Urban Dumpsite Research Articles

Biodegradation potential of Low-Density Polyethylene (LDPE) by soil-inhabiting ascomycetous microfungi isolated from urban dumpsites

ABSTRACT Urban dumpsites are excellent sources of microbes which can biodegrade numerous materials present in waste. This study focused on the assessment of the mycodegradation potential of LDPE (Low-Density Polyethylene) by ascomycetous microfungi from urban dumpsites in Sri Lanka. Out of the collection obtained from five localities in Sri Lanka, eight species of ascomycetes, viz. Talaromyces purpureogenus (GF85), T. beijingensis (GGF03), Penicillium citrinum (GF89), Purpureocillium lilacinum (GF99), Aspergillus flavus (GF94), Aspergillus sp. (GF82), A. terreus (MMF08), and Fusarium falciforme (GF77), demonstrated mycodegradation potential based on the primary screening. All the isolates were accurately identified based on morphology, Sanger sequencing, and phylogenetic analysis of nuclear internal transcribed spacer region with 5.8 s ribosomal DNA (ITS). Among the isolates, T. purpureogenus GF85 showed a 13–17% weight reduction of LDPE. The same fungus showed evidence of remarkable ability to cause biodeterioration of LDPE by Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). This study highlights the significance of extensive sampling, morphological, molecular characterisation, and comparative analysis of fungi from unexplored habitats towards developing sustainable solutions for the polyethylene waste crisis.

Assessment of dumpsites leachate, geotechnical properties of the soil, and their impacts on surface and groundwater quality of Sunyani, Ghana

Leachate from sanitary landfill and dumpsites have potential to cause soil and groundwater contamination, and disrupt ecosystems. However, there is little information about dumpsite leachates and geotechnical properties and their impacts on surface and groundwater in Bono region, Ghana. This study assessed dumpsites leachate, geotechnical properties of the soil, and their impacts on surface and groundwater quality in Sunyani. Six triplicate leachates, eleven triplicate groundwater and three triplicate surface water samples were taken at (up-stream, mid-stream and down-stream) urban dumpsite, and eight triplicate groundwater samples taken around peri-urban dumpsite. Water samples were stored (<4°C) in polyethylene bottle for laboratory analysis. Physicochemical properties of leachate and water samples were analyzed using standard methods. Heavy metals (Cd, Hg, Pb, Zn, Cr, Fe, Cu, and Ni) were determined using atomic absorption spectroscopy. Water quality index (WQI) and leachate pollution loads (LPL) were investigated, while plasticity index (Ip) and liquid index (Il) were determined using Atterberg limit test. The results showed that all leachate samples were heavily polluted with mean concentrations of chlorides ranged between (2830±220 and 63810±340), biochemical oxygen demand (358±36 to 820±80), ammonium ions (82.8±2.2 to 267.6±62), and cadmium (0.49±0.02 to 5.32±1.0); with their leachate pollution index (LPI) and LPL exceeding their leachate disposal standards (LDS>100). WQI ranged from 6.51 to 289, indicating excellent to heavily polluted groundwater sources. Surface water was heavily polluted with WQI between 0.84 and 776.75, with majority having WQI>100. The heavily polluted samples were located 75-155 m away from urban dumpsite. Moderate significant negative association was established between (WQI-P and WQI-H) and distance with multiple R2=0.4709, p=0.0191 and R2= 0.4482, p=0.02425 respectively. Statistically, strong significant negative association between (WQI-P & WQI-H) and Ip (p < 0.05). This implies that when plasticity index and distance from groundwater sources to dumpsite increased, WQI values decreased, and groundwater quality improved.

Assessing leachate contamination and groundwater vulnerability in urban dumpsites: a case study of the Ipata Area, Ilorin, Nigeria

