Using off-gas testing to map mixing gradients and audit blower capacity.

A water resource recovery facility sited in a region at a high elevation has experienced the effects of over-designing its blowers. In this case study, we used off-gas analysis and site-specific power tariffs to quantify actual process loading and air requirements, and we quantitatively evaluated various options for blower replacement or upgrade. Off-gas analysis mapped the oxygen uptake rate at the surface of the tank, suggesting that the tanks were not evenly loaded across their sections.

Increased AXL myeloid cells as pathognomonic marker in Langerhans cell histiocytosis and Langerin expression dependence of mTOR inhibition.

Langerhans cell histiocytosis (LCH) is characterized by an expansion and accumulation of pathological histiocytes expressing langerin (CD207) and CD1a in different organs under an inflammatory milieu. The origin of pathognomonic precursors of LCH is widely debated, but monocytes and pre-dendritic cells (pre-DC) play a significant role. Remarkably, we found an expansion of AXL cells in the CD11c subset of patients with active LCH, which also express the pathognomonic CD207 and CD1a.

Modeled and measured SARS-CoV-2 virus in septic tank systems for wastewater surveillance.

SARS-CoV-2 wastewater surveillance (WWS) at wastewater treatment plants (WWTPs) can reveal sewered community COVID-19 prevalence. For unsewered areas using septic tank systems (STSs) or holding tanks, how to conduct WWS remains unexplored. Here, two large STSs serving Zuma Beach (Malibu, CA) were studied.

Oxygen transfer comparison of jets and coarse bubble aeration in concentrated sludge.

The South Truckee Meadows Water Reclamation Facility (STMWRF) in Washoe County, Nevada, commissioned a biosolids facility with jet aerated aerobic digestion. The jet aerators were not performing as designed, so they were tested on-site in the new tanks in both clean and process water according to ASCE standards. The aerators failed by substantial margins.

Seasonal occurrence and fate of nanoparticles in two biological wastewater treatment plants in Southern California.

Nano-sized particles in wastewater are generally considered colloids, but their production and size distribution are not well understood. Organic nano-sized particles are more abundant than engineered nanomaterials in wastewater, where they may cause membrane fouling, harbor pathogens, and transport contaminants to the environment. To our knowledge, this study is the first to examine the seasonal behavior, removal, and the quantity and size of suspended particles (both unfiltered and filtered through a 450 nm filter) at multiple points within different processes along two water resource recovery facilities (WRRFs, formerly wastewater treatment plants).

Monitoring Circulating CD207CD1a Cells in Langerhans Cell Histiocytosis and Clinical Implications.

Langerhans cell histiocytosis (LCH) is a disorder characterized by an abnormal accumulation of CD207 and CD1a cells in almost any tissue. Currently, there is a lack of prognostic markers to follow up patients and track disease reactivation or treatment response. Putative myeloid precursors CD207 and CD1a cells were previously identified circulating in the blood.

Microplastics separation using stainless steel mini-hydrocyclones fabricated with additive manufacturing.

Microplastics have been widely detected in natural and engineered water systems and removing microplastics from various water matrices has become a major challenge. Mini-hydrocyclones (MHCs) have been previously applied to separate mediums of different phases. Given MHCs' capability of separating fine particles from liquid phase, three MHCs were designed and fabricated in stainless steel with 3D printing.

The third route: A techno-economic evaluation of extreme water and wastewater decentralization.

Water systems need to become more locally robust and sustainable in view of increased population demands and supply uncertainties. Decentralized treatment is often assumed to have the potential to improve the technical, environmental, and economic performance of current technologies. The techno-economic feasibility of implementing independent building-scale decentralized systems combining rainwater harvesting, potable water production, and wastewater treatment and recycling was assessed for six main types of buildings ranging from single-family dwellings to high-rise buildings.

Dynamic alpha factors: Prediction in time and evolution along reactors.

The performance of aeration - one of the most costly processes at water resource recovery facilities - is heavily impacted by actual wastewater characteristics which are commonly taken into account using the alpha factor (α). This factor varies depending on hydraulic and organic loading; such variance includes both time and spatial fluctuations. In standard design practice, it is often considered as a fixed number, or at best, a predefined time series.

