麦秸制浆造纸废水深度处理中试研究

采用催化氧化—絮凝—沉淀工艺深度处理麦秸制浆造纸废水,处理规模为200 m3/d.在进水COD为150 ～ 263 mg/L、色度为64～128倍、SS为50～ 88 mg/L的水质情况下,处理后出水水质稳定,COD为38～ 52mg/L,色度为2～8倍,SS为12～23 mg/L,出水水质达到GB3544-2008《制浆造纸工业水污染物排放标准》的要求.采用该工艺深度处理麦秸制浆造纸废水的费用不超过0.55元/m3.     

工业含铁废盐酸治理技术有突破

2001年 11月 1日,由长春铁塔厂与东北师范大学合作研究的工业含铁废盐酸资源化治理技术在长春通过专家鉴定。用该项技术处理工业含铁废盐酸污水,可实现盐酸回收、无二次污染、污水达标排放的目的。 我国现有各种电镀 (火镀 )厂 2000余家,按每个厂家日排 1吨废盐酸计算, 1年要排放废酸 70多万吨。目前,国内多数工厂采用中和法处理含酸废液,虽然中和法具有工艺简单、对设备要求不高、易操作的特点,但在处理废酸液过程中,会产生氢氧化铁和大量废水,致使污水难以达标排放,并带来二次污染。 新开发的工业含铁废盐酸资源化治理技术在解决废酸液方面具有明显的综合优势：设计简便,操作方便,方法实用;盐酸回收率高达 95％,硫酸亚铁总回收率达 97％;实现清洁化生产。因此该技术是目前代替中和法处理工业含铁废盐酸的理想方法。 据了解,采用这项技术处理 500吨含酸废液,扣除运行成本后,可获得 33.2万元经济效益。 专家指出,该技术可以电镀、金属表面抛光等行业广泛推广应用。 (于平 ) 中国环境报 2001年 11月 12日     

改性粉煤灰催化类Fenton试剂氧化法深度处理造纸废水

采用改性粉煤灰催化类Fenton试剂氧化法处理造纸废水,对COD去除率的各影响因素进行了研究。实验结果表明,在酸改性粉煤灰加入量为34 g/L、H2O2加入量为8.20 mmol/L、FeSO4加入量为8.8 mmol/L、反应时间为45 min、不调节pH的条件下,出水COD为56 mg/L,去除率可达76.45%。该法大大减少了运行费用,是一种有效的造纸废水深度处理方法。     

粉煤灰在废水处理中的应用

粉煤灰作为一种可再资源化的工业固体废弃物日益引起关注.粉煤灰处理废水的机理主要是吸附作用,影响粉煤灰吸附性能的主要因素有温度、粉煤灰粒度、pH值、吸附质性质、灰水比,粉煤灰处理生活污水、城市废水、印染废水、重金属废水、含氟、磷、有机质废水、造纸废水等应用前景广阔.     

造纸废水处理新技术的研究进展

造纸废水的处理一直是一个备受关注的环保难题,为此进行的研究也获得了很好的效果,如果这些技术能广泛应用于实践,将能基本上解决造纸废水的环境污染问题.高级氧化法、液膜法就是这类废水处理的新技术.从这些技术的机理、研究现状及存在问题出发,阐述了造纸废水处理新方法的研究实践及应用的可能性.     

国内简讯

废盐酸的综合利用在钨酸生产过程中,有大量废酸产生。目前国内都用石粉(主要成分CaCO_3)中和法治理废酸,此法虽具有简单易行的优点,但也存在治理不彻底和处理费用高的缺点。为寻求一种处理彻底,经济实用的治理方法,我们进行了废酸综合利用的试验。试验步骤如下: (1)沉降分离将废酸静置16小时以上,使细颗粒钨酸沉降与废酸分离。     

废酸浓缩回收装置的研究

废酸浓缩回收装置的研究化工、轻工、电镀、制药及冶金等行业,在某些生产过程中排放废硫酸、废盐酸、废硝酸等。这些废酸成分复杂,浓度变化大,绝大多数经中和处理后排放,处理费用高,造成资源浪费,甚至造成二次污染。国内对废酸的浓缩回收,通常采用钛质常压蒸发器或...     

