化工水处理设备管理及检修维护对策分析

随着化工生产的不断发展,水处理设备在保障生产环境和资源循环利用方面发挥着至关重要的作用。然而,目前在设备管理及检修维护方面存在一系列问题,直接影响了设备的性能和稳定性。为此,本文旨在分析当前存在的问题,并提出一系列科学合理的对策,以提高化工水处理设备的管理水平和维护质量。

环保概念下的磷化工水处理及其回收利用探讨

本文首先对原水处理工作进行分析,其次,对脱盐水处理工作进行单独解析,最后对生产系统排水分类再利用进行了较为详细的列举与方法解读,包括作为高位水池的补充水、作为二级泵站补充水、作为污水站水量、其他污水回收利用方法等。

煤化工水处理工艺常见问题分析

随着煤化工产业链的快速发展,煤化工水处理工艺问题得到了行业人士的高度重视,若是无法得到很好的解决,将直接影响到我国煤化工产业的可持续发展。因此就煤化工水处理工艺常见问题进行研究分析。

高密度沉淀池在煤化工水处理中的应用

介绍了高密度沉淀池的沉降原理、装置的组成和工艺流程;指出了高密池在运行中存在的7个常见问题,并提出了解决办法;总结了对高密池运行的10点心得体会。

渗透在化工水处理中的应用

在近些年我国社会经济快速发展的社会背景下,随着化学工业的不断崛起,使得化工废水的排放量也在不断增加,如果对化工废水不能正确处理,就会从根本上危害自然环境,并对人们日常的生产生活以及人们的身体健康都会造成持续性的破坏,所以化工废水的处理就有着至关重要的作用,通过在化工水的处理当中全面应用渗透技术,可以有效地达到净化和减少废水的自然环境和人类健康的威胁与影响的目的,并从根本上去除化工废水中的污染物,从中回收化工废水中的有用物质,使其能够实现回收再利用,在实现化工水的有效处理的同时也可以在一定程度上降低我国水资源压力,使化工行业能够从中实现健康可持续化发展。

反渗透在化工水处理中的应用

近年来,随着化工行业的迅速发展,化工废水的处理也日益引起人们的关注。化工产业是我国传统工业,其资源浪费严重、高能耗、耗水严重。在生产过程中,排出了很多有害物质,若不进行有效治理,将给周边地区带来巨大的危害。因此,化工企业应当意识到反渗透技术的优势,并把其运用到化工水处理中去。基于此,文章对反渗透技术的工作原理、优势进行了阐述,并对其在化工领域的应用进行了展望。笔者期望通过本文的研究,能够为从事这方面工作的人员提供参考。

Advances in Energy-Producing Anaerobic Biotechnologies for Municipal Wastewater Treatment

Municipal wastewater treatment has long been known as a high-cost and energy-intensive process that destroys most of the energy-containing molecules by spending energy and that leaves little energy and few nutrients available for reuse, Over the past few years, some wastewater treatment plants have tried to revamp themselves as ＂resource factories,＂ enabled by new technologies and the upgrading of old technologies. In particular, there is an renewed interest in anaerobic biotechnologies, which can convert organic matter into usable energy and preserve nutrients for potential reuse. However, considerable technological and economic limitations still exist. Here, we provide an overview of recent advances in several cutting-edge anaerobic biotechnologies for wastewater treatment, including enhanced side- stream anaerobic sludge digestion, anaerobic membrane bioreactors, and microbial electrochemical systems, and discuss future challenges and opportunities for their applications. This review is intended to provide useful information to guide the future design and optimization of municipal wastewater treatment processes.

Ozonation with ultrasonic enhancement of p-nitrophenol wastewater

Synergetic effects for p-nitrophenol degradation were observed in the ozonation with ultrasonic enhancement. The enhancements of removal rate for p-nitrophenol and TOC were around 116% and 294% respectively in comparison with the individual ultrasound and ozonation systems. The synergetic phenomenon is attributed to two physicochemical mechanisms: (1) Ultrasound decomposes ozone causing augmentation of the activity of free radicals; (2) Ultrasonic wave increased the concen- tration of O3 in solution because of ultrasonic dispersion.

Troubleshooting and Optimization of High-Strength Inhibitory Chemical Wastewater Treatment Process

Wastewaters from the chemical industry are usually of high-strength and may contain minor inhibitory and recalcitrant organics that are at times not readily identifiable. This paper describes the experience of a biological waste water treatment plant （WWTP） processing a COD concentration of 43000 mg·L^-1 wastewater from an oxochemical manufacturing plant. Stage improvements of the plant process by dilution of the inhibitory influent using other chemical wastewater streams resulting in a synergistic process effect, and removal of inhibitory organics by phase separation via acidification, effectively achieved process optimization producing a high quality effluent. In particular, the COD removal efficiency of granular sludge based anaerobic reactors increased from 56% to 90%. The final effluent COD decreased from 250mg·L^-1 to 50mg·L^-1, consistently meeting the COD concentration of 100 mg·L^-1 regulatory discharge limit. The success of the process enhancements supports the hypothesis that long-chain quaternary carboxylic acids act as substrate inhibitors in the biological process.

