The Logan City Environmental Department operates a facility that consists of 460 acres of fairly shallow lagoons (~ 5'deep) for biological wastewater treatment that meets targets for primary and secondary treatments (solids, biological oxygen demand (BOD), and pathogen removal). Significant natural algal growth occurs in these lagoons, which improves BOD removal through oxygenation and also facilitates N removal through volatilization as ammonia under high pH conditions created by algal growth. Phosphorus, however, is non-volatile and stays in the water and likely cycles in and out of algal cells as they grow and die in the lagoons. In the near future, the regulatory limits on phosphorus released from the Logan wastewater treatment facility are likely to become significantly lower to counter potential downstream eutrophication. One way to potentially lower phosphorus levels in the wastewater effluent is through management of algal growth in the lagoons. As mentioned above, algae growth naturally occurs in the treatment lagoons and if the algal biomass is harvested when growth yields are highest, the phosphorus contained in the cells could be removed to obtain phosphorus-free water. The algal biomass could then be used for production of biofuels. This research focuses on laboratory and pilot assessments to show the ability of algae indigenous to the Logan lagoons to uptake phosphorus and produce biomass that can be used for biofuel production.

Acrylic chambers and metal frames were installed at the sediment-water interface of streams impacted by the effluent from wastewater reclamation facilities in order to determine nitrogen rates for nitrification, denitrification, assimilation, ANAMMOX, and DNRA. Each chamber was dosed with an isotopic form of nitrate (15NO3 - ), and both isotopic (15N) and non-isotopic (14N) samples were collected. The project locations included East Canyon Creek near the East Canyon Wastewater Reclamation Facility in Park City, Utah and Box Elder Creek near the Brigham City Wastewater Treatment Plant in Brigham City, Utah. Separate chamber measurements were conducted upstream and downstream of each wastewater reclamation facility in order to determine the impact of the wastewater effluent on the stream. At the conclusion of the study, significant rates for both traditional (nitrification, denitrification, assimilation) and non-traditional nitrogen transformations (DNRA, ANAMMOX) were found at various locations. Specific transformations were found exclusively upstream or exclusively downstream of the wastewater treatment plant. Transformations that were found both upstream and downstream of the treatment plants were not significantly different, indicating no impact from the WWTPs on nitrogen transformations. Additionally, the use of isotopic nitrogen for the study did not prove necessary for determining nitrification and denitrification rates.

The current investigation indicates that the routine appearance of a noxious blue-green algal bloom of Aphanizomenon flos-aquae, in Hyrum Lake, a reservoir in northern Utah is a result of excess phosphorus. Data indicate that the algal growth is initiated by phosphorus liberated from the phosphorus rich bottom sediments, and at a time when nitrogen is present in excess in the lake relative to phosphorus. Results indicate that the Little Bear River is the major source of nitrogen and phosphorus contributing to the eutrophication of Hyrum Lake. Nitrogen and phosphorus fluctuations in the Little Bear River proved to be concurrent with nitrogen and phosphorus fluctuations in the reservoir.

Objective. The objective of the current study was to evaluate critical nutrients of industrialized foods and compare them with the technical parameters established in the Peruvian regulations, in its two stages of implementation, referring to front-of-package labeling before the beginning of its validity in June 2019. Methods. Cross-sectional study in which the critical nutrients of sodium, total sugar, saturated fat and transfat were analyzed from data declared in the nutritional labels of 511 processed and ultra-processed foods that were part of the products purchased for the consumption of 88 families of students from one private university in Lima. The technical parameters used to evaluate the critical nutrients are those established in the Regulation of Law 30021. All analyses were carried out with Excel and SPSS version 21, Student’s t-statistics and McNemar’s test were used. Results. 79 processed foods and 432 ultra-processed foods were analyzed. Of the total processed and ultra-processed products evaluated, it was found that for sodium 14.3% and 37.2% respectively exceeded the parameters in the first and second stages established in the regulations; for sugar 54.2% and 62.6%; while for saturated fats 52.8% and 59.5%, respectively. Solid foods are those that will have the greatest changes in front labeling between the first and second stages of implementation, unlike liquids that without changing the composition of their products, their front labeling would not vary significantly. Conclusions. The saturated fat present in solid products (processed and ultra-processed), exceeds the parameters in both stages of implementation in most products. Of the foods compared, regardless of type and category, the critical nutrient sugar was the one that was highly present in most of the products evaluated for the first and second stages of implementation. / Revisión por pares

No description available.

No description available.

No description available.

