importance of the phosphorus compounds is now widely realized. We report here the results of 31P NMR study on some phosphorus-containing compounds, namely, O-alkyl O-4-nitrophenyl methyl phosphonates with different alkyl chain-length (MePO-n), 4-nitrophenyl alkylphenylphosphinates with different alkyl chain-length (PhP-n), diethyl phosphono- acetonitrile anion and diethyl phosphite anion . Our results indicate that 31P NMR can not only be applied to not only the study of the hydrolytic reactions of MePO-8 and PhP-8 but also be applied to the study of the presence of the anions of diethylphosphonoacetonitrile and diethyl phosphite in nucleophilic reactions.

Physical and chemical effects of phosphorus-containing compounds on laminar premixed flame

Phosphorus-containing compounds are the promising halon alternatives for flame inhibitions. However, some literatures suggested that the phosphorus-related inhibitors may behave as the unfavorable ones that will increase the burning velocity under lean-burn conditions, and this indeed posed potential threats to the fire prevention and fighting. To seek deeper insights into the reaction process, a numerical investigation was actualized to study the phosphorus-related effects on methane-air flames. By replacing a phosphorus-related inhibitor with the corresponding decomposed molecules, the detailed promoting and inhibiting effects of combustion were separated from the general chemical effect. A comparative study was carried out to identify the interaction between the two effects under different combustion conditions. It is observed that the promoting effect becomes the dominant factor during the reaction process when the equivalence ratio is smaller than 0.60. In this lean-burn condition, the exothermic reactions were faster than the others within the reaction chains due to the reduction of radical recombination in hydrocarbon oxidation. The results are believed to be useful for the further application and improvement of flame inhibitors.

Synthesis of phosphorus-containing polyoxamacrocycles with one to two reactive thiophosphoryl chloride groups

Novel phosphorus-containing polyoxamacrocycles with one to two reactive thiophosphoryl chloride groups 5, 6, 7, 8 were synthesized from bishydroxyl compounds 1, 2, 3, 4 and thiophosphoryl chloride respectively. Their structures were confirmed by ^ 1H NMR, ^13C NMR, ^31p NMR and elemental analysis.

Graphene oxide/hydrotalcite modified polyethersulfone nanohybrid membrane for the treatment of lead ion from battery industrial effluent

In the present study, polyethersulfone based nanohybrid membranes were effectively fabricated by incorporating graphene oxide(GO) and hydrotalcite(HT) nanosheets into the membrane structure. HT was prepared to overcome the irreversible agglomeration behavior of GO at a high concentration which affects the performance of the membranes. In particular, the shedding of HT in formamide provides a two-dimensional nanosheet with a higher positive charge density to prevent the restacking of GO nanosheets. Here, exfoliated GO and HT with different combinations(1:1, 1:2 and 1:3) were infused in the membrane matrix to treat lead-acid battery effluent effectively. Finally, the hybrid membranes were characterized for hydrophilicity, mechanical strength and pure water flux. In combination with the superior properties of GO and HT, the prepared hybrid membranes can be used as effectively to improve the separation and permeation performance. The phase inversion process eliminated the leaching of nanoparticles from the membrane matrix. The reusability of the hybrid membrane was achieved using0.1 mol·L^(-1)NaOH solution and reused without significant reduction in lead removal efficiency. The cost analysis of the membrane was also estimated from the lab study. Therefore, the present study suggested the selective and sustainable treatment of lead from a real-life effluent.

Systematic Biological Upgrade of a Urea Fertilizer Effluent Treatment Plant Using GPS

The use of modeling and simulation has developed into a critical tool for the sustainable management of wastewater, especially when it comes to replicating the complex biochemical procedures required for fertilizer effluent treatment, which calls for a significant amount of wastewater-related data. The biological improvement of a urea fertilizer effluent via GPS* simulation was carried out in this work using a methodical process. Using established analytical techniques, temperature, total suspended solids (TSS), biochemical oxygen demand (BOD), total phosphorus (T/), chemical oxygen demand (COD), total nitrogen (TN), total nitrate (NO3), electric conductivity (EC), turbidity, residual chlorine, urea, NH3, and heavy metals (Cu, Cd, Cr, Pb, Ni, and Fe) were assessed. The research revealed that the measured values from the fertilizer factory outfall effluent had high concentrations of all the physicochemical water quality indicators, with the exception of TSS, PO4-, SO4-, and NO3-. These concentrations are higher compared to the authorized limits or suggested values by the Federal Environmental Protection Agency (FEPA). To improve the therapy biologically, however, a modeling and simulation program (GPS-X, version 8.0) was used with the physicochemical information gathered from the studied sample. The results of the treated water simulation showed that the concentrations of BOD5 and COD had been significantly reduced by 35% and 44%, respectively. Additionally, it was discovered that total phosphorus (TP), nitrate (N), and total nitrogen (TN) were all within the permitted FEPA limit. The results revealed good treatment performance of the wastewater with increasing concentration of acetic acid and sodium hydroxide. Hence, the results of this research work identify the need for proper treatment of fertilizer industry effluents prior to their release into the environment.

