Process Optimization on Anaerobic Treatment of Citric Acid Wastewater

[Objective] The aim was to obtain higher COD removal rate so as to guide the process of citric acid industrial wastewater. [Method] The effects of controllable factors, acidification time, hydraulic retention time, and influent COD concentration, in-anaerobic treatment process of citric acid wastewater on COD removal rate were studied and the COD removal rate was optimized by response surface method. [Result] There was no interaction between acidification time and the other two factors. It was showed that hydraulic retention time and influent COD concentration had significant effect on COD removal rate and there was interaction between the two factors. The optimum COD removing process conditions was as follows: acidification time 1.53 h, hydraulic retention time 3.52 h and influent COD concentration 2 698 mg/L. Under the optimized conditions, the COD removal rate was 93.31% and it was much closed to the experimental result, 93.29%. [Conclusion] Using response surface method to optimize the anaerobic treatment of citric acid wastewater can result in optimized achievement.

Toxicity Reduction of Municipal Wastewater by Anaerobic-anoxic-oxic Process

Objective This study was conducted to optimize the operational parameters of anaerobic-anoxic-oxic （A^2/O） processes to reduce the toxicity of municipal wastewater and evaluate its ability to reduce toxicity. Methods A luminescent bacterium toxicity bioassay was employed to assess the toxicity of influent and effluent of each reactor in the A2/O system. Results The optimum operational parameters for toxicity reduction were as follows： anaerobic hydraulic retention time （HRT） = 2.8 h, anoxic HRT = 2.8 h, aerobic HRT = 6.9 h, sludge retention time （SRT） = 15 days and internal recycle ratio （IRR） = 100%. An important toxicity reduction （%） was observed in the optimized A2/O process, even when the toluene concentration of the influent was 120.7 mg·L^-1. Conclusions The toxicity of municipal wastewater was reduced significantly during the A^2/O process. A^2/O process can be used for toxicity reduction of municipal wastewater under toxic-shock loading.

A modified active disturbance rejection control for a wastewater treatment process

Waste water treatment process(WWTP)control has been attracting more and more attention.However,various undesired factors,such as disturbance,uncertainties,and strong nonlinear couplings,propose big challenges to the control of a WWTP.In order to improve the control performance of the closed-loop system and guarantee the discharge requirements of the effluent quality,rather than take the model dependent control approaches,an active disturbance rejection control(ADRC)is utilized.Based on the control signal and system output,a phase optimized ADRC(POADRC)is designed to control the dissolved oxygen and nitrate concentration in a WWTP.The phase advantage of the phase optimized extended state observer(POESO),convergence of the POESO,and stability of the closed-loop system are analyzed from the theoretical point of view.Finally,a commonly accepted benchmark simulation model no.1.(BSM1)is utilized to test the POESO and POADRC.Linear active disturbance rejection control(LADRC)and the suggested proportion-integration(PI)control are taken to make a comparative research.Both system responses and performance index values confirm the advantage of the POADRC over the LADRC and the suggested PI control.Numerical results show that,as a result of the leading phase of the total disturbance estimation,the POESO based POADRC is an effective and promising way to control the dissolved oxygen and nitrate concentration so as to ensure the effluent quality of a WWTP.

Optimization Conditions of the Preparation of Activated Carbon Based Egusi (<i>Cucumeropsis mannii</i>Naudin) Seed Shells for Nitrate Ions Removal from Wastewater

Egusi seed shells (ESS) were used as precursor for the preparation of two activated carbons (ACs) following H3PO4 and ZnCl2 activation. The effect of factors controlling the preparation of ACs such as chemical activating agent concentration (2 - 10 M), activation temperature (400°C - 700°C) and residence time (30 - 120 min) were optimized using the Box-Behnken Design (BBD). The optimized activated carbons based H3PO4 (ACP) and ZnCl2 (ACZ) were characterized by N2 adsorption, elemental analysis, atomic force microscopy (AFM), Boehm titration and Fourier transformed infrared (FTIR) techniques. The specific surface area was found to be 1053.91 and 1009.89 m2·g-1 for ACP and ACZ respectively. The adsorbents had similar surface functionalities and were both microporous. The effect of various parameters such as initial pH, concentration, and contact time on the adsorption of nitrate ions on ACP and ACZ in aqueous solution was studied. ACZ demonstrated better adsorption capacity (8.26 mg·g-1) compared to ACP (5.65 mg·g-1) at the same equilibrium time of 20 min. The adsorption process was governed by a “physical interactions” phenomenon for both adsorbents.

