城市建设过程中的环境污染处理办法探究

我国城市建设最近几年发展非常迅速,在城市建设中,越来越多的工厂出现,促进了经济的快速发展。企业单位的数量不断的增多,导致环境受到了严峻的挑战。环境问题逐渐被全世界所关注,许多国家纷纷投入到环境治理的行列中,通过不断的努力将环境问题进行优化。政府鼓励节能减排、减少工厂对有毒物体的排放,保证空气的清晰,为生物提供一个良好的居住之所。

浅谈应急监测在突发性环境污染事故处理中的作用

随着我国科技水平的不断发展,人民已经进入了一个高效水平的时代。然而科技一方面给人类带来空前便利,另一方面也引发了诸多问题,其中环境污染问题尤为棘手。在诸多类别的环境污染问题中,突发性环境污染事故最具威胁性,它往往猝不及防的发生,在人们不加防备之时给人、物以重创,近年我国由于突发环境事故所造成的人员伤亡、财产损失的状况时有发生,如何着实有效处理突发性环境污染事故已成为当下热议话题。笔者在此文将对应急监测在突发性环境事故处理中的应用进行探讨分析。

环境面临的挑战与环境研究的最新进展

阐述了人类环境所面临的如全球气候变化、臭氧层破坏及酸雨等的严峻挑战。介绍了国内外环境研究的一些最新进展，简述了几种先进的污染处理技术。

垃圾渗滤液的生物处理技术初探

城市垃圾填埋场中的渗滤液的处理一直是环境工作者在工作中面临的一大难题。垃圾渗滤液是液体在填埋场重力流动的产物,主要来源于降水和垃圾本身的内含水。本文对目前国内垃圾渗滤液的生物处理工艺做了一个较为全面的总结。

垃圾焚烧发电厂烟气污染控制及防治对策

在如今的城市发电手段中,垃圾焚烧发电已经占据了很大的比例,而垃圾焚烧又正好是一种降低环境污染,废物再利用的"双赢"手段,被人们普遍的运用在了垃圾焚烧技术之中。而垃圾焚烧也一直是解决城市居民日常生活垃圾处理的主要技术手段,垃圾处理彻底、减容量大等优点使它在城市处置废弃物的时候也被普遍采用。不过垃圾焚烧还面临着自己的缺点,在处置废弃物的同时会产生环境污染以及对自然环境的不良影响。下面让我们围绕着垃圾发电厂的环境污染治理展开讨论。

浅谈ase在水环境监测中的应用

现代化萃取技术——快速溶剂萃取是固体物质中污染物监测的一种样品前处理技术，它根据溶质在不同溶剂中溶解度不同，在较高的温度和压力下选择合适的溶剂，高效、快速地萃取固体或半固体样品中的待测物。本文阐述了ase的技术性能和特点，讨论了该技术在水环境监测中的应用，展望了水环境中有机污染物监测技术的发展前景。

环保工程污水处理的有效措施研究

近年来,随着我国社会经济的快速发展,环境污染问题日益严重,环境保护成为人们关注的焦点。针对目前的水污染问题,中国采取了各种措施加强废水处理。现在,中国一些地区继续实施环保项目,并改善了污水处理系统。虽然废水处理投资大幅增加,但废水处理仍存在明显不足,影响了当地生态环境。因此,本文件介绍了适当的清洁技术和方法,以提高污水处理厂的能力和影响,从而确保环境保护技术事业的健康发展。

我国环保设备现状研究

环保设备产业是环保产业中的重要组成部分,环保设备的科技含量低、环保科技成果转化周期长等因素制约了我国环保设备产业的发展。发展环保设备产业要从技术、质量方面着手提高其核心竞争力,打破核心技术国外垄断的壁垒。

筼筜湖畔看温馨

家住筼筜湖畔湖滨四里社区的林宗老汉，怎么看也不像个年近7旬的古稀老人，他每天都要到南湖公园去，或溜鸟休闲，或练太极剑，或健身慢跑，或轻歌曼舞，或享受棋牌之乐。

Polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas emissions from municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins and furans （PCDD/Fs） emissions in flue gas from two types of municipal solid waste incinerators （MSWIs） most commonly used in China were investigated in this study. The selected incinerators include two grate-type MSWIs： MSWI-A （350 t/d） and MSWI-B 050 t/d）, and two fluidized bed MSWIs： MSWI-C （400 t/d） and MSWI-D （400 t/d）, which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber （WS） as air pollutant control device （APCD）. Results indicated that the emission concentration and the international toxic equivalents （I-TEQs） of the PCDD/Fs from the stacks were in the range of 1.210-10.273 ng/Nm^3 and 0.019-0.201 ng I-TEQ/Nm^3, respectively. They were greatly lower than the emission regulation standard of PCDD/Fs in China （1.0 ng I-TEQ/Nm^3）. However, only the PCDD/Fs emission level from MSWI-C was below 0.1 ng I-TEQ/Nm^3. Although the homologue profiles were distinct, the contributions of the 2,3,7,8-subsituted congeners to the total I-TEQ were similar among all the investigated MSWIs. Two major 2,3,7,8-substituted congeners, 2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD, account for 47% and 9% （average values） of the total I-TEQ values, respectively. The correlation between PCDD/Fs levels and composition of flue gas was also discussed.

