Philippe Moulin

Reverse osmosis desalination: Water sources, technology, and today's challenges

Reverse osmosis membrane technology has developed over the past 40 years to a 44% share in world desalting production capacity, and an 80% share in the total number of desalination plants installed worldwide. The use of membrane desalination has increased as materials have improved and costs have decreased. Today, reverse osmosis membranes are the leading technology for new desalination installations, and they are applied to a variety of salt water resources using tailored pretreatment and membrane system design. Two distinct branches of reverse osmosis desalination have emerged: seawater reverse osmosis and brackish water reverse osmosis. Differences between the two water sources, including foulants, salinity, waste brine (concentrate) disposal options, and plant location, have created significant differences in process development, implementation, and key technical problems. Pretreatment options are similar for both types of reverse osmosis and depend on the specific components of the water source. Both brackish water and seawater reverse osmosis (RO) will continue to be used worldwide; new technology in energy recovery and renewable energy, as well as innovative plant design, will allow greater use of desalination for inland and rural communities, while providing more affordable water for large coastal cities. A wide variety of research and general information on RO desalination is available; however, a direct comparison of seawater and brackish water RO systems is necessary to highlight similarities and differences in process development. This article brings to light key parameters of an RO process and process modifications due to feed water characteristics.

Excessive body weight as a new independent risk factor for clinical and pathological progression in primary IgA nephritis

Experimental evidence suggests a role for obesity in the formation and progression of some glomerular lesions, but data for human glomerulonephritis are lacking. In a cohort of 162 incident patients with biopsy-proven immunoglobulin A (IgA) nephropathy, we assessed whether the presence of an elevated body mass index (BMI >/= 25 kg/m(2)) at the time of the first renal biopsy (RB1) correlated with clinical data at RB1 (24-hour proteinuria, arterial hypertension, and renal function), pathological data (global optical score [GOS] with detailed pathological indices), and clinical progression to both arterial hypertension and chronic renal failure (CRF). In both univariate and multivariate analyses, the presence of an elevated BMI at RB1 was significantly associated with the severity of pathological renal lesions (GOS and vascular, tubular, and interstitial indices). Hypertension-free survival was significantly less in overweight patients (P: < 0.0001) compared with those with normal weight. In a Cox regression analysis for hypertension-free survival including 24-hour proteinuria greater than 1 g, GOS, and metabolic parameters, only elevated BMI and GOS were independent factors for the development of arterial hypertension. CRF-free survival was also significantly less in patients with an excessive BMI. In a multivariate Cox regression analysis for CRF-free survival, hypertension, GOS, and BMI at RB1 were independent risk factors for CRF. In IgA nephropathy, excessive body weight and/or BMI are underestimated predictive factors for the development of arterial hypertension and, ultimately, CRF.

Apoa5 Q139X truncation predisposes to late-onset hyperchylomicronemia due to lipoprotein lipase impairment

While type 1 hyperlipidemia is associated with lipoprotein lipase or apoCII deficiencies, the etiology of type 5 hyperlipidemia remains largely unknown. We explored a new candidate gene, APOA5, for possible causative mutations in a pedigree of late-onset, vertically transmitted hyperchylomicronemia. A heterozygous Q139X mutation in APOA5 was present in both the proband and his affected son but was absent in 200 controls. It was subsequently found in 2 of 140 cases of hyperchylomicronemia. Haplotype analysis suggested the new Q139X as a founder mutation. Family studies showed that 5 of 9 total Q139X carriers had hyperchylomicronemia, 1 patient being homozygote. Severe hypertriglyceridemia in 8 heterozygotes was strictly associated with the presence on the second allele of 1 of 2 previously described triglyceride-raising minor APOA5 haplotypes. Furthermore, ultracentrifugation fraction analysis indicated in carriers an altered association of Apoa5 truncated and WT proteins to lipoproteins, whereas in normal plasma, Apoa5 associated with VLDL and HDL/LDL fractions. APOB100 kinetic studies in 3 severely dyslipidemic patients with Q139X revealed a major impairment of VLDL catabolism. Lipoprotein lipase activity and mass were dramatically reduced in dyslipidemic carriers, leading to severe lipolysis defect. Our observations strongly support in humans a role for APOA5 in lipolysis regulation and in familial hyperchylomicronemia.

Low-pressure membrane integrity tests for drinking water treatment: A review.

