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Sludge foaming is a common problem in wastewater treatment plants negatively affecting operation of anaerobic digestion reactors. Therefore, in common practice, foam is removed from reactors without being fermented, leading to increase in sludge mass for disposal. However, foam is rich in lipids and can be a good source of methane if operational problems can be overcome. In this paper, in a two-stage experiment, we show that foam disintegration with free nitrous acid (FNA) can boost methane production and decrease foaming potential. In the first stage, the biochemical methane potential (BMP) of foam was evaluated to be higher by 19-63% (191-263NmL/gVS) than the BMP of waste activated sludge (WAS) (161 ± 1NmL/gVS) confirming previous assumptions. The main findings of the second stage (continuous experiments) are: (1) foam and WAS co-digestion leads to sludge stratification and thickened biomass accumulation in the upper part of the reactor, (2) FNA disintegration destroyed foam structure, resulting in lower biomass stratification and 14% higher methane production (134 mL/gVS) than observed in the reference reactor, (3) FNA disintegration of both substrates (foam and WAS) does not provide noticeable benefits in terms of biomass stratification. However, it does enhance methane production to 140 mL/gVS and sludge mineralization efficiency. A significantly higher impact of FNA on methane yield from foam than WAS was attributed to the high content of M.parvicella and the ability of these bacteria to adsorb and accumulate lipids. Anaerobic digestion of FNA disintegrated foam leads to substantial benefits in terms of methane production, reactor volume, and reagents consumption.

Biometrics is one of the basic detection techniques used in law enforcement activities on a daily basis. Like other techniques, it is constantly changing. This article aims to provide an overview of what was in the past, what is now, and what will be in the near future. It presents the selected methods of collecting some of the data, as well as the systems used to process them. In addition, practical guidance is provided on how individual biometric data should be collected and, for specific cases, it explains why the data collection procedure is carried out in one way and not another, and what it means for its subsequent processing. As problems sometimes arise during recovery of the material they have been presented together with an overview of the reasons for that. In addition to information on the technical aspects, the article also includes references to legal acts regulating issues related to biometrics.

The aim of this study was to determine the suitability of a rainwater harvesting system to cover the water demand for indoor hydroponic lettuce cultivation located in Wrocław (Poland). The analysis was performed on the basis of the recorded rainfall in Wrocław in 2000&ndash, 2019. The analyzed cultivation is located in a hall with an area of 300 m2, where the lettuce is grown vertically by the hydroponic method. The calculations of the rainwater harvesting (RWH) system were carried out considering the selection of the tank capacity for the collected water. The operation of the water storage is simulated using a yield after spillage (YAS) algorithm. It was evident that the proposed system might be an auxiliary system that relieves the water supply network or supports other water recovery systems (e.g., the water vapor condensation in a cross-flow heat exchanger operating as an element of the air conditioning system, proposed in Part 1 of this study). The harvesting system for the selected vertical farming indoor hall covers an average of 35.9% of water needs and allows a saving of 146,510 L of water annually for the cultivation. An average water demand coverage increases up to 90.4%, which allows a saving of 340,300 L per year when the RWH system is combined with water recovery from exhaust air from the hall.

Extraterrestrial colonization is a certain eventuality that would be nearly impossible without the efficient and robust resources of recovering life support systems. Knowledge of inputs is necessary for the development of such systems, especially for the first stages of design such as mass balancing and the selection of unitary processes. One of the most important inputs is blackwater, as this stream is the most polluted and rich in resources and needs to be treated and reused. In the paper, data from space missions and terrestrial sources concerning the flows, concentrations and loads in urine and feces are compared and analyzed. It is shown that results obtained during space missions are scarce and for many parameters no information is available. It is also shown how gravity influences the elemental composition of urine and feces. In contrast, data from terrestrial sources are abundant. The presented analysis shows that data from space and terrestrial systems are convergent for many parameters and that the available terrestrial data for those parameters can be used for mass balancing and unitary process selection without a high risk.

