Utilization of trommel sieve waste as an additive in Portland cement production

Large quantities of industrial wastes form in boron industry in Turkey every year. These wastes have dual problems of disposal and health hazards. The wastes such as borax slime, tincal waste, concentration wastes and thromel sieve waste (TSW) contain impurities that accelerate the normal setting and hardening of building materials produced from them. In this study, it was aimed to stabilize TSW produced during manufacture of borax from tincal. The effects of TSW added on the mechanical properties of Portland cement prepared by adding TSW to clinker were investigated. The utilization of TSW in cement industry as an additive was tested and compared with other materials.     

Cost reduction of the wastewater treatment plant operation by MPC based on modified ASM1 with two-step nitrification/denitrification model

The Activated Sludge Model No. 1 (ASM1) considers that nitrification and denitrification are single step processes and nitrite nitrogen (NO₂-N), which is an intermediate for the two processes, is not accounted for. The first part of this paper presents the development of an enhanced ASM1 with two step nitrification/denitrification processes and its implementation in the Benchmark Simulation Model No.1 wastewater treatment plant (WWTP). The secondary settler was considered to be reactive in order to achieve a better fit between the simulation model and the behavior of the real WWTP. The second part presents the investigation of Model Predictive Control approach for the advanced control of the WWTP. Two control strategies are implemented for the wastewater treatment plant and they are analyzed from the perspective of the benefits brought to the WWTP operation. The proposed control strategy shows a reduction of the operational costs and the improvement of the effluent quality index.     

Synthesis of non-isothermal heat integrated water networks in chemical processes

This paper presents a new approach for the simultaneous synthesis and optimization of heat integrated water networks. A new superstructure for heat exchanger network (HEN) synthesis is proposed. The procedure is based on mixed integer non-linear mathematical programming (MINLP). Four relevant examples are presented to illustrate various aspects of the proposed approach.     

磷肥含氟废水输送装置的技术改造

对含氟废水处理装置进行了改造 :增加水封罐 ,选用与水封罐相联的高硅铁卧式离心泵代替原立式液下泵。通过计算 ,确定了水封罐的容积和尺寸。改造后 ,不仅增加了废水调节池的有效容积 ,且泵的耐蚀性和耐磨性得以显著改善 ,装置得以正常运行。     

Optimal water purification using low grade waste heat in an absorption heat transformer

A proposal for rational energy saving using wasted heat is showed in the present paper. Thermodynamicmathematical model is presented like an effort for water purification from waste heat. This paper describes computing results of heat transformer operation for water purification using low grade waste heat. Equations, parameters and simplifications used in the model are briefly described. The main parameter of the carried out study is the coefficient of performance (COP) defined for reversed heat pumps and the second main parameter is absorber temperature, both parameters has been showed and correlated between them. Main objective of this work is to show the optimal operating condition for different process which deliver low grade waste heat and requires water purification. Assisted computing simulation was used for obtain these results. The main conclusion is an ecological proposal for optimal recover of low grade waste heat. Many operating conditions are showed in graphical form and discussed for different environment conditions.     

在氮气中处理聚丙烯腈纤维的不熔化工艺

聚丙烯腈纤维不熔化过程的前期(220℃)在氮气中热处理,后期(220℃)在空气中热处理,与常规全程空气中热处理进行对比,希望能够降低不熔化处理的成本。借助元素分析(EA)、热重分析仪(TGA)、环境扫描电子显微镜(ESEM)、力学性能分析等表征手段,研究了不同热处理方法对PAN不熔化纤维的氧化程度和皮芯结构影响以及碳化收率和碳纤维的力学性能。结果发现,与全程空气处理相比,经过氮气气氛处理后的不熔化纤维在后续处理过程中最终不熔化温度可以降低20℃,900℃碳化后的收率增加了3.8%,碳纤维的强度相当,初步估算节能8.7%。     

N2O and NO emissions from different N sources and under a range of soil water contents

