煤化工企业高盐废水的“零排放”技术

采用"混凝沉淀—微滤—组合反渗透"工艺对某煤化工企业的高盐废水进行浓缩处理,浓水通过蒸发结晶进行脱水,产水采用常规反渗透进行水回收。运行结果表明,经30 d运行,水回收率保持在85%以上,脱盐率稳定在95%以上,常规反渗透产水水质稳定,产水电导率、浊度、Cl-质量浓度和COD的平均值分别为12.5μs/cm,0.1 NTU,7.8 mg/L,1.8 mg/L,满足《炼化企业节水减排考核指标与回用水质控制指标》(Q/SH0104—2007)中污水回用于循环冷却水的水质指标和设计产水水质要求,实现了废水的近"零排放"。     

石化污水反渗透浓水“零排放”技术

采用微滤—反渗透(RO)—蒸发—结晶工艺处理某石化企业的RO浓水,实现了RO浓水的“零排放”.试验结果表明:经加碱、微滤后,污水硬度平均减小率为98.8％,排出的滤渣平均质量分数为9.4％,减少了污水中有机物和微生物对后续RO膜的污染;微滤产水无需降低pH,可直接进入RO系统,电导率减小率可达98.0％;蒸发可将总固体质量浓度由13 290 mg/L增至172 155 mg/L,产水电导率为66 μS/cm.     

气相色谱法测定水和土壤中苯醚甲环唑的残留量

研究并建立了气相色谱法测定水和土壤中苯醚甲环唑残留量的分析方法。实验结果表明：水中添加苯醚甲环唑的含量为0．005～0．500mg／kg时,平均回收率为97．9％～100．5％,相对标准偏差小于6．7％;土壤中添加苯醚甲环唑的含量为0．005～0．500mg／kg时,平均回收率为95．7％～109．5％,相对标准偏差小于7．5％。将该法用于水和土壤残留实验,土壤试样在拖药后10～88d进行采样分析,其残留消解动态回归方程为y=0．8803e^-0.0122x,相关系数为-0．915,消解半衰期为56．8d;水试样在施药后0～21d进行采样分析,其残留消解动态回归方程为y=0．2624e^-0.2539x,相关系数为-0．899,消解半衰期为2．7d。     

纳滤处理炼化污水反渗透浓水

分别采用4种纳滤膜处理某炼化公司的反渗透浓水。在初始COD为57.8 mg/L、TOC为23.94 mg/L、ρ(Ca2+)为289.0 mg/L、ρ(Mg2+)为54.6 mg/L、ρ(SO42-)为327.7 mg/L、ρ(Cl-)为1 106.8 mg/L的条件下,经纳滤处理后COD去除率达60%以上,污水COD降至30 mg/L以下,TOC去除率为31.9%~85.5%,阳离子的去除率为33.9%~97.0%,SO42-的去除率为63.3%~97.6%,Cl-的去除率较低。膜A的膜孔分布密集,具有很高的通量,对有机物和无机盐的截留效果较差;膜B和膜C对有机物和二价离子的截留效果较好;膜D的膜孔分布稀松,膜通量最低,对有机物和无机盐的截留能力均较强,但随出水体积的增加,对无机盐的截留能力下降较为明显。4种纳滤膜的性能各异,可满足不同企业的需求,具有良好的应用前景。     

煤化工企业高盐废水的“零排放”技术

采用“混凝沉淀-微滤-组合反渗透”工艺对某煤化工企业的高盐废水进行浓缩处理,浓水通过蒸发结晶进行脱水,产水采用常规反渗透进行水回收。运行结果表明,经30 d运行,水回收率保持在85%以上,脱盐率稳定在95%以上,常规反渗透产水水质稳定,产水电导率、浊度、Cl^-质量浓度和COD的平均值分别为12.5 μs/cm,0.1 NTU,7.8 mg/L,1.8 mg/L,满足《炼化企业节水减排考核指标与回用水质控制指标》（Q/SH0104-2007）中污水回用于循环冷却水的水质指标和设计产水水质要求,实现了废水的近“零排放”。     