Effects of Electroplating Effluents on Growth, Heavy Metals Accumulation and Concentrations in Amaranthus viridis Lin.

Pollution in recent times has become prevalent due to industrial expansion,hence,releasing pollutants into the environ-ment.Thus,this study aimed at investigating the effects of effluents from electroplating companies on growth,heavy metals accumulation and concentrations in Amaranthus viridis.Seeds of A.viridis were obtained from the National Institute of Hor-ticulture,Ibadan.Loam soils were collected from Lagos State University and two samples of electroplating effluents were obtained from Oregun,Lagos.Seeds were sown,nursed,and transplanted in a uniform bucket filled with 5 kg loam soil and transplanted seedlings were treated with Effluent A(5 and 10%conc.)and Effluent B(5 and 10%conc.)and control respec-tively.Growth parameters such as plant height and so on were measured and plant samples harvested were analyzed for heavy metal concentrations using Atomic Absorption Spectrophotometer.Data collected were subjected to a one-way analysis of variance.Results revealed that Effluents A and B are highly acidic and above discharge limits.Also,the result revealed that 5%conc.of Effluents A and B had more effects on growth(p<0.05)of A.viridis across the harvests than 10%conc.in relation to control.This result showed that the effluent samples affect the growth rhythms of plants.Results further revealed vigorous–1–1 accumulation of the heavy metals:Zn(241.66µg kg±0.10 at third harvest in Effluent A:10%),Cu(68.25µg kg±0.23 at–1–1 first harvest in Effluent B:5%),Cr(500µg kg±0.90 in harvests at all concentrations.)and Ni(500µg kg±0.90 at third harvest in Effluent B:5%)and all these metals are far above the control and permissible limits of WHO/FAO recommenda-tions.From this study,it could be concluded that electroplating effluents had adverse effects on growth and increased metals’bioaccumulation in A.viridis.Therefore,the treatment of effluents to enhance an eco-friendly environment should be done.

餐厨沼液滴灌水盐调控对土壤环境和西兰花产量的影响

为探究和评价餐厨沼液滴灌对土壤环境和作物生长的影响,通过盆栽试验研究氮磷钾等浓度施用条件下,滴灌水盐调控不同土壤水基质势水平[-20 kPa(W)和-30 kPa(P)]和餐厨沼液比例[0%(0)、10%(1)、16.7%(2)、25%(3)和33.3%(4)]对土壤盐分、无机氮含量和西兰花生长的影响。结果表明:土壤水基质势水平对土壤盐分有显著的影响,与P相比,W降低表层土壤饱和泥浆提取液电导率(ECe)13.0%;土壤ECe随沼液比例的增加而升高,33.3%沼液处理比其他处理高23.1%~46.8%。沼液比例对土壤铵态氮含量影响显著,0%沼液处理表层铵态氮是其他处理的2.2~3.0倍;餐厨沼液灌溉会降低西兰花产量,P_(2)、P_(3)和P_(4)处理下降显著。综合评价结果表明:W与P差异不显著,沼液比例越高影响越大,P_(0)处理与W_(1)、W_(2)和P_(1)处理差异不显著,但显著高于W_(3)、W_(4)、P_(2)、P_(3)和P_(4)处理。在等浓度施用氮磷钾条件下,餐厨沼液滴灌水盐调控仍会增加土壤盐分,降低土壤铵态氮含量和西兰花产量,但在控制土壤盐分和增加餐厨沼液可施用比例方面,-20 kPa明显优于-30 kPa。

滨海核电厂液态流出物间歇排放数值模拟分析

应用非结构化网格MIKE 21水动力模型及对流扩散模块,针对某滨海核电厂工程海域建立液态流出物排放数学模型,对核电厂运营期间液态流出物中核素在等浓度排放条件下4种不同典型潮时(涨憩、落急、落憩、涨急)起始的间歇排放进行数值模拟,并与连续排放进行比较,给出了不同工况下液态流出物在环境水域中全潮平均相对浓度分布及影响范围、不同半径海域内核素的平均相对浓度以及取水相对浓度特征值。对比分析显示,滨海核电液态流出物在受纳水体中的输移、扩散主要受潮流影响。落急时刻起始的间歇排放方式总体上在环境影响和取水浓度方面均具有显著优势。计算结果可为核电厂液态流出物排放方式的优化及海洋环境影响评价提供了依据。

