Physical and Mechanical Properties of Hempcrete

Background: Environment-friendly materials attract attention whilst the construction sector causes excessive global energy consumption and emission of greenhouse gas. Renewable plant-based biomaterials, which have a low environmental impact, are very beneficial in order to prevent environmental pollution and to preserve natural resources. Hempcrete provides environment-friendly construction materials as well as thermal and hygroscopic properties. Objective: This paper presents a review of hempcrete research about understanding the environmental effects and construction methods of hempcrete; moreover, the benefits and innovations it has provided throughout its life cycle, have been investigated. Methods: For this purpose, experimental studies of hempcrete were compared to each other in all aspects in order to determine density, thermal conductivity, vapor permeability, hygrometric behavior, durability, acoustic absorption, mechanical properties and life cycle analysis. Moreover, binder characteristics, hemp shiv proportions, water content, curing conditions and results have been focused on to explain the benefits of hempcrete. Results: The results obtained show that hempcrete has high porosity and vapor permeability, medium-low density, low thermal conductivity, Young’s modulus and compressive strength. Conclusion: Based upon the findings of the studies reviewed, hempcrete is an advantageous material in buildings with its extraordinary thermal and hygrometric behaviour. Hemp is also an eco-friendly and economical plant-based raw material for the construction industry.

Sustainable Use of Recycled Glass Powder as Cement Replacement in Concrete

Aims: This paper introduces a sustainable way of using Recycled Glass Powder (RGP) as a cement replacement in concrete. Background: In Australia, almost one million tons of glass waste is collected annually for recycling purpose. However, the inconsistency in chemical composition and the presence of impurities make glass recycling process difficult. Besides, the lack of local recycling plants coupled with high transportation costs makes the recycling process expensive. Objective: For the successful use of recycled glass in concrete for industrial applications, it is therefore, important to characterize the physical and chemical properties of recycled glass collected by the local councils. Furthermore, the effects of replacement levels of cement with recycled glass on the strength and durability properties of concrete need to be assessed as well. Methods: Mechanical strength and durability properties of concrete with 10%, 20% and 30% of RGP as a partial cement replacement were tested and compared with typical concrete and fly ash blend concrete. The relative strength test of mortar was conducted to assess the reactivity of glass powder with the cement. Results: RGP concrete showed an improvement in strength over time like fly ash. Using RGP significantly improved the resistance against chloride penetration with increasing glass powder content. Furthermore, RGP also met the relative strength requirement as per Australian Standard requirement to be considered as a supplementary cementitious material. Conclusion: This research showed that the use of RGP as cement replacement is feasible for replacement level up to 10%. The outcome of this research aims to contribute towards sustainable development by reducing the consumption of cement, as well as reduction of glass waste going into landfill.

Consumers’ Perceptions on Plastic Bags Tax Levy in Peri-urban Areas of Eswatini: A Case of Kwaluseni and Logoba Chiefdoms

Introduction: This study focused on assessing the perceptions of consumers on plastic bags tax levy in peri-urban areas of Eswatini, using Kwaluseni and Logoba chiefdoms as case studies. Methods: The areas of key focus include knowledge of and attitudes of consumers towards plastic bags pollution, strategies employed by consumers to manage plastic bags, consumers’ willingness to pay for plastic bags and what Eswatini Environment Authority has done so far in controlling plastic bags pollution. Results: A total of 165 households, (99 from Kwaluseni and 66 from Logoba) were conveniently sampled and interviewed with the aid of a questionnaire. Community leaders and an environmental inspector from Eswatini Environment Authority were also interviewed. The findings show that the use of plastic bags is increasing in both chiefdoms (92.93% at Kwaluseni and 92.42% at Logoba). Concerning what respondents do with the plastics bags after ferrying their goods home, 25% at Kwaluseni and 19% at Logoba of the respondents claimed to reuse some bags and throw away the rest. Conclusion: With regard to willingness to pay, the findings indicate that 49.70% of the respondents are willing to buy plastic bags.

Estimation of Infectious Medical Waste Quantities on a Per-patient Basis: An Observational Study at a Hospital

Introduction: Infectious medical waste management in hospitals is very important. The potential impacts of infectious medical waste discharged from hospitals on populations and society are considered greater than those of general industrial waste. Therefore, the estimation of infectious medical waste discharged from healthcare facilities should be accurate. The present study reports the quantity of infectious medical waste discharged per ward per day per inpatient by weight. Methods: In medical wards, the digestive surgery ward discharged the most infectious medical waste. In addition, the digestive surgery ward had the highest quantity of infectious medical waste per day per inpatient. Infectious medical waste quantity estimates based on beds were lower than those based on inpatients, with minimum and maximum underestimates of 6% and 21%, respectively. Results & Discussion: Infectious medical waste discharged per patient per day was low in the outpatient department. The operating room and the emergency department discharged 10-fold more infectious medical waste than the wards. The operating room, the emergency department, and the clinical inspection department accounted for 60% of infectious medical waste discharged from hospitals. Conclusion: Notably, there are considerable differences among departments when evaluating hospital waste, particularly in hospitals with surgery and critical care departments, which is different in the case of evaluations based on bed counts.

Guidelines for Practical Application of the EUROPE Model to Improve Production Units’ Resource Efficiency

Introduction & Objective: This paper describes the practical usage of the EUROPE (Efficient Use of Resources for Optimal Production Economy) model based on the equality principle to improve the resource efficiency of production units. Methodology: The EUROPE model is a tool to monitor, manage and evaluate how the economic, technological and environmental performance of a firm or other production unit changes over time. Results & Discussion: A manual for daily use was provided to industrial managers and practical operators in a municipal solid waste firm. The company was able to improve its economic, environmental and technological standards by employing the EUROPE model, which combines relevant aspects of all three standards in a single key performance indicator. The method involves allocating shadow costs to residuals and the technique is demonstrated in the case of a medium-sized Swedish municipal solid waste management firm. Conclusion: The case study indicates that the manual accompanying the model is useful for companies applying the model to industrial activities and solid waste management schemes.