An Application of the Taguchi Method (Robust Design) to Environmental Engineering: Evaluating Advanced Oxidative Processes in Polyester-Resin Wastewater Treatment

This paper presents the Taguchi Method, a statistical design modelling for experiments applied in environmental engineering. This method was applied to optimize the treatment conditions of polyester-resin effluent by means of Advanced Oxidative Processes (AOPs) using chemical oxygen demand (COD) as response parameter. The influence of each independent parameter including respective interactions was evaluated by Taguchi Method, which allowed determining the most statistically significant variables and conditions to best fit the process. Results showed that Taguchi Method is a very useful tool for environmental engineering field and possible simplifications of analysis and calculations through commercially available software.

响应面法优化零价铁活化过硫酸盐处理酱香型白酒废水

以贵州省仁怀市某白酒废水处理厂二沉池出水为研究对象,采用零价铁(Fe^(0))活化过硫酸盐(S_(2)O_(8)^(2-),PS)的高级氧化法对其深度处理,并进行工艺条件的优化。通过单因素实验考察了溶液初始pH、PS投加量、n(Fe^(0))∶n(PS)对白酒废水处理效果的影响,并采用响应面法进行优化验证。结果表明,过硫酸盐法可以有效地降低白酒废水的有机物浓度,优化工艺条件:溶液初始pH为4.08,PS投加量为理论投加量(1 mg/L COD完全氧化理论上需要12 mg/L PS)的1.39倍,n(Fe^(0))∶n(PS)=1.27。在此条件下,白酒废水的COD去除率达70.33%。

知识和数据驱动的污水处理反硝化脱氮过程协同优化控制

为有效提升城市污水处理过程的脱氮效果,提出一种知识和数据驱动的反硝化脱氮过程协同优化控制(Knowledge-data-driven cooperative optimal control,KDDCOC).所提方法主要有以下两个方面:首先,建立一种基于自适应知识核函数的协同优化控制目标模型,动态描述出水水质(Effluent quality,EQ)以及泵送能耗(Pumping energy consumption,PE)、关键变量的协同关系;其次,提出一种知识引导的协同优化算法(Knowledge guide-based cooperative optimization algorithm,KGCO),快速准确求解硝态氮(Nitrate nitrogen,SNO)优化设定值,提高KDDCOC的响应速度.KDDCOC利用比例−积分−微分(Proportional-integral-derivative,PID)控制器对硝态氮优化设定值进行跟踪,将提出的KDDCOC应用于城市污水处理过程基准仿真模型1号(Benchmark simulation model No.1,BSM1),实验结果表明,该方法能够提高出水水质,降低运行能耗,有效改善脱氮效果.

基于掺硼金刚石电极的工业废水处理研究进展

工业废水普遍具有可生化性差、污染物种类多、有机物含量高、难降解等特点,常规处理手段难使其达标排放。以电化学高级氧化工艺为代表的污水深度处理工艺处理污水效果显著,是近年来环境工作者的研究热点之一。掺硼金刚石(boron-doped diamond,BDD)电极理化性质优异,是目前电化学高级氧化处理废水最为理想高效的阳极材料,但关于大尺寸BDD电极的应用及处理真实工业废水的研究情况尚未及时总结归纳。本文以基于BDD电极的电化学高级氧化工艺过程为对象,对该过程涉及到的废水特点、工艺原理、BDD电极特点及制备方法、处理案例和工艺参数优化等方面的研究进展进行综述,重点聚焦不同污染体系下的大型实验室装置、中试装置和处理真实工业废水案例,总结了BDD电极材料开发情况和不同类型工艺的技术特点,探讨了工艺优化方面的研究进展和目前限制该技术大规模工业化应用的主要原因。最后对基于BDD电极的电化学高级氧化工艺应用前景和重点发展方向作出了展望。