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.

Degradation of 4-Chlorophenol Solution by Synergetic Effect of Dual-frequency Ultrasound with Fenton Reagent

4-Chlorophenol (4-CP) solution was treated by dual-frequency ultrasound inconjunction with Fenton reagent, and obvious improvement in the 4-CP degradation rate was observedin this advanced oxidation process. Experimental results showed that ultrasonic intensity,saturating gas and pH value affected greatly the 4-CP removal rate. Among four different saturatinggases (Ar, O_2, air and N_2), 4-CP degradation with Ar-saturated solution was the best. However, inthe view of practical wastewater treatment, using oxygen as the saturating gas would be moreeconomical. The addition of Fenton reagent followed the first-order kinetics and increased the 4-CPdegradation rate. The 4-CP removal rate increased by around 126% within 15 min treatment. Thesynergetic effect of dual-frequency ultrasound with Fenton reagent on 4-CP degradation was obviouslyobserved.

Comparative analysis of hydrogen-producing bacteria and its immobilized cells for characteristics of hydrogen production

A strain of hydrogen producing bacteria was immobilized by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate. The immobilized cells were insensitive to the presence of traces of O2. Moreover, the immobilized cells increased both the evolution rate and the yield of hydrogen production. Batch experiments with a medium containing 10 g/L glucose demonstrated the yields of hydrogen production by the immobilized and free cells were 2.14 mol/mol glucose and 1.69 mol/mol glucose, respectively. In continuous cultures at medium retention time of 2.0 h, the yield and the evolution rate of hydrogen production by the immobilized cells were 2.31 mol/mol glucose and 1 435.4 ml/（L·h） respectively. However, at medium retention time of 6.0 h, the yield and the evolution rate of hydrogen production by free cells were only 1.75 mol/mol glucose and 362.9 ml/（L·h）, respectively.

ECOLOGICAL RESTORATION:OUR HOPE FOR THE FUTURE?

Ecological restoration is widely employed from tens to millions of hectares in space,and from tens of days to thousands of years in time, which forces consideration of it thoroughly. We argue that three questions are the most important among the contents relevant of ecological restoration, including why, what and how to restore degraded systems. Why to restore determines whether or not the degraded ecological systems should be restored. What to restore is the goal of ecological restoration. The explicit goal of ecological restoration is necessary to guide ecological restoration workers in pursuit of excellence and prevent restoration from being swamped by purely technological activities. And how to restore means the methods and steps we should apply. To ensure the final success of ecological restoration, restored sites should be monitored and managed for long time to determine whether the selected methods are appropriate, and can be remedy better. Only to deal with these effectively, ecological restoration would be the hope for the future.

State Space Approach to Mass Exchange Network Synthesis

State space approach is an effective method to mass-exchange network (MEN) synthesis. By decomposing the network into two interactive parts, a distribution network and a process operator, the synthesis problem can be formulated into a mixed integer nonlinear programming (MINLP) model. In this article, a generalized state space model based on typical MEN is established and verified in two cases. A new asymmetrical operator and cost index are also adopted to speed up the solution process. The results demonstrate the efficiency of the proposed approach.

Performance of BAC process for treatment of micro-polluted water

Biological activated carbon (BAC) has been developed on the granular activated carbon by immobilization of selected and acclimated species of bacteria to treat the micro-polluted water. The BAC removal efficiencies for nitrobenzene, permanganate index, turbidity and ammonia were investigated. Effects of shock loading and SEM (Scanning Electron Microscope) observation on BAC were studied. Backwashing and its intensity of BAC were also discussed. The results showed that BAC took short time to start up and recover to the normal condition after shock loading. The shock loading studies showed that the removal efficiency of BAC was not completely inhibited even at high concentration of nitrobenzene. Backwashing performed once every 10-20 d, or an average of 15 d. Backwashing intensity was 12-14 L/(s·m2) with air and 3-4 L/(s·m2) with water.