Emissions of nitrous oxide (N₂O) and nitric oxide (NO) have been identified as one of the most important sources of atmospheric pollution from grasslands. Soils are major sources for the production of N₂O and NO, which are by-products or intermediate products of microbial nitrification and denitrification processes. Some studies have tried to evaluate the importance of denitrification or nitrification in the formation of N₂O or NO but there are few that have considered emissions of both gases as affected by a wide range of different factors. In this study, the importance of a number of factors (soil moisture, fertiliser type and temperature) was determined for N₂O and NO emissions. Nitrous oxide and NO evolution in time and the possibility of using the ratio NO:N₂O as an indicator for the processes involved were also explored. Dinitrogen (N₂) and ammonia (NH₃) emissions were estimated and a mass balance for N fluxes was performed. Nitrous oxide and NO were produced by nitrification and denitrification in soils fertilised with and by denitrification in soils fertilised with . Water content in the soil was the most important factor affecting N₂O and NO emissions. Our N₂O and NO data were fitted to quadratic (r=0.8) and negative exponential (r=0.7) equations, respectively. A long lag phase was observed for the N₂O emitted from soils fertilised with (denitrification), which was not observed for the soils fertilised with (nitrification) and was possibly due to a greater inhibiting effect of low temperatures on microbial activity controlling denitrification rather than on nitrification. The use of the NO:N₂O ratio as a possible indicator of denitrification or nitrification in the formation of N₂O and NO was discounted for soils fertilised with . The N mass balance indicated that about 50 kg N ha⁻¹ was immobilised by microorganisms and/or taken up by plant roots, and that most of the losses ocurred in wet soils (WFPS >60%) as N₂ and NH₃ losses (>55%).     

利用多种废水作水源的鞍钢冶炼净环水的水质稳定

介绍了鞍山钢铁公司冶炼净环水（ 净循环水） 系统,利用多种净化废水作补充水源,从而提高了水的重复利用率,缓解了鞍钢用水的紧张状况,并保证了水质稳定的经验．该经验的特点是：（１） 利用废水,例如焦化厂废水使净环水的水质稳定;（２） 把系统的高温回水用于矿山浮选,既可节能,又可降低净环水的浓缩倍数、结垢倾向和排污量;（３） 减少了建设新水源的工程费用;（４） 总共节约了人民币３ １２７ ．５ 万元,经济效益明显．该经验为废水资源的利用和老企业的技术改造,闯出了一条新路     

超临界水在降解废弃物及资源化中的应用

综述了超临界水的特性及其在降解废旧塑料、橡胶、纤维素等废弃物及资源化中的应用现状。与传统热分解方法相比,超临界水可实现对高分子废弃物的快速、有效分解,通过分解反应条件的控制,可以控制产物组成,是一种很有前途的废弃物资源化技术。     

离子交换除盐水处理系统中废液的利用

本文研究了利用离子交换除盐水处理系统再生废酸碱液．作氯－钠离子交换法的再生剂使用的原理、方法及其降碱软化工艺特性。     

Durability of concrete with addition of dry sludge from waste water treatment plants

This paper evaluates the use of dry sludge as an additive for concrete, for which it must be guaranteed that the resulting concrete has the appropriate mechanical strength and durability.In earlier work on the subject, it was shown that the addition of sludge reduces the mechanical strength of concrete. With the addition of 10% sludge in proportion to the amount of concrete, the mechanical strength decreases significantly, making it unsuitable for medium- to high-strength reinforced concrete.One possible area of application would be in the preparation of low-strength mass concrete that could be used for bases and subbases of roads with light traffic, as filler, etc.We subjected the concrete specimens to different types of accelerated attack in order to evaluate long-term performance and compare them with the reference concrete (not containing sludge).The following tests were made:

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Combined wet-dry cycles using fresh water, seawater and water containing 5% sulphates

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Accelerated ageing in an autoclave

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Accelerated carbonation

The performance of the concrete containing sludge was acceptable and comparable to the results obtained for the reference concrete not containing sludge.     

芬顿催化氧化法在焦化废水处理中的应用

针对芬顿催化氧化工艺存在的问题进行了原因分析,在药品选择、药品投加方案、投加条件、刮泥机运行时间、pH值调节、混凝沉淀池增加挡板等方面进行改进。将芬顿催化氧化法应用到净化焦化废水中,出水指标达到国家一级排放标准。     

改性膨润土对氨氮废水吸附性能的研究

用内蒙膨润土及其碱改性膨润土进行模拟氨氮废水的脱氮实验研究。结果表明,在氨氮溶液初始浓度为300 mg/L,pH值为3.0～7.0时,相对于天然膨润土,碱改性膨润土对氨氮的吸附量有了很大提高,其吸附等温线符合Freundlich和Langmuir方程,且对氨氮的吸附动力学符合准一级和准二级吸附动力学模型,说明化学吸附和物理吸附共同起作用;在应用于畜禽废水处理中,碱改性膨润土对氨氮去除率达到91.0%。     