This study explores the extent of leachate contamination and groundwater vulnerability in urban dumpsites, with a specific focus on the Ipata area in Ilorin, Nigeria. The study employs a combination of 2D Electrical Resistivity Tomography (ERT), soil classification, and physicochemical analyses to investigate the percolation of leachate into groundwater and its potential environmental and health implications. The ERT data unveiled subsurface layers, highlighting the presence of decomposed topsoil down to approximately 1.2m. Beneath this layer, a low-resistivity zone (6.53 to 10.7 ?m) indicated the potential risk of leachate percolation into groundwater. Soil classification revealed a shallow topsoil layer with insufficient clay content to hinder leachate penetration, emphasizing the need for enhanced containment measures. Physicochemical analysis of leachate, well water, and soil displayed variations in key parameters such as pH, electrical conductivity, total dissolved solids, and anion concentrations. Leachate exhibited high pH and electrical conductivity, suggesting elevated total dissolved solids, while well water remained within acceptable pH limits for drinking water. Heavy metal concentrations exceeded permissible WHO limits in topsoil, leachate, and well water, with cadmium presenting a high ecological risk. The absence of persistent organic pollutants (POPs) in the samples indicates a current focus on heavy metals as a primary concern. In conclusion, this study underscores the urgent need for proactive pollution abatement measures in urban dumpsites like Ipata. Regular monitoring of surface and groundwater quality is essential to safeguard public health and the environment.

Toxigenic Vibrio cholerae can cycle between environmental plastic waste and floodwater: Implications for environmental management of cholera

Globally, there has been a significant rise in cholera cases and deaths, with an increase in the number of low- and middle-income countries (LMICs) reporting outbreaks. In parallel, plastic pollution in LMICs is increasing, and has become a major constituent of urban dump sites. The surfaces of environmental plastic pollution can provide a habitat for complex microbial biofilm communities; this so-called 'plastisphere' can also include human pathogens. Under conditions simulating a peri-urban environmental waste pile, we determine whether toxigenic Vibrio cholerae (O1 classical; O1 El Tor; O139) can colonise and persist on plastic following a simulated flooding event. Toxigenic V. cholerae colonized and persisted on plastic and organic waste for at least 14 days before subsequent transfer to either fresh or brackish floodwater, where they can further persist at concentrations sufficient to cause human infection. Taken together, this study suggests that plastics in the environment can act as significant reservoirs for V. cholerae, whilst subsequent transfer to floodwaters demonstrates the potential for the wider dissemination of cholera. Further understanding of how diseases interact with plastic waste will be central for combating infection, educating communities, and diminishing the public health risk of plastics in the environment.

Enduring pathogenicity of African strains of Salmonella on plastics and glass in simulated peri-urban environmental waste piles

In low- and middle-income countries, plastic has become a major constituent of landfills and urban dump sites. Environmental plastic pollution can also provide a novel surface for the formation of microbial biofilm, which often includes pathogenic bacteria and viruses. Here, under conditions simulating a peri-urban waste pile typical of an African informal settlement, we aimed to determine if pathogenic Salmonella spp. can retain their virulence following a prolonged period of desiccation on the surfaces of environmental plastic and glass. We show that clinically (and environmentally) relevant strains of Salmonella including S. Enteritidis, S. Typhimurium and S. Typhi can persist on plastic and glass for at least 28-days and that temperature (which increases with the depth of an urban waste pile) is a key determinant of this survival. All three strains of Salmonella retained their pathogenicity (determined by using a Galleria mellonella model of infection) following their recovery from the plastisphere indicating that plastics in the environment can act as reservoirs for human pathogens and could facilitate their persistence for extended periods of time. Pathogens colonising environmental plastic waste therefore pose a heightened public health risk, particularly in areas where people are frequently exposed to plastic pollution.

Characterization of dumpsite waste of different ages in Ghana

Open dumping of municipal solid waste is a common practice in developing countries including Ghana and it creates major problems in many municipalities and towns in the countries, and therefore, the dumpsites need to be reclaimed or decommissioned after years of dumping. However, it becomes challenging to infer from the results of studies from other part of the world for dumpsites in Ghana since they may have different waste characteristics. Therefore, this study sought to characterize the dumpsite waste with different age groups from urban city and small town to ascertain the impacts of aging of deposited waste on waste fractions, it also assessed the waste components at different depths within the same and different age groups in both small-town and urban dumpsites; for waste deposited more than 5 years (Zone A), 2–4 years (Zone B), and less than 6 months (Zone C) in Bono region, Ghana. Waste (100 kg) was taken at surface, 0.5 m, 1.0 m and 1.5 m and reduced to 50 kg using coning and quartering method; dried, segregated and analyzed. Plastics waste (24.5–28.1%) increased with age at urban, and increased (5.4–8.5%) with depth at small town dumpsite. Plastic waste was second to Decomposed organic matter (DOM) at both dumpsites. The metal (<1.0%) at all depths in all age groups for both sites. DOM fine particle sizes (FPS) decreased with depth, 26.8% (surface waste) and 14.4% (1.5 m depth), at both dumpsites. Statistically significant effects of age on plastics, metal, DOM-CPS, DOM-FPS (p < 0.05) at urban dumpsite. However, at small town dumpsite, effect of age was statistically significant on only DOM-CPS and DOM-FPS (p < 0.05). The pH, EC, and TDS for both dumpsites decreased with increasing age, and increased with depth. The study provides relevant scientific findings for stakeholders to develop policy framework for dumpsite decommissioning or reclamation.

