Physical-chemical pretreatment as an option for increased sustainability of municipal wastewater treatment plants

Keywords : municipal wastewater treatment, physical-chemical pretreatment, chemically enhanced primary treatment, organic polymers, environmental sustainabilityMost of the currently applied municipal wastewater treatment plants in The Netherlands are based on the activated sludge process and include nitrogen and phosphorus removal. Physical-chemical pretreatment might be an option to improve the environmental sustainability of these wastewater treatment facilities. Physical-chemical pretreatment is meant to separate suspended and colloidal particles in the first step of treatment. The organic concentrate of separated particles is considered a product that can be digested to produce biogas. Since a large part of the organic pollutants in wastewater is present as not-dissolved material (65-70% of COD), the pollutant load to pursuing treatment steps is consequently reduced.In the first part of the thesis the concept of physical-chemical pretreatment was evaluated for its potential to design more sustainable treatment systems. Based on a review of unit operations, ten different scenarios for wastewater treatment were designed and evaluated along environmental and financial criteria. The evaluation showed that these scenarios could be designed more energy efficient (savings of 60-75% of energy) and smaller compared to currently applied treatment systems. The total cost of treatment scenarios, which combine pretreatment with secondary biological treatment appeared to be in the same range as that of a reference scenario. The scenario evaluation also revealed two important bottlenecks, namely (i) the use of metal-based flocculating agents results in the production of a considerable amount of extra inorganic sludge and in an increased salinity of the effluent and (ii) the removal of particles is partially accompanied by the removal of biodegradable COD which may affect the denitrification capacity of a biological post treatment step.The second part of the thesis describes experimental work into the identified bottlenecks. As alternatives to metal-based flocculating agents the potential application of organic polymers was investigated. Jar tests and experiments with continuous reactors showed that particle removal efficiencies of 70-90% could be achieved by applying these polymers in combination with eighter settling or dissolved air flotation. Especially cationic, high molecular weight polyelectrolytes showed interesting characteristics for practical application as they appeared effective at relatively low doses. A polymer dosing control strategy based on continuous measurement of the influent-turbidity proved effective to create different levels of particle removal, despite large concentration fluctuations in the influent. The effect of particle removal on the elimination of nitrogen was investigated by Nitrogen Uptake Rate (NUR) tests and experiments with a pilot scale activated sludge plant. It was found that with the removal of particulate COD, the biodegradable COD of the investigated wastewater was reduced by 50%. Calculations based on the values obtained in the experiments however indicated that well-designed plants that receive wastewater with an average COD/N ratio still contain sufficient denitrification capacity to comply with the nitrogen effluent constraint at particle removal efficiencies as high as 80-90%.</p

Prevalence of Peyronie and Ledderhose Diseases in a Series of 730 Patients with Dupuytren Disease

BACKGROUND: Dupuytren, Peyronie, and Ledderhose diseases are related fibroproliferative disorders characterized by abnormalities in the connective tissue of the palm of the hand, the tunica albuginea of the penis, and the sole of the foot, respectively. Concomitant prevalence rates of these diseases have only been described in a few small populations. This article aims to report on a large population and to raise awareness in surgeons treating Dupuytren disease for concurring related fibroproliferative disorders. METHODS: Patients diagnosed as having Dupuytren disease were recruited from outpatient clinics in the northern part of the Netherlands from 2007 to 2016. Questionnaires concerning demographics, clinical characteristics, the coexistence of Ledderhose and/or Peyronie diseases, and other factors were filled in by the participants and by plastic surgeons. RESULTS: For 730 men with Dupuytren disease, the surgeons' reported prevalence rate of Peyronie disease was 7.8 percent and of Ledderhose disease was 16.1 percent. The participants themselves reported prevalence rates of 8.8 percent for Peyronie disease and of 22.0 percent for Ledderhose disease. CONCLUSIONS: In the Dupuytren patient cohort, the prevalence of Peyronie disease was lower than that described in the literature. The prevalence of Ledderhose disease corresponded with the rates from the literature. However, both were underreported by plastic surgeons, which calls for a rise in awareness, recognition, and referral to a urologist when the conditions are bothersome or symptomatic

