Modelling nitrogen and phosphorus dynamics in soil fertigated with decentralised wastewater treatment effluent

Many residents in informal settlements lack proper sanitation. The decentralised wastewater treatment system (DEWATS) is a low-cost water borne onsite technology that can potentially provide sanitation in unserved areas. The management of DEWATS effluent is of environmental concern. Its use in agriculture helps improve livelihood and food security in peri urban areas. This study investigated environmental sustainability for fertigation using DEWATS effluent through modelling N and P dynamics in fertigated soils. The SWB Sci model, a crop growth and nutrient (N and P) simulation model was calibrated and validated based on field experiments conducted. The crop growth sub-model was successful and met all statistical criteria (r2 > 0.8 and D > 0.8). Use of DEWATS effluent showed to increase soil inorganic N and P within the top soil layers (0.3 m), which may be beneficial for crop production. However, proper management practices are recommended to prevent leaching and runoff losses

Nitrogen and phosphorus dynamics in plants and soil fertigated with decentralised wastewater treatment effluent

Municipalities in South Africa face problems in providing sanitation to unserved informal settlements in peri-urban areas and rural nodes. The Decentralised Wastewater Treatment System (DEWATS) connected to community ablution blocks can be an option, with the treated effluent then applied to agricultural land. However, the management of treated wastewater through irrigation of crops must be environmentally sustainable. This study therefore investigated nitrogen (N) and phosphorus (P) dynamics in soil irrigated with DEWATS effluent. A field study with banana and taro in a randomised complete block design with three blocks and two irrigation treatments (DEWATS effluent without fertiliser vs tap water + fertiliser) was carried out over a period of 992 days at the Newlands-Mashu Research Site, Durban, South Africa. Data were collected on crop N and P uptake, soil chemical properties, and nutrient leaching together with groundwater monitoring. Nitrogen and P uptake was not significantly different (p > 0.05) between the two irrigation treatments. Irrigation with DEWATS effluent increased soil N and P concentrations within the upper 0.3 m implying its importance as a fertiliser source. Leaching of N and P from DEWATS effluent treated plots was comparable to that from the tap water + fertiliser treatments. However, to manage excess water in the soil, practices such as irrigation to meet crop water requirements with room for rainfall and installation of subsurface drainage when possible can be employed.The Water Research Commission, South Africahttp://www.elsevier.com/locate/agwat2020-04-20hj2019Plant Production and Soil Scienc

Access to justice for all: Towards an “expansive vision” of justice and technology.

In this paper, the authors examine developments in the Canadian access to justice dialogue from Macdonald’s seminal 2005 analysis to the recent reports of the National Action Committee on Access to Justice in Civil and Family Matters [NAC]. They draw on the NAC’s call for an “expansive vision” of access to justice as the basis for critically evaluating examples of particular technologies used or proposed as responses to the access to justice crisis in Canada. In so doing, they illustrate the importance of conscious consideration of deliverables and beneficiaries in prioritizing technologies for deployment, in determining how the technology ought to be deployed, and in evaluating the potential of a technology to facilitate access to justice. The authors argue that nuanced accounts of the relationships between justice deliverables, technological mechanisms for delivery and intended justice beneficiaries are essential to developing good decision-making mechanisms with respect to access to justice and technology. Dans le présent article, les auteurs examinent l’évolution du dialogue canadien sur l’accès à la justice, depuis l’analyse fondamentale de Macdonald en 2005 jusqu’aux récents rapports du Comité national d’action sur l’accès à la justice en matière civile et familiale (CNA). Ils se fondent sur la « vision élargie » de l’accès à la justice réclamée par le CNA pour évaluer de façon critique les exemples de technologies particulières utilisées ou proposées pour répondre à la crise de l’accès à la justice au Canada. Ce faisant, ils illustrent l’importance d’examiner de façon consciente les livrables et les bénéficiaires pour classer par ordre de priorité les technologies à déployer, pour déterminer comment la technologie devrait être déployée et pour évaluer le potentiel d’une technologie de faciliter l’accès à la justice. Les auteurs soutiennent que des comptes rendus nuancés des rapports entre les livrables en matière de justice, les mécanismes de livraison technologiques et les bénéficiaires prévus sont essentiels pour élaborer de bons mécanismes décisionnels en ce qui concerne l’accès à la justice et la technologie

Intercomparison and characterization of 23 Aethalometers under laboratory and ambient air conditions : procedures and unit-to-unit variabilities

