CO_(2) mineralization by typical industrial solid wastes for preparing ultrafine CaCO_(3): A review

Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies.

Reaction Process of Chromium Slag Reduced by Industrial Waste in Solid Phase

M, a particular industrial waste, was selected to detoxify chromium slag at a high temperature. The carbon remaining in M reduced Cr （ Ⅳ ） of Na2 CrO4 borne in the chromium slag to Cr （ Ⅲ ） in the solid phase reaction, and its thermodynamics and kinetics were studied. The reduction process of Na2CrO4 by carbon produced CO, whiCh＇was endothermic. Under the experimental condition, the apparent activation energy was 4. 41 kJ·mol^-1 , the＇apparent order of reaction for Na2 CrO4 was equal to one, and the partial pressure of CO was only 0.22 Pa at 1 330℃.

Review of the fabrication and application of porous materials from silicon-rich industrial solid waste

Porous materials have promise as sound insulation, heat barrier, vibration attenuation, and catalysts. Most industrial solid wastes, such as tailings, coal gangue, and fly ash are rich in silicon. Additionally, a high silicon content waste is a potential raw material for the syn- thesis of silicon-based, multi-porous materials such as zeolites, mesoporous silica, glass-ceramics, and geopolymer foams. Representative sil- icon-rich industrial solid wastes (SRISWs) are the focus of this mini review of the processing and application of porous silicon materials with respect to the physical and chemical properties of the SRISW. The transformation methods of preparing porous materials from SRISWs are summarized, and their research status in micro-, meso-, and macro-scale porous materials are described. Possible problems in the application of SRISWs and in the preparation of functional porous materials are analyzed, and their development prospects are discussed. This review should provide a typical reference for the recycling and use of industrial solid wastes to develop sustainable “green materials.”

Research on Regional Industrial Solid Waste Comprehensive Utilization Ability Influencing Factors based on Panel Data

On the basis of panel data from 29 provinces and cities throughout the country in 2006-2010, a research is made on factors influencing regional industrial solid waste comprehensive utilization ability through a regression analysis method. Research result shows that a positive influence will generate on the comprehensive utilization ability of the industrial solid waste by three factors： regional industrial soldi waste treatment earning level, regional industrial soldi waste treatment investment level and regional industrial pollution treatment subsidy strength. And this thesis will propose suggestions from improving earning ability, enhartcing treatment investment and increasing government subsidy depending on result of empirical analysis.

Bird’s-eye view of recycled solid wastes in road engineering

Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements,bridges,tunnels,and accessory structures.The utilization of solid wastes is expected to offer sustainable solutions to waste recycling while enhancing the performance of roads.This review provides an extensive analysis of the recycling of three main types of solid wastes for road engineering purposes:industrial solid waste,infrastructure solid waste,and municipal life solid waste.Industrial solid wastes suitable for road engineering generally include coal gangue,fly ash,blast furnace slag,silica fume,and steel slag,etc.Infrastructure solid wastes recycled in road engineering primarily consist of construction&demolition waste,reclaimed asphalt pavements,and recycled cement concrete.Furthermore,recent exploration has extended to the utilization of municipal life solid wastes,such as incinerated bottom ash,glass waste,electronics waste,plastic waste,and rubber waste in road engineering applications.These recycled solid wastes are categorized into solid waste aggregates,solid waste cements,and solid waste fillers,each playing distinct roles in road infrastructure.Roles of solid waste acting aggregates,cements,and fillers in road infrastructures were fully investigated,including their pozzolanic properties,integration effects to virgin materials,modification or enhancement solutions,engineering performances.Utilization of these materials not only addresses the challenge of waste management but also offers environmental benefits aiming carbon neutral and contributes to sustainable infrastructure development.However,challenges such as variability in material properties,environmental impact mitigation,secondary pollution to environment by leaching,and concerns regarding long-term performance need to be further addressed.Despite these challenges,the recycled solid wastes hold immense potential in revolutionizing road construction practices and fostering environmental stewardship.This review delves into a bird’seye view of the utilization of recycled solid wastes in road engineering,highlighting advances,benefits,challenges,and future prospects.

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.

