71 research outputs found
Seasonal influence on the nutrient removal efficiency of a SPRAS wastewater treatment plant in the Free-State Province, South Africa
In Africa, untreated sewage discharge is one major source of water pollution that contributes to high oxygen demand and nutrient loading on the receiving water bodies, which threatens aquatic ecosystem and human health. Sludge Process Reduced Activated Sludge (SPRAS) plant could potentially address this challenge as a technology that has been found effective in the removal of nutrients from wastewater. The objective of the current study was to investigate the nutrient removal and treatment efficiency of a SPRAS treatment plant as a case study during the cold and warm seasons in the Free State Province, South Africa. The treatment effectiveness of the SPRAS plant was assessed by comparing the final effluent data to the South African General Authorization (SAGA) guidelines for discharging wastewater into water resources. Treatment efficiency was determined by comparing raw influent to the final effluent data. Ammonia was efficiently removed from wastewater in the colder seasons compared to the warmer seasons, at 97-99% and 87-89% removal efficiency range, respectively. Suspended solids, Carbon Oxygen Demand (COD), and ortho-phosphates were efficiently removed from wastewater during both warm and cold seasons, with efficiency ranges of 97-98%, 87-89%, and 67-98% respectively. E. coli in the final effluent was reduced to concentrations below the set SAGA limit during both warm and cold seasons. However, SPRAS was ineffective in nitrates removal during both seasons, where the final effluent concentration failed to meet the set SAGA limits. The observed nitrates removal ineffectiveness may be attributed to operating temperatures (minimum average range of 10.5 -13.5 °C) that were not optimal for the activity of the microbial communities driving the treatment process. It was evident from the analysed data that climatic conditions may influence the treatment efficiency of SPRAS technology, with treatment efficiency reduced when air temperatures were below optimal temperatures for the growth of the microbial communities. 
The analysis of physicochemical characteristics of pig farm seepage and its possible impact on the receiving natural environment
Pig farm seepage poses an environmental risk, considering that seepage can be generally applied on land without appropriate agronomic criteria or may accidentally spill on the natural environment. These environmental risks include increasing oxygen demand, nutrient loading of water-bodies, promoting toxic and algal blooms eutrophication, thus, leading to a destabilized environment. This research was conducted to determine the impact that the pig farm seepage may have the receiving environment based on the analyses of the physicochemical parameters of the adjacent environments. Wastewater and soil samples were collected between the periods of March 2013 to August 2013 and wastewater was analyzed for pH, temperature, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Dissolved Solids (TDS), salinity, turbidity, Dissolved Oxygen (DO), NO3, NO2, and PO4 3−. The results for wastewater samples for BOD (163 mg/L to 3350 mg/L), TDS (0.77 g/L to 6.48 mg/L), COD (210 mg/L to 9400 mg/L), and NO3 (55 mg/L to 1680 mg/L), were higher than the maximum permissible limits. Results of soil samples for TDS (0.01g/L to 0.88 g/L), COD (40 mg/L to 304 mg/L), NO3 (32.5 mg/L to 475 mg/L), and NO2 (7.35 mg/L to 255 mg/L) were also higher than recommended limits. The results revealed that the seepage from pig farm degraded the natural environment by causing eutrophication, promote toxic and algal blooms, increase oxygen demand and thus destabilize the homeostatic balance of the receiving environment.Keywords: Physicochemical parameters, pollution, soil, wastewater, seepage, pig farm, environmen
Depression, anxiety, and psychological distress among caregivers of young children in rural Lesotho: Associations with food insecurity, household death and parenting stress
Good mental health is a critical resource for mothers and caregivers of young children, given the central role of mental health in enabling responsive caregiving. However, fulfilling caregiving responsibilities under challenging circumstances such as extreme poverty, food insecurity, and gender inequality intensifies vulnerability to poor mental health. Previous research focuses on mental health of mothers, while in many LMICs children are cared for by other caregivers, such as grandparents. We examined the prevalence of mental health problems among primary caregivers of young children in rural Lesotho, and investigated factors associated with these mental health problems. We analysed baseline data from a cluster randomised controlled trial, where all caregivers with children between 1 and 5 years old across 34 villages were invited to participate. The analysis included mental health data from 781 caregivers of 998 children. We assessed caregiver mental health using three self-report screening instruments. Univariate and multivariate regression modelling tested