Effects of Various Agroindustrial Wastes on Nutrition Yield and Quality of Canola (Brassica napus L.)

Introduction:Canola is an important agricultural crop generally grown for oil and biofuel generation.Materials and Methods:The agroindustrial solid wastes of oregano and cumin wastes were used in a vegetation experiment to determine their effect on the nutrition, yield and quality of the canola plant (Brassica napusL.) The experiment was performed on 12 plots of 6 m2and was conducted with four treatments of composted oregano and cumin wastes, mineral fertilization and control in three replications. Physical and chemical properties and macro-micro nutrients were determined in the soils at the beginning and the end of the experiment.Results and Discussion:The leaves showed sufficient levels of N, P, K, Ca, Mg and low sufficient levels of Na, Fe, Cu, Zn and Mn. The boron content of the leaves was insufficient. Manganese and B were affected significantly by the applications. The applications did not affect plant height, shoot and carob number per plant, and seed numbers per carob significantly. Statistically, the highest number of plants per m2was observed in the plots to which cumin wastes were applied, and these plots also showed the maximum yield.Conclusion:Seed yield, protein and oil percentages were not affected significantly by the applications.

Exergetic Analysis of Bioethanol Production from Tunisian Waste Dates

Objective:This study aims at contributing to the area of sustainable bioethanol production system development. The main objective of this study is to thermodynamically evaluate a bioethanol production process from waste dates.Methods & Materials:To this end, several chemical engineering assessment tools have been simultaneously applied. These tools simulate the bioethanol production process using the SuperPro software in order to determine all the materials and energy exchanges. An exergy analysis is also carried out, based on the first and second laws of thermodynamics, in order to locate thermodynamic imperfections in the process.Results:The results obtained show that approximately 60% of the exergy fed to the process is recovered in the useful products (bioethanol and exhausted pulp used as feedstuff). The overall exergy destroyed in the process considered is about 377 kW which represents 7% of the exergy reaching the process. The distillation section, the most energy-intensive stage, constitutes the main contributor of exergy destruction, followed by the fermentation reactor with contributions of 47% and 33%, respectively.

Hazardous Wastes and Waste Generation Factors Originating from Battery and Accumulator Manufacturing Sector in Turkey

Background: Accurate and realistic data regarding hazardous waste generation is required to make improvements in the effective management of hazardous wastes. Battery and accumulator manufacturing industry is one of the priority industries which was investigated in this study under the project named “Hazardous Waste Management in Compliance with European Union Environmental Regulations in Turkey”. The project investigated a number of different industries for the development of an internet-based system named as “The Hazardous Waste Declaration System” in order to meet the requirements of Turkey for hazardous waste management. Objective: In this paper, hazardous waste generation factors were asserted by means of the type and quantity of the hazardous waste originated from the battery and accumulator manufacturing sectors. Method: For this purpose, field studies were conducted in an industrial plant operating in the sector, in order to determine all inputs and outputs of the current manufacturing process utilized. Concurrently, hazardous waste generation declarations made by the industries in the years 2009 and 2010 to the Hazardous Waste Declaration System were evaluated and a range of hazardous waste generation factors were created using the possible minimum and maximum quantities for each waste and the results were compared with the data given in the literature. Results: This paper presents the waste lists and the hazardous waste generation factors for the battery and accumulator manufacturing sectors. Conclusion: It is believed that the study will provide invaluable information for other battery and accumulator manufacturing industries from the point of types and quantities and the management of hazardous wastes generated.

Trade-offs between Manure Management with and without Biogas Production

Introduction: In rural developing countries with a traditional manure management, animal manure is a value-added agricultural commodity being utilized as a source of fuel and plant nutrients. The sustainable environmental management of this resource has to consider the whole upstream and downstream activities of current management systems. Methods & Materials: In line with this requirement, this study has integrated the Intergovernmental Panel on Climate Change (IPCC) method on manure managements into the life-cycle assessment of two different manure management systems: the traditional system without biogas production and the alternative system with biogas production. Special attention is given to compare the GHG emissions as well as Nitrogen (N), Phosphorous (P), and Potassium (K) Fertilizing Nutrients (NPK) from the two systems. Results: The great advantage of manure conversion to biogas is mainly due to the avoided wood (18 kg/animal.yr), crop-residues (12 kg/ animal.yr) and dung (8 kg/ animal.yr) used as cooking fuels in the region. If methane leakage is over 38% then this will offset the GHG emission reduction of manure-to-biogas system.

Alkalic Leaching and Stabilization of Arsenic from Pyrite Cinders

Introduction: Pyrite cinder is one of the important secondary resources, but typically contains a certain amount of arsenic, which is harmful to metallurgical process. It usually hopes to remove the arsenic prior to recycle the valuable element in the pyrite cinders. Methods & Materials: In this study, the arsenic in the cinders was selectively removed using the alkalic leaching method so as to reduce the loss of ferric and other valuable elements. Results & Discussion: The content of arsenic in pyrite cinders was reduced to 0.08% through the investigation of the factors, including particle size, alkaline concentration, temperature, solid-liquid ratio (S/L) and leaching time. Then, the ferric precipitation method was used to remove the arsenic in the leaching solution. More than 99% of the arsenic can be removed by controlling the pH and the ratio of ferric and arsenic (Fe/As) in ambient temperature, and the arsenic concentration in the solution was reduced to less than 0.5mg/L. Conclusion: It was found that the precipitated arsenic was mainly amorphous based on the analysis of sediment.