Experimental Study of the Fry-Drying Phenomena of Organic Wastes in Hot Oil for Waste-Derived Solid Fuel

In sludge treatment, drying sludge using typical technology with high water content to a water content of approximately 10% is always difficult because of adhesive characteristics of sludge in drying. Many methods have been applied, including direct and indirect heat drying, but these approaches of reducing water content to below 40% after drying are very inefficient in energy utilization of drying sludge. In this study, fry-drying technology with a high heat transfer coefficient of approximately 500 W/m2·°C was used to dry swine excreta, sewage and industrial sludge. Also waste oil was used in the fry-drying process, and because the oil’s boiling point is between 240°C and 340°C and the specific heat is approximately 60% of that of water. In the fry-drying system, the sludge is input by molding it into a designated form after heating the waste oil at temperatures between 130°C and 150°C. At these temperatures, the heated oil rapidly evaporates the water contained in the sludge, leaving the oil itself. After approximately 8 - 10 min, the water content of the sludge was less than 10%, and its heating value surpassed 20,000 kJ/kg. Indeed, this makes the organic sludge appropriate for use as a solid fuel. The dried swine excreta, sewage and industrial sludge can be used in an incinerator like low-rank coal or solid fuel.

Environmental risk assessment of industrial byproduct gypsum utilized for flling abandoned mines

In response to the basic policy of green and low-carbon circular development to solve resource,environmental and ecological problems,gypsum is considered to be a flling material for mine backflling.To explore the potential risks of gypsum to the groundwater environment due to the backflling of abandoned mines,a sequential batch leaching experiment was carried out in this paper,which used three types of industrial waste gypsum,namely,phosphorus gypsum(PG),titanium gypsum(TG)and fue gas desulfurization gypsum(FGDG).COMSOL Multiphysics 5.4 software was used to simulate and solve the migration process of the leached metal elements in the mine foor when these three gypsum types were used as flling materials to observe the concentration distributions and difusion distances of the metal elements from these three gypsum types in the mine foor.The results show that(1)during repeated contact of the three types of industrial waste gypsum with the leaching medium,the pH levels changed,and the changes in pH afected the leaching patterns for the heavy metal elements in the gypsum.(2)Based on the concentrations of the metal elements that were leached from the three types of gypsum,it can be determined that these three types of gypsum are not classifed as hazardous solid wastes,but they cannot be ruled out with regard to their risk to the groundwater environment when they are used as mine flling materials.(3)When the three types of gypsum are used as flling materials,the concentration distributions of the metal elements and their migration distances all exhibit signifcant changes over time.The concentration distributions,difusion rates and migration distances of the metal elements from the diferent gypsum types are afected by their initial concentrations in the leachate.The maximum migration distances of Zn in the foor from the PG,FGDG and TG are 8.2,8.1 and 7.5 m,respectively.

Analysis of Environmental Management for the Treatment of Plastic Waste in Mexico： Government Strategies

In Mexico, garbage represents a high pollution index according to national and international organizations; eighty percent of waste products stay in sanitary landfills, out of doors, where no tailings management exists. Plastic products represent 16% of this pollution （one and one-half kilos daily per person in a country with a population of 107 million people）. These sanitary landfills are methane deposits, and consequently emit gases and toxins that cause serious health problems. The object of this is to analyze governmental programs, strategies, policies and procedures which regulate both industrial sectors and society. Society and government share a responsibility since they must implement norms which include the separation, reduction, recycling and reuse of garbage. Results demonstrate that government strategies used to treat railings are complex and are directed more towards sanctions than to motivation. Furthermore these strategies discourage a cultural transformation toward industrial sustainability. Instead of reducing the garbage accumulation problem, they increase the difficulty.

