Recipient Organization
TEMPLE UNIVERSITY
1801 N. BROAD STREET
PHILADELPHIA,PA 19122
Performing Department
ENGINEERING:CIVIL & ENVIRONMEN
Non Technical Summary
Global water demand is projected to increase by 55% between 2000 and 2050 and over 40% of the world's population will live under severe water stress by the middle of this century. Together with increasing water demand, worldwide demand for fertilizer has been increasing by 2.4% per year and is expected to reach 200 million tons by 2021. Coupled with declining reserves of phosphate, an essential compound for fertilization, these present threats to global food security. In the United States, concentrated animal feeding operations such as swine, poultry, beef, and dairy farms produce more than 133 million tons of livestock wastewater every year. Based on their origin, livestock wastewater can contain elevated concentrations of carbon phosphorus and nitrogen that have the potential to be recovered as fertilizers. However, the current treatment technologies of livestock wastewater (e.g. activated sludge or trickling filter systems) are not designed for resource recovery and inadequate for sustaining long-term agricultural production, generating a gradual deterioration of soil and groundwater properties through the loading of nitrate, nitrite, pharmaceutical byproducts, and antibiotic residues from livestock. Without proper treatment, runoff or release of livestock wastewater from farms to aquatic ecosystems was shown to cause severe environmental impacts, e.g. eutrophication of rivers, lakes, and coastal oceans, as well as N2O and NH3 gas emissions that pollute the atmosphere. Therefore, there is a need to treat livestock wastewater prior to its discharge while recovering valuable compounds such as water and nutrients.The goal of the proposed effort is to turn livestock wastewater to valuable products including high-quality water fit for irrigation (i.e. no bacteria and low salinity), ammonia gas for energy/fertilizer production, and struvite, a slow-release fertilizer. To this end, we will develop a novel system by integrating microbial electrolysis cells, forward osmosis, and membrane distillation. These are microbiological, electrochemical and physical processes that can synergistically overcome the inherent limitations of each other. We will demonstrate the feasibility of the proposed system by monitoring the system performance in terms of organic removal, water reclamation, nutrient recovery, energy consumption, and capital cost. Fundamental aspects including fouling behaviors and microbial communities will be studied to provide a mechanistic understanding of the potential and limitation of the system. This project is expected to develop a robust, stable and cost-effective process for recovering solid fertilizer and water from livestock wastewater at low energy consumption. The produced water will meet EPA's regulations for irrigation. From a fundamental perspective, we anticipate to gain an in-depth understanding of the microbiology and fouling in the system. The system will be analyzed in terms of capital and operation cost and compared to additional biological and physical treatment options. Overall, the research will advance the management of livestock wastewater.
Animal Health Component
40%
Research Effort Categories
Basic
60%
Applied
40%
Developmental
0%
Goals / Objectives
Our main goal is to turn Livestock wastewater(LWW) from concentrated animal feeding operations (CAFOs) e.g. swine, poultry, beef, and dairy farms to valuable products including high-quality water fit for irrigation (i.e. no bacteria and low salinity), ammonia gas for energy/fertilizer production and struvite, a slow-release fertilizer, thereby closing resource cycles in agriculture. Four objectives are designed to reach the goal of this study.Objective 1. Assess and Optimize the Integrated MOD (Microbial Electrolysis - Forward Osmosis-Membrane Distillation) System Performance:Collect and assess LWW samples from local farms;Assess and optimize organic removal from LWW using microbial electrolysis cells (MECs) coupled with electroactive forward osmosis (EFO) as a function of operational conditions;Assess and optimize solid fertilizers and ammonia recovery at the EFO interface;Assess the membrane distillation (MD) efficiency and distillate quality;Integrated system assessment.Objective 2. Evaluate the relationship between the microbial ecology in the MEC and organic removal efficiency as influenced by the charged EFO membrane:DNA/RNA extraction and amplicon sequencing;Community analysis;Ecogenomics-based growth kinetic model.Objective 3. Evaluate fouling mitigation in EFO and MD membranes:Assess fouling in EFO systems;Assess fouling in solar MD systems.Objective 4. Estimate the overall economic feasibility and environmental impacts of the integrated treatment system:Cost assessment;System performance prediction at large scales.
