An integrated assessment of environmental, economic, social and technological parameters of source separated and conventional sanitation concepts: A contribution to sustainability analysis.

Resource recovery and reuse from domestic wastewater has become an important subject for the current development of sanitation technologies and infrastructures. Different technologies are available and combined into sanitation concepts, with different performances. This study provides a methodological approach to evaluate the sustainability of these sanitation concepts with focus on resource recovery and reuse. St. Eustatius, a small tropical island in the Caribbean, was used as a case study for the evaluation. Three source separation-community-on-site and two combined sewerage island-scale concepts were selected and compared in terms of environmental (net energy use, nutrient recovery/reuse, BOD/COD, pathogens, and GHG emission, land use), economic (CAPEX and OPEX), social cultural (acceptance, required competences and education), and technological (flexibility/adaptability, reliability/continuity of service) indicators. The best performing concept, is the application of Upflow Anaerobic Sludge Bed (UASB) and Trickling Filter (TF) at island level for combined domestic wastewater treatment with subsequent reuse in agriculture. Its overall average normalised score across the four categories (i.e., average of average per category) is about 15% (0.85) higher than the values of the remaining systems and with a score of 0.73 (conventional activated sludge - centralised level), 0.77 (UASB-septic tank (ST)), 0.76 (UASB-TF - community level), and 0.75 (ST - household level). The higher score of the UASB-TF at community level is mainly due to much better performance in the environmental and economic categories. In conclusion, the case study provides a methodological approach that can support urban planning and decision-making in selecting more sustainable sanitation concepts, allowing resource recovery and reuse in small island context or in other contexts.

Simultaneous recovery of calcium phosphate granules and methane in anaerobic treatment of black water: Effect of bicarbonate and calcium fluctuations.

Calcium phosphate (CaP) granules were discovered in the anaerobic treatment of vacuum collected black water (BW), using upflow anaerobic sludge blanket (UASB) technology. This allows simultaneous recovery of CaP granules and methane in the UASB reactor. However, the role of BW composition on CaP granulation is not yet understood. Moreover, CaP granulation was not observed in previous research on anaerobic treatment of BW, although similar treatment conditions were applied. Therefore, this study shows specifically the influence of bicarbonate and calcium fluctuations in BW on the phosphorus accumulation in the UASB reactor, which directly affects CaP granulation. Without calcium addition, 5% of the total phosphorus (P) fed was found as CaP granules in the reactor (61 mgP g-1dried matter), after 260 days of operation. Simultaneously, 65% of the COD in BW was efficiently converted into methane at 25 °C. Variations of bicarbonate and calcium concentrations in raw BW showed a significant influence on phosphorus accumulation in the UASB reactor. Geochemical modelling showed that the increase of soluble calcium from 39 to 54 mg L-1 in BW triggers supersaturation for calcium phosphate precursors (Cax(PO4)y). Concurrently, bicarbonate decreased from 2.7 to 1.2 g L-1, increasing further the ionic activity of calcium. Formation and accumulation of seed particles possibly enhanced CaP granulation. Preliminary results showed that addition of calcium (Ca2+/PO43- molar ratio of 3) increased the accumulation of total P in the UASB reactor to more than 85%. This further increases the granulation rate and consequently, the process feasibility.

Micropollutant removal from black water and grey water sludge in a UASB-GAC reactor.

The effect of granular activated carbon (GAC) addition on the removal of diclofenac, ibuprofen, metoprolol, galaxolide and triclosan in a up-flow anaerobic sludge blanket (UASB) reactor was studied. Prior to the reactor studies, batch experiments indicated that addition of activated carbon to UASB sludge can decrease micropollutant concentrations in both liquid phase and sludge. In continuous experiments, two UASB reactors were operated for 260 days at an HRT of 20 days, using a mixture of source separated black water and sludge from aerobic grey water treatment as influent. GAC (5.7 g per liter of reactor volume) was added to one of the reactors on day 138. No significant difference in COD removal and biogas production between reactors with and without GAC addition was observed. In the presence of GAC, fewer micropollutants were washed out with the effluent and a lower accumulation of micropollutants in sludge and particulate organic matter occurred, which is an advantage in micropollutant emission reduction from wastewater. However, the removal of micropollutants by adding GAC to a UASB reactor would require more activated carbon compared to effluent post-treatment. Additional research is needed to estimate the effect of bioregeneration on the lifetime of activated carbon in a UASB-GAC reactor.

Micropollutants in source separated wastewater streams and recovered resources of source separated sanitation.

The quality of anaerobic sludge and struvite from black water treatment system, aerobic sludge from grey water treatment system and effluents of both systems was assessed for organic micropollutant content in order to ensure safety when reusing these products. Use of anaerobic black water sludge and struvite as soil amendments is recommended based on the low micropollutant content. Aerobic grey water sludge is recommended for disposal, because of the relatively high micropollutant concentrations, exceeding those in sewage sludge. Effluents of black and grey water treatment systems require post-treatment prior to reuse, because the measured micropollutant concentrations in the effluents are above ecotoxicological thresholds.

The presence of brain white matter lesions in relation to preeclampsia and migraine.

INTRODUCTION: Identifying female-specific risk markers for cerebrovascular disease is becoming increasingly important. Both migraine and preeclampsia have been associated with higher incidence of brain white matter lesions (WML) and stroke. We assessed the association between WML and migraine among formerly (pre)eclamptic women. METHODS: A total of 118 women (76 formerly (pre)eclamptic and 42 control women) were screened for migraine and WML presence. Independent effects of migraine and (pre)eclampsia on WML were assessed. RESULTS: Migraine prevalence did not differ between the (pre)eclamptic (26/76; 34%); and control group (10/42; 24%), p = 0.17. Age-adjusted regression analysis failed to show a significant independent effect of migraine (OR 1.14; 95% CI 0.47-2.76; p = 0.77) on WML presence, and showed a non-significant effect of (pre)eclampsia (OR 2.30; 95% CI 0.90-5.83; p = 0.08). CONCLUSION: Migraine prevalence was not found to be an independent risk factor for WML prevalence in formerly (pre)eclamptic women. Since this study had a small sample size, larger prospective studies are needed to examine female-specific risk factors for WML and its consequences.

