Nutrient management in aquaponics : comparison of three approaches for cultivating lettuce, mint and mushroom herb

Nutrients that are contained in aquaculture effluent may not supply sufficient levels of nutrients for proper plant development and growth in hydroponics; therefore, they need to be supplemented. To determine the required level of supplementation, three identical aquaponic systems (A, B, and C) and one hydroponic system (D) were stocked with lettuce, mint, and mushroom herbs. The aquaponic systems were stocked with Nile tilapia. System A only received nutrients derived from fish feed; system B received nutrients from fish feed as well as weekly supplements of micronutrients and Fe; system C received the same nutrients as B, with weekly supplements of the macronutrients, P and K; in system D, a hydroponic inorganic solution containing N, Ca, and the same nutrients as system C was added weekly. Lettuce achieved the highest yields in system C, mint in system B, and mushroom herb in systems A and B. The present study demonstrated that the nutritional requirements of the mint and mushroom herb make them suitable for aquaponic farming because they require low levels of supplement addition, and hence little management effort, resulting in minimal cost increases. While the addition of supplements accelerated the lettuce growth (Systems B, C), and even surpassed the growth in hydroponic (System C vs. D), the nutritional quality (polyphenols, nitrate content) was better without supplementation

Wastewater treatment in the urban environment

Constructed wetlands are a valid option for wastewater treatment even in urban areas. In the city, they can be implemented in roof tops, abandoned industrial areas, vertical surfaces of buildings, backyards, porches and public parks. In the suburbs, greywater can be treated in private gardens and reused for irrigation. The performance and control restraints often found disappointing in nature-based systems have been overcome in the past two decades: current systems achieve effluent qualities similar to conventional sewage treatment plants. With area requirements expected to come down to 2.0 m2 per p.e. they would need only two or three times more space. To the core task of treating wastewater they add valuable ecosystem services like micro-climate regulation, rainwater retention, production of renewable energy and/or food, air filtering, noise reduction and recreational values as biotopes with flora and fauna. They represent a new philosophy of dealing with wastes: recycling of nutrients from a valuable resource instead of mere disposal. The new concepts of closing loops call for a more integrated approach represented by the ecological engineer. With its expertise in landscape design and plant usage, horticulture is a key science to promote ecological engineering

The multifunctional aquaponic system at ZHAW used as research and training lab

Aquaponics plays a part in promoting sustainable development on different levels in society, and its use is becoming ever more widespread. However, there are not enough trained specialists yet to build and operate such systems. The aim of this paper is to highlight the role of institutions of higher education – like ZHAW – can play to mitigate this deficit. ZHAW has the ability to execute applied research, teaching on BSc and MSc level, and is aiming to increase societal added value concerning education and health. Each of these levels has different demands on the aquaponic system concerning a multitude of factors, such as access, size, construction, climate control, diversity of production methods, recycling and closed loop systems, provision of energy from renewable sources and rainwater harvesting, treatment and use. To evaluate how these objectives are reached, the requirements on the system originating from each level are defined. These are used to evaluate the aquaponic system that was built and operated at ZHAW. Other aquaponic systems in use are compared to the ZHAW system, using the same evaluation criteria. The results show that the ZHAW Aquaponics Lab can reach all target levels, if the aquaponic farm of its spin-off company UrbanFarmers is viewed as an extension of it

Prognostic factors in patients with acute mesenteric ischemia-novel tools for determining patient outcomes

BACKGROUND Acute mesenteric ischemia (AMI) is a devastating disease with poor prognosis. Due to the multitude of underlying factors, prediction of outcomes remains poor. We aimed to identify factors governing diagnosis and survival in AMI and develop novel prognostic tools. METHODS This monocentric retrospective study analyzed patients with suspected AMI undergoing imaging between January 2014 and December 2019. Subgroup analyses were performed for patients with confirmed AMI undergoing surgery. Nomograms were calculated based on multivariable logistic regression models. RESULTS Five hundred and thirty-nine patients underwent imaging for clinically suspected AMI, with 216 examinations showing radiological indication of AMI. Intestinal necrosis (IN) was confirmed in 125 undergoing surgery, 58 of which survived and 67 died (median 9 days after diagnosis, IQR 22). Increasing age, ASA score, pneumatosis intestinalis, and dilated bowel loops were significantly associated with presence of IN upon radiological suspicion. In contrast, decreased pH, elevated creatinine, radiological atherosclerosis, vascular occlusion (versus non-occlusive AMI), and colonic affection (compared to small bowel ischemia only) were associated with impaired survival in patients undergoing surgery. Based on the identified factors, we developed two nomograms to aid in prediction of IN upon radiological suspicion (C-Index = 0.726) and survival in patients undergoing surgery for IN (C-Index = 0.791). CONCLUSION As AMI remains a condition with high mortality, we identified factors predicting occurrence of IN with suspected AMI and survival when undergoing surgery for IN. We provide two new tools, which combine these parameters and might prove helpful in treatment of patients with AMI