The combination of sidestream deammonification and bioaugmentation of the mainstream reactor using ammonia oxidizers from partial nitritation (PN) was not achieved before. This novel solution not only enables the efficient sidestream nitrogen removal, but also improves mainstream resistance to stress situations such as biomass washout or nitrogen overload. This feature is important for wastewater treatment plants (WWTPs) equipped with reject water deammonification as its implementation leads to lower nitrifier mass in the mainstream reactor and therefore diminish ability to cope with rapid increase in the loading rate (i.e. due to sidestream process failure). The proposed approach presents the use of the excess sludge from a modified PN process to boost the mainstream nitrification in unfavourable conditions. In a long-term laboratory experiment, the operation of an existing WWTP at low temperature was simulated in two reactors using real wastewater fluxes. One of them was augmented with the excess sludge from a PN reactor that treats reject water containing 20% of the WWTP N-load. The treatment efficiency in both reactors was tested under different nitrogen loading rates, as well as in the case of the of biomass loss. The bioaugmentation intensity was set according to the actual nitrogen load balance of the modelled WWTP, resulting in a daily seed volume only equal to 0.28% of the reactors' influent. Two incidents were simulated, where the nitrogen load increased by about 24.5% and 34%. In both cases, the nitrification efficiency in the non-augmented reactor dropped by about 45%, while the augmented reactor maintained efficient ammonium removal. The bioaugmentation effect was also noticeable during biomass washout — only in the non-augmented reactor nitrification was insufficient for over 60 days. These results undoubtedly show the possibility of combining two different approaches for sidestream nitrogen removal into one technology demonstrating the advantages of both component solutions.

This is the first study that identifies nitrogen loss and drier liquor parameters in a full scale sludge drying facility. Obtained data enabled proposing novel treatment based on deammonification process that allows not only nitrogen removal from drier liquor but also from gravity thickeners supernatant, the stream that is considered too cold for deammonification. The novel treatment approach is compared with nitrification/denitrification in activated sludge process in terms of greenhouse gas emissions. The nitrogen loss during drying was calculated based on two independent methods using full scale data from a long-term measurement campaign. According to results, 9.8–11.2% of nitrogen from dewatered sludge, or 4.9–5.5 g N/kg of TS, was vaporized during drying and then was captured through the purification of process air in drier liquor. Overall, over 40 tN/a from drier liquor and 77 tN/a from gravity thickeners supernatant is recirculated to the activated sludge process and results in the additional emission of 670 426 kg CO2e/a when nitrification/denitrification is applied. That can be lowered by 398 858 kgCO2e/a when the novel approach is considered.

Since the mid-1990s of the last century, DNA research has become synonymous with scientific progress in forensics. DNA profiling based on the analysis of STR loci polymorphism is considered the gold standard and constitutes an invaluable source of information, enabling, inter alia, the identification of suspects and wanted persons and the identification of corpses, including that based on kinship analysis. However, such analysis is laborious and time-consuming. To reduce this inconvenience, a technology described as rapid DNA has been developed.

Growing efforts are currently being addressed by ESA to support the next-generation of space professionals and researchers. ESA’s Education Office is successfully creating a network of individuals sharing and promoting dedication to space technology on the basis of the values of trust and cooperation. In this framework, students and early-career researchers can rely on experienced tutors and professionals to improve their area of expertise effectively.This paper provides a detailed insight of the utterly positive return on the careers of who had first-hand experience of ESA’s Academy activities, both through training courses and hands-on projects (as REXUS/BEXUS program). The authors have contributed in many different and unexpected ways to the advancement of their fields of study and/or work. Accordingly, the outcome of this paper is a vivid and varied patchwork of people from various professional backgrounds reflecting on their experience and thus depicting the actual situation of the young European generation in the space sector.What links the authors of this paper together is their participation in the five-day didactic training course “Concurrent Engineering Workshop” held in May 2018 at ESA ESEC facility. During the workshop, the students worked as a team to develop a mission architecture for a satellite impacting the Moon surface, surviving and deploying a scientific rover: LIAR mission (Lunar Impactor And Rover). The concurrent design study offered a realistic environment to work within, amidst different scientific backgrounds and expertise, thus leading to a challenging and rewarding learning opportunity. This paper will also discuss the Concurrent Engineering development cycle, by giving an overview of main carried out activities to present the most important lessons learned.During their involvement in ESA’s educational programs,the participants had been given a precious perspective on the tools and strategies behind ESA’s space missions. One year later, the participants are still in contact and committed to fruitful collaboration aimed, among other things, at creating a space start-up. The example highlights that educational support constantly proves to be the key to a successful and prolific future of space sector by encouraging and technically challenging passionate students.