实验室废水的处理

本文介绍了实验室废水的处理方法,将实验室浓、稀废水分别收集;浓废水分为浓有机废水,含汞、铬废酸和酸碱废水等三种,分别用焚烧法、水泥固定法与中和法处理;稀废水用活性炭吸附法处理。     

信息与动态

废酸洗液全封闭循环系统ChemicalEngineering,2004,111(7):16德国GoemaAG公司开发出一种工业化金属处理槽废酸洗液全封闭循环系统。目前,废酸洗液和漂洗液都是作为废水排放,因为还没有实际可行的回用该废液的方法。     

专利文摘

催化氧化处理苯甲醚废水的方法,不加药浮选处理含油废水的方法,一种用于油田钻井废水处理的集成化工艺和装置,一种造纸废水过滤装置,一种利用造纸废水处理污泥改良酸性土壤的方法,电活性铁氰化镍离子交换膜的制备及应用     

Determination of the Thermal Efficiency of Pre-boilover Burning of a Slick of Oil on Water

The burning rate of a slick of oil on a water bed is calculated by a simple expression derived from a one-dimensional heat conduction equation. Heat feedback from the flame to the surface is assumed to be a constant fraction of the total energy released by the combustion reaction. The constant fraction (χ) is named the burning efficiency and represents an important tool in assessing the potential of in situ burning as a counter-measure to an oil-spill. The total heat release, as a function of the pool diameter, is obtained from an existing correlation. It is assumed that radiative heat is absorbed close to the fuel surface, that conduction is the dominant mode of heat transfer in the liquid phase and that the fuel boiling temperature remains constant. By matching the characteristic thermal penetration length scale for the fuel/water system and an equivalent single layer system, a combined thermal diffusivity can be calculated and used to obtain an analytical solution for the burning rate. Theoretical expressions were correlated with crude oil and heating oil, for a number of pool diameters and initial fuel layer thickness. Experiments were also conducted with emulsified and weathered crude oil. The simple analytical expression describes well the effects of pool diameter and initial fuel layer thickness permitting a better observation of the effects of weathering, emulsification and net heat feedback to the fuel surface. Experiments showed that only a small fraction of the heat released by the flame is retained by the fuel layer and water bed (of the order of 1%). The effect of weathering on the burning rate decreases with the weathering period and that emulsification results in a linear decrease of the burning rate with water content.     

Calculation of carbon balances for evaluation of the biodegradability of polymers

Establishing carbon balances has been proven to be an applicable and powerful tool in testing biodegradability of polymers. In controlled degradation tests at a 4-L scale with the model polymer poly(-hydroxybutyrate) (PHB), it was shown that the degree of degradation could not be determined with satisfactory accuracy from CO₂ release alone. Instead, the course of degradation was characterized by means of establishing carbon balances for the degradation of PHB withAcidovorax facilis and a mixed culture derived from compost. Different analytical methods for determining the different carbon fractions were adapted to the particular test conditions and compared. Quantitative determination of biomass and residual polymer were the main problems in establishing carbon balances. Amounts of biomass derived from protein measurements depend strongly on assumptions of the protein content of the biomass. Selective oxidation of biomass with hypochlorite was used as alternative, but here problems arose from insoluble metabolic products. Determination of soluble components with the method of chemical oxygen demand (COD) also includes empirical assumptions but seems acceptable if the dissolved carbon fraction is in the range of some 10% total carbon. Results confirm both analytical assays and theoretical approaches, in ending up at values very close to 100%, within an acceptable standard deviation range under test conditions comparable to standard test practice.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.     

