Transforming Plastic Waste into Porous Carbon for Capturing Carbon Dioxide: A Review

Plastic waste generation has increased dramatically every day. Indiscriminate disposal of plastic wastes can lead to several negative impacts on the environment, such as a significant increase in greenhouse gas emissions and water pollution. Therefore, it is wise to think of other alternatives to reduce plastic wastes without affecting the environment, including converting them into valuable products using effective methods such as pyrolysis. Products from the pyrolysis process encompassing of liquid, gas, and solid residues (char) can be turned into beneficial products, as the liquid product can be used as a commercial fuel and char can function as an excellent adsorbent. The char produced from plastic wastes could be modified to enhance carbon dioxide (CO2) adsorption performance. Therefore, this review attempts to compile relevant knowledge on the potential of adsorbents derived from waste plastic to capture CO2. This review was performed in accordance with PRISMA guidelines. The plastic-waste-derived activated carbon, as an adsorbent, could provide a promising method to solve the two environmental issues (CO2 emission and solid management) simultaneously. In addition, the future perspective on char derived from waste plastics is highlighted.

Evaluation of the effects of sound exposure and low field electromagnetism on growth and antibiotics susceptibility of some microorganisms

Background The emergence of antibiotic-resistant microorganisms has been largely associated with drug misuse, drug abuse, and indiscriminate disposal of drugs; however, the interactions between some environmental factors and antibiotic resistance by microorganisms have been understudied. In this study, the effects of sound and electromagnetic field on the growth and antibiotic susceptibility of selected microorganisms to antibiotics were investigated. Results Microorganisms used include Gluconobacter oxydans ATCC 19,357, Rhodobacter sphaeroides ATCC 17,023, Citrobacter freundii ATCC 33,128, Yersina pestis ATCC 11,953, Bacillus subtilis 6633, Acetobacter aceti ATCC 15,973, Escherichia coli ATCC 25,922, Pseudomonas aeuriginosa ATCC 9027, Streptococcus pyogenes ATCC 19,613, Klebsiella pneumonia ATCC 25,955, Staphylococcus aureus ATCC 25,923 and Serratia marcescens ATCC 14,766. The antibiotics used were: Ciprofloxacin 5 μg, Imipenem 10 μg, Ampicillin 10 μg, Ceftazidime 30 μg and Tetracycline 30 μg for Gram-negative bacteria while Pefloxacin 10 μg, Gentamycin 10 μg, Amplicillin + Cloxacillin 30 μg, Cefuroxime 20 μg, Amoxacillin 30 μg, Ceftriaxone 25 μg, Ciprofloxacin 10 μg, Streptomycin 30 μg, Co-trimoxazole 30 μg, and Erythromycin 10 μg for Gram-positive bacteria, respectively. Acoustic treatment had varying effects on the antibiotics susceptibility profile of all test bacterial culture. Before exposure, P. aeruginosa had the highest zone of inhibition of 34 ± 3.4 mm, while B. subtilis had least inhibition zone of 12 ± 2.8. After exposure to acoustic treatment at 5000 Hz/90 dB at 72 h, C. freundii had highest zone of inhibition of 32 ± 0.7 mm and the least zone of 11 ± 1.4 mm observed in P. aeruginosa. At 1125 Hz/80 dB after 72 h, R. sphaeroides had highest zone of 34 ± 0.7 mm while A. aceti had least zone of inhibition of 10 ± 0 mm. Effect of electromagnetic flux treatment of 15 min showed E. coli to be the most inhibited having a growth rate of 0.08 log cfu/mL, antibiotics testing showed G. oxydans to have the highest zone of inhibition of 28 ± 3.5 mm and least zone was observed in B. subtilis having a zone of 13 ± 2.8 mm. Conclusion This study showed that environmental factor such as sound and electromagnetic flux (EMF) could interfere with the physiology of bacteria including resistance/susceptibility to antibiotics. However, further investigation will be needed to understand full mechanisms of action of sound and electromagnetic field on bacteria.

Effects Of Spent Engine Oil On Soil Characteristics And Selected Phytochemicals In Amaranthus Hybridus

Spent engine oil is hazardous to the environment. Indiscriminate disposal of spent engine oil drain from engines after servicing has been found to affect the environment. An experiment was carried out to determine the effect of spent engine oil pollution on soil characteristics and the ability of Amaranthushybridusto thrive in the soil supplemented with varying concentrations of spent engine oil ranging from 50- 300 mL. Soil pH was slightly increased due to spent engine oil pollution. Nitrogen, phosphorus and potassium were reduced in the polluted soils and the soil organic carbon was increased. Soil samples polluted with spent engine oil showed increased bulk and particle densities and also decreased water holding capacity and porosity. The spent engine oil pollution affected the phytochemicals and resulted in the increased concentration of anti- nutrient tannin and decreased concentrations of nutrients like alkaloids, flavonoids, etc. The results of this study suggest that spent engine oil at any concentration seriously affects the soil properties and phytochemical analysis showed the inhibitory effects of spent engine oil on Amaranthushybridus.

