A new process of combined pretreatment and dyeing: REST

Use of enzymes in textile processes has many advantages as far as the environmentally friendly processes are concerned. These advantages include water and energy savings, less chemical use, less fabric damage, mild and environmentally friendly process conditions. In this work, C.I. Reactive Yellow 15, C.I. Reactive Red 21 and C.I. Reactive Blue 19 were used to dye untreated woven cotton fabric in a laboratory scale dyeing machine, on a pilot scale jig and on a pilot scale winch by using a single bath combined process, in which various enzymes, namely, amylase, pectinase, and catalase were employed. This new process was named as the “Rapid Enzymatic Single-bath Treatment” (REST), since it was completed almost in half of the conventional dyeing time, and all of the stages, namely, desizing, scouring, bleaching and dyeing were carried out in a single bath without replacing the process water with fresh water until the end of the dyeing. In the REST process, the untreated, starch-sized fabric was first desized by amylase enzyme, and this was followed by a pectinase treatment in the same bath. The fabric was then bleached by H₂O₂ in the same bath, and after the hydrogen peroxide bleaching; the catalase enzyme was added to the bath to remove H₂O₂ residues before reactive dyeing. Without carrying out intermediate washings/rinsings between these processes, the reactive dyeing was carried out in a conventional way in the same bath, and finally, the fabric was taken from the bath and washed out. The colour yield was compared with the dyeings which were carried out conventionally in separate baths. Finally, the REST has many benefits in terms of water saving, reduced process time and energy consumptions compared to the conventional preparatory and dyeing process of cotton fabrics.     

Some aqueous reactions of potential importance in the atmospheric chemistry of mercury

Reactions of Hg(I) and Hg(II) with oxidizing and reducing agents have been investigated using stopped-flow and spectroscopic techniques. Hg₂²⁺ was found to be oxidized by HClO and radicals produced by Fentons reagent (Fe²⁺ + H₂O₂). The rate determining step in the reaction of Hg₂²⁺ and HClO is probably a relatively rapid reaction of Hg⁰ and HClO. A photochemically induced reduction of Hg(OH)₂(aq) to Hg⁰ was observed when irradiating with simulated sunlight (λ>290 nm), which may be a process of environmental importance. Aqueous Hg(CN)₂ and HgCl₂ were found to be stable. The rate of reduction of Hg(SO₃)₂²⁻ is not affected by irradiation. No oxidation of Hg₂²⁺ was found when mixing solutions containing H₂O₂ or Fe³⁺ or a mixture of the two which suggests that H₂O₂ is not an important oxidant for mercury under environmental conditions.     

基于LEAP模型的京津冀地区钢铁行业中长期减排潜力分析

京津冀地区是我国钢铁行业集中布局的地区,也是大气污染最突出的地区.分析京津冀地区钢铁行业各类治污工具的中长期减排影响,对于选择最优减排措施、加快推动该地区大气污染治理意义重大.构建基于LEAP模型的京津冀地区钢铁行业模型,以2015年为基准年,以每5 a为一个时间节点,结合规模减排、结构减排、技术减排、末端治理4种减排措施,模拟计算了4种单一政策情景及4种组合政策情景下2015-2030年京津冀地区钢铁行业主要污染物（SO₂、NO_x、PM₁₀、PM_2.5、CO₂）排放量及相应的减排影响.结果表明:在单一政策情景下,规模减排情景对5种污染物减排效果均十分显著.在组合政策情景下,4种减排措施叠加的综合减排情景效果最好,在该情景下京津冀地区钢铁行业到2030年SO₂、NO_x、PM₁₀、PM_2.5、CO₂排放量将分别削减27.73×104、17.85×104、42.94×104、27.35×104、23.15×107 t;在规模-末端治理情景下,除CO₂外其余污染物减排效果仅次于综合减排情景;规模-结构减排情景对PM₁₀和PM_2.5的减排效果相对明显;规模-技术减排情景对CO₂、SO₂、NO_x的减排效果相对明显.研究显示,京津冀地区钢铁行业需要在大力淘汰落后过剩产能、缩减产量等源头治理措施的基础上,持续加强末端治理、提高废钢比例、提升节能减排技术水平等协同治理能力,以提高治污减排效果.      