Fuzzy Control of Nitrate Recirculation and External Carbon Addition in A/O Nitrogen Removal Process

Nitrogen and phosphorous concentrations of effluent water must be taken into account for the design and operation of wastewater treatment plants. In addition, the requirement for effluent quality is becoming strict. Therefore, intelligent control approaches are recently required in removing biological nutrient. In this study, fuzzy control has been successfully applied to improve the nitrogen removal. Experimental results showed that a close relationship between nitrate concentration and oxidation-reduction potential (ORP) at the end of anoxic zone was found for anoxic/oxic (A/O) nitrogen removal process treating synthetic wastewater. ORP can be used as online fuzzy control parameter of nitrate recirculation and external carbon addition. The established fuzzy logic controller that includes two inputs and one output can maintain ORP value at - 86 mV and - 90 mV by adjusting the nitrate recirculation flow and external carbon dosage respectively to realize the optimal control of nitrogen removal, improving the effluent quality and reducing the operating cost.

Comparative Study of Ozonation and Catalyzed Ozonation Processes for Drinking Water Treatment by Pilot Test

The ozone consumption effect and organic removal ability of metal coated cordierite ceramic honeycombs catalytic ozonation （catazone） process and ozonation process were comparatively studied by pilot-scale experiments. By Scan Electron Microscope （SEM）, Atomic Force Microscope （AFM）, BET, and X-ray photoelectron spectroscopy （XPS） analysis, metal oxides attached to ceramic surface were found to be in the form of crystal cluster, and the pore structure of ceramics was less developed. The air flow statuses of vacant catazone and ozone contactors were inclined to be plug-flow and mixed flow, respectively. Comparing with ozonation process, the ozone mass transfer efficiency of catazone process is lower, and the ozone decomposition efficiency of catazone is higher. The former effect is more obvious in semi-batch experiment, and the latter effect is more obvious in continuous-flow experiment. Unsaturated organics removal efflciencies of the two oxidation processes are similar, and are less affected by dissolved ozone concentration when it is higher than 1 mg/L. More dissolved organics were detected in catazone process in continuous.flow reaction, and more CH3CI3 formation potential （CH3CI3FP） was removed by catazone in semi-batch mode, especially in the water with lower UV254 .

Greenhouse Gas Emissions from Sewage Treatment in China during 2000-2009

Based on the statistics from the China Statistical Yearbook （2000-2009） on environment and methods recommended by the IPCC, the amounts of greenhouse gas （GHG） emissions from domestic and industrial sewage treatment in China are estimated for the period of 2003-2009. CO2 emissions per capita from sewage treatment plants are also analyzed. The results show that the GHG emissions from sewage treatment plants increased steadily from 2003 to 2009; N20 emissions from domestic sewage are the major source of the total GHG emissions from domestic sewage; CH4 emissions from domestic sewage increase with the greatest speed; CH4 emissions from paper and pulp industry are the major source of industrial sewage emissions; CO2 emissions per capita increase constantly from 2003 to 2009.

Acid Separation, Catalytic Oxidation and Coagulation for ATC Waste Liquid Treatment

It is difficult to treat 2-amino-thiazoline-4-carboxylic acid （ATC） waste liquid effectively at present for its characteristics of high chemical oxygen demand （COD）, high salinity and low biodegradability. In order to solve this problem, this paper presents several kinds of physical-chemical treatment unit techniques, including acid separation, catalytic oxidation and coagulation. First of all, acid separation was adopted to precipitate relevant organics at isoelectric point. When the temperature and pH value of acid separation were controlled at about 5 ℃ and 2.2 respectively, the COD removal rate could reach 27.600. Secondly, oxidation was used to break chemical constitution of refractory organics. The optimal reaction parameters of catalytic oxidation should be 20 ℃, pH adjusted to 5.0 and [Fe2+] 300 mg/L. Then with 500 H2O2 added and after one-hour reaction, the COD removal rate could achieve about 5200. Finally, coagulation was adopted to remove a portion of refractory organics, and 1500 polymeric molysite flocculant was the best for the coagulation, and the COD removal rate could reach about 1500. Therefore, the proposed feasible process of physical-chemical pretreatment for ATC waste liquid could have about 7000 COD removed in total.