[COMMODE] a large-scale database of molecular descriptors using compounds from PubChem

BACKGROUND: Molecular descriptors have been extensively used in the field of structure-oriented drug design and structural chemistry. They have been applied in QSPR and QSAR models to predict ADME-Tox properties, which specify essential features for drugs. Molecular descriptors capture chemical and structural information, but investigating their interpretation and meaning remains very challenging. RESULTS: This paper introduces a large-scale database of molecular descriptors called COMMODE containing more than 25 million compounds originated from PubChem. About 2500 DRAGON-descriptors have been calculated for all compounds and integrated into this database, which is accessible through a web interface at http://commode.i-med.ac.at

Potential of algae turf scrubbers (ATS™) for elimination of phosphorus from swimming ponds

Algal Turf Scrubbers (ATS) are water treatment devices that use light and nutrients in the (waste)water to grow periphyton community; undesirable chemicals are removed by physical, chemical and biological processes. So far, most ATS systems were operated in water bodies with relatively high nutrient concentrations. Little is known about the performance of ATS under low concentration of phosphorous (P), yet there are potential applications where such conditions are met. The paper presents a series of experiments that focus on the implementation of small-scale ATS systems to eliminate P from natural swimming ponds (SP). SPs are typically subject to fluctuating P concentrations and require the maintenance of very low levels of P (< 10 μg L-1) in order to prevent undesirable algal growth. ATS systems proved to be capable of maintaining such low levels, both in laboratory and field conditions

Microbial diversity in different compartments of an aquaponics system

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)Aquaponics is a solution for sustainable production of fish and plants in a single semi-closed system, where nutrient-rich water from the aquaculture provides nutrients for plant growth. We examined the microbial communities within an experimental aquaponics system. Whereas the fish feces contained a separate community dominated by bacteria of the genus Cetobacterium, the samples from plant roots, biofilter, and periphyton were more similar to each other, while the communities were more diverse. Detailed examination of the data gave the first indications to functional groups of organisms in the different compartments of the aquaponic system. As other nitrifiers other than members of the genus Nitrospira were only present at low numbers, it was anticipated that Nitrospirae may perform the nitrification process in the biofilm

Tomato productivity and quality in aquaponics : comparison of three hydroponic methods

Aquaponics (AP) is a food production system that combines hydroponic (HP) crop production with recirculating aquaculture. Different types of hydroponic systems have been used for growing crops in aquaponics. However, very few studies have compared their suitability and efficiency in an aquaponic context. The study presented here compares tomato yield, morphological (external) and biochemical (internal) fruit quality, and overall tomato plant vitality from three different HP systems (nutrient film technique, drip irrigation system, and floating raft culture) and examines the distribution of nutrients in different parts of the tomato plant. Three replicate AP systems were set up, each incorporating the three different HP systems coupled with a separate recirculating aquaculture unit growing Nile tilapia. The results showed that the choice of the cultivation system had little influence on most of the above-mentioned properties. Tomato fruit mineral content was found to be in similar range for N, P, K, Ca, Mg, Fe, and Zn as reported in the literature. Yield and fruit quality were similar in all three systems. However, the drip irrigation system did perform slightly better. The slightly higher oxygen radical absorbance capacity (ORAC) of the fruits grown in AP in comparison to commercially produced and supermarket derived tomatoes might indicate a potential for producing fruits with higher health value for humans

A Cellular Automaton Framework for Infectious Disease Spread Simulation

In this paper, a cellular automaton framework for processing the spatiotemporal spread of infectious diseases is presented. The developed environment simulates and visualizes how infectious diseases might spread, and hence provides a powerful instrument for health care organizations to generate disease prevention and contingency plans. In this study, the outbreak of an avian flu like virus was modeled in the state of Tyrol, and various scenarios such as quarantine, effect of different medications on viral spread and changes of social behavior were simulated