Integrating Virus Monitoring Strategies for Safe Non-potable Water Reuse.

Wastewater reclamation and reuse have the potential to supplement water supplies, offering resiliency in times of drought and helping meet increased water demands associated with population growth. Non-potable water reuse represents the largest potential reuse market. Yet economic constraints for new water reuse infrastructure and safety concerns due to microbial water quality, and especially viral pathogen exposure, limit widespread implementation of water reuse.

A proof-of-concept experimental study for vacuum-driven anaerobic biosolids fermentation using the IntensiCarb technology.

This study demonstrates the potential of an innovative anaerobic treatment technology for municipal biosolids (IntensiCarb), which relies on vacuum evaporation to decouple solids and hydraulic retention times (SRT and HRT). We present proof-of-concept experiments using primary sludge and thickened waste activated sludge (50-50 v/v mixture) as feed for fermentation and carbon upgrading with the IntensiCarb unit. IntensiCarb fully decoupled the HRT and SRT in continuously stirred anaerobic reactors (CSAR) to achieve two intensification factors, that is, 1.

How elevation dictates technology selection in biological wastewater treatment.

Most wastewater treatment facilities are built using procedures from previous designs which are predominantly from sites and regions not located at high elevation. Recognizing this limitation, we assessed the effects of elevation above sea level on the suitability of process configurations and technologies as well as their associated energy costs. Using the International Water Association (IWA) benchmark simulation model No.

Quantification of energy and cost reduction from decreasing dissolved oxygen levels in full-scale water resource recovery facilities.

Aeration systems often lack the efficiency to maintain a desired residual dissolved oxygen (DO) concentration in the tank in part because little consideration is given to the dynamic daily and seasonal loading conditions. Although advanced aeration controllers exist, the majority of plants have DO set points typically based on common practice and literature values rather than site-specific conditions, which can result in DO set points higher than those necessary to meet treatment objectives. DO set point reduction strategies have primarily been proposed through either static or dynamic simulations.

Soft Sensing for On-Line Fault Detection of Ammonium Sensors in Water Resource Recovery Facilities.

The increasing demand for online sensors applied to advanced control strategies in water resource recovery facilities has resulted in the increasing investigation of fault-detection methods to improve the reliability of sensors installed in harsh environments. The study herein focuses on the fault detection of ammonium sensors, especially for effluent monitoring, given their potential in ammonium-based aeration control applications. An artificial neural network model was built to predict the ammonium content in the effluent by employing the information from five other sensors installed in the activated sludge tank: NH, pH, ORP, DO, and TSS.

Effects of flow velocity and bubble size distribution on oxygen mass transfer in bubble column reactors-A critical evaluation of the computational fluid dynamics-population balance model.

Computational fluid dynamics (CFD) is used to simulate a bubble column reactor operating in the bubbly (homogenous) regime. The Euler-Euler two-fluid model, integrated with the population balance model (PBM), is adopted to compute the flow and bubble size distribution (BSD). The CFD-PBM model is validated against published experimental data for BSD, global gas holdup, and oxygen mass transfer coefficient.

Dynamic load shifting for the abatement of GHG emissions, power demand, energy use, and costs in metropolitan hybrid wastewater treatment systems.

The installation of satellite water resource recovery facilities (WRRFs) has strengthened the ability to provide cheap and reliable recycled water to meet the increasing water demand of expanding cities. As a result, recent studies have attempted to address the problem of how to optimally integrate satellite systems with other sectors of the urban sphere, such as the local economy, the power supply, and the regional carbon footprint. However, such studies are merely based on the spatial domain, thus neglecting potential time-dependent strategies that could further improve the sustainability of metropolitan water systems.

Comparison of methods for nitrous oxide emission estimation in full-scale activated sludge.

Nitrous oxide (NO) gas transfer was studied in a full-scale process to correlate liquid phase NO concentrations with gas phase NO emissions and compare methods of determining the volumetric mass transfer coefficient, Ka. Off-gas and liquid phase monitoring were conducted at the Viikinmäki wastewater treatment plant (WWTP) over a two-week period using a novel method for simultaneous measurement of dissolved and off-gas NO and O from the same location. Ka was calculated with three methods: empirically, based on aeration superficial velocity, from experimentally determined O Ka, and using a static value of best fit.

