This study describes the design and corrosion-resistant materials for a high-efficiency waste-to-energy (WtE) plant. WtE technology is one of the most robust and effective alternative energy options to reduce CO2 emissions and to conserve limited fossil fuel resources, which are used by traditional power plants. The recently published 3rd edition of the CEWEP (confederation of european waste-to-energy plants) energy efficiency report demonstrated the energy efficiency criterion (R1 formula) that was introduced in the waste framework directive and has proven to be an incentive for WtE plants in Europe to improve their energy efficiency. The design combines the optimal use of the corrosion resistant properties of inconel with an efficient boiler design (Amsterdam) and turbine layout. It uses a steam-steam reheater to realize this efficiency as well as high availability and low maintenance. The high-efficiency WtE plant is an economical choice that makes a very positive contribution to sustainable electricity production.
This study was experimented by reviewing the possibility of applying non-sintered loess as a building material. And this study was to evaluate and compare flexural and compressive strengths characteristics of cementless mortar with non-sintered loess according to percentage of non-sintered loess and the type of curing without adding any cement. SEM, chloride ion penetration resistance and chemical resistance were also evaluated and compared to study characteristics of cement less mortar with non-sintered loess. In order to evaluate the characteristics of cement less mortar with non-sintered Loess. Test pieces were fabricated at 3, 7 and 28 days depending on the percentage of non-sintered loess and the type of curing. And also normal portland cement mortar were fabricated to compare with cementless mortar with non-sinteredloess. The result of this study, Properties of cementless mortar with non-sintered loess strength are generally lower thannormal portland cement mortar. However cementless mortar with non-sintered loess which is mixed 20% show equallyas normal portland cement mortar. Also, cement less mortar with non-sintered loess show excellent results than normal portland cement mortar in the durability characteristics. The purpose of this study was to expand the utilizable scope of non-sintered loess and to use the basic data as a applying building material in the future.
The several functions of manufactured the gypsum incorporating oyster shell powder coated by submicro-silver solution and carrried out the tests for the adsorption of formaldehyde and antibiotic actions. Several environmentally- friendly architectural materials, clay and flyash were tested for the comparison of the adsorption efficiency. The mortar by solidified and dried was exposed in the small chamber for the 180min with 4000 μg/m3 of the initial concentration of formaldehyde and observed high removal efficiency which result was not any difference in adsorption performance of other tested materials. The microbial flora analysis of oyster mortar coated by submicro-silver solution and the similarity test were performed and observed that the densities of Aeromonas sp. Enterococcus sp., and Micrococcus sp. were decreased and the densities of Staphylococcus sp., Escherichia sp., Bacillus sp., were taphylococcus sp, Escherichia sp., and Bacillus sp. were increased.
This research was conducted to configure an optimal membrane module system that would selectively separate hazardous gases which are emitted during the processes in the semiconductor industry. In order to identify the most integral characteristic results, a numerical analysis formula which incorporates the dimensions of pipe diameter and gas flow rate was utilized. Based on the results of the numerical analysis formula, a prototype designed with the main pipe being 100Awith gas outlets made with identical diameter thickness to the main pipe, set at equal intervals, was built. When the gas flow rate is set at 100 L/min, although the processing outlets 1, 2, and 3 showed 0.03 m/sec deviations in the rate of speed, when considering the variables of the average flow rate, the same emission rates are noted. However, in the instance of when the overall prototype pipe dimensions was enlarged to 200A and the gas flow rate was increased to 500 L/min, there was better stabilization. Therefore concluding that as the pressure rates flowing in the main pipe increases, more stable characteristics at the gas outlets can be found.
The brominated flame retardants (BFRs) have been used in many household products such as plastics of electronic equipment, furniture, textiles to increase their flame ignition resistance. Among the mixtures of BFRs, polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) have been widely used as commercial additive during the last decade. This study has been performed to investigate the concentration of BFRs in waste electrical and electronic equipment which has potential threat on environment and human health. We analyzed PBDEs, TBBPA and HBCD in 18 products from 2 TV manufacturing companies, 19 parts from 3 refrigerators, shredded plastic from recycling center, 3 other plastics from recovery process, and 43 small electronics using heating source. The concentration of PBDEs in TVs ranged from 306 mg/kg (manufactured since the year of 2000) to 145,027 mg/kg (manufactured in 1983~1997). The concentration range of PBDEs in rear housing is greater than those of front cover. The concentration of TBBPA were detected from 30 to 201 mg/kg and HBCD was not detected (ND) in all samples of TV. The PBDEs concentrations in plastics of refrigerator waste were detected from ND to 445 mg/kg, the concentration of PBDEs in upper housing cover is higher than those of other parts. The concentration of PBDEs in small electronics was not detected in most products but HBCD and TBBPA were detected several hundred ppm in 1 mixer and several dozen of ppm in 1 mixer, 1 coffee port and 2 electronic rice cookers, respectively. Based on the concentration characteristics of BFRs in waste electrical and electronic equipment, we will be established the environmentally sound strategies for the management policies of the waste containing BFRs.
