Development of value-added materials from municipal plastic solid waste

Abstract: Continuous consumption of plastic materials that brings about rapid and more plastic wastes (PWs) generation has become an issue of concern globally, specifically in low-income countries (LCs) where waste management services are still at an infant stage and are inadequate and unstainable. The explosion and acute generation of PWs are dependent on many factors including, incessant migration of citizens in search of greener pastures from rural areas to cities and continuous influx of economic migrants from surrounding African nations and other nations of the world to sub Sahara Africa (SSA) region, changes in consumption pattern, rapid economic and industrial growth etc. The most startling thing about the severe plastic waste (PW) generation is that many citizens are not even aware of the negative/damaging impact of their activities on public health and the natural environment. Besides, the management of PW is now a challenge owing to factors like; insufficient budget for waste management (WM), unavailability of land spaces in cities for the construction of new disposal facilities, bad legislation and policies; and poor education and awareness campaigns. Hence, this study aims to enlighten the populace on the need for a change of attitude and behaviour towards municipal plastic solid waste management and to support recycling for greener cities and a sustainable future. To achieve this, a cross section of the students of the University of Johannesburg, South Africa were interviewed via a structured questionnaire survey and a logistic prediction model was developed to evaluate the attitudes and behaviours of the students towards recycling. Moreover, polystyrene plastic wastes (PSPWs) were recycled via solvothermal technique (chemical recycling) where a hybrid organic-inorganic nanocomposite (a value-added material) was developed. The synthesised nanocomposites (NCs) were characterized by XPS and EDX; XRD, FTIR, SEM, TEM and DLS; TGA, DSC and BET. Moreover, the neat (control) and unprocessed recycled polystyrene (rPS) were also characterized by NMR and GPC.Ph.D. (Chemical Engineering

Utilization of organic fraction of municipal solid waste (OFMSW) as compost: a case study of Florida, South Africa

Abstract: Composting of municipal solid waste is one of the means of diverting organic waste from the waste streams thus eliminating the use of landfills. This process will ensure availability of cheaper materials which can enhance soil fertility thus leading to reduction of pollution and increasing life span of the landfill site. Availability of reliable data on waste composition and characterization studies will be invaluable to policy makers for formulation of policy on proper waste management. Also, quantification and characterization of municipal solid waste (MSW) are vital tools for decision making for adequate planning on sustainable solid waste management (SSWM)..

Municipal solid waste composition determination in the city of Johannesburg

Abstract: This paper aims at determining the composition of various waste components at Robinson Deep landfill site (LS). The waste composition study was conducted during the summer in 2015 at Robinson LS to evaluate the various component of wastes received at the site. This was done in order to determine the amount of organic wastes that are generated daily as a basis for waste to energy (WtE) proposition in the City of Johannesburg (CoJ). The methodology used was in accordance with two international standards. Hands sorting were utilized and the samples were classified into nine broad categories. The categories include; paper, organics, plastics, metals, glasses, textiles, construction and demolition (C &D), special care and other wastes..

Characterisation of fruits and vegetables wastes in the city of Johannesburg

Abstract: Municipal solid waste (MSW) composition study is very important as a baseline to utilizing fresh fruit and vegetables (FFVs) wastes in waste to energy (WtE) project. The aim of this paper is to determine the composition of various waste components at the Johannesburg FFVs market. The study was conducted during the summer in 2015 to evaluate the various components of fruit and vegetable wastes (FVWs) generated at the market. This was done in order to evaluate the amount of FVWs that are generated daily at the market as a starting point for waste to energy (WtE) proposition for the City of Johannesburg (CoJ). Two international standards: ASTM D5231-92 - 2008 (American Standard Test Method) and UNEP/IETC -2009 (United Nations Environment Programme/International Environmental Technology Centre) were used as yardsticks for the procedure used. Samples were classified based on their colours; green (vegetables and fruits), blue/purple (vegetables and fruits), tan/brown (vegetables and fruits), yellow/orange (vegetables and fruits), red (vegetables and fruits) and other wastes which include corrugated boxes, metals, woods, plastic crates and other composite wastes. Samples were further classified into 135 classes in which some were not available due to seasonal variation and the samples were manually sorted by hands. From the results of the analysis, fruits constituted 55%, vegetables 38%, corrugated boxes and cartons 3%, metals, plastics, woods and other wastes all constituted 1% each