上海中心城区污水处理厂提标改造工程调试总结及设计建议

通过“十三五”期间上海中心城区污水处理厂提标改造及新建工程的实施经验,就已有污水处理厂提标改造涉及改造切换方面要点、污水处理厂建成后的调试过程要点、污水处理厂整体设计优化方面要点等方面,提出需关注的重点内容。

工业水处理工艺优化与回用探讨

目前冶炼行业废水成分较为多样复杂,处理水的去向持续受到关注。文章介绍了某冶炼厂针对重金属离子的传统废水处理工艺以及改进后的废水处理工艺,并对当前存在的问题进行了分析,结合生产模式,提出了改进工艺的方法。结果表明:在当前生产条件下,不锈钢材质的设备更适用于生产废水处理回用。相比较水处理工艺1(污酸处理系统+深度处理系统),对水处理工艺2(化学法工艺)进行改进更为便利,且对提高循环水水质而言更高效便利,有利于促进废水的“零排放”,提高循环水质量。

基于循环氨水的废水处理工艺优化

循环氨水废水源自多个工业领域,包括农业、食品加工、化工和制药等,其主要成分是氨氮和其他污染物。这些废水不仅对环境构成潜在威胁,还会影响公共卫生和可持续发展。本文中,深入分析传统循环氨水废水处理工艺存在的问题,包括处理效率低、运行成本高等。通过深入理解这些问题,探讨了一种基于循环氨水的废水处理工艺优化方法,以推动废水处理向更高效、更可持续的方向发展,促进生产和生态系统之间的协同共赢,实现更可持续的未来。

浅谈生物法处理含油废水的研究进展

经济的发展使石油的需求量不断增大,并产生了大量的含油废水,对人类健康和环境造成了极大的危害。生物法因处理含油废水成本低、效果好,备受关注。本文介绍了生物膜法、活性污泥法、生态系统净化法等,着重介绍了生物膜法,并提出在今后的生物法研究中应更加注意对耐高温、高盐、高浓度石油废水降解菌株的筛选,以提高生物法的处理效率。

CCPP燃机EP废水处理工艺的优化与应用

通过对CCPP燃机EP废水处理工艺的设计优化,采用二级氧化脱氰+混凝澄清+活性炭过滤工艺,可以保证系统出水水质达到直接排放要求。因系统投资小,废水处理费效比较高,完全可以替代传统的生化氧化法处理EP废水,提高CCPP机组的经济性。

基于深度强化学习的造纸废水处理过程多目标优化

本课题提出了一种基于多智能体深度强化学习的动态优化方法,以期实现造纸废水处理过程的运行成本和能耗的协同优化。实验采用了基准仿真1号模型(BSM1)模拟造纸废水处理过程的生化反应和沉淀过程,并利用模型数据对强化学习智能体进行训练,最后用实际的造纸废水数据对搭建的模型系统进行验证。结果表明,基于多智能体深度强化学习的废水处理系统能够保障排水质量,实现成本与能耗的多目标优化控制,其性能表现优于传统方法。

水热炭的柴油吸附性能专业综合实验设计与教学实践

设计了一个包含水热炭制备、形貌结构表征、单因素实验以及响应面优化法确定最佳吸附条件的专业综合实验。该实验首先制备出茼麻草水热炭,再利用扫描电镜、X射线衍射仪以及红外光谱仪对水热炭进行形貌结构表征。考察水热炭投加量、柴油初始浓度、溶液pH值以及接触时间对柴油吸附性能的影响,最后利用Design-expert 8.0软件进行响应面优化。通过本实验的开展,学生可了解国内外含油废水的污染状况与治理技术,熟悉水热炭制备方法,掌握水溶液中水热炭吸附柴油的性能评价方法。

