Solid Waste Production Research Articles

Benefits and Application of Nanotechnology in Environmental Science: an Overview

As a result of world population growth, consumption of energy and materials is increasing, leading to environmental consequences. Some of these consequences include increased production of solid waste, increased air pollution caused by vehicles and industrial plants, contamination of surface and groundwater. Nanotechnology has the potential of improving the environment through direct application of nanomaterials for detecting, preventing, and removing pollutants and indirect application of them by using better industrial design process and production of products compatible with the environment. Nanoparticles show higher reactivity due to their small size and high surface. While this characteristic has various benefits and applications, it may have risks for the safety of employees and the environment, such as stay suspended in the air for a long time, possibility of accumulation in the environment, easy absorption, and damage to various organs of the body. This review has investigated the applications of nanotechnology in waste management, controlling and reducing air pollution, water treatment, and nanomaterials safety.

Coastal solid waste prediction by applying machine learning approaches (Case study: Noor, Mazandaran Province, Iran)

Nowadays, intelligent systems are used as innovative tools in different environmental issues. However, the prediction of short-term waste, unlike the long-term scale, is less developed due to more uncertainties and the difficulty in determining measurable independent parameters. In this study, two types of artificial neural networks (MLP and RBF) and two decision tree algorithms (CHAID and CART) have been used as effective tools for short-term forecasting of total waste production in coastal areas of Noor in Mazandaran Province, Iran. So that, average temperature, daily rainfall, sunny hours, maximum relative humidity and maximum wind speed were determined as the most important independent parameters, while the amount of waste produced in the coastal areas of Noor was considered as the dependent variable. Wastes from the coastal areas were gathered and their weights were analysed during 12 months from July 2017 through June 2018. Samplings were carried out twice a week, three weeks of a month and 12 months of a year, overall 72 times a year. The required meteorological data was gathered from the meteorological station in Noor. Then the sensitivity analysis was performed to check the independency of the major independent parameters. Thereafter, the mentioned machine learning approaches were applied to predict the short-term total waste production in IBM SPSS Modeler version 18 environment. In the applied models, 60% of data were used in training the model and the other 40% were used for model evaluation. The results indicated that the CHAID tree algorithm exhibits a better performance in predicting total solid waste production compared to CART, MLP and RBF models. The mean absolute error and the correlation coefficient (R) of CHAID algorithm was 0.067 and 0.828, respectively.

Hydrogeochemical Behavior of Reclaimed Highly Reactive Tailings, Part 1: Characterization of Reclamation Materials

The production of solid mine wastes is an integral part of the extraction and metallurgical processing of ores. The reclamation of highly reactive mine waste, with low neutralizing potential, is still a significant challenge for the mining industry, particularly when natural soils are not available close to the site. Some solid mine wastes present interesting hydro-geotechnical properties which can be taken advantage of, particularly for being used in reclamation covers to control acid mine drainage. The main objective of this research was to evaluate the use of mining materials (i.e., tailings and waste rock) in a cover with capillary barrier effects (CCBE) to prevent acid mine drainage (AMD) from highly reactive tailings. The first part of the project reproduced in this article involves context and laboratory validation of mining materials as suitable for a CCBE, while the companion paper reports laboratory and field results of cover systems made with mining materials. The main conclusions of the Part 1 of this study were that the materials studied (low sulfide tailings and waste rocks) had the appropriate geochemical and hydrogeological properties for use as cover materials in a CCBE. Results also showed that the cover mining materials are not acid-generating and that the LaRonde tailings are highly reactive with pH close to 2, with high concentrations of metals and sulfates.