Studies on catalytic reduction of nitrate in groundwater

Catalytic reduction of nitrate in groundwater by sodium formate over the catalyst was investigated. Pd-Cu/γ-Al₂O₃ catalyst was prepared by impregnation and characterized by brunauer-emmett-teller (BET), inductive coupled plasma (ICP), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX). It was found that total nitrogen was effectively removed from the nitrate solution (100 mg/L) and the removal efficiency was 87%. The catalytic activity was affected by pH, catalyst amount used, concentration of sodium formate, and initial concentration of nitrate. As sodium formate was used as reductant, precise control in the initial pH was needed. Excessively high or low initial pH (7.0 or 3.0) reduced catalytic activity. At initial pH of 4.5, catalytic activity was enhanced by reducing the amount of catalyst, while concentrations of sodium formate increased with a considerable decrease in N₂ selectivity. In which case, catalytic reduction followed the first order kinetics. Translated from Acta Scientiae Circumstantiae, 2006, 26(4): 567–571 [译自: 环境科学学报]     

UASB反应器对印染废水中碳、氮、硫的协同去除研究

采用"UASB-缺氧好氧-混凝沉淀"组合工艺对印染废水进行中试处理研究.结果发现,UASB反应器不仅可以解决印染废水可生化性低、色度高的问题,还对废水中的碳、氮、硫具有协同去除作用,优化条件下UASB可将废水B/C从0.18~0.26提高至0.4以上,对色度、COD、TN、SO_4~(2-)、S~(2-)平均去除率分别为77.0%、36.4%、38.5%、77.5%、60.1%.同时,为了探究碳、氮、硫协同去除机理,对优化条件下的运行数据进行了分析并采用454高通量测序技术进行菌种鉴定.结果表明,UASB反应器内存在硫酸盐还原、厌氧氨化、同步脱硫反硝化和硝化反硝化4种作用,从而造成了碳、氮、硫的同步去除.菌种鉴定未发现产甲烷菌,说明产甲烷菌受到了抑制,UASB反应器很好地停留在了水解酸化阶段.进一步结合小试研究得出,硫酸盐还原是促使硝化反硝化、脱硫反硝化产生的原因,同时也促进了有机物去除.总体而言,硫酸盐还原促进了碳、氮、硫的协同去除.     

Pilot study on bromate reduction in ozonation of water with low carbonate alkalinities by carbon dioxide

A pilot study was carried out to explore the application of carbon dioxide for pH depression in a bubble column and its ability to inhibit bromate formation for water with a low alkalinity. Results showed that in the absence of ammonia, CO2 was capable of reducing bromate 38.0%–65.4% with one-unit pH depression. CO2 caused a slightly lower bromate reduction (4.2%) than did H2SO4 when the pH was depressed to 7.4, and a more a pronounced lower reduction (8.8%) when the pH was depressed to 6.9. In the presence of 0.20 mg/L-N ammonia, bromate was largely inhibited with 73.9% reduction. When the pH was depressed to 7.4, CO2 and H2SO4 showed an 11.3% and 23.5% bromate reduction respectively, demonstrating that the joint use of CO2 and ammonia might be a plausible strategy of blocking all three bromate formation pathways. CO2 could be applied through the aeration diffuser together with ozone gas, resulting in a similar bromate reduction compared with the premixing method through Venturi mixer.     