Low-pressure membrane systems, including microfiltration (MF) and ultrafiltration (UF) membranes, are being increasingly used in drinking water treatments due to their high level of pathogen removal. However, the pathogen will pass through the membrane and contaminate the product if the membrane integrity is compromised. Therefore, an effective on-line integrity monitoring method for MF and UF membrane systems is essential to guarantee the regulatory requirements for pathogen removal. A lot of works on low-pressure membrane integrity tests have been conducted by many researchers. This paper provides a literature review about different low-pressure membrane integrity monitoring methods for the drinking water treatment, including direct methods (pressure-based tests, acoustic sensor test, liquid porosimetry, etc.) and indirect methods (particle counting, particle monitoring, turbidity monitoring, surrogate challenge tests). Additionally, some information about the operation of membrane integrity tests is presented here. It can be realized from this review that it remains urgent to develop an alternative on-line detection technique for a quick, accurate, simple, continuous and relatively inexpensive evaluation of low-pressure membrane integrity. To better satisfy regulatory requirements for drinking water treatments, the characteristic of this ideal membrane integrity test is proposed at the end of this paper.

Chemical cleaning/disinfection and ageing of organic UF membranes: A review

Membrane separation processes have become a basic unit operation for process design and product development. These processes are used in a variety of separation and concentration steps, but in all cases, the membranes must be cleaned regularly to remove both organic and inorganic material deposited on the surface and/or into the membrane bulk. Cleaning/disinfection is a vital step in maintaining the permeability and selectivity of the membrane in order to get the plant to its original capacity, to minimize risks of bacteriological contamination, and to make acceptable products. For this purpose, a large number of chemical cleaning/disinfection agents are commercially available. In general, these cleaning/disinfection agents have to improve the membrane flux to a certain extent. However, they can also cause irreversible damages in membrane properties and performances over the long term. Until now, there is considerably less literature dedicated to membrane ageing than to cleaning/disinfection. The knowledge in cleaning/disinfection efficiency has recently been improved. But in order to develop optimized cleaning/disinfection protocols there still remains a challenge to better understand membrane ageing. In order to compensate for the lack of correlated cleaning/disinfection and ageing data from the literature, this paper investigates cleaning/disinfection efficiencies and ageing damages of organic ultrafiltration membranes. The final aim is to provide less detrimental cleaning/disinfection procedures and to propose some guidelines which should have been taken into consideration in term of membrane ageing studies. To carry out this study, this article will detail the background of cleaning/disinfection and aging membrane topics in a first introductive part. In a second part, key factors and endpoints of cleaning/disinfection and aging membranes will be discussed deeply: the membrane role and the cleaning parameters roles, such as water quality, storing conditions, cleaning/disinfection/aging agents/conditions/protocols. The third and last part will be developed the parameters, methods and ways of characterization at our disposal and commonly used to develop and implement membrane cleaning and/or ageing studies.

Measurement of Two-Dimensional Movement Parameters of the Carotid Artery Wall for Early Detection of Arteriosclerosis: A Preliminary Clinical Study

The aim of this study was to clinically investigate the association between the risk factors of early-stage atherosclerosis and the two-dimensional (2-D) movement of the artery wall. To meet this objective, a speckle tracking approach for the estimation of the 2-D trajectory of the vessel wall was proposed and applied to B-mode ultrasound (US) sequences of the left common carotid artery (CCA). A deformable skeleton model was also introduced in the block matching scheme. Finally, the 2-D movements of both proximal and distal walls were investigated in three different local regions, with 1.5 × 0.3 mm(2) kernel blocks. A clinical study was conducted in which two different populations (26 young healthy volunteers and 26 older diabetic patients) were studied. The results show that the mean amplitude value of the diameter change ΔD, of the longitudinal displacement of the proximal wall ΔX(p) and of the longitudinal displacement of the distal wall ΔX(d) were 0.65 ± 0.17 vs. 0.41 ± 0.12 mm (p < 0.001), 0.48 ± 0.21 vs. 0.26 ± 0.18 mm (p < 0.001) and 0.48 ± 0.20 vs. 0.35 ± 0.23 mm (p = 0.006) for the young healthy volunteers and the older diabetic patients, respectively. The results of the three dynamic parameters ΔD, ΔX(p) and ΔX(d) were systematically and significantly lower for the diabetic subjects, respectively 37%, 46% and 27%. The method introduced in this feasibility study might constitute a pertinent approach to assess the presence of early-stage arteriosclerosis by the noninvasive estimation of the 2-D motion of the intima-media complex in the CCA.