Experimental Study on the Basic Properties of a Green New Coal Mine Grouting Reinforcement Material

Waste tires are internationally recognized as hazardous waste. Many waste tires storing in the open air for a long time will not only waste the land resources but also pollute the environment after the incineration. Meanwhile, the cumulative accumulation of fly ash in China has also been one of the largest sources of solid waste in coal mines. Under the action of high winds, the accumulated fly ash forms flying dust, which pollutes the environment and endangers human health. Herein, a new type of grouting material for floor reinforcement was developed based on solid waste products using the waste tire rubber particles and fly ash. Using this new material, disaster accidents such as flooding and casualties caused by the inrush of the floor-confined water due to floor fractures, activation, and expansion in the mining process can be greatly reduced, thereby ensuring the safety of coal mine production. The grout body was prepared using a large amount of fly ash, waste tire rubber particles and clay, and mixing additives. The ratio optimization test, uniaxial compressive strength test, permeability characteristic test, stability test, and microanalysis of mine water environment were performed. From the test results, the macrophysical and chemical properties including optimal mix ratio, compressive strength, permeability coefficient, and stability of mine water environment were obtained. The microstructural properties of the grouts were analyzed using scanning electron microscopy microanalysis methods. Considering the situation of the coal floor and attempting to use as many solid waste products as possible, the optimized proportion that can meet the requirements of low cost, high bonds, and dense filling is as follows: 20% of rubber particles, 65% of fly ash, 15% of clay, and 1% of nanosilica. Furthermore, this study can provide scientific reference for large-scale floor grouting reinforcement and large-scale utilization of solid waste products.

Effect of solid waste fermentation substrate on wheat (Triticum aestivum L.) growth in closed artificial ecosystem

Bioregenerative Life Support System (BLSS) is a closed artificial ecosystem and could provide oxygen, food, water and other substrates for long-term deep space survival. The treatment and recycle of the solid waste are crucial and rate-limiting steps in BLSS, and it's reported that the solid waste such as the inedible plants and human feces could be fermented aerobically and then reused as fertilizer for growing plants in BLSS, which may be an effective way to improve the solid waste recycling rate. However, the recycling performance and the effect on the system need to be evaluated. In this study, the fermented and decomposed solid waste product from the 365d BLSS experiment with human involved in Lunar Palace 1 was utilized, and was added to the Hoagland nutrient solution as a supplementary fertilizer in the weight proportion of 5% and 10%, respectively, for the cultivation of wheat (Group-5% and Group-10%). Then, the effects on wheat germination, morphology, photosynthesis, biomass, the conductivity of the cultured substrates and microorganisms were detected and compared with those of the CK group cultured using only Hoagland nutrient solution. The results showed that this planting method had no inhibitory effect on the wheat germination, root length and yield, and might even promote the vegetative growth of wheat in terms of Vigor index, plant height, leaf area and net photosynthesis rate to some extent. The added solid waste fermentation substrate as well as the planting environment in Lunar Palace 1 both had significant influences on the rhizosphere microorganisms of wheat. The bacteria diversity was more abundant than fungi at phylum level, and the relative abundance varied along with the wheat growth period. The relative abundance of the cellulose degrading microorganisms including Actinobacteria and Ascomycota increased in Group-5% and Group-10% compared with CK group along with the growth of wheat. Moreover, the proper reuse of the fermentation substrate could reduce the use of inorganic salts by 9.8%-11.9% and save 40L•m − 2 of water for wheat cultivation. This research has considerable application significance in future deep space exploration.

Toxicity of Soil Leachate from Coal Gangue and Its Surrounding Village of Barley(Hordeum vulgare)

Coal gangue is a harmful solid waste product of coal mining. When it accumulates for a long time, it becomes harmful to the surroundings. To investigate the adverse effect of coal gangue on the surrounding environment, this study investigated the effects of coal gangue and its downstream village on the growth toxicity and genotoxicity of barley at different dilution concentrations (1：27, 1：9, 1：3, and 1：1) via hydroponic experiments. As a result, low concentration coal gangue showed a slight promotion effect on the growth of roots and shoots of barley, while coal gangue and village soil, which have a high concentration, could seriously inhibit their germination and growth. At the same time, with the increase of the concentration of coal gangue, malondialdehyde (MDA) in barley leaves increased, and chlorophyll (Chl) increased first and then decreased, while the village soil showed a lower toxic effect. In addition, our results showed that higher concentrations of coal gangue and village soil could decrease the mitotic index and increase the micronucleus rate in root tip cells, indicating that the toxicity mechanism of coal gangue to barley may be involved in genotoxicity. These results provide experimental evidence for the ecological risk assessment of the coal gangue and its surrounding environment.