associations between caregiver, child and household variables and (1) depression symptoms (PHQ-9), (2) anxiety symptoms (GAD-7), (3) psychological distress (SRQ-20), (4) suicidal ideation and (5) help-seeking for mental health. This study reported a high prevalence of symptoms of psychological distress (46.2%), depression (25.7%), anxiety (17.1%) and suicidal ideation (27.5%) among caregivers. Greater prevalence was associated with food insecurity, parenting stress or recent death in the family/household. Older caregivers reported higher rates of psychological distress and depression, while younger caregivers reported higher rates of anxiety. Suicidal ideation was associated with greater food insecurity and parenting stress, and lower caregiver education. Our findings support the need to address intersecting public health issues to improve conditions for caregivers in these settings. Targeting modifiable risk factors such as food insecurity among individuals within a society who carry disproportionate burdens of caregiving should be prioritised, especially in contexts of scarcity, where mental health is not prioritised
The Effect Of Filler Localization On The Properties Of Biopolymer Blends, Recent Advances: A Review
ArticleIn recent times, the field of biopolymer (BP) blends has been the focus of
intensive fundamental and applied researches. Such BP combinations possess
unique properties that are different from those of the individual components.
However, most polyester polymers are thermodynamically immiscible because
of their poor interactions. In the past, a third component, known as a welldefined
diblock or triblock copolymer, whose chemical structure is identical to
that of the main components, was usually used as a compatibilizer in order to
emulsify the interfacial phase, decreasing the interfacial tension and refining
the phase size. Currently, nanofillers are used to improve the phase morphologies
of immiscible BP blends. The main advantage of using nanofillers, when
compared to copolymers, is that the former can simultaneous act as nanoreinforcements
and compatibilizers. In this review, the addition of nanofillers
as the third component in the BP blend systems are reported in relation to
their morphologies, barrier properties, shape memory, thermal, and mechanical
properties. The effects of selectively localized nanofillers on the properties
of the BP blends are also explored, with the aim of establishing the relationships
between the localization of the fillers and the overall properties of the BP
blends. Furthermore, the effect of the processing techniques on the localization
of the nanofillers/BP blend is also reported. The review article discusses recent
progress from 2014 up to 2019 on filler localization of BP blend
nanocomposites
The future of ocean plastics: designing diverse collaboration frameworks
This paper aims to guide the stakeholder engagement process related to plastic pollution research in marine environments. We draw on advice identified during an online workshop (Ocean Plastic Workshop 2022) organized by Early Career Ocean Professionals (ECOPs) from 11 countries, held in April 2022. International experts and workshop participants discussed their experiences in the collaborative development and implementation of ocean plastic pollution projects held worldwide, guided by three main questions: (i) What is the role of scientists in a multi-stakeholder project? (ii) How should scientists communicate with other stakeholders? (iii) Which stakeholders are missing in collaborative projects, and why are they missing? This multidisciplinary, co-learning approach highlights the value of stakeholder engagement for ocean plastic projects with an end goal to identify and implement ocean plastic solutions via innovative technologies, informing policy, community engagement, or a combination of all three approaches. The target outcomes of the workshop described in this paper include the identification of transdisciplinary (academic-stakeholder) engagement frameworks and specific suggestions that can serve as guidelines for the development of future plastic pollution projects
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Improving early childhood care and development, HIV testing, treatment and support, and nutrition in Mokhotlong, Lesotho: study protocol for a cluster randomized controlled trial
Background
Since 1990, the lives of 48 million children under the age of 5 have been saved because of increased investments in reducing child mortality. However, despite these unprecedented gains, more than 200 million children in low and middle income countries (LMIC) cannot meet their developmental potential due to poverty, poor health and nutrition, and lack of necessary stimulation and care. Lesotho has high levels of poverty, HIV and malnutrition, all of which affect child development outcomes. There is a unique opportunity to address these complex issues through the widespread network of informal preschools in rural villages in the country, which provide a setting for inclusive, integrated Early Childhood Care and Development (ECCD), HIV and nutrition interventions.