催化臭氧氧化—生物活性炭吸附组合工艺处理反渗透浓水

采用催化臭氧氧化—生物活性炭吸附组合工艺处理反渗透(RO)浓水,比较了4种催化剂催化臭氧氧化的性能,优化了初始RO浓水pH、臭氧氧化时间、生物活性炭柱空床停留时间(EBRT)等工艺条件。实验结果表明:以WP-01为催化剂催化臭氧氧化RO浓水时无需调节废水pH;臭氧氧化反应5 min时RO浓水的BOD5/COD达0.28,可生化性得到显著改善;WP-01催化剂重复使用30次其催化活性没有明显下降;生物活性炭吸附单元的EBRT控制在30 min左右,可确保出水COD稳定在50 mg/L以下,符合GB 18918—2002《城镇污水处理厂污染物排放标准》的一级A标准;催化臭氧单元处理每吨RO浓水的电费约为1.22元。     

石化厂污水反渗透浓水的催化臭氧氧化处理

针对某炼油厂二沉池出水回用过程中产生的反渗透浓水高盐、高硬、低COD和可生化性差的特点,采用催化臭氧氧化工艺处理,出水达标排放.实验确定了对臭氧氧化催化效果最好的催化剂,合适的反应条件为:反应时间大于30 min,臭氧质量浓度15-30 mg/L.经催化臭氧氧化处理后,反渗透浓水的COD降低至60 mg/L以下,满足排放要求,同时反渗透浓水可生化性提高.     

十三烷基苯磺酸钠和辛基酚聚氧乙烯醚二元复配溶液的定量分析

采用向十三烷基苯磺酸钠(STBS)和非离子表面活性剂辛基酚聚氧乙烯醚(OP-10)二元复配溶液中添加β-环糊精(β-CD)的方法,降低STBS和OP-10之间定量检测时的相互干扰。实验结果表明:添加β-CD时,可提高STBS的检测准确性,降低STBS对OP-10的检测干扰;在二元复配溶液中,STBS和OP-10的方法回收率分别在100.8%~102.0%,97.4%~102.2%之间,检测误差分别在2.0%和2.6%以内;Cl-,SO42-,Na+,Ca2+的存在对二元复配溶液中STBS和OP-10的检测干扰可忽略;将该方法应用于地层水水样中,仍可准确定量分析STBS和OP-10的含量。     

负载MnO2陶瓷膜催化臭氧氧化处理石化污水反渗透浓水

采用陶瓷膜催化臭氧氧化技术处理石化污水反渗透浓水.考察了MnO2/Al2O3陶瓷膜和Al2O3陶瓷膜对臭氧分解率、羟基自由基浓度以及水中有机物处理效果的影响.实验结果表明:MnO2/Al2O3陶瓷膜能够显著提高臭氧分解率,生成的羟基自由基浓度相比单独臭氧体系提高了21.2％;在臭氧投加量为50 mg/L时,MnO2/A...     

“UBF-BAF-气浮-UF-树脂吸附-RO”工艺处理印染废水

采用“复合式厌氧流化床反应器（UBF）-曝气生物滤池（BAF）-气浮-超滤（UF）-树脂吸附-反渗透（RO）”工艺对低浓度印染废水进行深度处理，通过60 d的现场试验重点考察了树脂吸附对RO产水率、产水水质以及浓水水质的影响。试验结果表明：低浓度印染废水经该工艺处理后，RO产水COD≤30 mg/L、产水率为75%～80%，满足中水回用要求；RO浓水COD≤150 mg/L、色度≤50倍、SS约为35 mg/L，符合纳管排放标准；系统稳定运行期间，平均处理成本为5.11元/t，扣除中水回用节约的用水费用后，综合处理成本仅1.36元/t。     

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.     

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.     

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。     

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.     

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.     

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.     

Effect of depth of landfill on the characteristics of soil-like material of aged waste: a case study of Bhalswa dumpsite,India

Journal of Material Cycles and Waste Management - This study characterizes the municipal solid waste (MSW) accumulated for more than 25 years at Bhalswa dumpsite, Delhi, India. 50...