A Review of Solid Waste Management Strategies in Nigeria

The global population and increased urbanization have resulted in the increased production of municipal solid waste, thus, becoming a critical issue as a result of its poor management and inappropriate disposal. This is particularly the case of developing countries. This study assessed Solid Waste Management (SWM) strategies commonly adopted by different state waste management Authorities in Nigeria with a view to develop a sustainable roadmap for the management of solid waste in Nigeria. It assessed the Traditional Solid Waste Management Strategy (TSWMS), Waste Minimisation Strategy (WMS) as well as the Technological Strategy (TcS) employed, laying focus on their challenges and benefits. The study depended on a desktop study approach; hence, data were obtained from secondary data as the main source of information with emphasis on published journals, conference papers, newspaper posts and statutory reports from government agencies relevant to the current study. Results from the review showed that waste management across various parts of Nigeria is poor, interwoven with several challenges at all phase of the management process with little benefits recorded on alternative SWM strategy. The reason for the low success rate of some of this management strategies were noted as; increase in population, area covered, increase in urbanization and industrialization, tenure of government, over dependence on government authorities for waste management, finance and other factors of the environment. Although most waste authorities rely heavily on the TSWMS, WMS and the TcS showed a better and promising alternative strategy when inculcated into the already existing strategy. Based on this finding, a roadmap for the actualization of a sustainable integrated solid waste management strategy was recommended for adaptation and adoption by the Nigerian SWM Authorities and Agencies. Keywords: Nigeria, Solid Waste Management, Traditional Solid Waste Management Strategy, Waste Minimisation Strategy, Technological Strategy, Waste Authorities. DOI: 10.7176/JEES/10-6-11 Publication date: June 30 th 2020

A Comparative Carbon Footprint Analysis of Disposable and Reusable Vaginal Specula

(Abstracted from Am J Obstet Gynecol 2020; doi: 10.1016/j.ajog.2020.02.007) In an attempt to save time, as well as reduce costs and transmission of infections, many health care systems in the United States have increased use of disposable medical equipment, which generally decrease costs upfront compared with their reusable alternatives. Use of disposable instruments, however, is associated with increased solid waste production and may increase greenhouse gas emissions, negatively impacting the environment.

Environmental Challenges of Urbanization in Southeast Asia

One of the most important trends in the modern stage of the socio-economic development of the countries of Southeast Asia is the acceleration of the process of urbanization which will determine the future of the region. By 2050, the share of the urban population in the total population of the region is due to increase to 65% compared to 42% at present. The author stresses that the process of urbanization in SEA has a number of distinctive characteristics. Firstly, it should be noted the uneven distribution of the urban population among the countries of the region. Secondly, there is an accelerated growth of medium-sized cities. Thirdly, in the socio-economic and political systems of Southeast Asian countries, large cities and primarily capitals still dominate Being the foundation of economic growth and social progress, urbanization at the same time has many challenges, one of which is the threat of environmental degradation for almost half of the region’s population. With all the diversity of socio-economic development and the political structure of the countries of the region, the environmental situation in their cities, and especially the capitals, is strikingly similar, which indicates the presence of common causes of environmental crisis. The article notes that environmental tension in cities, primarily subjected to problems associated with urbanization, are at the same time a consequence of the national environmental crisis, the cause of which is the realization of a model of extensive economic development, the implementation of which is accompanied by the over-exploitation of natural resources and increased pollution. The deterioration of the environmental situation in cities, which reveals itself in a high level of air and water pollution, restricting public access to drinking water sources and sanitary facilities, increasing the production of solid waste with imperfect disposal technologies, devalues the results of the economic and social progress of Southeast Asian countries.The author discusses in detail the main environmental problems of cities, analyzes the causes of their occurrence and assesses the possibilities for their prevention. The latter involves an integrated approach to overcoming the environmental crisis along with implementing measures at different levels and in different areas. The author comes to the conclusion that despite the fact that in recent years there have been some positive changes in the approach of the authorities to solving the most acute environmental problems, nevertheless, it is doubtful that the environmental situation will noticeably improve in the near future without changing the philosophy of development itself