Characterization, management and utilization of landfill municipal solid waste : a case study of Soweto

M.Tech.Abstract: The management of solid waste (SW) has become a crucial issue confronting low and middle income countries. This problem emanates from the generation of SW which is currently on a large scale as cities expand. The aims of this study were to determine the composition of the various waste components disposed of to the Marie Louise landfill site (LS), evaluates the elemental composition and proximate analysis of the organic fraction of municipal solid waste (OFMSW), conducts an economic analysis of setting up a recycling facility and to finally evaluating the perception of the general public with regards to the current waste management (WM) services in the City of Johannesburg (CoJ). The objectives of this study were to determine the various waste components disposed of to the LS as a baseline to propose complete diversion of wastes from going to the LS; to determine the suitability of food waste (FW) generated as a potential source of compost and biogas generation; to carry out an economic evaluation of setting up a recycling facility as a source of revenue to the municipality and potential source of jobs opportunities for the youths in the municipality and finally to assess the level of awareness of the people towards municipal solid waste management (MSWM). The waste composition studies were conducted during the summer in 2015 and during the winter in 2016 at the LS. The results of the analysis were classified into two groups based on two of the services offered by Pikitup (PU) (the municipality) (Dailies non compacted and Round collected refuse (RCR) compacted wastes collection services). STATA 12 software was used to determine seasonal variation on the main components of the wastes generated between the summer and the winter exercises for both services. The results obtained showed that p-values were too extreme (when the null hypothesis is true, the p-value is the probability of obtaining a result equal to or “more extreme” than what was actually observed. The p-values obtained for both the Dailies and for the RCR were (p-value = 0.9775) and (p-value = 0.9760) respectively. Analysis of variance (ANOVA) was also used to evaluate seasonal variation in both seasons on both services for the sub-division of the waste streams. Results obtained showed (p-value = 0.9999) for Dailies and (p-value = 0.9913) for RCR. These results show that the differences between the winter and summer for both services were not statistically significant. The elemental composition and proximate analysis of the FW was also evaluated. The analysis gave a C/N of 22.66 and an empirical formula of C27H44NO16. An engineering economic evaluation was conducted to determine the financial feasibility of this project. From the analysis, IRR on investment was found to be 41%, IRR on equity was found to be 80%,.

Challenges of wastewater generation and management in sub-Saharan Africa: A Review

The continuous growth in population and industrial development has prompted wastewater (WW) generation in enormous volume with resultant effects on the quality of water in sub-Saharan Africa (SSA). The generated WW flows into freshwater thereby depleting water quality in the region as the amount of WW treated before discharge into the environment is < 10%. There have been several studies that focused on the effect of water pollution and its related issues on public health and the environment. Undeniably, there is a substantial capacity for progress in wastewater management (WWM) with its numerous benefits to the public and the environment. The global community has been faced with a water quality crisis emanating from rapid population growth, poor wastewater treatment (WWT), etc. SSA comprises ∼1 billion people with ∼25% who are having access to quality drinking water, and < 30% having access to essential sanitation services. Thus, this study aims to offer a summary of challenges facing wastewater management in the SSA region, wastewater as a resource, wastewater treatment plants, and wastewater as a resource in a circular economy. This high point presents the summary of health challenges/effects of untreated wastewater on the environment and public health and their associated diseases/illnesses. And environmental and economic benefits of effective wastewater management. A significant examination was made of the statutory regulations, social acceptability, economic aspects, and solution to wastewater issues were all emphasized

