Study on Rural Solid Waste Collection and Transportation Mode and Route Optimization Strategy in the Cold Regions of Northern China

Rural vitalization is a major strategy for reform and development of agriculture and rural areas in China,the key task of which is improving rural living environment.Imperfect rural solid waste(RSW)collection and transportation system exacerbates the pollution of RSW to rural living environment,while it has not been established and improved in the cold region of Northern China due to climate and economy.Through the analysis of the current situation of RSW source separation,collection,transportation and disposal in China,an RSW collection and transportation system suitable for the northern cold region was developed.Considering the low winter temperature in the northern cold region,different requirements for RSW collection,transportation and terminal disposal,scattered source points and single terminal disposal nodes in rural areas,the study focused on determining the number and location of transfer stations,established a model for transfer stations selection and RSW collection and transportation routes optimization for RSW collection and transportation system,and proposed the elite retention particle swarm optimization–genetic algorithm(ERPSO–GA).The rural area of Baiquan County was taken as a representative case,the collection and transportation scheme of which was given,and the feasibility of the scheme was clarified by simulation experiment.

Establishment and application of performance evaluation model for collection and transportation system of municipal solid waste

On the basis of analyzing the typical waste collection and transportation mode,the evaluation index system for performance of the waste collection and transportation system was proposed with three grades,which related to six factors,such as economic evaluation,high efficient evaluation,environmental impact assessment,resource evaluation,evaluation of security and emergency,evaluation of management and society. With the performance evaluation theory,the performance evaluation model of waste collection and transportation system was constructed,which quantified the grading standard of index and determined the index weight in analytic hierarchy process (AHP). After evaluating the waste collection and transportation system of the main districts of Chongqing city,the results show that the it has an excellent performance evaluation grade with very high performance level of three indices involving evaluation of management and society,environmental impact assessment,evaluation of security and emergency and quite low performance level of two indices that include high efficient evaluation and economic evaluation.

Hydrogen inhibition effect of chitosan and sodium phosphate on ZK60 waste dust in a wet dust removal system:A feasible way to control hydrogen explosion

Wet dust removal systems used to control dust in the polishing or grinding process of Mg alloy products are frequently associated with potential hydrogen explosion caused by magnesium-water reaction.For purpose of avoiding hydrogen explosion risks,we try to use a combination of chitosan(CS)and sodium phosphate(SP)to inhibit the hydrogen evolution reaction between magnesium alloy waste dust and water.The hydrogen evolution curves and chemical kinetics modeling for ten different mixing ratios demonstrate that 0.4wt%CS+0.1wt%SP yields the best inhibition efficiency with hydrogen generation rate of almost zero.SEM and EDS analyses indicate that this composite inhibitor can create a uniform,smooth,tight protective film over the surface of the alloy dust particles.FTIR and XRD analysis of the chemical composition of the surface film show that this protective film contains CS and SP chemically adsorbed on the surface of ZK60 but no detectable Mg(OH)_(2),suggesting that magnesium-water reaction was totally blocked.Our new method offers a thorough solution to hydrogen explosion by inhibiting the hydrogen generation of magnesium alloy waste dust in a wet dust removal system.

Current Status of Sludge Collection, Transportation and Treatment in Ho Chi Minh City

In the process of construction and development, Ho Chi Minh City is discharging about six types of sludge: 1) sludge from urban wastewater drainage systems;2) sludge from industrial wastewater drainage system;3) sludge from the canal dredging activities periodically;4) sludge from septic tanks;5) sludge from the water treatment station/plant;6) sludge from the construction sites. Sludge’s components are very different among types of sludge, sludge from the sewer network and canal dredging contain mainly sand and soil (70% - 90% dry weight), while the sludge from the wastewater/water treatment station/plant and from septic tanks contain mainly biodegradable organic substances (55% - 80% dry weight). The concentrations of all above-mentioned sludge (except sludge from the hazardous industrial wastewater treatment plant) are lower than toxic threshold. The volume of total sludge is about 3000 - 4000 m3/day (5000 - 6000 tons/day), excepting the amount of sludge generated from the water treatment plant (which is collected and treated separately). Sludge from wastewater treatment plants and septic tanks is collected, transported and recycled to become organic fertilizer. The other types of sludge are collected, transported, and disposed at the “unknown” locations, even though they have different values for use.