Dynamic impact of cellulose and readily biodegradable substrate on oxygen transfer efficiency in sequencing batch reactors.

Aeration is a major contributor to the high energy demand in municipal wastewater treatment plants. Thus, it is important to understand the dynamic impact of wastewater characteristics on oxygen transfer efficiency to develop suitable control strategies for minimizing energy consumption since aeration efficiency is influenced by the biodegradation of pollutants in the influent. The real-time impact of acetate as a readily biodegradable substrate and cellulose as a slowly biodegradable substrate were studied at different operational conditions.

Stem cell transplantation for children with hemophagocytic lymphohistiocytosis: results from the HLH-2004 study.

We report the largest prospective study thus far on hematopoietic stem cell transplantation (HSCT) in hemophagocytic lymphohistiocytosis (HLH), a life-threatening hyperinflammatory syndrome comprising familial/genetic HLH (FHL) and secondary HLH. Although all patients with HLH typically need intensive anti-inflammatory therapy, patients with FHL also need HSCT to be cured. In the international HLH-2004 study, 187 children aged <18 years fulfilling the study inclusion criteria (5 of 8 diagnostic criteria, affected sibling, or molecular diagnosis in FHL-causative genes) underwent 209 transplants (2004-2012), defined as indicated in patients with familial/genetic, relapsing, or severe/persistent disease.

When the fourth water and digital revolution encountered COVID-19.

The ongoing COVID-19 pandemic is, undeniably, a substantial shock to our civilization which has revealed the value of public services that relate to public health. Ensuring a safe and reliable water supply and maintaining water sanitation has become ever more critical during the pandemic. For this reason, researchers and practitioners have promptly investigated the impact associated with the spread of SARS-CoV-2 on water treatment processes, focusing specifically on water disinfection.

Increasing oxygen transfer efficiency through sorption enhancing strategies.

The link between aeration efficiency and biosorption capacity in water resource recovery facilities was extensively investigated, with special emphasis on wastewater characteristics and the development of strategies to maximize adsorption. Biosorption of oxygen transfer inhibitors (i.e.

A composite indicator approach to assess the sustainability and resilience of wastewater management alternatives.

Evaluating the sustainability of wastewater management alternatives is a challenging task. This paper proposes an innovative methodology to assess and compare the sustainability of four wastewater management alternatives: a) centralised water resource recovery facility (WRRF) based on activated sludge (AS); b) centralised WRRF with membrane bioreactors (MBR); c) decentralised WRRFs with upflow anaerobic sludge blanket reactors and trickling filters; d) centralised-decentralised hybrid system. In doing so, a composite indicator embracing total annual equivalent costs, carbon emission intensity, eutrophication and resilience (based on robustness and rapidity metrics) was developed using the analytic hierarchy process (AHP) method.

Oxygen transfer and plant-wide energy assessment of primary screening in WRRFs.

Primary screening is gaining interest as a method to achieve removal performances comparable to primary clarification while reducing the footprint and increasing operational elasticity. Aeration efficiency indicators in a pilot sequential batch reactor (SBR) and a full scale water resource recovery facility (WRRF) were investigated after the implementation of rotating belt filters/screens (RBF). To compare the impact between screened (350 μm) and nonscreened primary influent, two identical treatment lines were monitored using off-gas and respirometric measurements.

The Fourth-Revolution in the Water Sector Encounters the Digital Revolution.

The so-called fourth revolution in the water sector will encounter the Big data and Artificial Intelligence (AI) revolution. The current data surplus stemming from all types of devices together with the relentless increase in computer capacity is revolutionizing almost all existing sectors, and the water sector will not be an exception. Combining the power of Big data analytics (including AI) with existing and future urban water infrastructure represents a significant untapped opportunity for the operation, maintenance, and rehabilitation of urban water infrastructure to achieve economic and environmental sustainability.

Relationship between manual air valve positioning, water quality and energy usage in activated sludge processes.

Diffused aeration is the most implemented method for oxygen transfer in municipal activated sludge systems and governs the economics of the entire treatment process. Empirical observations are typically used to regulate airflow distribution through the adjustment of manual valves. However, due to the associated degrees of freedom, the identification of a combination of manual valves that optimizes all performance criteria is a complex task.