Aquaculture Reuse Water, Genetic Line, and Vaccination Affect Rainbow Trout (Oncorhynchus mykiss) Disease Susceptibility and Infection Dynamics

Infectious hematopoietic necrosis virus (IHNV) and Flavobacterium psychrophilum are major pathogens of farmed rainbow trout. Improved control strategies are desired but the influence of on-farm environmental factors that lead to disease outbreaks remain poorly understood. Water reuse is an important environmental factor affecting disease. Prior studies have established a replicated outdoor-tank system capable of varying the exposure to reuse water by controlling water flow from commercial trout production raceways. The goal of this research was to evaluate the effect of constant or pulsed reuse water exposure on survival, pathogen prevalence, and pathogen load. Herein, we compared two commercial lines of rainbow trout, Clear Springs Food (CSF) and Troutex (Tx) that were either vaccinated against IHNV with a DNA vaccine or sham vaccinated. Over a 27-day experimental period in constant reuse water, all fish from both lines and treatments, died while mortality in control fish in spring water was <1%. Water reuse exposure, genetic line, vaccination, and the interaction between genetic line and water exposure affected survival (P<0.05). Compared to all other water sources, fish exposed to constant reuse water had 46- to 710-fold greater risk of death (P<0.0001). Tx fish had a 2.7-fold greater risk of death compared to CSF fish in constant reuse water (P ≤ 0.001), while risk of death did not differ in spring water (P=0.98). Sham-vaccinated fish had 2.1-fold greater risk of death compared to vaccinated fish (P=0.02). Both IHNV prevalence and load were lower in vaccinated fish compared to sham-vaccinated fish, and unexpectedly, F. psychrophilum load associated with fin/gill tissues from live-sampled fish was lower in vaccinated fish compared to sham-vaccinated fish. As a result, up to forty-five percent of unvaccinated fish were naturally co-infected with F. psychrophilum and IHNV and the coinfected fish exhibited the highest IHNV loads. Under laboratory challenge conditions, co-infection with F. psychrophilum and IHNV overwhelmed IHNV vaccine-induced protection. In summary, we demonstrate that exposure to reuse water or multi-pathogen challenge can initiate complex disease dynamics that can overwhelm both vaccination and host genetic resistance.

Membrane-based conceptual design of reuse water production from candy factory wastewater

Intense pressure on water resources has led to efforts to reuse reclaimed processing wastewater in the food industry. There are tight rules for water quality, but efficient separation technologies such as reverse osmosis possess good possibilities for water reuse. This study developed a membrane-based reuse water concept for wastewater from the candy industry emphasizing the pre-treatment stage in the concept to reduce fouling. The wastewater contained suspended solids, sugar compounds and the ingredients for candy gelation, which had a tendency to foul membranes, making pre-treatment essential for successful concept. Cross-rotational ultrafiltration, which featured enhanced fouling prevention for membranes, functioned well for the removal of challenging substances. Conventional filtration technologies were impractical due to a low flux, even when the viscosity of the wastewater was reduced using surfactants. The wastewater had a high chemical oxygen demand, meaning that there were a strong fouling potential for reverse osmosis membranes, but also high osmotic pressure. A spiral wound reverse osmosis functioned well when the wastewater was pre-treated, and it produced good quality water with respect to all the other studied parameters except the chemical oxygen demand. However, chemical oxygen demand rejection was 99% since the concentration in the wastewater was originally very high.

Environmental, Economic, and Social Potentialities of Ornamental Vegetation Cultivated in Constructed Wetlands of Mexico

Sustainable development implies the proper use of natural resources, such as water resources, but the environmental, economic, and social benefits should also be considered. In the water sector, for example, sanitation is one of the challenges that arise in rural localities. However, issues related to it may be solved with the use of constructed wetlands (CWs), which may allow the cultivation of ornamental plants with phytoremediation properties. Through a content analysis, the environmental, economic, and social potential of ornamental species used in Mexico for phytoremediation in CWs is documented in this study. The environmental potential of the plants was considered based on their phytoremediation properties. The economic potential was determined from research articles and from the National Agri-Food Information System. The social potential was analyzed considering the ornamental and artisanal use of the plants. In total, 21 species of phytoremediation plants were identified. Anthurium andreanum and Zantedeschia aethiopica stand out for their commercial value, reported in 2018 to be 272,875 and 30,318 USD, respectively, at the national level. The social potential was identified by the ornamental or artisanal use for flower arrangements and weaving. This study reveals that the use of CWs with ornamental vegetation is a sustainable option to clean wastewater, reuse water, and generate economic incentives. Thus, it is essential to provide the community with adequate training for the management of CWs in those sites that lack treatment systems.

Application and Assessment of Different Decentralized Waste Water Treatment Technologies for a Hot-Dry Climate in Jordan for Reuse Purpose

Jordan faces chronic water scarcity due to the very limited water resources and increasing water demand. Also increasing the energy cost of wastewater treatment raises the need to think about Sustainable Energy-Water-Environment Nexus in a dry climate. Moreover, wastewater treatment near to the generation place and reuse it at the same points is needed for decreases energy demand, save the cost and protect the environment. However, the innovations in decentralized wastewater technologies in Jordan aiming not only to treat the municipal wastewater but also to reuse water, energy, and nutrient again. Lab-analysis shows extremely high treatment efficiency that can be achieved by studied technologies to reduce BOD5 to 98.8%, COD to 96.5% and achievement high nitrification rate and good reduction of the parameters TSS, NO3, TN, and E. coli, to meet the Jordanian Standards for reuse.

Sustainability requirements of implementing water-reuse concepts for new industrial park developments in water-stressed regions

Requirements for wastewater management and water-reuse concepts concerning sustainability are gaining greater importance, especially in times of climate change. Industrial park developments are often hindered due to water scarcity. Thus, nowadays, the reuse of wastewater is becoming more and more important to increase the availability of water and to enable new developments. The sustainable Industrial WasteWater Management Concept with the focus on Reuse (IW2MC → R) provides a solution strategy to produce reuse water from industrial wastewater within production plants. To achieve sustainability, certain requirements are essential since the reuse water can be provided directly via an optimized wastewater treatment process for subsequent use. Hence, it is then ‘fit for purpose’. This enables a more efficient application of reuse water. Furthermore, due to environmental issues, it is important to construct space-saving water resource recovery facilities for reducing land consumption within industrial parks.