IUWA Waste Manager软件在米东工业园区的试用

用IUWA Waste Manager软件分析乌鲁木齐市米东工业园区的固体废物管理状况,结合循环经济理念,提出园区固体废物环境管理建议和循环化改造方案。

Industrial solid waste flow analysis of eco-industrial parks： implications for sustainable waste management in China

Sustainable waste management in the industrial ecology perspective brings enormous challenges to the existing methodology of waste analysis at the industrial park （IP） scale. In this study, a four-step method was proposed for industrial solid waste （ISW） flow analysis of eco-industrial parks （EIPs） and applied to two IPs in eastern China. According to a park-wide census of 619 industrial enterprises and 105 questionnaires by a survey from 2006 to 2008, the results indicated that： 1） at the enterprise scale, more than 60% of enterprises were small- ISW-generation enterprises which encountered great difficulties on effective waste management; 2） at the IP scale, though the two IPs have set up their own environmental management systems and passed the ISO 14001 certification, the efficiencies of the ISW manage- ment systems have yet to be improved in the industrial ecology perspective; and 3） at the regional scale, more than 97% of ISW flowed within the provincial region, indicating that the provincial governments prevented the wastes from flowing into their own ＂back yard＂. Effective waste management should be placed in a broader perspective. Approaches to sustainable waste management may include wastes exchange, efficient waste and information flow, virtual EIP, waste minimization clubs and regionalization of waste management.

Heavy Metal Release from Some Industrial Wastes: Influence of Organic and Inorganic Acids, Clay Minerals, and Nanoparticles

Knowledge about heavy metal release from industrial solid wastes(ISWs) is crucial for better management of their environmental risks. This study was conducted to investigate the effect of organic and inorganic acids, clay minerals, and nanoparticles(NPs) on the release of heavy metals from sugar factory waste, ceramic factory waste, leather factory waste, and stone cutting waste. The influence of the extractants on heavy metal release from these ISWs was in the following descending order: citric acid > oxalic acid > nitric acid≥ sulfuric acid > Ca Cl2. Addition of clay minerals and NPs as adsorbents decreased heavy metal release, which was significantly lower in NP-treated wastes than in the clay mineral-treated wastes. On the other hand, the presence of organic and inorganic acids increased heavy metal adsorption by NPs and clay minerals. These results suggest that NPs can be applied successfully in waste remediation,and organic and inorganic acids play an important role in the removal of heavy metals from the studied adsorbents.

碳中和背景下我国固废资源化利用产业发展研究

固废资源化利用可以节约大量的资源和能源,具有循环利用、节能减碳的优势,对于推动加快形成绿色低碳生产方式和生活方式、实现“双碳”战略目标、促进美丽中国建设具有重要意义。本文结合典型案例分析,梳理了国内外固废资源化利用产业的发展现状,分析了我国固废资源化利用产业在产业化进程、资金投入、技术创新等方面存在的主要问题。在此基础上,提出了我国固废资源化利用产业的发展建议,推动产业化进程,促进“产业链、创新链、人才链、资金链”融合赋能;加大激励支持力度,夯实金融保障基础;打造科创资源高地,强化项目示范引领;集聚人才优势,搭建高水平合作平台,全面推进固废资源化利用产业的高质量发展。

Evaluation of Effluent Discharge from Steel Manufacturing Industries on the Proliferating Environmental Degradation in Nairobi Metropolitan in the Republic of Kenya

The overall objective of this study was to establish the effects of steel industrial effluent on Nairobi metropolitan water system and its impact to the society. The study sought to identify various types of wastes produced by factories, assess how the waste generated is managed and disposed, examine the effects of effluent discharge on Nairobi River and finally propose mitigation measures. The research adopted a qualitative design and employed a number of methods: direct observations, document reviews to content analysis of the past studies, which in the end generated invaluable data. The study revealed that there are four categories of waste generated: solid waste, liquid waste, footbath chemicals as well as thermal wastes. It was also found that waste management in place was not effective enough leading to water and soil pollution. Other causes of pollution were found out to emanate from gasses contamination to the air and chemicals used during steel processing. The findings will inform the community of the harmful effects of untreated water and how it impacts on their health and productivity. It will also help the stakeholders in the environmental conservation to articulate issues of policy and influence agenda setting in the national and sub-national levels.