Since 1961, a fourold increase in application of fertilizers in the United States has helped to double crop yields. Nutrients not used by crops are often transported to aquatic ecosystems adjacent to agricultural fields. In the Lower Mississippi Alluvial Valley, nutrients enter agricultural drainage ditches and are transported to receiving water bodies, eventually reaching the Gulf of Mexico. The annual occurrence of a hypoxic zone in the Gulf of Mexico is caused by nitrogen loads from the Mississippi River Basin. Objectives of these studies were: (1) evaluate how organic carbon amendments affect nitrate-nitrogen removal in agricultural drainage ditch systems, (2) determine effects of organic carbon amendments and flow rate on nitrate-nitrogen removal in a semi-controlled field setting using experimental drainage ditches, and (3) assess relationships between organic carbon and nitrogen content of overlying water, pore water, and sediments of drainage ditches throughout the Lower Mississippi Alluvial Valley. In laboratory experiments, nitrate-nitrogen removal in dissolved and particulate organic carbon treatments was greater than 90% compared to as low as 60% in control treatments. The optimal carbon-to-nitrogen ratio of organic carbon amendments for efficient nitrate-nitrogen removal was 5:1. Studies in experimental drainage ditches revealed that flow substantially lowered the ability of organic carbon amendments to remove nitrate-nitrogen with a maximum percent nitrate-nitrogen reduction of 31.6% in a dissolved organic carbon treatment, although implementation of low-grade weirs in experimental drainage ditches did result in removal of nitrate nitrogen in all treatments and at all flow rates. Examining the nitrogen and organic carbon contents in agricultural drainage ditches throughout the Lower Mississippi Alluvial Valley revealed that organic carbon content in overlying water, pore water, and sediments is lower than observed in other wetland-like ecosystems and indeed may be limiting denitrification and other nitrogen removal processes. Increasing organic carbon content overall could be achieved by using organic carbon amendments, but this body of research highlights that additional studies are necessary to ensure successful implementation of organic carbon amendments that reach their greatest potential as a management practice to effectively remove nitrate-nitrogen in the realistic settings of agricultural drainage ditches.

Water conservation practices are being widely implemented to alleviate sediment and nutrient losses from agricultural land and unsustainable groundwater use for irrigation. Tailwater recovery (TWR) systems are conservation practices being implemented to collect and store runoff to reduce nutrient losses and provide a source of irrigation water. This collection of research is focused on evaluating TWR systems through the following actions: 1) investigate ability to reduce solids and nutrients delivery to downstream systems, 2) compare differences in solid and nutrient concentrations in surface water samples from TWR systems to irrigation water from a TWR systems; 3) determine the potential to irrigate water containing solids and nutrients; 4) quantify a water budget for TWR systems; 5) conduct cost and benefit analyses of TWR systems; and 6) analyze economic cost to reduce solids and nutrients and to retain water. Tailwater recovery systems did not significantly reduce concentrations of solids and nutrients; however, loads of solids, P, and N were significantly reduced by 43%, 32% and 44%, respectively. Mean nutrient loads per hectare available to be recycled onto the landscape were 0.20 kg ha-1 P and 0.86 kg ha-1 N. Water budget analyses show these systems save water for irrigation but were inefficient. Net present value (NPV) and benefit cost ratios were positive and >1 for producers who owned the land, but remained <1 if land was rented. However, beyond improvements to irrigation infrastructure, farms with a TWR system installed lost NPV of $51 to $328 per ha. Mean total cost to reduce solids using TWR systems ranged from $0 to $0.77 per kg, P was $0.61 to $3,315.72 per kg, and N was $0.13 to $396.44 per kg. The mean total cost to save water using TWR systems ranged from $189.73 to $628.23 per ML, compared to a mean cost of groundwater of $13.99 to $36.17 per ML. Mechanistically, TWR systems retain runoff on the agricultural landscape, thereby reducing the amount of sediment and nutrients entering downstream waterbodies and provide an additional source of water for irrigation; however, more cost-effective practices exist for nutrient reduction and providing water for irrigation.

This study examined the effect of manipulating forest floor and harvest residue inputs on nutrient availability and carbon content in the context of intensive forest management. Treatments were removal and addition of forest floor and slash, and a reference. Tree volume, litterfall, and root biomass were measured to assess aboveground productivity and soil moisture and temperature, available nitrogen and phosphorus, O-horizon, and mineral soil for below ground processes. Organic matter additions increased stand bole volume, carbon at 20-60cm, and total nitrogen in the mineral soil. Severely removing the floor and harvest residues did not result in any large differences in below or above ground productivity, soil carbon or nitrogen pools. Removing a potential nutrient pool did not severely affect stand productivity through mid-rotation but could be a concern in subsequent rotations.