基于达标约束的南京市环境空气质量情景模拟

以2030年南京市6项污染物达标为约束,在2015年大气污染物排放清单基础上,利用CMAQ模型分析了PM_(2.5)对南京本地不同前体物排放的敏感性,通过情景分析预测排放清单,模拟了4种减排情景的空气质量变化,最终获得达标约束下大气污染物总量控制指标.模拟结果显示,减少一次颗粒物PPM (primary particulate matter)排放对降低大气中的PM_(2.5)浓度最为有效;在周边地区减排的基础上,本地减少PPM排放对PM_(2.5)年均浓度下降的相对贡献可达88%,其次为NH_3、NOx、SO_2与VOCs减排,其相对贡献分别为10. 3%、5. 5%、3. 2%与0. 5%;相比2015年,4种情景下南京市主要大气污染物减排比例在22%～53%,未来控制活动水平对减排SO_2、NH_3与CO较有效,而NOx和VOCs末端治理方面还有较大空间;将SO_2、NOx、PM10、PM_(2.5)、BC、OC、CO、VOCs及NH_3的排放量分别控制在2. 43×104、8. 47×10~4、9. 42×10~4、3. 74×10~4、0. 19×10~4、0. 30×10~4、26. 56×10~4、13. 08×10~4及1. 50×10~4t以内时,预计南京市6项污染指标可以达到国家环境空气质量二级标准.     

东莞市低碳路径下加速电气化对CO2和污染物协同减排影响

城市是能源消耗的中心，电气化可以整合城市能源结构，实现清洁能源高效利用，探究城市低碳路径下加速电气化的协同减排影响对实现城市减污降碳至关重要.基于长期能源替代规划模型(LEAP-DG),设置了基准情景、低碳情景和加速电气化情景等3类情景，评估电气化措施在不同电力结构下的减排潜力，量化重点部门的措施贡献，探讨广东省典型制造业城市东莞的协同减排效果.结果表明，电力结构优化促进了电气化措施的协同减排效果，低碳路径下加速电气化将进一步降低电力污染物排放强度，2050年，东莞市CO₂、 NO_x、 VOC和CO减排7.35×10⁶、 1.28×10⁴、 1.62×10⁴和8.13×10⁴ t, SO₂和PM_2.5消费侧减排量和生产侧增排量达到平衡.电气化渗透速率和电力结构优化协调发展是电气化措施实现减排效益的关键，工业和交通部门加速电气化将同时降低CO₂和大气污染物排放，交通部门得益于燃油车和电动车的高...     

Baseline options and greenhouse gas emission reduction of clean development mechanism project in urban solid waste management

The Clean Development Mechanism (CDM) was adopted in the Kyoto Protocol as a flexibility mechanism to reduce greenhouse gases (GHGs) and has been started with such projects as improving efficiency of individual technology. Although applying various countermeasures to urban areas has significant potentials for reducing GHGs, these countermeasures have not been proposed as CDM projects in the practical stage. A CDM project needs to be validated that it will reduce GHGs additionally compared with a baseline, that is, a predictive value of GHG emissions in the absence of the project. This study examined the introduction of solid waste incineration with electricity generation into three different cities, A, B and C. The combination of main solid waste treatment and fuel source are landfill and coal, respectively, in City A, incineration and natural gas in City B, and landfill and hydro in City C. GHG emission reductions of each city under several baseline options assumed here were evaluated. Even if the same technology is introduced, the emission reduction greatly varies according to the current condition and the future plan of the city: 1043–1406 kg CO₂/t of waste in City A, 198–580 kg CO₂/t in City B, and wide range of zero to over 1000 kg CO₂/tin City C. Baseline options also cause significant difference in the emission reduction even in the same city (City C). Incinerating solid waste after removing plastics by source separation in City B increased GHG emission reduction potential up to 730–900 kg CO₂/t, which enhances the effectiveness as a CDM project. This revised version was published online in August 2006 with corrections to the Cover Date.     