Seismic behavior of tire waste-sand mixtures for transportation infrastructure in cold regions

Tire wastes have many properties that are valuable from a geotechnical engineering perspective, such as low density, high strength, thermal insulation, energy absorption capacity, permeability, durability, compressibility, resilience, and high frictional strength. Thus, tire wastes offer good thermal characteristics in resisting frost penetration and have good drainage characteristics, being as permeable as coarse granular soil for fill materials. The many advantages of tire wastes make the material suitable for transportation infrastructure construction in cold regions. Also, tire wastes with high damping prop- erty make them a preferable admixture with sand for transportation infrastructures in seismic regions, This study aimed to determine the seismic performance of certain tire waste-sand mixtures in cold regions. A 70% sand-30% tire crumb mixture by weight （TC30） with a very high damping property was selected for analysis as an engineering material for transportation infrastructure. Small-scale shake-table tests were conducted on this material as well as on a sand-only sample under two different temperatures, 0 ℃ and 20 ℃, to simulate cold-region and moderate-temperature performance, respectively. The 1999 lzmit Earthquake Excitation （EW） （Mw = 7.4） was taken as the input motion. Test results showed that the tire waste-sand mixture at 0 ℃ showed better seismic performance than that at room temperature, suggesting that a tire waste-sand mixture in cold regions may reduce seismic hazards to infrastructure.

New application notion of pipeline transport——integrated in industry solid waste innocuous and efficient disposition

In order to solve transport problems of industry solid,firstly,a new applicationnotion of pipeline transport was presented,that is to say,combining pretreatment andtransport with disposal techniques of industry solid waste.Secondly,the integrated dis-posal and transport system for industry solid waste was introduced,in particular,the oper-ating principles,equipment set-up,key technology and technical parameters.Next,thispaper illustrated the application of this integrated system.Such as it can transport coalsludge with sufficiently high solids content(about 72%～77%)and high apparent viscosity(about 1 000～3 000 Pa.s)directly by pipeline having no use for water and addition agent.Generally,the transport distance is about 1 000 m.This system has been successfullyused in innocuous disposition and efficient utilization of other industrial byproducts or solidwastes,such as city sludge and paper making waste.The integrated system causes nopollution to the environment for its complete seal and realizes protecting the environment,conserving the energy,promoting the development of cycling economic.Finally,the paperdiscussed the research works that were needed for studying such pipeline transport sys-tem and narrates the relevant condition and application status.

Simulation of groundwater and nuclide transport in the near-field of the high-level radioactive waste repository with TOUGHREACT

In order to know the mechanism of groundwater transport and the variation of ion concentrations in the near-field of the high-level radioactive waste repository,the whole process was simulated by EOS3 module of TOUGHREACT.Generally,the pH and cation concentrations vary obviously in the near-field saturated zone due to interaction between groundwater and bentonite.Moreover,the simulated results showed that calcite precipitation could not cause obvious variations in the porosity of media in the near-filed if the chemical components and their concentrations of groundwater and bentonite pore water are similar to those used in this study.

Erosion and transport mechanisms of mine waste along gullies

Mine waste debris flows continue to occur in China, and the disaster prevention and mitigation of these flows faces severe challenges since the mechanisms determining erosion and transport of mine waste along gullies are not yet fully understood. The erosion and delivery process of mine waste heaps was reproduced through flume experiments with the method based on field survey data of the Daxicha mine waste debris flow gully in the Xiaoqinling gold mining area. The results showed that the erosion and movement of mine wastes could be divided into three modes: minimal sediment movement, sediment sorting and delivery, and a large amount of sediment transfer. Moreover, there was an obvious amplification effect on peak discharge along with the formation and failure of temporary landslide dams during the erosion process. The correlation between the coefficient of peak discharge amplification and three dimensionless influencing factors, flume gradient, dimensionless volume, and dimensionless particle size, were comprehensively analyzed. An empirical formula for the coefficient of peak discharge amplification was proposed and verified based on 16 sets of experimental data. These preliminary results can provide a scientific reference for future research on disaster prevention and mitigation of mine waste debris flows.