Protozoa are significant components of activated sludge which purify the effluent of free swimming bacteria as well as trigger floc formation. In addition, their presence is often used as an indicator of process quality. In classical models, the impact of protozoa on biomass is implicitly included in the bacteria decay rates, which in most cases gives a sufficient level of detail. However, modeling of certain processes, such as bioaugmentation, would greatly benefit from a functional model including protozoa grazing explicitly. To further establish the approach for protozoa grazing modeling, the authors have summarized the current state of knowledge in this area, as well as pointed out crucial elements that have to be considered. Aspects of the endogenous oxygen uptake rate (OUR), the preference of protozoa towards particular bacteria groups, and alternative sources of nutrient are presented and discussed. Based on the drawn conclusions, the authors have proposed a modeling concept towards protozoa grazing that will maintain both stability and accordance with generally accepted activated sludge models (ASM). The presented approach includes a division of each bacteria group into dispersed and flocculated bacteria that emerge from newly formed flocculation and deflocculation processes, with a different level of grazing on both components.

Urine nitrification is one of the possibilities for the future recovery of water and elements for soilless crop production in space systems. The start-up of artificial urine nitrification was conducted for over 85 days in a sequencing batch reactor (SBR). Two free ammonia (FA) incidents occurred, which gave the opportunity to demonstrate the impressive ability of nitrifiers to resist temporary inhibition by FA without long lasting adverse effects. The failures led to very high FA concentrations of 280 and 84 gN-NH3/m3, respectively. Sludge was exposed to FA for 19 and 27 h. It was possible to restore nitrification with simple remedy actions (dilution and pH restoration). No inhibitory effects on the nitrification rate were seen after implementation of the remedy actions and the nitrification rate increased considerably (up to 300% of the pre-failure value) due to decrease in salinity. After a few days of normal operation and salt concentration, the nitrification rate returned to the pre-failure values in both cases.

In order to be able to permanently settle other celestial bodies, it is necessary to create an efficient and closed life support system. Such a system will allow high autonomy and significantly reduce operating costs in a future colony. Grey water is a major waste stream in terms of the water volume generated by colonists, and its reuse is necessary. One possibility is to reuse it in aeroponic cultivation without treatment, which will in turn reduce its transported mass. The article focuses on water, carbon and other elements (N, P, K, Ca, Mg, Na) that are included in the mass balance of part of a life support system containing the aeroponic cultivation of lettuce that is supplied with clean water and water contaminated with one surfactant, crewmembers and a urine nitrification reactor. Three surfactants (Sodium Laureth Sulfate (SLES), Sodium Dodecylbenzene Sulfonate (SDBS), Sodium Methyl Cocoyl Taurate (SMCT)) in two concentrations, reflecting concentrated and diluted grey water, were tested. The growth of lettuce exposed to low concentrations (ca. 0.07 g·L−1) of surfactants has a moderate (SLES, SMCT) or no (SDBS) impact on the mass of grown plant. Exposition to high concentrations (>1.0 g·L−1) led to the complete failure of cultivation (SDBS, SMCT) or to very limited growth (SLES). In all cases, exposition to surfactants in low concentrations causes differences in the mineral composition of lettuce. In most cases, crops cultivated on water containing surfactants were characterized by a decreased harvest index (the ratio of edible biomass to total biomass). For the most cultivations the relative mass balances of water, C, N, P and K were generally unaffected by surfactants, while for Ca, Mg and Na, noticeable differences occurred. The data provided in the paper gives clues about which surfactant could be used in a future extraterrestrial colony.