Optical properties of bimetallic (SrO-K2O) nanofillers

Abstract : In this study, bimetallic nanofiller capable of usage as reinforcement was synthesized from expanded polystyrene (EPS). Bimetallic materials consist of two different metals. The bimetallic nanofiller consisting of SrO and K2O was successfully developed by the hydrothermal method which many researchers have well utilized to prepare nanoparticles in recent times. This study aims to synthesize and characterize bimetallic SrO-K2O, nanofillers from recycled expanded polystyrene (EPS). Products obtained were characterized by Zeta potential and Raman spectra. The Zeta potential was used to determine the surface charge of the nanofillers in solution. The Raman spectroscopy was used to determine the crystalline structure of the nanofillers. Based on the results, it was concluded that stability of nanoparticle materials in acidic medium decreases as the pH increases, and for the basic medium, stability reduces with decrease pH. The mixture of SrO and K2O to form SrO-K2O bimetallic oxide affects the stability of the nanofillers produced both in the acidic and basic medium. The Raman spectra indicated the Dband and Gband of the synthesized SrO, K2O and bimetallic SrO-K2O at 1006, 1008 and 1004 cm-1 and 1598, 1610 and 1606 cm-1 respectively. It was concluded that the shift in band gaps were because of structural changes in the molecules of the recycled expanded polystyrene

Development and size distribution of polystyrene/ZnO nanofillers

Abstract : In this paper, the preparation and characterization of ZnO nanofillers from polystyrene (PS) polymer waste for use as reinforcement was presented. This was done to achieve a better means of upcycling polymer wastes that have become social menace in recent times. The PS/ZnO nanofillers was synthesized through the hydrothermal synthesis of nanocomposites in an enclosed reactor. The reactor was kept in an oven at a specified temperature for a period. A product obtained was characterized using Fourier transform infrared (FTIR) analysis and Particle size analyser (PSA). The FTIR was utilized to determine the functional groups present in the synthesized nanofillers. The Particle size analyser was used to determine the distribution of particle size within the polymer matrix. The absorption peak obtained in the FTIR analysis confirmed the presence of ZnO in the synthesized material and the results from particle size analysis showed that about 80% of the particle was accommodated within the whole sample

An Economic Analysis of Energy Consumption at Student Residences in a South African-Based Academic Institution Using <i>NARX</i> Neural Network

One of the issues associated with the supply of electricity is its generation capacity, and this has led to prevalent power cuts and high costs of usage experienced in many developing nations, including South Africa. Historical research has shown that the annual rate of increase for electricity has grown at an alarming rate since 2008 and, in some years, has grown as much as 16%. The objectives of this study are to estimate the cost analysis of electricity usage at the twenty-nine residences of the University of Johannesburg (UJ-Res) and propose a model for our university, as well as other South African universities, to become more energy-efficient. This was achieved by analyzing the tariffs between 2015 and 2021. A forecast was made for a period of five years (2021 to 2026) using a non-linear autoregressive exogenous neural network (NARX-NN) time-series model. From the results obtained, the better NARX-NN model studied has a root mean squared error (RMSE) of 2.47 × 105 and a determination coefficient (R2) of 0.9661. The projection result also shows that the annual cost of energy consumed will increase for the projected years, with the year 2022 being the peak with an estimated annual cost of over ZAR 30 million (USD 2,076,268)

Adsorbent technologies and applications for carbon capture, and direct air capture in environmental perspective and sustainable climate action

The contribution of greenhouse gas and anthropogenic CO2 to climate change is an undeniably issue that needs urgent attention from the environmental point of view. Global warming, a consequence of continued CO2 emissions will gradually result in ecosystem disruption and drought. With the increasing problem of greenhouse gas (GHG) and the established environmentally unfriendly consequences associated with it, carbon capture and storage (CCS) was proposed as a measure to successfully reduce carbon footprints and a process of choice in proffering solutions to this challenge. To meet the Paris agreement's target of maintaining the global temperature rise below 2 °C necessitates the capture and removal of up to 20 Gt CO2 per annum by the end of the century. However, going by the current global CO2 capture and storage capacity of 0.0385 Gt CO2/annum (including the current direct air capture (DAC) capacity of 9,000 tons CO2/annum), it will take close to 21,000 years to achieve this set goal. Hence, the need to adopt sustainable low-temperature sorbent technology with efficient adsorption capabilities that will meet up with the bourgeoning operating cost and energy demand for DAC technology. In this review, sustainable and emerging adsorbent materials and technologies employed in carbon capture and storage were highlighted. Also, economic, and environmental benefits and public perception of carbon capture technology were enumerated