Papers by Keyword: Municipal Solid Waste (MSW)

Abstract: The plastics from municipal solid waste (MSW) were modified to improve cleanness for adding value. The stir and sonication were performed as cleaning processes. Xylene, tetrachloroethylene, chloroform, acetone and toluene were used as solvent cleaning. The most suitable cleaning process was sonication method with cleaning time of 5 min and the appropriate solvent was xylene for washing the plastic wastes for further study in terms of thermo-mechanical and rheological properties. The cleaning process was successful as evidence in thermogravimetric analysis (TGA) results. The properties of new plastics, cleaned plastic wastes and plastic wastes were compared and analyzed. Tensile strength of the specimens from plastic wastes was slightly decreased; however, elongation and impact strength of cleaned plastic wastes and plastic wastes sharply dropped as compared to new plastics. Tensile modulus of cleaned plastic wastes was slightly better than that of new plastics. Thermal stability of plastic waste was slightly lower than that of new plastic. Shear storage modulus (Gʹ), shear loss modulus (Gʺ) and shear viscosity (η) of new plastics showed the maximum value; on the other hand, those properties of cleaned plastic wastes and plastic wastes were similar. The cleaning method with solvent did not destroy thermo-mechanical and rheological properties of the cleaned plastic wastes.

Abstract: An investigation of the effect of the addition of char from agricultural residues on the torrefaction of moist municipal solid waste (MSW) pellets (40 wt.% moisture) was carried out in a microwave oven (500-800 W for 4-12 minutes). Char from agricultural residues, including corncob, palm shell, straw, and bagasse, was used as the microwave absorbers to enhance the absorption of microwave irradiation. It was found that the addition of char from bagasse yielded the lowest remaining mass (or mass yield) and volatile matter (VM) content, but the highest temperature and heating value, of the torrefied MSW pellet. Moisture in the MSW pellet with or without the addition of microwave absorber was completely removed after being torrefied for 8-12 minutes. The VM contents remained in the MSW pellets with the addition of microwave absorbers were lower than that in the MSW pellet without the addition of microwave absorber. The addition of microwave absorbers led to an increase in carbon (C) content but a decrease in oxygen (O) content of the torrefied MSW pellets, compared to those of the raw MSW pellet. The heating values of the torrefied MSW pellets with the addition of microwave absorbers were equivalent to that of sub-bituminous coal, enhanced from that of the raw MSW pellet, which was lower than that of lignite.

Abstract: Artificial impermeable liner is the commonly used engineering technology method to prevent the Municipal Solid Waste (MSW) landfill leachate from polluting groundwater. The domestic and foreign researcher have discovered that the landfill impermeable liner was easy to have leaks during artificial liner laying down because of mechanical or the artificial mal-operation. The integrity test of impermeable liner for landfill began at the year of 2008. So a large number of historical landfill (construction completed before 2008) had become the pollution sources to local ecosystem because of the impermeable liner leakage. This article discussed the present situation of historical landfill leakage pollution, and propose technical and administrative measures to control those pollution in China.

Abstract: The amounts of municipal solid waste (MSW) are increasing dramatically in metropolis, such as Shanghai in China, due to rapid economic development and urbanization, and it has brought a significant challenge to ecological situation of the city. It is concerned to establish an innovated management system for MSW reducing, recycling, and reusing (3Rs). Thus, information technologies are introduced with the objectives to establish an integrated, and cost-effective solid waste management system. In this system, Radio Frequency Identification (RFID) technology is applied to collection, transportation, and disposal of MSW. Meanwhile, source separation is also combined as a best practice for management of trash and recyclable materials. The paper infers that the establishment of information management system of MSW will offer opportunities to MSW management by reducing secondary pollution and improving efficiency of collection and transportation.

Abstract: Inevitably, energy plays a vital role on our social life and fossil fuel forms of energy meet the most part of our energy demand. Fossil fuels are exhaustible whereas global energy demand is increasing. Furthermore, they pose significant and principal adverse impacts on environment and public health. As a consequence, societies are seeking alternatives to substitute the fossil fuel consumption. The issue of utilizing agriculture waste to produce energy has always been the matter of debate for the societies.