Protection of groundwater from migration of infiltrates from a chromic waste storage site and methods of treating these infiltrates

This work presents the results of investigations to develop and implement methods to effectively collect and purify infiltrates from heaps, situated in the region of Alwernia near Cracow, where more than 3 million tonnes of waste material resulting from the production of chromium compounds have been stored. It describes a system for the protection of groundwater from these infiltrates which contain 50-400 g m-3 Cr6+, as well as the effectiveness of cheap and simple chemical methods to purify these chromic wastewaters. The infiltrate collection system and the most effective method to decrease the concentration of Cr6+ to a level below 0.1 ppm, as required by Polish and European Union regulations, were implemented in the Alwernia Chemical Works S. A. in the years 1998-1999.

Adding Sputum Collection and Transportation Services for Early Identification TB Cases in Hard-to-Reach Difficult Terrain—Will It Help?

A community engagement project was designed and implemented to reach 10.6 million population in 13 districts of Uttarakhand state—India, to identify presumptive TB patients (PTBPs) and link to free diagnostics services, either through referral or sputum collection and transportation (SCT). The objective of this study is to determine additional yield of TB patients achieved by providing SCT services in comparison to referrals of PTBPs identified in hard-to-reach areas. This was before and after comparative study conducted between April-June 2014 (2Q2014-before) to July-September 2014 (3Q2014-after). SCT was advised for all PTBPs identified from community level interventions between July-September 2014 (3Q2014-after). In 3Q2014, additional 279 (34%) PTBPs were examined in the microscopy centre with an additional 36 (51%) new smear positive (NSP) patient diagnosed. A total of 46 NSP (128%) were contributed by SCT alone. Higher proportion (94%) of TB patients was initiated on treatment in 3Q2014 in comparison to 2Q2014 (91%). SCT as a strategy for early case detection in hard-to-reach difficult terrain yields positive results in comparison to mere referral of PTBPs.

Investigation of Inhabitants' Wishes on Classified Collection of Waste in Wanghua District of Fushun

In order to disclose present situation and problem of classified collection of municipal solid waste in Wanghua District of Fushun and ana- lyze its practicability, questionnaire was designed in this paper, random research was adopted in Wanghua District, and statistic analysis of investi- gation result was conducted. This investigation could provide basis for popularizing classified collection of municipal solid waste in the whole nation.

Greenhouse Gas Emissions and Cost Analyses for the Treatment Options of Food Waste and Human Excrement

This study suggested environmental and economic evaluations by developing a scenario according to the various treatment options of food waste in Korea. In particular, the study evaluated the possibility about the combined treatment of food waste and human excrement after using food waste disposers (FWDs). The scenario including only composting (133 kg CO2 equiv./ton-household organic waste) or only FWDs (125 kg CO2 equiv./ton-household organic waste) was superior to the other scenarios in the environmental aspect and the scenario including only composting (101 USD/ton-household organic waste) was superior to the other scenarios in the economic aspect. However, the study discovered that 52% of greenhouse gas emission was reduced when sewage pretreatment was conducted in houses after using FWDs and also when biogas was collected on site and utilized in the private power station. Furthermore, the energy saving effect due to recovery of biogas has found to be larger in the environment aspect than in the economic aspect.

Readiness of Healthcare Facilities to Implement Onsite Healthcare Waste Management Protocols and Incineration Guidelines in Tanzania

The aim of this study was to assess Readiness of Healthcare facilities to Implement onsite Healthcare Waste Management Protocols and Incineration Guidelines in Tanzania. To address this, a national assessment was conducted country wide to assess readiness of Healthcare Facilities (HCFs) to undertake various Healthcare Waste Management (HCWM) initiatives with particular focus to adherence to HCWM protocols and incineration guidelines. The assessment of healthcare waste management was conducted in facilities in the 26 regions of Tanzania mainland for one month. A standardized checklist and tools were used to assess and monitor various aspects related to healthcare waste management using open source software for data collection (ODK). Data were analyzed using SPSS computer software. It was observed that 46.2%, 33.3% and 25% of the health centres, district hospitals and regional hospitals did not have appointed supervisors, which makes it difficult for the HCFs to perform better in managing healthcare waste in their respective facilities. It was further revealed that healthcare facilities have made remarkable improvement in the overall healthcare waste management with evidence of ongoing common activity on purchasing injection safety boxes (69.2%) and purchasing of waste bins (53.8%) at all levels. On average, about 70% of the HCFs have plans and budget though inadequate to support HCWM activities. In a conclusion Healthcare Facilities must designate a better system to compressively address healthcare waste management issues. Again the findings provide evidence for those engaged in improving HCF conditions to develop evidence-based policies and efficient programs, enhance service delivery systems, and make better use of available resources.