Geophysical Assessment of Impact of E-Waste Pollutants on the Subsurface Soil of Alaba International Market Dumpsite in Lagos, Nigeria.

Soil degradation forms a part of the significant impacts arising from indiscriminate disposal of e-waste. This study was aimed at assessing the magnitude of legacy contamination by e-waste, particularly, its depth and spread in the subsurface soil of Alaba International Market e-waste dumpsite in Lagos, Nigeria through the analysis of VES and 2D-Wenner array configuration data acquired on the dumpsite. The results of the VES data and 2D resistivity analysis showed that Alaba dumpsite was highly impacted by e-wastes due to the permeable geo-electric characteristics of the lithologic units beneath the dumpsite. The lithogy enables the pollutants to spread laterally and progressively increase in depth through sand column subsurface to more than 30m. It also showed that the contaminated zones are characterised by resistivity values ranging from 5.0 to 8.3 Ω.m. The study site is highly populated with wells and boreholes as the main sources of water for the community, thus the findings from this study could facilitate Lagos State Government decisions on improving protection for groundwater resources around the study area.

Toxicity of Workplace Aluminum Particles: Insights from Earthworm (Eisenia fetida) Tests in Soil Mixtures

Lifestyle changes have led to increasing use of alternative materials in building construction, fabrication of furniture and household appliances. Apart from the associated light weight and aesthetics, Aluminum products endure various pressures that range from climatic factors to pest attacks; hence, they are more durable than wood and other conventional materials. Activities of fabricators are widespread in many Nigerian cities and these result in traces of Aluminum particles derived from cutting, shaping and surface filing. The resulting recalcitrant dust particles can exert adverse consequences on biota. Therefore, this study examined the effects of different levels of Aluminum particles on earthworm in soil mixtures by assessing their behaviour, mobility and mortality in a five-week ecotoxicity test. Worms became sluggish after only two-week exposure and this culminated in loss of mobility and ultimately mortality in exposed organisms. Mortality of worms was highest (80 – 100%) in soil mixtures with the most proportion of Aluminum particles and decreased correspondingly with contaminant levels. However, there was no mortality of worms in soil mixtures without any Aluminum particles. Lethal concentration (LC50) values of 2.564g/kg, 0.995g/kg and 0.851/kg were determined at two, four and five weeks, respectively. The results suggest that worms in the course of foraging in soil, can internalize contaminating Aluminum particles, which may lead to adverse consequences in exposed population. Considering the role of earthworms in breakdown of soil organic matter and nutrient cycling, indiscriminate disposal of Aluminum particles across various landscapes may have consequences on soil fertility, food security and sustainability.

Simulation-based analytical design for aluminium recycling processing plant

Indiscriminate disposal of beverage cans as waste poses a great threat to the environment, causing flooding, landfill, and blockage of drainages, leading to land pollution and sometimes accident. Hence, there is a need to design a system capable of converting these wastes into usable products. In this study, a simulation-based analytical design for aluminum recycling processing plant was carried out to ascertain the efficiency and reliability of the design before fabrication using finite element analysis (FEA) approach. The simulation results revealed a lesser maximum stress of 6.323 MPa for the furnace outer casing under the action of load with a displacement of 0.0795 mm. The stress of the machine components is less than the yield strength of the selected materials, making the machine fit and workable. The analytical results agree with the numerical analysis; hence the conceptual design is fit for fabrication based on the design analysis and evaluation. After the design analysis and simulation, the designed recycling process plant parts are found to be under negligible deflection and stress which is far below the yield strength of chosen materials.

The Health-trash Nexus in Challenging Environments: A Spatial Mixed Methods Analysis of Accra, Ghana

Background: Increasing urbanization in Ghana has led to a waste management crisis with multiple public health consequences. The contextualized mapping of what is dumped, where and why might provide vital on-the-ground support to address the problem itself, as well as the spillover disease impacts. One of the biggest challenges, however, are the required spatial and temporal granular data. Methods: In this paper, we employ a spatial mixed methods approach to investigate the issue of waste management through the lens of health and disparity in Teshie, a suburb of Accra, Ghana. Environmental health risks digitized and mapped from these data sources included trash, plant overgrowth, drains and stagnant water. Results: There was an overlaying relationship between trash and open drains. Open drains encouraged the indiscriminate disposal of trash and also served as a cheaper alternative to paying for waste pick up. Poverty played an intricate role in influencing a trash disposal complex at the sub-neighborhood scale.Conclusion: The trash situation in Teshie is a complex one with varied levels of risks for infectious diseases.