Grey to Green: Rehabilitation of urban dump site through regenerative landscape design

Attempt to rehabilitate the degraded land has been made, and has evidenced many successful redevelopments atop of the land. This paper attempts to look into the specific role of landscape architects in remedying the former dump site. The conceptual design by using principles of the regenerative landscape has been experimented through the proposed remediation of ex-landfill in Mukim Krubong, Malacca. Utilisation of the tropical plant species as an adaptive mechanism to ecologically remedying the contaminated land has been identified. It is hoped that the findings of this paper could contribute to expanding knowledge for sustainable landscape regeneration.© 2016. The Authors. Published for AMER ABRA by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning &amp; Surveying, Universiti Teknologi MARA, Malaysia.Keywords: Regenerative landscape design; urban dump site; rehabilitation; Mukim Krubong ex-landfill

Grey to Green: Rehabilitation of urban dump site through regenerative landscape design

Attempt to rehabilitate the degraded land has been made, and has evidenced many successful redevelopments atop of the land. This paper attempts to look into the specific role of landscape architects in remedying the former dump site. The conceptual design by using principles of the regenerative landscape has been experimented through the proposed remediation of ex-landfill in Mukim Krubong, Malacca. Utilisation of the tropical plant species as an adaptive mechanism to ecologically remedying the contaminated land has been identified. It is hoped that the findings of this paper could contribute to expanding knowledge for sustainable landscape regeneration.© 2016.The Authors. Published for AMER ABRA by e-International Publishing House, Ltd., UK. Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies, Faculty of Architecture, Planning &amp; Surveying, UniversitiTeknologi MARA, Malaysia.Keywords: Regenerative landscape design; urban dump site; rehabilitation; Mukim Krubong ex-landfill

Seasonal variations in trace metal levels, speciation and physicochemical determinants of metal availability in dumpsite soils within Akwa Ibom State, Nigeria

Physicochemical properties, total metals and metal species were investigated in surface soil samples from six urban dumpsites within Akwa Ibom State, Nigeria. Results obtained indicated that Pb, Cd and Cr levels were higher in the dry season than in wet season, whereas Ni levels were higher during the wet season. Soil pH, organic matter and cation-exchange capacity (CEC) showed higher values in wet season than in dry season, whereas sand and clay levels were higher in the dry season. Speciation analysis showed the principal fraction of the metals to be Pb (reducible), Cd (acid extractable) and Ni (residual), whereas Cr existed in the residual fraction during the dry season and in the acid-extractable fraction during the wet season. Soil pH was positively correlated at p<0.1 with all metals in both seasons, sand was negatively correlated with the metals in both seasons, and CEC was negatively correlated with all metals in both seasons, except Pb in the wet season. Organic matter showed variable relationships with metals in both seasons. Seasonal variations affected metal availability and physicochemical properties of the soil. Total metal concentrations followed the order Pb>Ni>Cd>Cr, whereas their bioavailability followed the trend Cd>Pb>Cr>Ni.

"Beyond the Dumping Ground": A Critique of the Basic Ecclesial Community Model as a Strategy for Development in an Urban Site

Basic Ecclesial Communities (BEC) are small communities of Christians organized by church workers seeking to transform the prevailing society into a more equitable and just society. The paper looks at an organized scavenger community located in an urban dump site. The untenable conditions of the site work against the organizers' intention to develop a self-sustaining community. Hence, they overemphasize income-generating strategies, instead of social transformation, because they must help to meet the basic needs of the residents. Unlike rural BECs which may opt to lessen their contact with the capitalist marketplace to develop more communal agrarian modes of practice, urban BECs may not so easily meet their daily subsistence needs outside the market system. This raises other questions: Are church-led and bottom-up initiatives enough without material support from the government? Is there a point at which capitalism becomes a sufficiently dominant ideology to render ineffective alternative courses of ac...