Rapid removal of ammonium from domestic wastewater using polymer hydrogels

To date, technologies to recover ammonium from domestic wastewater from the mainstream have not found widespread application. This is largely due to the low ammonium concentrations in these wastewater streams. This paper reports on the use of polymer hydrogels for rapid sorption of ammonium from domestic wastewater coupled with efficient regeneration by mild acid washing. The sorption capacity of the hydrogel was 8.8-32.2 mg NH4-N/g, which corresponds to removal efficiencies ranging from 68% to 80% NH4-N, increasing proportionally with the initial ammonium concentration. It was, however, unaffected by changes in pH, as the sorption capacity remained constant from pH 5.0-8.0. Importantly, effective regeneration of the hydrogels under mildly acidic conditions (i.e. pH 4.0) was demonstrated with minimal loss in sorption performance following multiple sorption/desorption cycles. Overall, this study highlights the potential of low-cost polymer hydrogels for achieving mainstream ammonium recovery from domestic wastewater

A novel electrochemical process for the recovery and recycling of ferric chloride from precipitation sludge

During wastewater treatment and drinking water production, significant amounts of ferric sludge (comprising ferric oxy-hydroxides and FePO4) are generated that require disposal. This practice has a major impact on the overall treatment cost as a result of both chemical addition and the disposal of the generated chemical sludge. Iron sulfide (FeS) precipitation via sulfide addition to ferric phosphate (FePO4) sludge has been proven as an effective process for phosphate recovery. In turn, iron and sulfide could potentially be recovered from the FeS sludge, and recycled back to the process. In this work, a novel process was investigated at lab scale for the recovery of soluble iron and sulfide from FeS sludge. Soluble iron is regenerated electrochemically at a graphite anode, while sulfide is recovered at the cathode of the same electrochemical cell. Up to 60±18% soluble Fe and 46±11% sulfide were recovered on graphite granules for up-stream reuse. Peak current densities of 9.5±4.2Am-2 and minimum power requirements of 2.4±0.5kWhkgFe-1 were reached with real full strength FeS suspensions. Multiple consecutive runs of the electrochemical process were performed, leading to the successful demonstration of an integrated process, comprising FeS formation/separation and ferric/sulfide electrochemical regeneration

Serum lipids, apoproteins and nutrient intake in rural Cretan boys consuming high-olive-oil diets

A high intake of olive oil has produced high levels of high-density and low levels of low-density lipoprotein cholesterol in short-term dietary trials. To investigate long-term effects of olive oil we have studied the diet and serum lipids of boys in Crete, where a high olive oil consumption is the norm. Seventy-six healthy rural Cretan boys aged 7–9 years were studied. The diet was assessed by a 2-day dietary recall. Blood was collected according to a standardized protocol and sera were analyzed in a rigidly standardized laboratory. The mean daily intake of energy was 11.0 MJ (2629 kcal). The intake of fat (45.0% of energy) and oleic acid (27.2% of energy) was high, and that of saturated fat low (10.0% of energy), reflecting a high consumption of olive oil. The high consumption of olive oil was confirmed by a high proportion of oleic-acid (27.1 %) in serum cholesteryl fatty acids. Mean concentration of serum total cholesterol was 4.42 mmol 1−1 (171 mg dl−1 ), of HDL-cholesterol 1.40 mmol 1−1 (54 mg dl−1), of serum triglycerides 0.59 mmol I−1 (52 mg dl−1 ), of apo-A1 1210 mg 1−1 and of LDL apo-B 798 mg 1−1. The body mass index of the Cretan boys (18.2 kg m−2) was on average 2 kg m−2 higher than that of boys from other countries. Contrary to our expectation, the Cretan boys did not show a more favourable serum lipoprotein pattern than boys from more westernized countries studied previously using the same protocol. Our hypothesis that a typical, olive-oil-rich Cretan diet causes a relatively high HDL- to total cholesterol ratio is not supported by the present findings

Ergonomics in control room design

Ergonomic contributions in early design phases of large-scale projects are not yet common practice. In this paper a description is given of a control room design project, in which ergonomists participated from the very beginning. First, the scope of the project and a methodical approach to the design are introduced. This is followed by an overview of the activities of ergonomists in this particular project. The second part of this paper concerns the experiences with this methodical approach and design practice. These are discussed by the former control room project manager, one of the ergonomists, the interior architect and a user representative. It is concluded that it is possible to include ergonomics as well as user participation in every design phase without getting behind on time schedules and keeping within available budgets. A lot of useful design and engineering data could be derived from the situation analysis in the existing situation and the full-scale mock-up evaluation that was carried out. Besides workplace design, job design (operator workload) and work organization design were essential to the success of the project

Microbial technology with major potentials for the urgent environmental needs of the next decades