Abstract: The process of biodrying could be a good solution for municipal solid waste management, allowing the production of fuel with an interesting energy content. In this study, bio-drying the mixed municipal solid waste (with the size among 15-80 mm) with different aeration modes were conducted. During the experiment, temperature, oxygen content and moisture content were determined, and continuous measurements of H₂S and CH₄ were taken. The results indicated that the thermophilic phases of all treatments beside T1 were met the Chinese standard of >55°C for 5-7 days for sanitation. The aeration mode of T4 was in favor of reduced the H₂S and CH₄ emission during MSW bio-drying. Under the condition of this study, the bio-drying cycle should be determined for 18 days. Intermittent ventilation mode is more effective to reduce the moisture content in MSW bio-drying process. So the aeration mode of T4 (2.0L/min, 30min run/30 min stop) was the first choice during MSW bio-drying.

Abstract: Bio-drying process, degrading part of the easily biodegradable organic fraction contained in waste, produces heat that combined with an adequate airflow-rate, allows the fast evaporation of waste moisture content. Three ventilation methods were used to investigate the effect of bio-drying pretreatment on municipal solid waste (MSW) characteristics (including water content, mass, heating value and the gross energy capacity). The results show that the water content of MSW decreased from 61.5% to minimum 23.7% after 18 days bio-drying, whereas its lower heating value (LHV) increased an average of 168% from 5413 kJ/kg. In the three trials, the highest LHV amounted to 15.8 MJ/kg, which achieved the LHV demand of solid recovery fuel (SRF). In bio-drying process, the average water removal rate was 80.6%. Smaller organic matter degradation led to a great decline of the water content; therefore, the decrease of gross energy capacity of MSW is not significant.

Abstract: Simulated municipal solid waste (MSW) based on the actual proportional characteristics of MSW was loaded into a simulated leachate recirculation bioreactor landfill and the abundance of common and tolerant microbes exposed to dibutyl phthalate (DBP) were investigated in the initial, acidic and methanogenic phases. The results showed that the abundance of bacteria was greatest, while that of actinomycetes was smallest. The growth of microorganisms was not significantly inhibited by DBP during the initial phase; however, the growth of actinomycetes and fungi was inhibited during both the acidic and methanogenic phases, and the inhibition of actinomycetes was greater than that of fungi. When the DBP concentration was 5.0 g l^-1, the inhibition ratio against actinomycetes was 89.5% and 80.9% in the refuse from the acidic phase and methanogenic phase, respectively, while it was 86.2% and 51.0%, respectively, against fungi during the same period. The toxic effects of DBP on microorganisms in refuse occurred in the order of actinomycetes > fungi > bacteria. In addition, the populations of bacteria, fungi and actinomycetes were significantly and positively correlated with dehydrogenase activity, but negatively correlated with the VSS and BDM of refuse (P<0.01).

Abstract: The management of municipal solid waste (MSW) in China is facing urgent problems with rapid industrialization and urbanization. This article focused on the status of Hangzhou, capital city of Zhejiang province, China. The regulations, policies, implementation, barriers and solutions about source separation, separate collection, clean & direct transportation, treatment and disposal were introduced. Source separation, separate collection and clean & direct transportation were seriously carried out from 2010. MSW was classified into four kinds, such as kitchen waste, hazardous waste, recyclable waste and other waste. Four kinds of wastes were collected, transported, treated and disposed, respectively. At the same time, a questionnaire survey was conducted in 2011 on 200 households in Xiasha and Gongshu Districts in Hangzhou. The results indicate that many citizens cannot effectively and correctly separated different kinds of solid wastes. Kitchen waste was directly disposed in landfill, because there is no composting plant in Hangzhou City. The collection of recoverable waste and hazardous waste was not in control of municipal solid waste management (MSWM) system. In order to optimize MSWM system in Hangzhou, the government and the citizen must make efforts in source separation, comprehensive treatment system, effective regulations and policies.

Abstract: Landfill liner leakage detection has become the necessity procedure before the landfill put into operation. The dipole detection technology is studied and which can find the leaks of liner without any destruction of liner. This article discusses the key factors affecting the dipole sensitivity including the resistivity and thickness of the medium above the liner, and the distance between the dipole and the liner, the dipole spacing. The results indicate that higher resistivity of the medium, the thinner the liner is. Based on which the dipole method device is developed. Almost 68 landfill liner leakage detection surveys had been done recently in China using dipole technology. The results show that every landfill detected has leaks in liner, and the leaks detected per hectare is about 22 unit and 24 unit per landfill. Dipole technology has become the primary method in landfill liner leakage detection and play the critical role in landfill liner construction quality supervision.