Household Waste Reduction Effect of Sorted Collection of Recyclable Waste in Japan

The purpose of this study is to analyze the household waste reduction effect of sorted collection of recyclable waste in Japan using a panel data analysis, which considers time-series and cross-section data simultaneously. Also, the study shows the effect of the type of sorted items on the quantity of household waste disposed. We used the data attained from 103 cities recorded over three years, and applied the quantity of total waste disposed, the quantity of combustible waste, the quantity of other waste （waste excluding combustible and recyclable waste）, and the quantity of combustible plus other waste as objective variables, respectively, in the models. The result suggests that when the number of sorted items is increased marginally, the quantity of household waste decreases by about 0.5%-3.3% or 1.28-4.17 grams per capita per day. In addition, it is shown that sorting out white trays is effective in reducing the quantity of combustible waste. Sorting out paper containers and packages is also effective in reducing the quantity of other waste and combustible plus other waste.

Informal Sector Solid Waste Collection and Recycling in Zaria, Nigeria

Management of solid wastes has become a critical issue for almost all the major cities in Nigeria. Although the responsibility for solid waste management remains primarily with the local government councils, several other stakeholders are playing significant roles in the system. In Zaria, the scavengers, waste pickers and collectors eke out a living by collecting waste and selling recyclable materials out of the urban solid wastes. The paper utilized data collected using questionnaire survey, in-depth discussion guides and open-ended interviews to examine the socio-economic characteristics, the functions, aspects of involvement of children, the working conditions and problems of waste collectors and pickers in Zaria. The paper found that the sector is the only means of solid waste collection in several sections of the town and is a source of livelihood for the poor. The activities help in realizing the aim of modern waste management, that is to move up the solid waste management hierarchy by reducing reliance on disposal and increasing recycling. In spite of these important functions, informal waste collection and recycling are associated with problems of unsanitary conditions and health risks to the communities and the waste collectors. Recommendations have been made to integrate the informal sector into the formal waste management by incorporating the employment needs of the urban poor and enhancing the efficiency of government in addressing the main problems.

Optimization of Planning Routes in Solid Waste Collection

This paper presents an optimization model for solving the planning problem of collection and transportation of solid waste in medium-sized cities. As final results, are expected to promote cost savings to the public coffers, as well as environmental benefits. The developed mathematical model is formulated as a problem of linear programming with mixed-integer variables and transcribed into software GAMS （general algebraic modeling system）. The practical application was tested using data collected in the central region of a Brazilian city with approximately 90,000 inhabitants. The deterministic model used allowed an optimal solution. It was found after inclusion of restrictions that eliminated the appearance of sub-routes. It was concluded that the optimal routes allow for a 38% reduction in total distance traveled, which can generate savings of $320.00 per day regarding maintenance and fuel trucks.

Generation of Transportation Fuel from Solid Municipal Waste Plastics

Transportation fuels derived from imported fossil fuels are subjected to the price fluctuations of the global marketplace, and constitute a major expense in the operation of a vehicle. Emissions from the evaporation and combustion of these fuels contribute to a range of environmental and health problems, causing poor air quality and emitting greenhouse gases that contribute to global warming. Alternative fuel created from domestic sources has been proposed as a solution to these problems, and many fuels are being developed based on biomass and other renewable sources. Natural State Research, Inc. proposes a different alternative hydrocarbon fuel which is produced from abundant waste plastic materials. This fuel burns more efficiently and cleaner than commercial gasoline and diesel. The process exists to efficiently convert waste plastic into a reliable low cost source of fuel.