石墨烯生产废液中双球状碳酸锰的提取及其电化学储锂性能

根据“双碳”目标和循环经济的要求,废弃物务必应收尽收。鉴于此,以Na2CO_(3)为沉淀剂,通过一步化学沉淀反应从石墨烯生产废液中提取了淡黄色MnCO_(3)粉末,并研究其电化学储锂性能。结果表明,废液中Mn离子的去除率为99.9%,MnCO_(3)粉末的回收率为92.6%。MnCO_(3)粉末由0.5~1.5μm的双球状颗粒组成,属于六方晶系;MnCO_(3)负极在0.5 A/g和1.0 A/g分别循环300圈后,其可逆放电容量分别为570 mAh/g和418 mAh/g。本文的研究结果为回收石墨烯工业废水提供了新思路,有助于降低环境污染排放。

碘量法和BOD快速测定仪测定医疗出水BOD浓度的研究

通过碘量法和BOD快速测定仪测定雅安职业技术学院医疗出水BOD浓度,探究这2种方法的差异。采取碘量法测定6份平行样品的溶解氧BOD依次为6.89、6.67、6.73、6.62、7.03、6.76 mg·L^(-1),平均值AV为6.78 mg·L^(-1),标准偏差为0.15,相对标准偏差为0.02,具有统计学意义。采取快速测定法测定6份平行样品的溶解氧BOD依次为6.55、6.45、6.72、6.66、6.54、6.78 mg·L^(-1),平均值AV为6.62 mg·L^(-1),标准偏差为0.12,相对标准偏差为0.02,具有统计学意义。结合国家《医疗机构水污染物排放标准》(GB18466—2005)的排放标准,分别采用国标GB7489—87制定的碘量法和快速检测仪对医疗排放水进行BOD检测,符合污水排放标准。从标准差数据来看,碘量法的标准差为0.151,快速测定法的标准差为0.124,2种方法相比较,快速测定法比碘量法更精确。与快速测定仪的测定步骤相比较,碘量法在测定过程中容易受到环境温度、气压、压力、实验操作误差等因素的影响,相对来说,数据波动比较大。

颗粒活性炭-纳滤处理二级出水中有机物膜污染机制研究

采用颗粒活性炭(Granular Activated Carbon,GAC)、生物活性炭(Biological Activated Carbon,BAC)两种过滤单元分别与纳滤(Nanofiltration,NF)组合对污水厂二级出水进行深度处理,分析二级出水直接NF、GAC-NF以及BAC-NF三种不同处理工艺对有机物的去除效果以及膜污染机制.研究发现,BAC-NF组合工艺对溶解性有机碳(DOC)、微生物代谢副产物类和腐殖酸类有机物的去除效果更好,去除率分别为85.2%、76.2%和82.0%;BAC-NF组合工艺的膜比通量(J/J0)最高,每个周期末的J/J0分别为0.69、0.65和0.63,膜污染总阻力最低,仅为5.97×10^(10)m^(-1);膜污染特征曲线表明二级出水直接NF为滤饼层污染,GAC-NF和BAC-NF先发生中间堵塞之后形成滤饼层污染;其中,BAC-NF以膜孔中间堵塞污染为主,膜污染程度最轻;通过扩展的德亚盖因-兰多-弗韦-奥弗比克(Extended Derjaguin-Laudau-Verwey-Overbeek,xDLVO)理论分析发现BAC-NF组合工艺污染后膜表面的疏水性最弱,膜表面Zeta电位值最大;BAC-NF组合工艺在过滤初期,水中有机物不容易到达膜表面,膜污染程度最轻.在过滤中后期,水中有机物与膜表面有机物之间很难产生粘附,形成的滤饼层最疏松.综上,BAC-NF组合工艺能有效缓解膜污染,可为再生水深度回用提供一种可靠的技术.