The urban harvest approach as framework and planning tool for improved water and resource cycles.

Water and resource availability in sufficient quantity and quality for anthropogenic needs represents one of the main challenges in the coming decades. To prepare for upcoming challenges such as increased urbanization and climate change related consequences, innovative and improved resource management concepts are indispensable. In recent years we have developed and applied the urban harvest approach (UHA). The UHA aims to model and quantify the urban water cycle on different temporal and spatial scales. This approach allowed us to quantify the impact of the implementation of water saving measures and new water treatment concepts in cities. In this paper we will introduce the UHA and its application for urban water cycles. Furthermore, we will show first results for an extension to energy cycles and highlight future research items (e.g. nutrients, water-energy-nexus).

Impact of crop-manure ratios on energy production and fertilizing characteristics of liquid and solid digestate during codigestion.

The influence of maize silage-manure ratios on energy output and digestate characteristics was studied using batch experiments. The methane production, nutrients availability (N and P) and heavy metals' content were followed in multiflask experiments at digestion times 7, 14, 20, 30 and 60 days. In addition, the available nutrient content in the liquid and solid parts of the digestate was evaluated. Aanaerobic digestion favoured the availability of nutrients to plants, after 61 days 20-26% increase in NH4+ and 0-36% increase in PO4(3-) were found in relation to initial concentrations. Digestion time and maize addition increased the availability of PO4(3-). Inorganic nutrients were found to be mainly available in the liquid part of the digestate, i.e. 80-92% NH4+ and 65-74% PO4(3-). Manure had a positive effect on the methane production rate, whereas maize silage increased the total methane production per unit volatile solids in all treatments.

Long-term cerebral imaging after pre-eclampsia.

OBJECTIVE: Formerly eclamptic women demonstrate cerebral white matter lesions (WMLs) several years following the index pregnancy. The pathophysiology is unclear and may be related to the predisposition for cerebrovascular/cardiovascular disease in such women and/or the occurrence of posterior reversible encephalopathy syndrome whilst pregnant. The aim of this study was to assess the presence and severity of WMLs and their relationship with the severity of the neurological symptoms during the index pregnancy and several current cardiovascular risk factors in formerly pre-eclamptic women. DESIGN: This was a retrospective cohort study. SETTING: The Neuroimaging Centre at the School for Behavioural and Cognitive Neurosciences, Groningen, the Netherlands. POPULATION: Seventy-three formerly pre-eclamptic women were matched for age (37 ± 6 years) and elapsed time since index pregnancy (5.1 ± 3.7 years) with parous control women. METHODS: Cerebral magnetic resonance imaging scans were performed on cases and controls. Scans were rated by a neuroradiologist blind to the patient category. MAIN OUTCOME MEASURES: The presence and severity of cerebral WMLs. RESULTS: Formerly pre-eclamptic women had WMLs significantly more often (37%) and more severely (mean, 0.11; median, 0.00; range, 0-2.34 ml) than controls (21%, P = 0.04; mean, 0.015; median, 0.00; range, 0-0.13 ml; P = 0.02). Current hypertension and a history of early-onset pre-eclampsia (<37 weeks) were independently associated with the presence of WMLs (ß = 1.34, P = 0.02 and ß = 1.73, P = 0.01, respectively). CONCLUSIONS: Our findings indicate that pre-eclampsia might be a risk marker for early cerebrovascular damage. The predisposition of formerly pre-eclamptic women to later cardiovascular and cerebrovascular disease may be an important factor for the development of cerebral WMLs. Whether a history of posterior reversible encephalopathy syndrome may be an additive risk factor for the development of these lesions remains unknown.

Perceptions of women, nurses, midwives and doctors about the use of video during birth to improve quality of care: focus group discussions.

The use of video during birth for quality of care was discussed in focus groups with women, nurses, midwives and doctors. Qualitative analysis revealed three categories of importance. First, goals and benefits: improving quality of care, teaching, research and legal issues are important potential applications. Second, limitations: concerns for privacy, fear of feedback and use of video in case of adverse events. Third, rules and regulations: goals and scope of the use of video need to be clearly described, access to video needs to be secured, and time until destruction needs to be specified. Video capture of birth is considered useful and seems acceptable if specific conditions are met.

The effect of operational conditions on the hydrodynamic characteristics of the sludge bed in UASB reactors.

This work aims to evaluate the hydrodynamic properties of the sludge bed of Upflow Anaerobic Sludge Blanket (UASB) reactors based on its settleability and expansion characteristics. The methodologies used for the evaluation of the settleability of aerobic activated sludge, and for the expansibility of a sludge bed of Expanded Granular Sludge Bed reactors and Fluidised Bed Reactors were adapted and applied to the particular characteristics of the sludge of UASB reactors. An easy-to-build experimental set-up was developed to assess the parameters necessary for the equations of settleability and of expansibility. The results obtained from the sludges of seven differently operated reactors show that, for the treatment of low strength wastewater, settleability increased and expansibility decreased at decreased hydraulic retention time, from 6 to 1 h, and/or increased influent concentrations, from 136 to approximately 800 mg chemical oxygen demand/L. The results also show that it is useless to design an UASB reactor with a longer hydraulic retention time to cope with hydraulic shock loads, as a more expansible sludge will develop at such condition.