固体废物的工业窑炉协同处置进展

工业窑炉协同处置固体废物是降低碳排放的重要途径。将固体废物作为替代燃料或原料在现有高温窑炉中进行处置,不仅可以减少污染物排放,还可实现固体废物的减量化、无害化和资源化利用。本文介绍了水泥窑、电厂燃煤锅炉、钢铁冶炼窑炉、煤气化炉等工业窑炉协同处置固体废物技术的现状,分析了多氯代二苯并-对-二口恶英/多氯代二苯并呋喃(PCDD/Fs)和重金属两类典型污染物的排放特征,指出了该技术当前存在的问题,并对其发展方向进行了展望。

团聚体级配对固废改良膨胀土耐久性的影响

通过工业固废改良膨胀土团聚体的搅拌破碎试验以及破碎土的耐久性试验,揭示了团聚体尺寸效应对改良效果的影响,并分析了其影响机理.结果表明:掺入铁尾矿砂和电石渣能加速土团聚体在搅拌过程中的破碎;大粒径团聚体内部膨胀土的改良效果较差,容易产生裂隙;粒径大于15 mm的团聚体含量越高,试样的耐久性越差;相对于电石渣改良土,复合改良土的耐久性更好;对于应用于底基层的电石渣改良土和复合改良土,建议控制粒径大于15 mm土团聚体的含量分别小于2.5%和21.8%.

工业固废CO_(2)矿化协同减污降碳关键技术进展

针对工业过程CO_(2)和固废排放的问题,减污降碳刻不容缓。CO_(2)矿化技术在封存CO_(2)的同时固废得到资源化利用,受到广泛关注。论述了不同工业固废作为CO_(2)矿化原料的利用情况,对比分析了不同矿化工艺优缺点及CO_(2)矿化机理,总结了不同CO_(2)矿化工艺研究现状和工业化应用情况。研究发现,目前针对固废CO_(2)矿化缺乏机制性解释,无法有效控制金属离子的浸取过程和矿化过程中气液固传质的效率,同时矿化形成的碳酸盐产品存在粒径大、易团聚、功能单一等问题。未来需进一步研究浸渍过程中表面溶剂扩散等控制浸取速率和程度的机制;深入研究碳酸盐成核结晶动力学机制及碳酸盐晶体形貌、粒度调控方法;构建煤基固废浸取、矿化溶质气-液-固传输模型,进行工艺参数优化和过程强化并确定放大规律;进一步加强CO_(2)矿化利用技术全生命周期和经济评价;最后,需加大CO_(2)矿化利用技术的中试、示范技术集成和成套工艺建设,为规模化减污降碳技术的工业化发展奠定技术支撑。

以煤矸石为原料制备P型沸石微粉的研究

基于煤矸石利用率较低的现状和煤矸石富含硅铝成分的特征,提出了将煤矸石废弃物制备成沸石分子筛矿物微粉的思路。以七台河市煤矸石为原材料,采用碱融-水热法合成P型沸石分子筛微粉末,探讨了陈化温度、液固比、碱固比等反应条件对P型分子筛形貌的影响,获得最佳工艺条件为:硅铝比为1∶1,陈化温度为50℃,液固比为7∶1,碱固比为0.8∶1。SEM测试结果显示,合成产物的微观形貌为粒径6μm左右的球形沸石分子筛。XRD测试结果表明,产物特征峰与NaP型分子筛标准特征峰相吻合。

FPCC改良过湿土力学性能及微观特性研究

为达到提高过湿土强度并合理利用工业固废的目的,利用粉煤灰、磷渣、电石渣及水泥所制备的煤灰-磷渣-电石渣-水泥胶凝材料(FPCC)对过湿土进行改良,对FPCC掺量分别为4%、6%、8%及10%的过湿土进行无侧限抗压强度试验、加州承载比(CBR)试验、抗压回弹模量试验和电子显微镜(SEM)微观扫描,并利用Matlab软件与Image-Pro Plus(IPP)软件分析其孔隙特征及分布情况,FPCC改良过湿土的力学性能及微观特性。结果表明:FPCC用于过湿土改良效果显著,掺加6%FPCC时过湿土28 d龄期各指标均满足使用要求;28 d龄期FPCC过湿土中产生了大量水化产物,随着掺量的增大,水化产物增多;随着FPCC掺量的增大,土体内部孔隙率降低、孔隙直径减小、孔隙丰度增大及孔隙定向角有序化。FPCC改良过湿土具有良好的强度及承载能力,考虑到节约水泥用量以及更合理地利用工业固废,建议FPCC掺量为6%。