颗粒活性炭-纳滤对二级出水中条件致病菌和有机物的去除效能

再生水回用是解决水资源短缺的重要途经,被广泛应用于工业生产、城市绿化方面,但其中含有大量的条件致病菌,对环境及人体健康具有潜在威胁。研究拟对污水厂二级出水采用颗粒活性炭(Granular Activated Carbon,GAC)、生物活性炭(Biological Activated Carbon,BAC)两种过滤单元与纳滤(nanofiltration,NF)组合工艺,来达到水中三种条件致病菌(军团菌、铜绿假单胞菌和鸟分枝杆菌)、大肠杆菌和有机物的去除的目的,采用直接NF、GAC-NF和BAC-NF三种处理工艺对去除效果进行分析。结果表明:在GAC过滤的滤速为5 cm/h,NF的过滤压力为0.4 MPa条件下,直接NF及其组合工艺均可实现二级出水中条件致病菌的完全去除,相较于直接NF和GAC-NF,BAC-NF工艺对水中DOC、UV254、微生物代谢副产物类和腐殖酸类有机物的去除率最高,分别为85.2%、74.5%、76.2%和82.0%;水中条件致病菌与大肠杆菌、DOC之间均有显著相关性,可以通过强化水中大肠杆菌和有机物的去除,达到提高不同组合工艺对条件致病菌削减的目的;BAC表面生物膜细菌中的假单胞菌、气单胞菌、硝化螺旋菌和不动杆菌占比最高,上述细菌对条件致病菌的生长繁殖起抑制作用;生物膜真核微生物中的线虫和轮虫占比最高,这两种微生物能通过捕捉的方式实现对水中条件致病菌的削减。

污水厂尾水对河流水质和底泥细菌群落的影响

污水厂的出水即尾水,其排放关系到受纳水体的水质和生态状况。分析了武汉市某污水厂尾水排放指标,采用水槽试验探究了污水厂尾水对河流水质指标和底泥细菌群落的影响。结果表明:尾水排放促进了河水中硝酸盐氮的降解,总磷去除更加稳定;尾水使河水pH值提高了0.3、电导率上升幅度55%、溶解氧降低了0.6 mg/L。尾水排放之后,底泥细菌群落的丰富度升高、多样性降低,抑制厌氧菌Anaerolineaceae和SBR1031,促进好氧菌Pseudomonas;反硝化菌Azospira、Dechloromonas、Pseudomonas、Sphingomonas增多,促进了NO_(3)^(-)-N的降解。底泥中致病菌奈瑟菌属、军团菌属、消毒残生细菌相对丰度上升。

智慧水厂能耗监测评价与异常诊断管理平台研究

为提升污水处理厂水处理过程的运行能效,加速推进智慧水厂向节能化、数字化方向转型,设计了一种面向污水处理厂的能耗监测评价与异常诊断管理平台。平台基于建筑信息模型和能耗管理系统,通过采集污水处理厂运行数据与气象数据等信息,建立基于机器学习算法的动态监督能耗预测模型,实现厂区运行状况实时监测与评价。运维管理人员可依据平台生成的状态评价指数,进行厂区能源结构调整与异常用能识别与诊断。最后,以实际案例数据验证了平台各功能模块的可行性与有效性。分析结果表明,平台预警模块可以监测反馈96%的异常用能情况。

臭氧氧化在乙醇SBR出水资源化中的应用研究

为节约水资源,降低生产成本,该研究提出将序批式活性污泥法(sequencing batch reactor activated sludge process,SBR)出水回用于乙醇生产拌料工序。实验结果表明,SBR出水直接回用将导致乙醇发酵被抑制,对SBR出水进行臭氧氧化处理20 min后,SBR出水回用乙醇发酵的抑制性完全解除。研究证明NO_(2)-是SBR出水中的主要抑制物,当NO_(2)-质量浓度达到5 mg/L时就会对发酵产生抑制,表现为酵母细胞数减少且死亡率升高,细胞形态被破坏,对葡萄糖的利用率降低。转录组学研究结果表明,酵母细胞经NO_(2)-胁迫处理后,三羧酸循环与磷酸戊糖途径通量减小,使细胞代谢被抑制,生命活动减弱,因而抑制乙醇发酵。

沼液二级生化出水铁硫协同同步硝化-自养反硝化深度脱氮

针对沼液二级生化出水仍含高浓度硝态氮(NO-3-N)、氨氮等问题,文中研究了铁硫协同同步硝化-自养反硝化的影响因素。结果表明,在无外加碳源的条件下,铁硫协同同步硝化反硝化可有效提高TN、NO^(-)_(3)-N和氨氮的去除率。同时,在S/N为2的条件下,对TN、NO^(-)_(3)-N、氨氮去除率分别达到51.25%、83.63%、67.33%。氮去除动力学结果表明,TN去除规律在0~15 h内符合一级反应动力学特征,且其反应速率常数(0.0510 h^(-1))大于不投铁硫的空白组(0.0355 h^(-1))。微生物群落演变规律表明,铁刨花及硫代硫酸钠的投加会使微生物群落丰富度提高、多样性降低,且投加铁硫可显著提高自养反硝化菌[硫杆菌属(Thiobacillus)、铁杆菌属(Ferribacterium)]及异养反硝化菌[聚糖菌属(Defluviicoccus)、Candidatus_Competibacter、陶厄氏菌属(Thauera)]的丰度。