富拉尔基发电总厂200MW机组除尘器改造

对富拉尔基发电总厂5号炉的设计条件进行了分析，针对燃用低硫煤，飞灰比电阻高，场地较小，除尘效率要求高的情况，在电除尘器的设计上采取有效措施，达到了排放要求。     

Review of the kinetics of alkaline degradation of cellulose in view of its relevance for safety assessment of radioactive waste repositories

The degradation of cellulose (a substantial component of low- and intermediate-level radioactive waste) under alkaline conditions occurs via two main processes: a peeling-off reaction and a basecatalyzed cleavage of glycosidic bonds (hydrolysis). Both processes show pseudo-first-order kinetics. At ambient temperature, the peeling-off process is the dominant degradation mechanism, resulting in the formation of mainly isosaccharinic acid. The degradation depends strongly on the degree of polymerization (DP) and on the number of reducing end groups present in cellulose. Beyond pH 12.5, the OH^- concentration has only a minor effect on the degradation rate. It was estimated that under repository conditions (alkaline environment, pH 13.3-12.5) about 10% of the cellulosic materials (average DP = 1000-2000) will degrade in the first stage (up to 10⁵ years) by the peeling-off reaction and will cause an ingrowth of isosaccharinic acid in the interstitial cement pore water. In the second stage (10⁵-10⁶ years), alkaline hydrolysis will control the further degradation of the cellulose. The potential role of microorganisms in the degradation of cellulose under alkaline conditions could not be evaluated. Proper assessment of the effect of cellulose degradation on the mobilization of radionuclides basically requires knowing the concentration of isosaccharinic acid in the pore water. This concentration, however, depends on several factors such as the stability of ISA under alkaline conditions, sorption of ISA on cement, formation of sparingly soluble ISA-salts, etc. A discussion of all the relevant processes involved, however, is far beyond the scope of the presented overview.     

Study of Aging Characteristics of Ternary Blends of Polyethylenes—II

Six film samples of low-density polypropylene (LDPE)/linear LDPE (LLDPE)/high-density polypropylene (HDPE) with varying ratios of LDPE (20–45 ... wt%) and LLDPE (25–50 wt%) having a fixed amount of HDPE at 30 wt% were prepared by blown film extrusion technique. The samples were aged at four different temperatures, 55°, 70°, 85°, and 100°C, for four different time periods in the interval of between 150 hours and up to 600 hours. The change in the structure of various constituents and the formation of various oxygenated (peroxy and hydroperoxy) and unsaturated groups during thermo-oxidative degradation was discussed by infrared spectroscopy. The visiosity-average molecular weight was found to have decreased slowly in the initial aging hours and temperatures, whereas it decreased by 10% with its previous value tensile strength that is, 100°C when aged for 600 hours. The tensile strength of the sample first increased by 67% at 55°C and 89% at 70°C up to 450 hours, whereas the values increased by 52.5% at 85°C and 33.9% at 100°C when aged for 150 hours and then decreased. The percentage elongation at break increased by 2.7% at 55°C and 10.7% at 70°C for 150 and 300 hours of aging, respectively, whereas the percentage decreased when aged at 85°C and 100°C for up to 600 hours of aging. The values of gel content (percent) increased and initial degradation temperature decreased with aging time and temperature.     

Selection of adsorbents for treatment of leachate: batch studies of simultaneous adsorption of heavy metals

The simultaneous adsorption of copper (Cu), cadmium (Cd), nickel (Ni), and lead (Pb) ions from spiked deionized water and spiked leachate onto natural materials (peat A and B), by-product or waste materials (carbon-containing ash, paper pellets, pine bark, and semi-coke), and synthetic materials (based on urea-formaldehyde resins, called blue and red adsorbents) or mixtures thereof was investigated. The adsorbents that gave the highest metal removal efficiencies were peat A, a mixture of peat B and carbon-containing ash, and a mixture of peat A and blue. At an initial concentration of 5 mg/l for each metal, the removal of each species of metal ion from spiked water and spiked leachate solutions was very good (>90%) and good (>75%), respectively. When the initial concentration of each metal in the solutions was twenty times higher (100 mg/l), there was a noticeable decrease in the removal efficiency of Cu²⁺, Cd²⁺, and Ni²⁺, but not of Pb²⁺. Langmuir monolayer adsorption capacities, q_m, on peat A were found to be 0.57, 0.37, and 0.36 mmol/g for Pb²⁺, Cd²⁺, and Ni²⁺, respectively. The order of metal adsorption capacity on peat A was the same in the case of competitive multimetal adsorption conditions as it was for single-element adsorption, namely Pb²⁺ > Cd²⁺ ≥ Ni²⁺. The results show that peat alone (an inexpensive adsorbent) is a good adsorbent for heavy metal ions.     