Aerosolized black carbon is monitored worldwide to quantify its impact on air quality and climate. Given its importance, measurements of black carbon mass concentrations must be conducted with instruments operating in quality-checked and ensured conditions to generate data which are reliable and comparable temporally and geographically. In this study, we report the results from the largest characterization and intercomparison of filter-based absorption photometers, the Aethalometer model AE33, belonging to several European monitoring networks. Under controlled laboratory conditions, a total of 23 instruments measured mass concentrations of black carbon from three well-characterized aerosol sources: synthetic soot, nigrosin particles, and ambient air from the urban background of Leipzig, Germany. The objective was to investigate the individual performance of the instruments and their comparability; we analyzed the response of the instruments to the different aerosol sources and the impact caused by the use of obsolete filter materials and the application of maintenance activities. Differences in the instrument-to-instrument variabilities from equivalent black carbon (eBC) concentrations reported at 880 nm were determined before maintenance activities (for soot measurements, average deviation from total least square regression was -2.0% and the range -16% to 7 %; for nigrosin measurements, average deviation was 0.4% and the range -15% to 17 %), and after they were carried out (for soot measurements, average deviation was 1:0% and the range -14% to 8 %; for nigrosin measurements, the average deviation was 0.5% and the range -12% to 15 %). The deviations are in most of the cases explained by the type of filter material employed by the instruments, the total particle load on the filter, and the flow calibration. The results of this intercomparison activity show that relatively small unit-to-unit variability of AE33-based particle light absorbing measurements is possible with well-maintained instruments. It is crucial to follow the guidelines for maintenance activities and the use of the proper filter tape in the AE33 to ensure high quality and comparable black carbon (BC) measurements among international observational networks.Peer reviewe

Intercomparison and characterization of 23 Aethalometers under laboratory and ambient air conditions: procedures and unit-to-unit variabilities

Aerosolized black carbon is monitored worldwide to quantify its impact on air quality and climate. Given its importance, measurements of black carbon mass concentrations must be conducted with instruments operating in qualitychecked and ensured conditions to generate data which are reliable and comparable temporally and geographically. In this study, we report the results from the largest characterization and intercomparison of filter-based absorption photometers, the Aethalometer model AE33, belonging to several European monitoring networks. Under controlled laboratory conditions, a total of 23 instruments measured mass concentrations of black carbon from three wellcharacterized aerosol sources: synthetic soot, nigrosin particles, and ambient air from the urban background of Leipzig, Germany. The objective was to investigate the individual performance of the instruments and their comparability; we analyzed the response of the instruments to the different aerosol sources and the impact caused by the use of obsolete filter materials and the application of maintenance activities. Differences in the instrument-to-instrument variabilities from equivalent black carbon (eBC) concentrations reported at 880 nm were determined before maintenance activities (for soot measurements, average deviation from total least square regression was-2.0% and the range-16% to 7 %; for nigrosin measurements, average deviation was 0.4% and the range-15% to 17 %), and after they were carried out (for soot measurements, average deviation was-1.0% and the range-14% to 8 %; for nigrosin measurements, the average deviation was 0.5%and the range-12%to 15 %). The deviations are in most of the cases explained by the type of filter material employed by the instruments, the total particle load on the filter, and the flow calibration. The results of this intercomparison activity show that relatively small unit-to-unit variability of AE33-based particle light absorbing measurements is possible with wellmaintained instruments. It is crucial to follow the guidelines for maintenance activities and the use of the proper filter tape in the AE33 to ensure high quality and comparable black carbon (BC) measurements among international observational networks. © 2021 Author(s). This work is distributed under the Creative Commons Attribution 4.0 License

Outcome of hematopoietic cell transplantation for DNA double-strand break repair disorders

Background: Rare DNA breakage repair disorders predispose to infection and lymphoreticular malignancies. Hematopoietic cell transplantation (HCT) is curative, but coadministered chemotherapy or radiotherapy is damaging because of systemic radiosensitivity. We collected HCT outcome data for Nijmegen breakage syndrome, DNA ligase IV deficiency, Cernunnos-XRCC4-like factor (Cernunnos-XLF) deficiency, and ataxia-telangiectasia (AT). Methods: Data from 38 centers worldwide, including indication, donor, conditioning regimen, graft-versus-host disease, and outcome, were analyzed. Conditioning was classified as myeloablative conditioning (MAC) if it contained radiotherapy or alkylators and reduced-intensity conditioning (RIC) if no alkylators and/or 150 mg/m(2) fludarabine or less and 40 mg/kg cyclophosphamide or less were used. Results: Fifty-five new, 14 updated, and 18 previously published patients were analyzed. Median age at HCT was 48 months (range, 1.5-552 months). Twenty-nine patients underwent transplantation for infection, 21 had malignancy, 13 had bone marrow failure, 13 received pre-emptive transplantation, 5 had multiple indications, and 6 had no information. Twenty-two received MAC, 59 received RIC, and 4 were infused; information was unavailable for 2 patients. Seventy-three of 77 patients with DNA ligase IV deficiency, Cernunnos-XLF deficiency, or Nijmegen breakage syndrome received conditioning. Survival was 53 (69%) of 77 and was worse for those receiving MAC than for those receiving RIC (P=.006). Most deaths occurred early after transplantation, suggesting poor tolerance of conditioning. Survival in patients with AT was 25%. Forty-one (49%) of 83 patients experienced acute GvHD, which was less frequent in those receiving RIC compared with those receiving MAC (26/56 [46%] vs 12/21 [57%], P=.45). Median follow-up was 35 months (range, 2-168 months). No secondary malignancies were reported during 15 years of follow-up. Growth and developmental delay remained after HCT; immune-mediated complications resolved. Conclusion: RIC HCT resolves DNA repair disorder associated immunodeficiency. Long-term follow-up is required for secondary malignancy surveillance. Routine HCT for AT is not recommended.Peer reviewe