Depressive symptoms are associated with unhealthy lifestyles in hypertensive patients with the metabolic syndrome

Objective Metabolic syndrome results from a complex interaction between lifestyle and genetic factors. Among this population, adhesion to healthy recommendations is a cornerstone of cardiovascular disease prevention. We examined the association between depression and multiple unhealthy behaviours in hypertensive patients with the metabolic syndrome. Research design and methods Eight hundred and forty consecutive hypertensive subjects with the metabolic syndrome were studied in our secondary-care centre. Separated scores reflecting unhealthy behaviours (physical inactivity, smoking and unhealthy diet) were combined to produce a global unhealthy lifestyle score. The Hospital Anxiety and Depression scale was used to assess and quantify depression. We performed a separate analysis for each sex. Results The prevalence of depression (13.0 versus 7.3%, P < 0.001) was greater in women than in men. Presence of depression was significantly associated in both men and women with unhealthy diet (in particular, excessive cholesterol and total caloric intake) but also with decreased physical activity in men and with smoking habits in women. In both sexes, the global unhealthy lifestyle score, reflecting a cluster of unhealthy behaviours, was positively correlated with the depression score. In multivariate analysis, the depression score appeared in both sexes as an independent determinant of unhealthy lifestyle. Conclusions Among hypertensive subjects with the metabolic syndrome, depressive symptoms along a continuum of severity are independently associated with multiple unhealthy lifestyles. This suggests that even minor forms of depression may impact on adhesion to health behaviours beyond major depressive symptoms and/or psychiatric condition.

The effect of antiscalant addition on calcium carbonate precipitation for a simplified synthetic brackish water reverse osmosis concentrate.

The primary limitations to inland brackish water reverse osmosis (RO) desalination are the cost and technical feasibility of concentrate disposal. To decrease concentrate volume, a side-stream process can be used to precipitate problematic scaling salts and remove the precipitate with a solid/liquid separation step. The treated concentrate can then be purified through a secondary reverse osmosis stage to increase overall recovery and decrease the volume of waste requiring disposal. Antiscalants are used in an RO system to prevent salt precipitation but might affect side-stream concentrate treatment. Precipitation experiments were performed on a synthetic RO concentrate with and without antiscalant; of particular interest was the precipitation of calcium carbonate. Particle size distributions, calcium precipitation, microfiltration flux, and scanning electron microscopy were used to evaluate the effects of antiscalant type, antiscalant concentration, and precipitation pH on calcium carbonate precipitation and filtration. Results show that antiscalants can decrease precipitate particle size and change the shape of the particles; smaller particles can cause an increase in microfiltration flux decline during the solid/liquid separation step. The presence of antiscalant during precipitation can also decrease the mass of precipitated calcium carbonate.

Increased levels of endothelial microparticles CD144 (VE-Cadherin) positives in type 2 diabetic patients with coronary noncalcified plaques evaluated by multidetector computed tomography (MDCT)

OBJECTIVE The combination of both morphological and cellular markers of subclinical atherosclerosis, in addition to conventional risk factors, may help to improve cardiovascular prevention in type 2 diabetic patients. The aim of our cross-sectional study was to evidence a putative increase in endothelial (EMP) or platelet (PMP) microparticles, in type 2 diabetic patients with coronary noncalcified plaques detected by multidetector CT (MDCT). METHODS AND RESULTS Microparticles and coronary MDCT were assessed in 56 type 2 diabetic patients with different cardiovascular risk levels. Both EMP (r=0.35, p=0.022) and PMP (rho=0.34, p=0.022) were correlated with hsCRP. EMP were elevated in patients with acute coronary syndromes (p=0.034). EMP count was significantly higher in the presence of noncalcified diseased segments (p=0.01). By contrast, there was no association between hsCRP and noncalcified atheroma. This increase in EMP in noncalcified diseased segment carriers remained borderline significant after adjustment for coronary heart disease and hsCRP. Conversely, there was no association of PMP count with noncalcified diseased segments and no difference in PMP count between patients with and without acute coronary syndrome. No significant association between either EMP and PMP counts and mixed or calcified diseased segments was observed. CONCLUSIONS We report for the first time an association between plasma EMP-CD144+ and coronary noncalcified plaques assessed by MDCT in a population of type 2 diabetic patients. EMP might be used as a surrogate marker of unstable plaques, and might help to improve cardiovascular prediction in diabetic patients with intermediate risk.

Savings and re-use of salts and water present in dye house effluents

Abstract Cotton dyeing using reactive dyes generates warm wastewater strongly colored, containing suspended solids,concentrated NaCl and widely varying acid amounts. Dyeing one kilogram of cotton with reactive dyes requires from70 to 150 L water, 0.6 kg NaCl and 40 g reactive dye. We have worked out a process for the treatment of used reactivedye baths which consists of 4 steps: pre-filtration, neutralization, nanofutration and reverse osmosis. At the end of this treatment a recyclable brine is obtained which contains the total salt added in the initial dye bath, pure waterwhich is reusable for further operations and a small volume of concentrated liquor containing hydrolyzed reactivedyes and dyeing auxiliaries. In this study, we used industrial effluents resulting directly from an industry of dyeing. All the types of dyestuffs used by the dyer were studied. The tests were first carried out on small volumes (15 L) then larger (300 L) to validate the process. No difference was found between re-dye obtained either by usual process orusing the brine recycled. Every step of the process was studied separately then together so as to optimize the whole process.