Solid-State Conversion of Magnesium Waste to Advanced Hydrogen-Storage Nanopowder Particles.

Recycling of metallic solid-waste (SW) components has recently become one of the most attractive topics for scientific research and applications on a global scale. A considerable number of applications are proposed for utilizing metallic SW products in different applications. Utilization of SW magnesium (Mg) metal for tailoring high-hydrogen storage capacity nanoparticles has never been reported as yet. The present study demonstrates the ability to produce pure Mg ingots through a melting and casting approach from Mg-machining chips. The ingots were used as a feedstock material to produce high-quality Mg-ribbons, using a melting/casting and spinning approaches. The ribbons were then subjected to severe plastic deformation through the cold rolling technique. The as-cold roll Mg strips were then snipped into small shots before charging them into reactive ball milling. The milling process was undertaken under high-pressure of pure hydrogen gas (H2), where titanium balls were used as milling media. The final product obtained after 100 h of milling showcased excellent nanocrystalline structure and revealed high hydro/dehydrogenation kinetics at moderate temperature (275 °C). The present study shows that primer cold rolling of Mg-strips before reactive ball milling is a necessary step to prepare ultrafine magnesium hydride (MgH2) nanopowders with advanced absorption/desorption kinetics behavior. These ultrafine powders with their nanocrystalline structure are believed to play an important role in effective gas diffusion process. Moreover, the fine titanium particles came from the ball-powder-ball collisions and introduced to the Mg matrix have not only acted as micro-scaled milling media, but they played a vital catalyzation role for the process.

Treatment of reclaimed municipal solid waste incinerator sands using alkaline treatments with mechanical agitation

Solid waste production is rapidly increasing, and municipal solid waste incinerator plants provide a practical and sustainable solution to significantly reduce the volume of waste. Incinerator ash is a byproduct of the combustion process, and lightweight sands can be reclaimed from the ash for use in cementitious materials once treated for hydrogen gas production. This work investigates treatment methods for reclaimed sands for use in concrete. A novel method based on a propriety patent to capture the amount of hydrogen gas production from reclaimed sands is presented using a steel pressure chamber, pressure transducer, and data acquisition system. The setup is maintained under a constant temperature, pressure, and agitation using an environmental incubator. Treatment methods using sodium hydroxide, reused sodium hydroxide, alumina, and alumina + sodium hydroxide are investigated. It is found that sodium hydroxide is an effective treatment solution for reclaimed sands, with the ability to reuse the solution multiple times. Alumina is found not to be an effective treatment method when used alone. Concrete is made using treated reclaimed sands, where it is shown through scanning electron microscopy imaging that large voids in the cement matrix due to hydrogen gas production are significantly reduced in size.

Biogas from Tannery Solid Waste Anaerobic Digestion Is Driven by the Association of the Bacterial Order Bacteroidales and Archaeal Family Methanosaetaceae.