A purpose of the present study is to derive optimum study factors for removal of heavy metals using combined alternating current electric/magnetic field and electric membranes for the area contaminated with heavy metals in soil or underground water. ORP (Oxidation Reduction Potential) analysis was conducted to determine an intensity of tendency for oxidation or reduction of the samples contaminated with heavy metals, and electrical membrane treatment was used with adjustment of concentrations and voltages of liquid electrode to derive a high removal rate. Then, electrolysis was carried out to collect deposits, and electrical conductivity increased again. However, as time passed, the ions were decomposed, and ionic bonds of the heavy metals started to decompose due to a magnetized water device connected to each line, resulting in gradual stabilization. Gas generated at the electrode is reduced with production of low heat resulting in an increased reaction rate, accompanied by no oxidation in anion exchange membrane and cation exchange membrane without occurrence of a reduction phenomenon. Also power consumption may be reduced with a small amount of electricity, and treatment efficiency was also shown to be increased.
It is known that cement, when mixed with wood chip, may face problems in hardening depending on the type of wood. This study examined the wood chip pretreatment effect of the method of soaking fine wood chip in 100oC water and then drying it and the effect of hardening accelerator on the setting time, strength and thermal conductivity of normal consistency wood chip mortar with a flow value of approximately 110%. Mortar experiment showed that use of woodchip caused the water content required to obtain the same flow value to increase and the setting time to be overly delayed. It was shown that water treatment of wood chip in boiling water to solve such problem was not so meaningful in normal consistency wood chip mortar but that use of hardening accelerator was more effective in solving retardation of setting and improving compression strength and specific strength.
Carbonization process with pig manure is carried out to estimate the reaction kinetics with increasing carbonization time and temperature in the process. From the examination of conversion characteristics of pig manure, carbonization reaction can be described by the 1st order kinetic reaction. Degree of carbonization, which can be expressed by C/H mole ratio, is increased with increasing carbonization temperature. As increased carbonization temperature from 250oC to 400oC, reaction rate constant in the 1st order kinetic reaction is also increased from 0.0622 min-1 to 0.1999 min?1. Frequency factor and activation energy in Arrhenius equation for pig manure in the carbonization process can be decided by 1.06 × 10-3min-1 and 5441.8 kcal/kmole, respectively. From the results of the reaction kinetics including TGA and SEM analysis, it is desirable that pig manure should be carbonized below carbonization temperature 400℃.
This research performed physico-chemical analysis of MSW (municipal solid waste) for design and operation of gasification generation system. The MSW sample was analyzed by proximate, ultimate, heat value method and sampled each residential type classified apartment, house, urban and rural in by seasonal generation According to statistics of 2010MSW generation in Korea, On average, Namwon generated about 101.4 ton of trash and recycled almost 57.5 ton of this material per day, equivalent to a 56.7 percent recycling rate. It was recycled 0.73 kilograms out of individual waste generation of 1.29 kilograms per person per day. In 2011, On average, Namwon generated about 46.7 ton without recycled material per day, and individual generation was 0.60 kilograms. It was virtually identical with statistics data in 2010. In the physico-chemical analysis results, it was composed of 84.1 percent of combustible and 15.9 percent of Noncombustible. On average, heat value was 2,529 kcal per kilogram in condition of LHV and wet. The MSW sample was included 32.0 percent of moisture, 21.9 percent of ash, 26.8 percent of carbon, 14.4 percent of oxygen, 3.7 percent of hydrogen and 1.3 percent of others. Estimate of technical potential energy of MSW was 1,278 toe per year, equivalent to a 33.3 percent of total potential energy.
The materials flow of nickel was analyzed into up-stream and down-stream based on the literature survey. Discharge and recycling stages in the down-stream were analyzed through the field survey. The waste nickel resources circulation flow were analyzed into 4 stages such as discharge·import, collection·disuse, resource recovery and product production·export, which are divided into nickel scrap and stainless steel scrap. The nickel scrap of 1,500 ton was collected and recycled and exported, which are from battery, catalyst and etc. The stainless steel scrap of 55,200 ton are recycled from domestic and imported sources, which are 28,800 ton and 26,400 ton, respectively. The resource circulation rate of 45.3%is obtained from the above flow and the various plans are suggested each stage to increase resource circulation rate. At discharge·import stage, it is suggested this kind of waste may be classified as resources if the classification of waste is done in detail and suitably. Also, it is suggested to apply quota tariff to this kind of waste. At collection·disuse stage, the plan of stabilizing supply and demand is suggested through the improvement of bidding system. At resource recovery stage, the fostering plan for specialized crushing companies and the win-win plan between conglomerate and medium-small companies are suggested. At product production·export stage, it is suggested the integrated approval for licensing to register as waste-treating facilities instead of exempting registration under the present condition to activate recycling industries.
