Analysis of Macro- and Microplastics in Riverine, Riverbanks, and Irrigated Farms in Arusha, Tanzania.

Microplastics and macroplastics have been reported in different urban rivers and agricultural soil across the globe. However, the interlink between them has not been previously assessed. The present study evaluated the relationship between macro- and microplastics in the surface water and sediments in riverine, riverbanks, and soils from irrigated farms in Arusha, Tanzania. Detached pieces from macroplastics and suspected particles of microplastics from the samples were analyzed using the total attenuated reflectance-Fourier transform infrared spectroscopy. Statistical analysis showed that the number of microplastics in the sediments was higher than those in the surface water and that in irrigated farms was of four times higher than those found in riverine. Besides, the numbers of microplastics and macroplastics in the irrigation farms were exponentially related, while the macroplastics from the riverbanks had an inverse relationship with the rivers' profile elevation. Macroplastics of polyethylene type dominated in the riverbanks and irrigated farms with an occurrence frequency of 100%, while polystyrene was abundant in all analyzed microplastics samples. In addition, those irrigation farms adjacent to canals had a significant number of microplastics and macroplastics than the distant farms. This study provides new information for the region and others that divert water from an urban river for irrigation.

Potential of anaerobic co-digestion in improving the environmental quality of agro-textile wastewater sludge.

Sludge from textile effluent treatment plants (ETP) remains a challenge for many industries due to inefficient and limited waste management strategies. This study explores the potential of using anaerobic digestion (AD) to improve the environmental quality of textile ETP sludge. The AD of ETP sludge is affected by the low C/N ratio (3.7), heavy metal content, and toxicity. To improve the process, co-digestion of ETP sludge with different substrates (sewage sludge, cow dung, and sawdust) under mesophilic conditions (37 °C), followed by a thermochemical pretreatment was assessed. The results showed that anaerobic co-digestion of the textile sludge with the co-substrates is effective in reducing pollution load. It was found that organic matters degraded during the 30-day AD process. The chemical oxygen demand and biological oxygen demand reduction was in the range of 33.1-88.5% and 48.1-67.1%, respectively. Also, heavy metal (cadmium, lead, iron, and, mercury) concentration was slightly reduced after digestion. Maximal biogas yield was achieved from co-digestion of textile sludge and sewage sludge at a mixing ratio of 3:1, 1:1, and 1:3, and methane content was respectively 87.9%, 68.9%, and 69.5% of the gas composition. The results from this study show that co-digestion will not only reduce the environmental pollution and health risks from the textile industry but also recover useful energy.

Perceptions of Inclusivity and Sustainability in Urban Sanitation in Global South Cities.

Citywide Inclusive Sanitation (CWIS) calls for sustainable urban sanitation services for all, but the definitions of "inclusion" and "sustainability" within the framework leave room for interpretation. This study aims to provide an initial understanding of how these terms are currently interpreted by a range of sanitation actors in six cities of the Global South. Urban sanitation professionals from private (n = 16), public (n = 28), non-governmental (n = 43), and academic (n = 10) institutions were interviewed using a standardized tool, and data was analyzed to identify themes and trends. Terms such as "everyone" or "for all" shed little light on how to ensure inclusion, though disabled people, women, children, and the poor were all highlighted when probed. Greater specificity of beneficiary groups in policy is likely to enhance their visibility within sanitation service provision. All three pillars of sustainability identified within CWIS were referenced, with different stakeholders focusing more closely on environmental, social, or economic sustainability, based on their organizational goals and interests. Greater collaboration may foster a balanced view across the pillars, with different organizations acting as champions for each one. The findings can facilitate discussions on a shared understanding of multi-stakeholder engagement in achieving inclusive and sustainable sanitation service provision.

What Proportion Counts? Disaggregating Access to Safely Managed Sanitation in an Emerging Town in Tanzania.

Sustainable Development Goal (SDG) 6.2 sets an ambitious target of leaving no-one without adequate and equitable sanitation by 2030. The key concern is the lack of local human and financial capital to fund the collection of reliable information to monitor progress towards the goal. As a result, national and local records may be telling a different story of the proportion of safely managed sanitation that counts towards achieving the SDG. This paper unveils such inconsistency in sanitation data generated by urban authorities and proposes a simple approach for collecting reliable and verifiable information on access to safely managed sanitation. The paper is based on a study conducted in Babati Town Council in Tanzania. Using a smartphone-based survey tool, city health officers were trained to map 17,383 housing units in the town. A housing unit may comprise of two or more households. The findings show that 5% practice open defecation, while 82% of the housing units have some form of sanitation. Despite the extensive coverage, only 31% of the fecal sludge generated is safely contained, while 64% is not. This study demonstrates the possibility of using simple survey tools to collect reliable data for monitoring progress towards safely managed sanitation in the towns of global South.