The search for renewable energies has been one of the biggest challenges of the last decades. Sludge and solid wastes of many sources have been used to produce biogas of high calorific value. Thus, this work aimed to evaluate the biogas production of solid waste originating from a tannery that uses chromium salts as a tanning agent and to characterize the physicochemical parameters and microbial composition of the biogas-producing biomass. Wastes were collected and the parameters were evaluated at the initial and final time points of the anaerobic incubation process. At the end of 150days, there was a production of 26.1mLg-1 VSS of biogas with 52% of methane. The highest amount of biomethane observed was related to the archaeal family Methanosaetaceae and bacterial order Bacteroidales. Knowledge about changes in the microbial composition can provide tools for manipulation, isolation, and inoculation of the microorganisms inside the bioreactors to maximize methane production.

Seasonal Variation of Solid Waste Components in Ranya District, Iraq.

Municipal solid waste can be considered as one of the significant environmental issues in worldwide, as a result of industrial revolution, economic development and overpopulation. The current study focused on seasonal variation of solid waste production and composition. The study was conducted during winter and summer seasons in 2019. Solid waste samples were collected from the collector trucks from eight different zones in Ranya district. The results revealed that the average of total solid waste generation in the district estimated as (286.9 tons/day) and (1.108 kg-capita/days). The analysis of the waste content detected that the largest portion of the district solid waste is organic material which forming an average of 67.05%. Followed by cloth & textile, plastic, paper & cardboards, metal and glass, which their quantities are 11.93%, 8.19%, 7.12%, 3.05% and 2.65% respectively. The seasonal variation impacts on solid waste has been preserved obviously in this research study, more specifically in metal, glass and organic waste contents, which their quantities increased substantially from wet to dry season, (6.2 to 11.61 tons/day), (6.26 to 9.07 tons/day) and (177.5 to 207.62 tons/day) respectively. Moreover, the total generated solid waste magnitude of the district picked up changed from 268.37tones/day for wet season to 305.44tones/day for dry season.

Sifat Fisik Dan Mekanik Papan Komposit Dari Serat Tandan Kosong Kelapa Sawit (TKKS) Hasil Penguraian Secara Mekanis Dengan Perekat Gambir

Oil palm empty fruit bunches (OPEFB) are a solid waste product from the oil palm industry that are about 70% fiber. Previous research has indicated that this fiber can be used to produce composite board. Gambier can be used in an adhesive to produce these boards as it has strong adhesive properties. This research investigates the suitability of four types of OPEFB fiber resulting from different mechanical separation speeds and three adhesive made from differing concentrations of Gambier (12%, 14%, 16%) to produce high quality composite board. The results of the research suggest the type of the fiber and the concentration of the gambier used significantly influence the density of the resulting board and that there are interactions between these two variables. The water content of the board is significantly influenced by the type of OPEFB fibre but not by the concentration of gambier or any interaction between these variables. Thickness swelling, modulus of rupture (MOR) and modulus of elasticity (MOE) are all influenced by type of fiber and concentration of gambier without any significant interaction between these two factors. The best types of fiber was those labeled A and B. The best performing composite board was produced from the longer B fibers and 16% gambier adhesive. This board a had density of 0.86 g/cm3, MOR 251.3 kg/cm2 and strength parallel to the grain of 145.6 kg/cm2. This data suggests that the density, water content and MOR of the boards made with this combination of material meets standard SNI 03-2105-2006 however the thickness swelling of the board fails this standard.

Study of the leaching alterability in Soxhlet Extractor of ceramic materials with incorporation of ashes resulting from the incineration of urban solid waste