The influence of operational flexibility on the exploitation of CO2 reduction potential in industrial energy production

Energy conservation is a key measure for reducing CO₂ emissions. However, realising the emission reduction potential of an energy conservation investment depends on many factors, such as energy prices. The EU emissions trading scheme has made the investment analysis more complicated and increased the economic value of operational flexibility under fluctuating carbon prices. The different operational options in industrial energy production complicate the estimation of CO₂ reduction potential in the investment phase. Increasing operational flexibility enables optimisation in the economic dimension, which may lead to less than optimum CO₂ reduction. In our case study, which analysed the effects of an energy conservation investment made in the pulp and paper industry, the deviation from the expected emission reduction was around 30% over the period from 2000 to 2007. However, it seems that with high carbon prices, increasing operational flexibility has no significant effect on the carbon emissions. In policy-making, the freedom of action that is made possible by increasing operational flexibility should be taken into account when evaluating the contribution of an individual energy efficiency investment towards meeting the national targets for energy efficiency improvement and CO₂ emission reduction.     

双氧水协同生化法强化处理印染废水

传统生化法对印染废水的处理有一定的局限性.本文研究了双氧水协同水解酸化-接触氧化系统,对印染废水进行强化处理.采用污泥挂膜、生化系统启动、双氧水协同启动的方法,将双氧水投加到水解酸化时的条件严格控制为:投加3m L·L~(-1)、投加量100.0 m L、流速0.67 m L·min-1、投加频率1次·d-1,可使整个系统成功启动与稳定运行.实验结果表明,双氧水协同水解酸化-接触氧化可对印染废水中的特征污染物进行有效强化处理.其中,COD平均去除率为89.8%,氨氮平均去除率为96.7%,PVA平均去除率为87.4%,废水平均脱色率为92.1%.采用16S rDNA宏基因组高通量测序技术,对比分析了接种种泥、水解酸化污泥和接触氧化污泥微生物的群落结构.结果表明,经过驯化,水解酸化和接触氧化微生物群落均发现了显著变化.其中,水解酸化污泥优势菌门主要为变形菌门Proteobacteria、拟杆菌门Bacteroidetes和疣微菌门Verrucomicrobia;接触氧化污泥优势菌门主要为浮霉菌门Planctomycetes、变形菌门Proteobacteria和酸杆菌门Acidobacteria.该实验从宏观和微观角度,均证实双氧水协同生化法强化处理印染废水具有技术可行性.     

Biphasic reduction model for predicting the impacts of dye-bath constituents on the reduction of tris-azo dye Direct Green-1 by zero valent iron (Fe)

Influence of common dye-bath additives, namely sodium chloride, ammonium sulphate, urea, acetic acid and citric acid, on the reductive decolouration of Direct Green 1 dye in the presence of Fe⁰ was investigated. Organic acids improved dye reduction by augmenting Fe⁰ corrosion, with acetic acid performing better than citric acid. NaCl enhanced the reduction rate by its ‘salting out’ effect on the bulk solution and by Cl⁻ anion-mediated pitting corrosion of iron surface. (NH₄)₂SO₄ induced ‘salting out’ effect accompanied by enhanced iron corrosion by SO₄^2 − anion and buffering effect of NH₄⁺ improved the reduction rates. However, at 2 g/L (NH₄)₂SO₄ concentration, complexating of SO₄^2 − with iron oxides decreased Fe⁰ reactivity. Urea severely compromised the reduction reaction, onus to its chaotropic and ‘salting in’ effect in solution, and due to it masking the Fe⁰ surface. Decolouration obeyed biphasic reduction kinetics (R² > 0.993 in all the cases) exhibiting an initial rapid phase, when more than 95% dye reduction was observed, preceding a tedious phase. Maximum rapid phase reduction rate of 0.955/min was observed at pH 2 in the co-presence of all dye-bath constituents. The developed biphasic model reckoned the influence of each dye-bath additive on decolouration and simulated well with the experimental data obtained at pH 2.     

