Digital Knowledge Collection:

Comparative performance and statistical analysis of DEGBR and EGSB reactors for treating high-strength poultry slaughterhouse wastewater

Wed, 01 Jan 2025 00:00:00 GMT

Title: Comparative performance and statistical analysis of DEGBR and EGSB reactors for treating high-strength poultry slaughterhouse wastewater Authors: Dyosile, Phumeza Akhona; Njoya, Mahomet; Ntwampe, Seteno Karabo Obed; Ellis, Timothy G.; Basitere, Associate Professor Moses Abstract: High-rate anaerobic bioreactors (HRABs) are increasingly employed for treating high-strength wastewaters due to their ability to handle elevated organic loading rates (OLRs) at reduced hydraulic retention times (HRTs). This study compares the performance of two HRAB configurations the up-flow Expanded Granular Sludge Bed (EGSB) and the down-flow Expanded Granular Bed Reactor (DEGBR) for poultry slaughterhouse wastewater (PSW) treatment. Both systems included a biological pre-treatment stage and post-treatment with a membrane bioreactor (MBR). The DEGBR consistently outperformed the EGSB, achieving COD, TSS, and FOG removals of 87%, 92.5%, and 89.4%, respectively, versus 53.9%, 68.4%, and 66.9% for the EGSB. When integrated with pre-treatment and MBR polishing, the DEGBR-based system achieved > 99% removal across all parameters. Statistical analysis confirmed the significance of these differences (p < 0.05). These results demonstrate the DEGBR–MBR system’s robustness, stability under variable loading, and suitability for decentralised PSW treatment in resource-limited settings, offering a scalable and energy-efficient solution for broader industrial wastewater applications.

Current techniques for identifying, quantifying, and characterizing micro and nanoplastics with emphasis on strengths, limitations, and challenges

Wed, 01 Jan 2025 00:00:00 GMT

Title: Current techniques for identifying, quantifying, and characterizing micro and nanoplastics with emphasis on strengths, limitations, and challenges Authors: Gqomfa, Babalwa; Dlangamandla, Cynthia; Ntwampe, Seteno Karabo Obed; Chidi, Dr Boredi Silas; Maphanga, Thabang Abstract: Microplastic and nanoplastic (MNP) contamination has infiltrated nearly every facet of life, including food, water, air, and soil. The persistence of MNPs within different matrices poses a significant environmental and human health risk, underscoring the necessity for standardised methods to detect, characterise, identify, and quantify these emerging pollutants of concern. Traditional detection methods, such as visual inspection and gas chromatography, have limitations and are thus unsuitable for rapid, repetitive analyses. As such, advanced techniques like Fourier-transform infrared (FTIR) spectroscopy, hyperspectral imaging, and artificial intelligence (AI) interfaces are becoming favoured. FTIR spectroscopy is the most popular method used today to identify and quantify MNPs. Furthermore, recent advancements in micro-FTIR (μ-FTIR)-AI image processing have enabled the semi-automation of MNP identification concentrated on different filter membranes without pre-sorting. Integrating AI tools in combination with μ-FTIR analysis can significantly boost its functionality as automated image processing facilitates quicker identification and quantification of MNPs. Overall, challenges remain in MNP detection due to plastic particle size constraints, contamination from organic matter, and a lack of standardised protocols, complicating the identification and quantification of these pollutants in environmental matrices and biological samples. Despite extensive research, there remains a pressing need for reliable, cost-effective analytical techniques. Moreover, establishing uniform definitions, characterisation methods, sampling techniques, risk assessment frameworks, and regulatory guidelines for MNPs is imperative for their effective management and regulation.

An overview of the prevalence of micro- and nanoplastics in the Southern African development community: a potential risk to environmental and public health

Wed, 01 Jan 2025 00:00:00 GMT

Title: An overview of the prevalence of micro- and nanoplastics in the Southern African development community: a potential risk to environmental and public health Authors: Gqomfa, Babalwa; Ntwampe, Seteno Karabo Obed; Chidi, Dr Boredi Silas; Maphanga, Thabang; Dlangamandla, Cynthia Abstract: Rapid urbanisation, industrial development, and inadequate solid waste management systems, finances, and even legal frameworks have exacerbated Southern African Development Community (SADC) plastic waste and micro and nanoplastics (MNPs) proliferation, raising serious public health and ecological concerns. There is scant information on the occurrence of MNPs in the SADC, especially in rivers, streams, wetlands, and lakes which are vital as freshwater sources and food producers. This systematic review analyses the occurrence of MNPs within the water bodies of SADC. The literature, which included 84 published papers, was collected through the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology with additional literature (n = 39) that confirmed MNPs' presence in these ecosystems. Some prominent examples of water bodies that have shown the prevalence of MNPs are Namibia’s Main River and South Africa's Crocodile and Vaal Rivers. Pollution caused by urban runoff and degradation of plastic waste stemming from industrial activities is critically damaging to the environment, particularly the soil, water, food web, and biodiversity of the region. Overall, there is a dearth of research directed towards investigating the occurrence of MNPs in SADC countries with most studies concentrating on bulk plastic waste, underscoring the need for public awareness and stricter regulations on plastic production and waste to mitigate MNP pollution.

The influence of season and land use on the occurrence of Metarhizium spp. in the Cape Peninsula region, South Africa

Wed, 01 Jan 2025 00:00:00 GMT

Title: The influence of season and land use on the occurrence of Metarhizium spp. in the Cape Peninsula region, South Africa Authors: Rhoda, Ilyaas; Prins, Alaric; Keyster, Marshall; Le Roes-Hill, Marilize; Nchu, Felix Abstract: To investigate the environmental relationships between the occurrence of Metarhizium spp., season and land use in the Cape Peninsula region, soil samples were collected from randomly selected sampling sites within nature reserves and agricultural farms. Soil samples from the same sites were collected in different seasons (winter and summer), and Metarhizium spp. were isolated from the soil samples by insect baiting and plating soil, and identified. Soil pH, texture, and nutrient contents of air-dried composite soil samples were analysed, and the seasonal rainfall data were recorded. The associations between the number of Metarhizium isolates with soil nutrient contents and seasonal rainfall were assessed. Farm sites had a significantly higher number of Metarhizium isolates (36 of 40 isolates collected) and higher concentrations of soil macronutrients, P, Ca and N (NO3), than in soil samples from the reserves, while higher average monthly rainfall in winter correlated with higher occurrences of Metarhizium isolates. In conclusion, wet, cold winters and vegetable farming favoured the higher occurrence of Metarhizium spp. in the Cape Peninsula region.