A Review of Chemical Industry Wastewater Treatment

With the development of China＇ s industry, the domestic industrial parks greatly emerge and thus give rise to the diversity of pollutants in chemical wastewater. In this paper, the main sources of China＇ s chemical industry wastewater, main pollutants types and the wastewater characteristics of the chemical industry＇ s different branches are introduced, the related technologies and methods mainly applied to chemical industry wastewater treatment at home and abroad are analyzed and the application of different chemical wastewater treatment process is explained, and also all sorts of treatment technologies, methods, and processes are reviewed, and finally the study achievements and problems of all technol^ogies are concluded.

Study on Filtration Performance of Silica/ Alumina Slurry in the Process of Recycling Mother Liquor of NaY Zeolite

In order to recover the SiO_2 contained in the mother liquor in the course ofNaY zeolite synthesis to minimize pollution, the influence of various preparation conditions on thefiltering velocity of gel slurry was studied using the SiO_2/Al_2O_3 gel recovered from the NaYmother liquor in the laboratory. The results of study had shown that at a SiO_2/Al_2O_3 ratio in thefeed equating to 9∶1 the SiO_2 recovery rate and Al_2O_3 utilization rate were high with a fasterflow velocity of the filtrate. The pH value of the system had great impact on the flow velocity offiltrate. Between the two methods for regulating the pH value, the one for formation ofsilica/alumina gel slurry by addition of sulfuric acid prior to adding aluminium sulfate in thesolution could secure a faster filtration velocity. The filtration velocity was decreased in tandemwith increasing SiO_2 concentration in mother liquor, meanwhile an increase in dry filter cakeyield.

A systematic strategy for multi-period heat exchanger network retrofit under multiple practical restrictions

A systematic strategy for retrofit of the multi-period heat exchanger network （HEN） on the basis of the multi- objective optimization is developed. In this three-stage procedure, a simplified multi-objective optimization model of the multi-period lIEN is first established and then solved to target the retrofit, aiming to minimizing the total annual cost and total annual CO2 emissions. The obtained Pareto front represents series of retrofit targets under different emission limitations, from which the most desirable one can be selected. The matching of the existing and the required heat exchangers is further implemented to finalize the retrofit, which will meet the practical retrofit requirements and matching restrictions. The application of the proposed procedure is illustrated through a case study of a HEN in a vacuum gas oil hydro-treating unit.

Standards on the Bildegradability of Surfactants in China

This paper described general situation of surfactant production and waster water treatment in China, and introduced Chinese standards on chemical biodegradation. Furthermore, it summarized at three level of Chinese relevant standards. Finally, it explored in detail the particular differences between Chinese standards and OECD methods.

Treatment of Textile Industrial Wastewater from Water Jet Loom Machine

The objective of this research was to investigate the optimum condition for treatment of textile industrial wastewater from water jet loom machine by chemical coagulation and electrocoagulation methods. The variables of chemical coagulation method were type and amount of chemicals, pH and stirring rate. For electrocoagulation method, the variables were electrode materials, electric potential and contact time. It was found that the optimum condition of chemical coagulation method was 10% （w/w） of aqueous solution of aluminum sulphate 80 mL and 0.01% （w/w） of aqueous solution of coagulant aids, cationic polymer 32 mL per 4 L of wastewater at oH 8. The mixture solution was rapidly stirred with 120 rpm for 1 min and then slowly stirred with 20 rpm for 20 rain. The removal efficiency of turbidity, COD and oil content were 88.88%, 85.20% and 77.72%, respectively. For electrocoagulation method, the optimum condition was using aluminum electrode with 35 V and 150 min of contact time. The removal efficiency of turbidity, COD and oil content were 98.86%, 91.63% and 89.84%, respectively. It can be concluded from this study that the textile industrial wastewater treatment from water jet loom machine with electrocoagulation method is more efficient than that with chemical coagulation method.

Solar Photochemical Pre-Treatment for Sulphurous Ground Water Purification Process

The sulfurous water deposit exploitation in volcanic, swamp, or wetland regions, represents an alternative option for potable water supply in cities and communities around the world. However, before its consumption, it must be treated by the application of physicochemical or biological methods with the ability to separate high contents in sulfates, hydrogen sulphite and sulphides which have laxative, allergic and toxic properties in humans. Conventional methods require the supply of chemical compounds or the adequate control of different parameters such as pH, temperature, etc., and the constant maintenance within their reactors. For these reasons, the systems could have elevated operating costs and require additional steps to enable the treatment of its separated products and the final disposal of its residual waste generated. In this research, compound parabolic collectors are implemented for the use of solar energy radiation, UV-B type, in Solar Advanced Oxidation Processes in H2O2/O3/UVsolar homogeneous phase. Its application during the pre-treatment of four sulfur water wells from the region of Puebla, Mexico, demonstrated its ability to transform their sulfur compounds in sulfates of easy removal by a later stage of reverse osmosis, in an approximately 15 min treatment time process.