Population expansion, especially in metropolitan areas, has led to an increase in the production of urban solid waste (USW) by domestic and commercial activity in urban centres. Reducing the production of these wastes is an extremely difficult task. However, the reduction processes, themselves, have the potential to produce a number of useful residues. This study focuses on the residues of incinerated USW, which produces ashes of varying compositions. This study investigates a mixture of two ashes, one resulting from the incineration of USW from LIPOR II (Intermunicipal Waste Management Service of Porto Region) and another from ValorSul (Valorisation and Treatment of Solid Waste of Lisbon and West Regions), both processed by EcoInCer (Ecological Innovations Ceramics company). Ashes from several samples of USW incorporating clays were tested to identify physical and mechanical characterisations, with a view to identifying useful ecological ceramic materials which could be used by the ceramics industry. Ceramic samples with 0%, 10% and 20% of ashes were incorporated in a clay matrix composed of 5% kaolin and 95% red clay, and submitted to leaching alterability in Soxhlet Extractor. The obtained results demonstrate the ways in which the ash percentage and the firing temperature can be important in the alterability of a ceramic material.
 Keywords: Ceramic materials, Leaching, Urban solid waste

Metallurgical Waste in Construction Industry

The paper discusses a negative effect of metallurgical waste on the ecosystem, costs and benefits of a potential use of solid metallurgical waste products in production of building materials with the purpose to reduce their harmful effect on the environment and preserve nonrenewable natural resources. The most usable products a component of which is metallurgical waste, such as slag concrete and blocks, as well as break stone are compared with products made of natural raw materials. The most appropriate application fields with the minimal harm to human health and nature are recommended.

Аssessment of the risk of emergency situations during the storage of galvanic waste

The article is dedicated to the research of the consequences of emergencies related to the storage of waste (sludge) on the territory of the enterprise, as well as directly in the process of carrying out technological processes for the estimation of danger to health and human life. The problem of industrial and household waste recycling is becoming more pressing problem nowadays taking into consideration constantly increasing volume of waste generation, while the rate of its processing is incomparably small. As a result, hundreds of millions of tons of various solid wastes must be recycled and disposed. The scale of annual production and accumulation of solid waste requires the creation of powerful processing plants with a capacity of millions tons per year with their industrial development. The environment is considered to be safe when its condition meets legislated criteria, standards, limits and standards established by legislation concerning cleanliness (not pollution), not exhaustion, environmental sustainability, sanitary requirements, ability to satisfy the interests of citizens. The level of environmental pollution in the areas of production of plates, galvanizing and painting plants, which are the greatest sources of environmental hazard and belong to main pollutants. The question of risk estimation and management in different production branches of Ukraine and leading countries nowadays became urgent and significant because of repeated use of chemical elements, imperfection of disinfection and utilization processes. The work objective lies in estimation of hazard level to human health and life consequent on occurring emergencies, connected with galvanizing processes and waste conservation (sludge) on the territory of the enterprise. Sludge hazard classes during production of plates and galvanics are defined, allowing a possibility of searching the ways for increasing ecological safety level of territories of enterprises, involved in plate and galvanics production. Application of “risk” definition lead to impossibility of the development of unified approach to its estimation. Plenty of risk types exists, among which is ecological risk. National standard of Ukraine (ДСТУ 2156-93. Industrial safety. Definitions) specifies rick of industrial enterprises as probability of potential danger realization, initiated by industrial enterprises and (or) negative consequences of this realization. On the grounds of research results of galvanic sludge content the effective content and dangerous substances content was determines. Two examples of sludge taken from different Ukrainian enterprises, kept inside plantsite area, were shown. It was determined that hazard index is above normal and this risk level is inadmissible. Emergencies, accompanied by storage area dismemberment and lead to galvanic sludge insertion into the environment, increasing risk for human health. Obtained level of carcinogenic risk and hazard index indicate on the necessity of carrying complex of resolutions concerning prevention of emergencies and minimizing their consequences. Following researches have to be directed for search of alternatives of sludge storing on the territories of enterprises, for wastes utilization with separation of valued components and recurrent use of solutions in technological processes.