Cardiovascular risk and kidney function profiling using conventional and novel biomarkers in young adults: the African-PREDICT study

Background: Low- and middle-income countries experience an increasing burden of chronic kidney disease. Cardiovascular risk factors, including advancing age, may contribute to this phenomenon. We (i) profiled cardiovascular risk factors and different biomarkers of subclinical kidney function and (ii) investigated the relationship between these variables. Methods: We cross-sectionally analysed 956 apparently healthy adults between 20 and 30 years of age. Cardiovascular risk factors such as high adiposity, blood pressure, glucose levels, adverse lipid profiles and lifestyle factors were measured. Various biomarkers were used to assess subclinical kidney function, including estimated glomerular filtration rate (eGFR), urinary albumin, uromodulin and the CKD273 urinary proteomics classifier. These biomarkers were used to divide the total population into quartiles to compare extremes (25th percentiles) on the normal kidney function continuum. The lower 25th percentiles of eGFR and uromodulin and the upper 25th percentiles of urinary albumin and the CKD273 classifier represented the more unfavourable kidney function groups. Results: In the lower 25th percentiles of eGFR and uromodulin and the upper 25th percentile of the CKD273 classifier, more adverse cardiovascular profiles were observed. In multi-variable adjusted regression analyses performed in the total group, eGFR associated negatively with HDL-C (β= -0.44; p &lt; 0.001) and GGT (β= -0.24; p &lt; 0.001), while the CKD273 classifier associated positively with age and these same risk factors (age: β = 0.10; p = 0.021, HDL-C: β = 0.23; p &lt; 0.001, GGT: β = 0.14; p = 0.002). Conclusion: Age, lifestyle and health measures impact kidney health even in the third decade

Glimpses into the molecular pathogenesis of Peyronie's disease

Peyronie's disease (PD) is a fibroproliferative disease of the penis. Since little is known about the molecular pathogenesis of PD, we compared the biochemical make-up of PD plaques with normal tunica albuginea to clarify pathological processes in the scarred tissue. Protein and mRNA levels were measured in plaques and in unaffected pieces of the tunica albuginea. We investigated the presence of myofibroblasts, the deposition of collagens, and some key elements of Wnt and YAP1 signaling at protein level. The expression of 45 genes, all related to collagen homeostasis and extracellular matrix proteins, was quantified. In plaques, more myofibroblasts were present, and we observed an activation of Wnt signaling and YAP1 signaling. Increased levels of the collagens types I and III confirm the fibrotic nature of plaques. The mRNA ratio of collagen types III, IV, and VI to type I was increased. The expression of lysyl hydroxylase 3 was higher, whereas a decreased expression level was seen for fibronectin and cathepsin K. The biochemical composition of plaques was different from unaffected tunica albuginea: the relative and absolute abundance of various extracellular matrix proteins were changed, as well as the quality of collagen and the level of the collagen-degrading enzyme cathepsin K

Increased prescription rate of anti-infective agents after diagnosis of myelodysplastic syndromes