Several needs in the context of the water-energy-food nexus will become more prominent in the next decades. It is crucial to delineate these challenges and to find opportunities for innovative microbial technologies in the framework of sustainability and climate change. Here, we focus on four key issues, that is the imbalance in the nitrogen cycle, the diffuse emission of methane, the necessity for carbon capture and the deterioration of freshwater reserves. We suggest a set of microbial technologies to deal with each of these issues, such as (i) the production of microbial protein as food and feed, (ii) the control of methanogenic archaea and better use of methanotrophic consortia, (iii) the avoidance of nitrification and (iv) the upgrading of CO2 to microbial bioproducts. The central message is that instead of using crude methods to exploit microorganisms for degradations, the potentials of the microbiomes should be used to create processes and products that fit the demands of the cyclic market economy

See no Evil: Challenges of security surveillance and monitoring

While the development of intelligent technologies in security surveillance can augment human capabilities, they do not replace the role of the operator entirely; as such, when developing surveillance support it is critical that limitations to the cognitive system are taken into account. The current article reviews the cognitive challenges associated with the task of a CCTV operator: visual search and cognitive/perceptual overload, attentional failures, vulnerability to distraction, and decision-making in a dynamically evolving environment. While not directly applied to surveillance issues, we suggest that the NSEEV (noticing – salience, effort, expectancy, value) model of attention could provide a useful theoretical basis for understanding the challenges faced in detection and monitoring tasks. Having identified cognitive limitations of the human operator, this review sets out a research agenda for further understanding the cognitive functioning related to surveillance, and highlights the need to consider the human element at the design stage when developing technological solutions to security surveillance

Diet, faecal pH and colorectal cancer.

We suggest that a lower faecal pH may be correlated with a lower mortality of large-bowel cancer and that faecal pH should always be considered in epidemiological studies on the role of diet in colon carcinogenesis

Rapid Assessment of Floating Macroplastic Transport in the Rhine

Most marine litter pollution is assumed to originate from land-based sources, entering the marine environment through rivers. To better understand and quantify the risk that plastic pollution poses on aquatic ecosystems, and to develop effective prevention and mitigation methods, a better understanding of riverine plastic transport is needed. To achieve this, quantification of riverine plastic transport is crucial. Here, we demonstrate how established methods can be combined to provide a rapid and cost-effective characterization and quantification of floating macroplastic transport in the River Rhine. We combine visual observations with passive sampling to arrive at a first-order estimate of macroplastic transport, both in number (10–75 items per hour) and mass per unit of time (1.3–9.7 kg per day). Additionally, our assessment gives insight in the most abundant macroplastic polymer types the downstream reach of the River Rhine. Furthermore, we explore the spatial and temporal variation of plastic transport within the river, and discuss the benefits and drawbacks of current sampling methods. Finally, we present an outlook for future monitoring of major rivers, including several suggestions on how to expand the rapid assessment presented in this paper.</p

Autotrophic nitrogen assimilation and carbon capture for microbial protein production by a novel enrichment of hydrogen-oxidizing bacteria

Domestic used water treatment systems are currently predominantly based on conventional resource inefficient treatment processes. While resource recovery is gaining momentum it lacks high value end-products which can be efficiently marketed. Microbial protein production offers a valid and promising alternative by upgrading low value recovered resources into high quality feed and also food. In the present study, we evaluated the potential of hydrogen-oxidizing bacteria to upgrade ammonium and carbon dioxide under autotrophic growth conditions. The enrichment of a generic microbial community and the implementation of different culture conditions (sequenced batch resp. continuous reactor) revealed surprising features. At low selection pressure (i.e. under sequenced batch culture at high solid retention time), a very diverse microbiome with an important presence of predatory Bdellovibrio spp. was observed. The microbial culture which evolved under high rate selection pressure (i.e. dilution rate D = 0.1 h) under continuous reactor conditions was dominated by Sulfuricurvum spp. and a highly stable and efficient process in terms of N and C uptake, biomass yield and volumetric productivity was attained. Under continuous culture conditions the maximum yield obtained was 0.29 g cell dry weight per gram chemical oxygen demand equivalent of hydrogen, whereas the maximum volumetric loading rate peaked 0.41 g cell dry weight per litre per hour at a protein content of 71%. Finally, the microbial protein produced was of high nutritive quality in terms of essential amino acids content and can be a suitable substitute for conventional feed sources such as fishmeal or soybean meal

Carbon emission avoidance and capture by producing in-reactor microbial biomass based food, feed and slow release fertilizer : potentials and limitations

Jo De Vrieze is supported as postdoctoral fellow from the Research Foundation Flanders (FWO-Vlaanderen). IP, KR and WV acknowledge support from the Australian Research Council (ARC), project DP170102812. KR acknowledges support from the Research Foundation Flanders (FWO-Vlaanderen), project G018814N and Interreg project EnOP. The input from PS contributed to the following projects: DEVIL [NE/M021327/1], MAGLUE [EP/M013200/1], U-GRASS [NE/M016900/1], Assess-BECCS [funded by UKERC] and Soils-R-GRREAT [NE/P019455/1].Peer reviewedPostprin