Project Methods
This project will apply engineering principles to link physical, electrochemical and microbiological processes. The uniqueness aspects of our methods lie in the deep integration of individual components from the perspective of both water and energy. Instead of simple stacking of MEC, EFO and MD, they are connected in a complementary and synergistic way that overcomes the inherent limitations of each other. The general scientific methods include:Identify the question: the characteristics of LWW and the potential of resource recovery;Formulate hypotheses: coupling MEC with EFO and MD will lead to simultaneous LWW treatment and resource recovery in an effective and cost-efficient way;Experimentation: 4 objectives and the subtasks associated with them;Analysis: parameters to be analyzed include organic removal, water reclamation, nutrient recovery, energy consumption, capital cost, fouling behaviors, microbial communities. These will be accomplished by adopting the techniques from general physics, analytical chemistry, electrochemistry, material engineering and microbial ecology.Samples will be collected in triplicates. Each sample will be marked with the sampling date, name initials and sample identification number, and stored at 4 oC with minimum exposure to sunlight. Chemical analysis will be conducted according to respective standard methods. Precision, accuracy, representativeness, completeness, and comparability of the data will be determined using standard Environmental Protection Agency methods. Calibration/QA/QC of analytical instruments will be conducted as specified by individual standard method. Project team members will be required to draft protocols for analytical method and submit results as formatted data to periodical review by the whole team. Each project team member will be responsible for recording details of experimental conditions and observations in dedicated laboratory notebooks with page numbers. Data generated by online recording instruments (e.g., potential, current) analytical instruments (e.g., concentrations) will be stored as the software output formats. Any derivative data (e.g. standard curves, kinetic rates calculated from concentration data) will be developed in Microsoft Excel. Archived data in spreadsheets will include formulas used in calculations as well as the resulting "finished" data. The spreadsheets will have information linked to the records in laboratory notebooks and the raw data output from software. Data will be analyzed as soon as raw data are collected, thus allowing efficient management and rapid sharing of the data with others. Statistical analysis will be done per sample, giving mean values and standard deviation, and significance (i.e. T-test).Efforts:Research results will be incorporated into undergraduate- and graduate-level courses, including CEE 2711 Environmental Chemistry and Microbiology and CEE 3715 Microbiological Principles of Environmental Engineering at Temple University;Systems developed in this project will be made available to undergraduate laboratory courses;Undergraduate students will be included in the project and gain research opportunities, promoting them to pursue graduate education;PIs, graduate and undergraduate students participating in the research will present their work at national conferences and disseminate the findings;At least two graduate students will complete their thesis/dissertations based on this projects.Evaluation:Organic removal: biochemical oxygen demand (BOD), chemical oxygen demand COD, volatile suspended solids (VSS), and total suspended solids (TSS) will be monitored using commercially available kits throughout the project. Nutrients and specific ions (N, P, Mg, Ca, K) will be measured using Ion Chromatography. Concentrations below EPA regulations are considered indicator of successful organic removal.Water reclamation: water recovered by EFO and MD will be quantified and MD is expected to remove all bacteria, organic compounds and 99% of salts.Nutrient recovery: Solid fertilizer recovery will be evaluated according to insights from a recently funded USGS National Institutes for Water Resources project. Briefly, struvite has been shown to form near the charged ERM but not on it as a result of the increased negative surface charge. Following formation, the solid fertilizer will be collected at the bottom of the MEC. Collected solids will be dried and analyzed for surface morphology and composition through energy-dispersive X-ray spectroscopy scanning electron microscopy (SEM-EDX). Chemical composition will be determined by X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Size distribution will be analyzed through a particle size analyzer. To understand the transformation route of N and P in the system, we will perform a mass balance taking into account the initial N and P concentrations in the MEC, final concentrations in the draw solution and concentrations and masses removed as ammonia and solid fertilizer.Energy consumption: Energy consumption by MEC and EFO will be calculated using current and voltage input. Solar energy for MD will be monitored using a Multifunction Irradiance Meter. Net energy consumption will be obtained and compared with the total energy demand of conventional technologies for wastewater treatment (activated sludge process), energy recovery (anaerobic digester), and water reclamation (reverse osmosis).Capital cost: We will perform a cost analysis of the coupled process and each treatment step, considering the energy required for filtration, pump operation, applied voltage, and backwashing if required. Data will address a small scale lab system and used to estimate a larger system for treating a larger volume. Data will be presented as energy requirement per treated distillate volume (kWh/m3). The calculation will also take into account the capital cost of membrane and reactor modules and membrane fabrication/materials. In addition, we will add a section related to the products recovered from the MOD such as ammonium sulfate, struvite, treated water, etc. Here we will include the evaluated volume/mass-produced per day and the current market price range. MOD treatment will be compared to advanced physical treatments e.g. RO, NF, ion exchange, adsorption, and advanced biological treatment e.g. Anammox, nitrification, denitrification, and biological nutrients removal.Fouling behaviors: Fouling will be assessed by continuous detection of the permeate EFO flux change with time. In addition, following each experiment, we will assess the fouling on the EFO membrane using microscopy imaging including deal/live and EPS staining and ATP detection in addition to SEM imaging and TOC analysis. Organic content will be imaged and evaluated using FTIR, AFM, and SEM. These are common approaches for fouling assessment. If the fouling is considered to decrease flux by more than 30%, EFO membranes will be cleaned by applying higher electrical potential of up to 5V as previously described and using osmotic backwashing.Microbial communities: The microbial communities are expected to contain core populations that are resistant to high NH4+ and PO4- concentrations to ensure stable system performance.