A new method for assessing CO2-emissions from container terminals: a promising approach applied in Rotterdam

At present, the notion is generally accepted that societies have to combat climate change. The reduction of CO₂-emissions, an important cause for global warming, has become a priority, and consequently there is increasing pressure on governments and industries to come forward with initiatives to reduce CO₂-emissions. This is highly relevant for the transport sector, as the share of transportation is still increasing, while other sectors are reducing their CO₂-footprint. The main purpose of this paper is to present a methodology to analyse the CO₂-emissions from container terminals, illustrated by the Port of Rotterdam.The objective of this paper is twofold. Firstly, the development of a methodology to analyse and gain a better understanding of the CO₂-emissions by container terminals in port areas is described. Secondly, the most effective solutions to reduce CO₂-emissions by container terminals in port areas are identified. The study provides insight into the processes of container transshipment at the terminals and the contribution of these processes to the CO₂-emissions of the container terminals. Using these insights, potential solutions to reduce the CO₂ at the terminals are identified and policy proposals are made for the operators of existing terminals and for governments.The most effective measure for CO₂ reduction is undoubtedly the adaptation of the terminal layout as in the example of the Rotterdam Shortsea Terminal. This makes it possible to reduce the CO₂-emissions of the current terminals by nearly 70 per cent. The other perspective is the incorporation of mixing 30 per cent biofuels with the presently used diesel. This results in a reduction of CO₂-emissions by between 13 and 26 per cent per terminal and a reduction of the emissions of the total container sector by 21 per cent. On the basis of these findings, concrete recommendations are made to reducing CO₂-emissions at container terminals.     

ClO2氧化-活性炭吸附法处理染色废水的试验研究

用ClO     

Effective removal of phosphorus from high phosphorus steel slag using carbonized rice husk

High phosphorus steel slag and carbonized rice husk are two common wastes characterized by high generation and low secondary use values.Through the reduction of high phosphorus steel slag by biomass,both wastes were fully utilized,thus reducing the negative impact on the environment.In this study,variables such as temperature,time,and amount of reactants were changed to determine the optimal conditions for the reaction of steel slag with carbonized rice husk at high temperatures.The actual amoun...     

厌氧水解酸化-好氧氧化A1/A2/O工艺剩余污泥减量

在碱减量印染废水A₁/A₂/O生物处理系统,通过污泥回流、把剩余污泥回流到A₁段,利用A段污泥的水解、酸化和O段微生物的好氧氧化作用可有效实现对回流剩余污泥的减量,同时O段好氧污泥的表观产率系数下降,系统产生的剩余污泥量减少.厌氧水解酸化-好氧氧化A₁/A₂/O工艺实现污泥减量由3段共同完成:A₁段实现回流剩余污泥的“液化”和惰性化;A₂段对系统污泥减量起到了强化作用;而O段微生物的合成作用在逐渐减弱.6个月连续运行的动态试验表明,在A₁段的容积负荷(COD_Cr)为2.54 kg·(m³·d)^-1、水力停留时间为7.56h条件下,A₁段利用水解酸化作用对回流剩余污泥的减量达到67.87%,系统O段好氧污泥的表观产率系数也下降到试验初始时的45.5%.在A₁/A₂/O污泥减量系统中,各段污泥性状发生了变化,A₁段污泥[MLVSS/MLSS]值从试验开始时的0.718 2下降到0.592 2,A₂段污泥[MLVSS/MLSS]值从0.667 3下降到0.526 7,剩余污泥的减量是活性污泥逐渐惰性化过程,污泥的粒度分析也证明了这一点.     

基于燃料生命周期的中国铁路排放趋势

铁路运输是现代运输的主要方式之一,在空气质量改善和"双碳"目标的双重约束下,厘清铁路运输CO₂和污染物排放趋势,对于交通领域的减污降碳工作具有重要意义.基于燃料生命周期法分析了中国火车2001~2018年的CO₂和污染物排放特征,在此基础上,结合情景分析评估了2019~2030年的铁路排放趋势.结果表明,随着铁路电气化进程的推进、内燃机车新车投入使用和燃油标准的不断升级,铁路运输燃料生命周期的CO₂和污染物排放整体分别呈上升和下降趋势,而其上游阶段的排放占比逐年升高.2018年铁路运输的CO₂、NO_x、CO、BC和SO_x排放总量分别为3780.29万t、11.98万t、3.94万t、0.20万t和3.08万t.情景分析表明,加快电力结构改善和降低单位运输能耗分别是降低铁路CO₂、SO_x和NO_x、BC、CO排放的最佳单一控制手段.积极应对铁路减污降碳工作的综合情景下,CO₂、NO_x、CO、BC和SO_x的减排率可分别达35%、37%、39%、32%和45%.电力结构改革和铁路电气化进程的停滞均会造成铁路运输排放总量的显著增加,铁路减污降碳工作仍需高度重视.     