Heavy metals in urban grounds in Ekaterinburg (Russia)

Problem Statement. Urban grounds have an artificial origin, they are formed as a result of construction activities, contain solid waste products and pollutants along with natural mineral and organic raw materials. Not all the cities have a system of registration of the urban ground types. The assessment of the pollution degree of urban grounds plays a key role in the environmental quality assessment in urban areas. The objective of the study is to conduct quantitative assessment of pollution with heavy metals for the urban grounds (on the example of Ekaterinburg, Russia). The material for the study is represented by the results of environmental engineering surveys conducted in Ekaterinburg in 2012–2015. The samples of the urban ground were collected with vertical stratification to a depth of 7 m in different geographical parts of the city. The content of Pb, Zn Cu, Mn and Ni, and the level of acidity were determined in the urban ground samples. Results. The analysis of vertical ground profiles showed a decrease in Pb, Zn and Ni content with increasing the depth. The accumulation of typical pollutants for urban environment (Pb, Zn and Cu) was found in the upper ground layer 0-20 cm. The metal content in the layer 0-20 cm was up to 5 times higher than the metal content in the lower horizons with a twofold decrease in metal concentration to depth of 1 m. In artificial ground in Ekaterinburg, there was a tendency to alkalization of soils with increasing depth (pH of the surface layer 0–20 cm was 6.5, when pH value was close to 8 at the depth > 4 m).

Magnesiation roasting-acid leaching: A zero-discharge method for vanadium extraction from vanadium slag

Present methods of vanadium extraction from vanadium slag suffer from serious environmental pollution due to the large production of solid waste and wastewater. This study proposes a cleaner method of magnesiation roasting–acid leaching, where magnesium oxide is considered to be a recyclable roasting additive. The maximum extraction efficiency achieved in case of vanadium is 95.56%, and the obtained vanadium pentoxide has a high purity of 99.07%. The magnesium in the leaching liquor is recovered as MgO with purity of 99.21%, and recovery rate of 90.13%, which is recycled as the roasting additive. Furthermore, manganese, ammonium sulfate, and water are recovered and recycled from the wastewater, while the ammonia produced during vanadate calcination is recycled. The resulted leaching residues are recyclable by burning in a blast furnace to recover their iron content for reuse. Herein, the recycling and reuse of all the wastewater and leaching residues result in zero discharge, significant cleanliness, and high resource utilization. This work has opened a new pathway of establishing significantly cleaner production process for environmental sustainability via design and incorporation of inner recycling of wastes into the process in which these wastes are produced.

Leaching kinetic study of sulfuric acid roasted mixed-type rare earth concentrate for reducing the solid-waste production and chemical consumption

The Baotou bastnaesite and monazite mixed rare earth ore is one of the most significant rare earth ore in the world and is mainly processed by the sulfuric acid roasting method. However, the high content of Fe and P in the leaching solution contributes to a large amount of radioactive precipitate waste produced in the purification process, and that causes the primary loss of rare-earth elements (REEs) and the environmental issue and safety concern. The goal of this paper is to reduce the solid-waste by improving the selective leaching efficiency of REEs based on a leaching kinetics study of REEs, Fe and P in the H2SO4 system. The experiments were carried out focusing on the effect of acidity, roasted concentrate particle size, temperature, and liquid-solid ratio on the leaching kinetics. The results indicate that the equilibrium leaching time of REEs (<15 min) and P (<10 min) is far less than that of the Fe (60 min to more than 180 min) which is highly depended on temperature. The leaching kinetics model of REEs, Fe and P follows the shrinking core model but is governed by different limiting step: both REEs and P are controlled by diffusion, while Fe is controlled by chemical reaction. A possible leaching mechanism is proposed. Based on the kinetic study, the dissolution of Fe is inhibited and its content in the leaching liquid is reduced by controlling the leaching time. Meanwhile, the result of neutralization for purifying the leaching solution shows that the amount of solid waste generated in the neutralization process is reduced by 19% with improving 3% REEs recovery and reducing 15% MgO consumption. This study shows a good prospect for improving the sulfuric acid roasting method to be a cleaner and lower chemical consumption process in dealing with the bastnaesite and monazite mixed rare earth ore.