The development in the field of space engineering is aimed at achieving another milestone, which is the creation of an extraterrestrial colony on, for example, Mars. Missions of this kind will be long-term and long-distance, which results in the need to design systems with a high degree of self-sufficiency. It is synonymous with high recovery resources. This article is a concept proposed for the needs of the Mar Colony Prize competition – Design The First Human Settlement On Mars, created by The Mars Society. This competition assumed designing highly-autonomous base for 1000 people. This means, that all environmental systems must be connected with each other and work in closed loops. In this paper four main environmental systems are proposed and characterized. The state of art of each subsystems technology is presented.

Design of efficient and robust life support systems will require huge effort. In closed systems such as future extra-terrestrial colonies or spaceships, all produced wastes will have to be perfectly purified and all resources will have to be recovered. This isn’t possible now even in life support systems built on Earth. Future extra-terrestrial closed life support system will have to be robust and simple as possible to decrease risk of failure and transport costs. One of the attempts to simplify the treatment of wastes is to use greywater as water source in soil-less cultivation without pretreatment. In this paper results of two lab-scale aeroponic experiments are shown. These experiments were aimed at determining possibility of using grey water directly as water source for aeroponic cultivation of lettuce. Two surfactants (SBDS,SMCT) with concentrations varying from 0.08 to 1.5 g/L and model grey water (containing SLES surfactant) were tested. Experiments shown that high concentrations of SBDS and SMCT are detrimental for lettuce growth while similar concentration of SLES inhibit but do not stop lettuce growth. With lower concentrations of surfactants growth of lettuce is possible. Moreover results shows decrease in surfactants mass in model grey water used as nutrient solution which may indicate development of bacteria in root zone that are able to use surfactants as substrates.

One of the crucial steps in the development of self-sufficient extra-terrestrial human colonies is water and biomass management. One of the attempts to simplify the treatment scheme is to directly implement greywater into soil-less cultivation as no greywater treatment unit would be necessary. In this case, the most essential key factor is the influence of surfactants. In this paper, an analysis of various experiment designs is investigated and shown. While full factorial design of experiment would require more than 500 000 tests, with duration of at least 30 days each, an approach to reduce this number to a total of 5 experiments is shown in this paper for initial experiments.

The article presents the concept of experimental research system to investigate aeroponic cultivation in microgravity condition. The main scientific objective is to define the forces acting in droplet-root system exposed to microgravity conditions especially the adhesion and cohesion phenomena. The concept of a research platform is presented in this paper and includes electrical, hydraulic and optical system.

The article presents a concept of a biomass cultivation and a wastewater treatment system in future Planetary Base (PB) e.g. Moon or Mars, designed for eight-person crew. These two subsystems are part of Life Support System (LSS), which aims at providing proper environmental condition for human habitation.

The article presents a concept of an EWS (early warning system) for toxic sewage detection upstream from Wroclaw Wastewater Treatment Plant. It includes design and construction of three toxicity warning stations, situated in municipal sewage system. Early detection of toxic contaminants provides time for corrective actions. Wastewater toxicity level is based on activated sludge OUR (Oxygen Uptake Rate) measurement. The database of normal level of activated sludge OUR is collected during the measurement initial phase. Hence, if toxic event occurs, device will measure decreased OUR value and WWTP operators will be alarmed. Additionally, flow measurement is carried out. It allows to estimate the volume of a toxic stream. Development of the early warning system requires solving minimum six different scientific and technical issues and is a subject for a complex research project.