The a priori risk for infections in patients with myelodysplastic syndromes (MDS) is unknown. This study examines prescription rates of anti-infective agents in MDS patients before and after diagnosis, in both in- and outpatient settings, to provide information on infection management in clinical practice. We performed a population-based study using the HemoBase registry, containing data of all MDS patients diagnosed since 2005 in Friesland, the Netherlands. Community and hospital pharmacies provided prescription data from 1995 to 2020. Data were obtained for 203 of 292 patients (70%). Patients received significantly more anti-infective agents, predominantly antibacterials (70%), after diagnosis compared to before: 148.7 defined daily dose/1000 days (DID) (95% CI: 146.9-150.5) and 55.1 DID (95% CI: 54.5-55.8, p < 0.01), respectively, corresponding to median 23.5 and 7.6 treatment days/year. Higher-risk (449.9 DID) and lower-risk patients (129.1 DID) both received significantly more anti-infective agents after diagnosis; comorbidities, neutropenia, and age did not show significant differences relative to prescription rates. Before diagnosis, 10% of patients had infection-related hospital admissions versus 38% after diagnosis. In conclusion, MDS patients received significantly more anti-infective agents compared to before diagnosis. This is the first study that has quantified the prescription rate of anti-infective agents within and beyond the clinical setting in MDS

REFERQUAL: A pilot study of a new service quality assessment instrument in the GP Exercise Referral scheme setting

Background The development of an instrument accurately assessing service quality in the GP Exercise Referral Scheme (ERS) industry could potentially inform scheme organisers of the factors that affect adherence rates leading to the implementation of strategic interventions aimed at reducing client drop-out. Methods A modified version of the SERVQUAL instrument was designed for use in the ERS setting and subsequently piloted amongst 27 ERS clients. Results Test re-test correlations were calculated via Pearson's 'r' or Spearman's 'rho', depending on whether the variables were Normally Distributed, to show a significant (mean r = 0.957, SD = 0.02, p < 0.05; mean rho = 0.934, SD = 0.03, p < 0.05) relationship between all items within the questionnaire. In addition, satisfactory internal consistency was demonstrated via Cronbach's 'α'. Furthermore, clients responded favourably towards the usability, wording and applicability of the instrument's items. Conclusion REFERQUAL is considered to represent promise as a suitable tool for future evaluation of service quality within the ERS community. Future research should further assess the validity and reliability of this instrument through the use of a confirmatory factor analysis to scrutinise the proposed dimensional structure

Verteporfin as a Medical Treatment in Peyronie's Disease

Introduction: In Europe and the United States, verteporfin (Visudyne; VP) is registered and used in treating macular degeneration. Research showed that VP decreased expression of fibrotic genes in fibroblasts collected from nodules of patients suffering from Dupuytren's disease, plausibly by de-activating transcription in the Yes Activated Protein (YAP) pathway. Aim: To analyze the effect of VP on myofibroblasts cultured from Peyronie's disease (PD) plaques. Methods: At surgery for PD we took biopsies from the plaques of 5 patients. By immunostaining, the presence of the pathologic myofibroblasts was determined. After culturing cells, VP was dispensed in starvation medium for 24 and 48 hours and messenger(m)RNA levels of COL1A1, ACTA2, COL5A1, EDA-FN, LOXL2, CCN2, SER-PINH1, PLOD2, and YAP were quantified and compared with controls with real-time polymerase chain reaction. Main Outcome Measure: mRNA-levels of COL1A1, ACTA2, COL5A1, EDA-FN, LOXL2, CCN2, SERPINH1, PLOD2, and YAP. Results: The pathologic phenotype of cells isolated from PD plaques was confirmed with baseline immunofluorescent stainings that showed considerable levels of a-smooth muscle actin, being a marker for the presence of myofibroblasts. The mRNA ratios of all the genes related to fibrosis (COL1A1, etc.) except YAP decreased significantly after treatment with VP within 24 and 48 hours. These results suggest inhibition of fibrosis in the YAP cascade, downstream of YAP. Conclusion: In our opinion, urologists must move the focus to disease before deformity, and the search for new oral or intralesional agents, well-tolerated and effective in both the acute and chronic phase of PD must continue. VP blocked the expression of genes related to fibrosis in the YAP cascade in myofibroblasts derived from PD plaque. Mohede DCJ, de Jong IJ, Bank RA, et al. Verteporfin as a medical treatment in Peyronie's disease. Copyright (C) 2018, The Authors. Published by Elsevier Inc. on behalf of the International Society for Sexual Medicine