Methods
We are conducting a cluster randomised controlled trial in Mokhotlong district, Lesotho, to evaluate a newly developed community-based intervention programme to integrate HIV testing and treatment services, ECCD, and nutrition education for caregivers with children aged 1-5 years living in rural villages. Caregivers and their children are randomly assigned by village to intervention or control condition. We select, train, and supervise community health workers recruited to implement the intervention, which consists of nine group-based sessions with caregivers and children over 12 weeks (eight weekly sessions, and a ninth top up session one month later), followed by a locally hosted community health outreach day event. Group-based sessions focus on using early dialogic booksharing to promote cognitive development and caregiver-child interaction, health-related messages, including motivation for HIV-testing and treatment uptake for young children, and locally appropriate nutrition education. All children aged 1-5 years and their primary caregivers living in study villages are eligible for participation. Caregivers and their children will be interviewed and assessed at baseline, immediately after completion of the intervention, and 12 months post intervention.
Discussion
This study provides a unique opportunity to assess the potential of an integrated early childhood development intervention to prevent or mitigate developmental delays in children living in a context of extreme poverty and high HIV rates in rural Lesotho. This paper presents the intervention content and research protocol for the study
Nucleation and crystallization in bio-based immiscible polyester blends
Bio-based thermoplastic polyesters are highly promising materials as they combine interesting thermal and physical properties and in many cases biodegradability. However, sometimes the best property balance can only be achieved by blending in order to improve barrier properties, biodegradability or mechanical properties. Nucleation, crystallization and morphology are key factors that can dominate all these properties in crystallizable biobased polyesters. Therefore, their understanding, prediction and tailoring is essential. In this work, after a brief introduction about immiscible polymer blends, we summarize the crystallization behavior of the most important bio-based (and immiscible) polyester blends, considering examples of double-crystalline components. Even though in some specific blends (e.g., polylactide/polycaprolactone) many efforts have been made to understand the influence of blending on the nucleation, crystallization and morphology of the parent components, there are still many points that have yet to be understood. In the case of other immiscible polyester blends systems, the literature is scarce, opening up opportunities in this environmentally important research topic.The authors would like to acknowledge funding by the BIODEST project ((RISE) H2020-MSCA-RISE-2017-778092
VISIBE AND INFRARED SPECTRAL CHARACTERISATION OF CHINESE CABBAGE (<i>BRASSICA RAPA L. SUBSPECIES CHINENSIS</i>), GROWN UNDER DIFFERENT NITROGEN, POTASSIUM AND PHOSPHORUS CONCENTRATIONS
There is a need to intensify research efforts on improving productivity of indigenous vegetables in South Africa. One research avenue is operationalizing remote sensing techniques to monitor crop health status. This study aimed at characterising the spectral properties of Chinese cabbage (Brassica Rapa L. subspecies Chinensis) grown under varying fertilizer treatments: nitrogen (0 kg/ha, 75 kg/ha, 125 kg/ha, 175 kg/ha and 225 kg/ha), phosphorus (0 kg/ha, 9.4 kg/ha, 15.6, 21.9 kg/ha and 28.1 kg/ha) and potassium (0 kg/ha, 9.4  kg/ha, 15.6 kg/ha, 21.9 kg/ha and 28.1 kg/ha). Visible and infrared spectral measurements were taken from a total of 60 samples inside the laboratory. Contiguous spectral regions were plotted to show spectral profiles of the different fertilizer treatments and then classified using gradient boosting and random forest classifiers. ANOVA revealed the potential of spectral reflectance data in discriminating different fertiliser treatments from crops. There was also a significant difference between the capabilities of the two classifiers. Gradient boost model (GBM) yielded higher classification accuracies than random forest (RF). The important variables identified by each model improved the classification accuracy. Overall, the results indicate a potential for the use of spectroscopy in monitoring food quality parameters, thereby reducing the cost of traditional methods. Further research into advanced statistical analysis techniques is needed to improve the accuracy with which fertiliser concentrations in crops could be quantified. The random forest model particularly requires improvements
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