Physicochemical and bacteriological assessment of ricemill wastewater discharged into river Benue, Nigeria

Rapid industrialization affects the environment in different ways through indiscriminate disposal of large amount of wastewater into the surrounding water bodies thereby causing serious problems to the environment. This study was conducted to assess the suitability of the ricemill wastewater being discharged into River Benue. Wastewater was sampled from point of discharge (sampling point A) and 20 meters away from the final entry into river Benue (sampling point B). Standardized methods were employed to analyze biochemical oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), total heterotrophic count (THC), nitrate, phosphate, sulphate and pH in the sampled wastewater. Results were generated and compared with permissible standards Results generated from the analyses indicate that in sampling point A, pH ranged from 4.28 to 5.23, TDS ranged from 1478 - 1615 mg/L while THC ranged from1540 - 1600 cfu/ml. In point B, (BOD) ranged from 4.8 - 3.6 mg/L, (COD) ranged from 4.1 - 3.1mg/L, (TDS) 586 - 348mg/L, (THC) 608 - 512 cfu/ml and pH 7.32 - 6.43. Considering these results, (TDS), (THC), nitrate and THC were above permissible limits of World Health Organisation (WHO) and National Environmental standards and regulations Enforcement Agency (NESREA) respectively. Owing to these results, treatment measures and regulatory policies are suggested with a view to checkmating the abuse of river Benue through indiscriminate disposal of wastewater so as to avert imminent dangers it might likely pose to aquatic ecological system.

Histopathological changes in gills and liver of Clarias gariepinus fingerlings exposed to acute concentrations of dry cell battery

Waste dry cell batteries are frequently improperly disposed and subsequently washed into water bodies-- causing deleterious effects on fish particularly Clarias gariepinus which inhabits diverse freshwater habitats. Acute toxicity of water-soluble fractions of waste dry cell batteries was investigated on C. gariepinus fingerlings under laboratory conditions in 96 hours. Ten (10) C. gariepinus fingerlings were exposed to acute concentrations (0.31, 0.63, 1.25, 2.50, and 5.00 g/L) of waste dry cell batteries and a control (0.00 g/L), each duplicate replicated. Histopathological alterations evident in the gills were lamellar fusion, hyperplasia, inter-lamella space occlusion, hypertrophy and erosion of secondary lamellae. The liver showed nuclear and hepatocytes degeneration, vacuolation and portal congestion. Acute concentrations of water-soluble fractions of waste dry cell batteries caused significant (P<0.05) changes in the histomorphology of the gills and liver of C. gariepinus fingerlings, therefore indiscriminate disposal of waste dry cell batteries around riparian ecosystem should be safeguarded to reduce the declining diversity and abundance of freshwater fish species. Keywords: African catfish, 96 hr.LC50, Fingerlings, Histopathology Zinc-carbon battery

Reinforcing effects of seaweed nanoparticles in agar-based biopolymer composite: Physical, water vapor barrier, mechanical, and biodegradable properties

In recent times, the indiscriminate disposal of post-consumer plastic packaging material has received global attention. There is a need to develop an alternative packaging material from bio-based polymers to reduce plastic waste pollution. This work studied the effects of loading seaweed nanoparticles into an agar matrix by analyzing the physical, mechanical, water vapor barrier, and biodegradation properties, as well as the surface morphological properties of biopolymer composite. The results showed that the addition of seaweed nanoparticles in the biopolymer matrix improved the properties of the agar-based biopolymer composite, except for the water vapor barrier properties of the biopolymer composite. The biopolymer composite film loaded with 6 w/w% seaweed nanoparticles appeared to achieve the highest mechanical strength. In addition, scanning electron microscopy analysis verified that the 6% w/w% seaweed nanoparticles biopolymer composite showed a homogenous surface morphology and had a strong adhesion on the interfaces of the filler and matrix. The samples had a desirable density of 0.0131 cm-1g-1 and a desirable biodegradability when 8 w/w% nanoparticles was used. This study verified that seaweed nanoparticles are compatible with agar matrix in terms of the enhancement of biopolymer composite properties.