新型氧化石墨烯生物纳米材料对印染废水中镉和孔雀石绿的去除性能及机制

印染废水因其成分复杂,并且难以被自然去除,己成为环境的重点污染源之一.本研究采用甘蔗渣还原液还原氧化石墨烯,并负载伯克霍尔德菌成功制备了新型生物纳米材料MNMs.采用SEM-EDS-Mapping和Raman分析证实该材料具有较好的结构稳定性和良好的吸附效果,并对印染废水的典型污染物Cd²⁺和孔雀石绿的联合去除率均达到80%以上.GC-MS检测结果证实该复合纳米材料可将孔雀石绿降解为N,N-二甲基苯胺和4-（二甲基氨基）二苯甲酮.动力学拟合分析表明Cd²⁺和孔雀石绿被MNMs吸附过程遵循伪二级速率模型（R²>0.99）,而MG的降解过程更遵循伪一级速率模型（R²>0.99）.MNMs对Cd²⁺和MG的理论最大吸附量分别为84.03 mg·g^-1和45.25 mg·g^-1.研究结果表明,该生物纳米材料对水溶液中Cd²⁺和孔雀石绿有较好的去除效果,未来可应用于工业印染废水的污染控制.     

郑州市公交车队电动化减污降碳环境效益

公交车队电动化是道路交通部门实现减污降碳的重要手段,评估当前公交车队电动化减排成效,对推进大中型城市公交全面电动化具有重要参考意义.基于燃料生命周期法分析了郑州市公交车队电动化前后CO₂和污染物排放特征,并评估了不同电动化情景下的车队排放.结果表明,本轮电动化使公交车队燃料生命周期内CO₂和PM_2.5排放量分别增长32.6%和42.6%,CO、NO_x和VOC排放量下降了28%,34%和25%.优化发电结构对于电动化过程中的CO₂及PM_2.5减排尤为重要,在全面电动化和发电结构优化的最佳情景下,CO₂、CO、NO_x、VOC和PM_2.5减排可达38.7%、80.1%、84.4%、92.2%、30.2%.在全面电动化进程中,应优先对中长里程线路车辆进行电动化替换,此外,插电混动天然气车型的纯电动化替换对减排利弊兼有,同步推进车队替换和电力结构调整进程才能实现减污降碳协同增效.     

中国平板玻璃生产碳排放研究

平板玻璃行业是典型的高能耗、高排放行业,目前关于中国平板玻璃行业的碳排放问题还没有得到深入的研究.因此,本文调查了中国300余条主要的平板玻璃生产线,并在此基础上从范围1(工艺过程和化石燃料燃烧引起的直接排放)和范围2(净购入电力和热力在生产阶段引起的间接排放)评估了中国平板玻璃行业从2005年到2014年的CO_2排放情况.结果发现,中国平板玻璃行业CO_2排放量逐年增加,由2005年的2626.9×10~4t逐步上升到2015年的4620.5×10~4t.研究表明:能源消耗是平板玻璃行业碳排放的最主要来源,占比在80%左右,节能降耗是促进平板玻璃行业CO_2减排的主要途径;平板玻璃生产原料中碳酸盐的热分解是CO_2的主要来源之一,占总排放量的20%左右,控制平板玻璃配合料的气体率,在减少平板玻璃生产过程中的CO_2排放有很大潜力;推荐平板玻璃新建项目使用天然气并配备大型熔窑(日熔化量650 t以上)的浮法玻璃生产线,以减少CO_2排放.