袋式除尘器气流分布数值计算研究

采用结构化/非结构化混合网格技术、多孔介质模型及k-ε两方程湍流模型,对某袋式除尘器及进出口管道内的气体流场进行了数值计算.计算结果表明,合理布置导流板后,袋式除尘器两箱体流量偏差为1.8％;除尘器下游滤袋单元处理气量偏大,中游滤袋单元处理气量较小,最大流量与最小流量偏差为22.3％；靠近除尘器进口处灰斗内存在气流回流特性,易造成粉尘的二次附着现象.     

Effect of Degree of Substitution of Octenyl Succinate Starch on Enzymatic Degradation

Octenyl succinate starch of degree of substitution (ds) 0.03, 0.07, and 0.11 was synthesized in an aqueous medium. These compounds were then tested for the susceptibility to enzymatic degradation. The multiple-enzyme regime of -amylase, amyloglucosidase, and pullulanase was chosen for the evaluation. This combination of enzymes had been proven to degrade 99.5% of unmodified starch to glucose and hence was chosen for this study. It was found that even small amounts of subsituent caused a considerable decrease in the extent of degradation. The net extent of degradation decreased with increasing ds. Surprisingly, the amount of glucose from all three substituted substrates was quite similar, suggesting the effect small amounts of subtituent had on the enzymatic activity.     

Effects of temperature on the release of nutrient elements of solid organic materials under conditions of oversaturation

The effects of temperature on the release of chemical components of six solid organic materials under conditions of oversaturation were investigated in this paper. The six materials were peat moss (PM), weathered coals (WC), charred rice husks (CRH), sawdust (Sd), turfgrass clippings (TC), and chicken manure (CM). Significant differences were observed in the available nitrogen and phosphorus content of the aqueous extracts of organic materials at different temperatures. The available nitrogen content in aqueous extracts of PM and WC at 25 °C was higher than that registered at 15 °C and 35 °C. Available nitrogen content in the aqueous extracts of CRH, Sd, TC, and WC at 35 °C was higher than at 15 °C and 25 °C. The available phosphorus content in the aqueous extracts of organic materials at 35 °C was higher than that available at 15 °C and 25 °C, with the exception of Sd. In addition, the release of available phosphorus in the aqueous solution of organic materials at different temperatures varied constantly for 108 h. The release of potassium (K⁺) and sodium (Na⁺) ions in the aqueous extracts of organic materials was basically steady over time, with the exception of CM. High temperature (35 °C) may significantly hasten the release of K⁺ from organic substrates (except for WC) with low temperatures significantly inhibiting release of K⁺ in Sd and CRH. High temperatures (35 °C) might significantly facilitate the release of Na⁺ in CM and TC. However, no significant differences were manifested in the release of Na⁺ from organic substrates at different temperatures, with the exception of CM and TC. Moreover, no significant differences were observed in the release of calcium, magnesium and iron ions with time, nor were there any significant differences in the contents of iron ions in the aqueous extracts of organic materials at different temperatures. The results indicate that multiple mediums should be pretreated in water for a week before being used for planting. They should be used when all mineral elements of organic materials are steady and ignoring the effect of organic mediums.     

Kinetics of Hydrolytic Degradation of PLA

The chemical recycling of poly(lactic acid) (PLA) to its monomer is crucial to reduce both the consumption of renewable resources for the monomer synthesis and the environmental impact related to its production and disposal. In particular, the production of lactic acid from PLA wastes, rather than from virgin raw materials, it is also possible to achieve considerable primary energy savings. The focus of this work is to analyse deeply the PLA hydrolytic decomposition by means of a kinetic model based on two reactions mechanism. To this end, new experimental data have been gathered in order to investigate a wider temperature range (from 140 to 180 °C) and to extend the water/PLA ratio up to 50 % of PLA by weight. The reported results clearly highlight that more than 95 % of PLA is hydrolyzed to water-soluble lactic acid within 120 min, when it is hydrolyzed within 160–180 °C. Furthermore, the kinetic constant is highly influenced by reaction temperature. The proposed “two reactions” kinetic mechanism complies satisfactorily with the experimental data under analysis.