利用凹凸棒土制备废水氨氮吸附剂的研究

以凹凸棒土为主要原料,制备废水氨氮吸附剂,采用正交实验设计,考察了添加剂含量、焙烧温度、焙烧时间等因素对氨氮去除率的影响。结果表明,添加剂含量10%,焙烧温度500℃,焙烧时间1 h时,所制备的吸附剂性能指标最好,对废水中氨氮的去除率可达85%。     

三环公司废水综合治理

介绍云南三环分公司废水综合治理情况。该公司废水实施清污分流,统一处理回收利用后,实现了废水零排放,消除了外排废水对水资源的污染,缓解了公司供水压力,取得了较好的环保效益和社会效益。     

Gasification of food waste with steam in fluidized bed

Biomass has became an important renewable alternative energy resource. Million tons of food sludge, which is difficult to handle because of its rank smell and water content, is generated in Korea. Thermochemical conversion is one way to convert biomass to energy; it can be divided into carbonization, liquefaction, and gasification. Carbonization of food waste was carried out in a conventional stainless steel autoclave of 2 L capacity at different temperatures. Since gasification produces hydrogen-rich synthesis gas, which can be used for methanol synthesis, gasification of carbonized solid was studied in the fluidized-bed gasifier. The reaction parameters in the gasification of carbonized solids were investigated. Presented at the Int’l Symp. on Chem. Eng. (Cheju, Feb. 8–10, 2001), dedicated to Prof. H. S. Chun on the occasion of his retirement from Korea University.     

Application of oxidation–reduction potential as a controlling parameter in waste activated sludge hydrolysis

In order to destroy the refractory structure of waste activated sludge (WAS) and increase its biodegradability, chemical pretreatment by adding NaOH was used in this study to enhance the hydrolysis of the WAS collected from the Taipei Min-Sheng Sewage Municipal Wastewater Treatment Plant located in northern Taiwan. Experiments were conducted with four total suspended solids (TSS) concentrations (0.5–2.0%) and four NaOH dosages (20–80 meq/l) at 25 °C. It was found that the optimal condition for WAS hydrolysis was TSS of 1% and NaOH dosage of 40 meq/l; 45% of soluble chemical oxygen demand (SCOD) was solubilized in the pretreatment time of 10 h. When the WAS was hydrolyzed by adding NaOH, profiles of oxidation–reduction potential (ORP) values were monitored on-line; also, a model covering the relationship between the change of ORP value and increase in SCOD was developed. This verified that the ORP monitoring technique is not only useful to investigate the solubilization rate but also suitable for the determination of optimal solubilization in WAS treatment. Considering the release of nitrogen by alkaline pretreatment, profiles of total Kjeldahl nitrogen, ammonia-nitrogen and amino acids were investigated.     

Impinging zone reactor and its mathematical model for ozonation of waste water

The impinging zone reactor combines the high shear associated with gas‐liquid co‐injection and the impingement of two jet streams to bring about high intensity mixing in a power efficient manner. The reactor has been field tested and proven to be effective and economical for ozonation of wastewater to reduce COD (Chemical Oxygen Demand) and color. A reactor mathematical model has been developed based on fundamental principles where ozone self‐decomposition in water and mass transfer enhancement due to fast reactions are explicitly considered. The model is especially useful for reactor scale‐up design and optimization.     

Behavior of hydrothermal decomposition of silk fibroin to amino acids in near-critical water

The behavior of protein decomposition to amino acids in near-critical water is elucidated by using silk fibroin as a model compound. Results show that serine (Ser), aspartic acid (Asp) and other complex amino acids, obtained initially in significant amount, gradually decreased as reaction time and temperature were increased. At temperature higher than 523 K, it is likely that Gly and Ala underwent further decomposition. Regarding the effect of various additives, no significant effect on the yield of amino acids was observed with the addition of oleic acid. However, the presence of NaOH and formic acid (FA), both in 5 mol% aqueous solution, had significant effect on the yield. The effect of alkalinity and acidity, the production of amino acids was enhanced in either acidic or basic conditions.     

改性凹凸棒石和沸石对氨氮废水吸附性能的研究

采用焙烧、钠化、酸化和碱化4种改性方法对天然凹凸棒石和沸石进行改性,其中碱化改性对氨氮吸附能力提高最大,研究了碱化样品的结构及对氨氮废水的吸附性能。结果表明,碱改性品在氨氮溶液初始浓度300 mg/L,pH值2.5~8.0时,对氨氮的吸附量较高;对氨氮的吸附等温线符合Freund lich和Langmu ir方程式。同时,对氨氮的吸附动力学符合准二级吸附动力学模型,并以化学吸附为主。用于畜禽废水处理中,对氨氮去除率最高达到87.6%。