基于正交试验的流化床工艺处理含氟废水的优化试验

为探究流化床工艺处理含氟废水的效果并对影响除氟效果的主次因素进行确定,以反应后上清液中氟离子质量浓度为评价指标,对比钙氟比(物质的量比)、初始氟质量浓度、pH、回流流量对除氟效果的影响。研究结果表明,通过正交试验得到最终的优化工艺条件如下:钙氟比为0.7、初始氟质量浓度为600 mg/L、pH为7、回流流量为60 mL/min,在优化工艺条件下得到最终上清液中的氟离子质量浓度为9.46 mg/L。各因素对流化床工艺除氟效果的影响从大到小依次为钙氟比、回流流量、pH、初始氟质量浓度,其极差R分别为11.2、5.3、4.5、3.0。

工业废水处理中除硅工艺研究

采用混凝法对废水进行除硅处理,考察镁剂投加量、pH、碱类型、反应时间及絮凝剂等因素对硅化合物去除效果的影响,确定最佳除硅工艺参数。实验结果表明,在镁剂投加比耗为11,用Ca(OH)2调节pH至10.5,反应时间为45 min,使用絮凝剂等条件下除硅效果最佳。另外采用分步除硅除硬工艺对含硅废水处理后,硅含量降低至10mg/L以下,硬度降低至20 mg/L以下。该研究通过工艺参数调变有效去除工业废水中硅化合物,为废水除硅工艺优化提供参考。

煤化工废水脱酸脱氨流程的多目标优化

对某气化厂85 t/h煤化工废水单塔脱酸脱氨流程进行模拟,在此基础上建立以塔釜再沸器热负荷最小化和产物收率(氨气+酸性气)最大化为优化目标的多目标优化模型。由于化工流程的特殊性,对现有的多目标粒子群算法进行改进,加入边界检验以提升运算速度。运用改进后的算法对模型进行求解,得到一组Pareto解集。以目前工况为基准,选定2个Pareto解进行分析。结果表明,在维持当前塔釜再沸器热负荷基本不变的情况下,产物收率增加10.21%;在维持当前产物收率基本不变的情况下,塔釜再沸器热负荷降低16.98%。

破乳+O_(3)/H_(2)O_(2)组合工艺处理含油废水的研究

以天津市某燃料油库区产生的含油废水为研究对象,选择破乳+O_(3)/H_(2)O_(2)高级氧化+活性炭吸附深度处理组合工艺,结果表明,经破乳反应温度25℃、反应时间为25 min、PAM投加量1 mg/L、pH 7、破乳剂投加比例0.4%时,破乳效果最佳,COD和石油类的去除率为56.5%;经O_(3)/H_(2)O_(2)氧化工艺,在温度25℃、pH 8±0.2、O_(3)流量2.5 L/min、质量浓度26 mg/L、H_(2)O_(2)投加量0.56 g/L、反应时间60 min时,COD和石油类的去除效果达到理想效果,去除率分别为69.25%和79.83%;深度处理过程中,活性炭投加量与废水质量比为1:10、吸附平衡时间为15 min,COD和石油类的去除率分别为41.17%和93.72%,经组合处理后的出水COD和石油类浓度分别为289.4 mg/L和0.33 mg/L,满足《GB/T 31962—2015污水排入城镇下水管水质标准》B级标准和《DB 12/356—2018天津市污水综合排放标准》三级排放标准,为处理含油废水提供理论支撑。

强化絮凝联合生化处理技术在高盐含油废水处理中的应用

高盐含油废水具有污染性强以及处理难度大的特点,采用单一的处理方式往往无法达到理想的处理效果。因此,为了更加高效地处理高盐含油废水,采取强化絮凝联合生化处理的方式对其进行处理,通过室内实验优化了相关处理参数。结果表明:复合絮凝剂FHR-2对高盐含油废水的絮凝处理效果最好,其最佳加量推荐为200 mg·L^(-1)。一段生化处理阶段的水力停留时间推荐为40 min,污泥质量浓度推荐为4 g·L^(-1),废水的pH推荐为7左右。二段生化处理阶段的水力停留时间推荐为5 h,污泥质量浓度推荐为5 g·L^(-1),废水的pH推荐为7左右。目标高盐含油废水采取强化絮凝联合生化处理技术处理后的COD值可以降低至24.6mg·L^(-1),含油量可以降低至3.5 mg·L^(-1),达到了国家标准GB8978—1996中规定的一级排放标准要求。