Incinerated sewage sludge ash (ISSA) is regarded as a valuable resource having great potential for the recycling of phosphorus. The P content of ISSA is known as around 10% as a P. Therefore, this study was undertaken to investigate the precipitation and separation characteristics of phosphorus from the acid-extracted solution of ISSA. The incinerated sewage sludge ash was leached by 1 N sulfuric acid with solid/liquid ratio of 10 for 30 min. The extracted solution contained about 1.1% of P and other metals, Al, Fe, Ca and Mg, with over than 1,000 mg/L. Some heavy metals such as Cu, Pb and Cr are presented as impurities as well. Most of Al and Fe in the extracted solution were precipitated with P when titrating it to pH 3.6. The precipitated form were assumed to AlPO4, FePO4·2H2O respectively, and Pb and Cr were precipitated in this stage as well. At this experiment, about 62.9% of the initial P was precipitated and removed from the solution. It was also find that all of the P extracted can not be recovered as a precipitate with a simple addition of NaOH, even though titrated to pH 11.6. The precipitated P also contained some impurities such as Al, Fe, and some heavy metals, which means that further researches are needed for the efficient separation and recovery of P from ISSA.
There are many stringent environmental regulations on the management of waste electrical and electronic equipments (WEEE) in most developed countries. WEEE directive aims at increasing collection and recycling rate of WEEE whereas, while the restriction of the use of certain hazardous substances (RoHS) aims at restricting hazardous materials during the production of electrical and electronic equipment (EEE). TV housing rear covers consist of small portion of brominated flame retardants (BFRs). Improper management and disposal of such waste can pose impacts on the environment and human health. In Korea, there are very few available statistical data regarding BFRs levels in TVs housing rear covers. In order to provide additional measures related to management of BFRs, there is a need for a quantitative material flow study on the amount of BFR found in TVs. This can be achieved by the aid of material flow analysis of the TV sets and by studying the Deca-BDE components present in the TV housing read covers. In this study, the relevant data were collected from the statistical reports and through field site visits to the WEEE recycling facilities with surveys. Static and dynamic material flow analysis (MFA) was conducted to determine material flow of BFRs (Deca-BDE) in the management of waste TVs. According to this study, in 2011, households in Korea use 73,821 ton of TV sets of which23, 592 ton of waste TV sets were collected and recycled by municipalities and producers. Extended Producer Responsibility (EPR) played a major role in recycling of WEEE. In this study, it was predicted that Deca-BDE in usestage would reach down to 51.73ton by 2016. In addition, the amount of Deca-BDE present at the disposal and recycling stage is estimated to be approximately 2.45ton by 2018.
In this study, waste landfill site was used as a bioreactor landfill for the treatment of anaerobically digested food wastewater, and a basic study on waste landfill injection of anaerobically digested food wastewater was conducted. To study the effect of different operating condition on the quality of lysimeter leachate, 3 lysimeters were operated at different condition (i.e., Lys 1 = no recirculation, Lys 2 = leachate recirculation, Lys 3 = leachate recirculation after one day aeration), and the results of leachate quality were as followings. pH Level of leachate became similar to the digested food wastewater after 63 days of operation(equivalent to the 11.2% of bed volume) and Cl- concentration of leachate was higher than injected food wastewater during whole 6 months of operation period. Leachate COD showed stable values after 70 days of operation,and reduction rate of COD concentration after 6 months was 86%, 89, and 90% for Lys 1, Lys 2, and Lys 3, respectively. The reduction rates of TKN concentration were 19, 28, and 65% for Lys 1, Lys 2, and Lys 3. Lys 3 showed the most effective TKN reduction. Leachate recirculation after one day aeration resulted effective reduction of cumulative COD and TKN mass, which were 61% and 40% respectively, compared to the no recirculation case
With the changing lifestyle in the so-called IT era, smart phone era and aging society, there have been growing interests in new types of waste. Under these circumstances, we conducted a survey on discharge of waste, focusing on small electrical and electronic waste (e-waste), packaging products, and lifestyle. The survey was carried out on 1,000 ordinary people of 19 to 60-something years old in 16 regions by the Random Digit Dialing (RDD) method. For the purchase of small electrical and electronic devices, 42.4% of the respondents answered the most recent product they had bought was a cell-phone and the most recently discarded item was also cell-phones (17.4%). In general, purchased and discarded small electrical and electronic items showed a similar trend. To the question on how to discard their small electrical and electronic devices, the largest number of respondents (29.3%) answered that they return them to the store where they bought the product, and younger generations in their 20s and 30s, unmarried people, and students preferred to throw them into standard plastic garbage bags. It was found that most frequently used disposable packaging products were in the order of paper, plastic bags, paper cups, and wooden chopsticks, and take-out food containers were used on average 2.03 times per month. Also, take-out food containers were more used by men over women, cities over rural areas, and families withthree or more members. In addition, most frequently purchased items via the internet or home shopping were found to be in the order of clothes, food, cosmetics, and electrical and electronic devices. It is estimated that the wide use of internet is boosting purchase of a variety of items like food and cosmetics as well as clothes.