Numerical research on flow and thermal transport in cooling pool of electrical power station using three depth-averaged turbulence models

This paper describes a numerical simulation of thermal discharge in the cooling pool of an electrical power station, aiming to develop general-purpose computational programs for grid generation and flow/pollutant transport in the complex domains of natural and artificial waterways. Three depth-averaged two-equation closure turbulence models, k-ε, k- w, and k- w, were used to close the quasi three-dimensional hydrodynamic model. The k- w model was recently established by the authors and is still in the testing process. The general-purpose computational programs and turbulence models will be involved in a software that is under development. The SIMPLE （Semi-Implicit Method for Pressure-Linked Equation） algorithm and multi-grid iterative method are used to solve the hydrodynamic fundamental governing equations, which are discretized on non-orthogonal boundary-fitted grids with a variable collocated arrangement. The results calculated with the three turbulence models were compared with one another. In addition to the steady flow and thermal transport simulation, the unsteady process of waste heat inpouring and development in the cooling pool was also investigated.

Effects of Hyperosmolality on Expression of Urea Transporter A2 and Aquaporin 2 in Mouse Medullary Collecting Duct Cells

In this study,the effects of hyperosmolality on the expression of urea transporter A2 (UTA2) and aquaporin 2 (AQP2) were investigated in transfected immortalized mouse medullary collecting duct (mIMCD3) cell line.AQP2-GFP-pCMV6 and UTA2-GFP-pCMV6 plasmids were stably transfected into mIMCD3 cells respectively.Transfected mIMCD3 and control cells were cultured in different hy-pertonic media,which were made by NaCl alone,urea alone,or an equiosmolar mixture of NaCl and urea.The mRNA and protein expression of AQP2 was elevated by the stimulation of NaCl alone,urea alone and NaCl plus urea in AQP2-mIMCD3 cells;whereas NaCl alone and NaCl plus urea rather than urea alone increased the mRNA and protein expression of UTA2 in UTA2-mIMCD3 cells,and all the expression presented an osmolality-dependent manner.Moreover,the mRNA and protein expression of UTA2 rather than AQP2 was found to be synergistically up-regulated by a combination of NaCl and urea in mIMCD3 cells.It is concluded that NaCl and urea synergistically induce the expression of UTA2 rather than AQP2 in mIMCD3 cells,and hyperosmolality probably mediates the expression of AQP2 and UTA2 through different mechanisms.

Critical Analysis of the Challenges of Solid Waste Management Initiatives in Keko Machungwa Informal Settlement, Dar es Salaam

Solid waste is inevitable because by nature every human activity generates a certain amount of solid waste. The rate of solid waste generated tends to increase with the increase in population. Despite existence of various efforts on solid waste collection, still the quantity of solid waste collected is small compared to the solid waste generated. The situation is even worse in unplanned settlements of developing countries, where, ineffective solid waste collection is contributed to by haphazard solid waste disposal and hence environmental pollution. Therefore, having an effective and efficient solid waste management system is a major challenge in cities of developing countries, and thus more consulted efforts are needed. This paper presents finding based on the study carried out in Keko Machungwa informal settlement in Dar es Salaam, Tanzania. The study explored challenges facing solid waste management initiatives in Keko Machungwa and recommended measures for improvement. Data for this study was collected through documentary review, household interviews, focus group discussions, physical observations and official interviews. The analysis reveals that solid waste generated in Keko Machungwa is 16 tones per day, among those, only 4.56 (less than 50%) are collected. About 11.44 tones of uncollected waste are illegally dumped into a seasonal stream and in different vacant lots hence causing blockage of the seasonal stream. Different groups engaged in solid waste collection are deterred by many challenges. The challenges include: lack of cooperation among the existing solid waste collection organs, inaccessibility in some places, low public participation, financial constraints and unwillingness of local community to pay for solid waste collection fees. The paper recommends four options on how solid waste management, particularly collection in Keko Machungwa can be enhanced. 1) Alliance among the existing organ, 2) placing dust-bins in different points within the settlement, 3) linking the fees of solid waste collection to other public services and 4) education and awareness creation campaigns accompanied by community stakeholder consultations.