Degradation of chlorophenol by in－situ electrochemically generated oxidant

A novel in-situ electrochemical oxidation method was applied to the degradation of wastewater containing chlorophenol. Under oxygen sparging, the strong oxidant, hydrogen dioxide, could be in-situ generated through the reduction of oxygen on the surface of the cathode. The removal rate ofchlorophenol could be increased 149% when oxygen was induced in the electrochemical cell. The promotion factor was estimated to be about 82.63% according to the pseudo-first-order reaction rate constant (min^-1). Important operating parameters such as current density, sparged oxygen rate were investigated. Higher sparged oxygen rate could improve the degradation of chlorophenol. To make full use of oxygen, however, sparged oxygen rate of 0.05 m3/h was adopted in this work. Oxidation-reduction potential could remarkably affect the generation of hydrogen peroxide. It was found that the removal rate of chlorophenol was not in direct proportion to the applied current density. The optimum current density was 3.5 mA/cm^2 when initial chlorophenol concentration was 100 mg/L and sparged oxygen rate was 0.05 m^3/h.

Water Environment Pollution in Three-Gorge Reservoir Area and Treatment Technology

After the erection of Three-Gorge Reservoir, the water environment in the reservoir area will be turned into water bodies like lakes, and the self-clarification ability of water will also be much slower than ever. Now, the quality of water in most segments in upper reaches of Yangtze River cannot meet the requirements of l-ll class Environment Quality Standard (GHZB1-1999). In Yangtze River, dialing River and Wujiang River, the main indexes such as colon bacillus, nonionic ammonia, chemical oxygen demand (COD), petroleum, phenol, total phosphorus (TP), heavy metal, etc., have exceeded the standard limits. The water bodies of the reservoir area are facing serious risk of eutrophicationm. To solve that problem, a countermea-sure of multi-spot diverted treatment and separate discharge is recommended. For doing this, lots of small-scale wastewater treatment facilities employing updated activated sludge treatment technologies are to be set up. Up to now, a number of sewage treatment technologies to control eutrophication of water have been developed, which include processes of sequencing batch activated sludge (SBR), absorbing bio-degradation (AB), oxidation channel, package intermittent aeration system (PIAS), intermittent cycle extended aeration system (ICEAS), UNITANK and so on. The Effective one to be applied in the reservoir area should convey the requirements of ecological agriculture, forestry and urban planning, and be accompanied by legal support for appropriate exploitation of natural resources.

Problems of drinking water treatment along Ismailia Canal Province, Egypt

The present drinking water purification system in Egypt uses surface water as a raw water supply without a preliminary filtration process.On the other hand,chlorine gas is added as a disinfectant agent in two steps,pre-and post-chlorination.Due to these reasons most of water treatment plants suffer low filtering effectiveness and produce the trihalomethane(THM) species as a chlorination by-product.The Ismailia Canal represents the most distal downstream of the main Nile River.Thus its water contains all the proceeded pollutants discharged into the Nile.In addition,the downstream reaches of the canal act as an agricultural drain during the closing period of the High Dam gates in January and February every year.Moreover,the wide industrial zone along the upstream course of the canal enriches the canal water with high concentrations of heavy metals.The obtained results indicate that the canal gains up to 24.06×106 m3 of water from the surrounding shallow aquifer during the closing period of the High Dam gates,while during the rest of the year,the canal acts as an influent stream losing about 99.6×106 m3 of its water budget.The reduction of total organic carbon(TOC) and suspended particulate matters(SPMs) should be one of the central goals of any treatment plan to avoid the disinfectants by-products.The combination of sedimentation basins,gravel pre-filtration and slow sand filtration,and underground passage with microbiological oxidation-reduction and adsorption criteria showed good removal of parasites and bacteria and complete elimination of TOC,SPM and heavy metals.Moreover,it reduces the use of disinfectants chemicals and lowers the treatment costs.However,this purification system under the arid climate prevailing in Egypt should be tested and modified prior to application.

Image-based Water Level Measurement Method under Stained Ruler

This paper propoes the water level measuring method based on the image, while the ruler used to indicate the water level is stained. The contamination of the ruler weakens or eliminates many features which are required for the image processing. However, the feature of the color difference between the ruler and the water surface are firmer on the environmental change compare to the other features. As the color differeaces are embossed, only the region of the ruler is limited to eliminate the noise, and the average image is produced by using several continuous frames. A histogram is then produced on the height axis of the produced intensity average image. Local peaks and local valleys are detected, and the section between the peak and valley which have the greatest change is looked for. The valley point at this very moment is used to detect the water level. The detected water level is then converted to the actual water level by using the mapping table. The proposed method is compared to the ultrasonic based method to evaluate its accuracy and efficiency on the various contaminated environments.