Effluent Water Characterization of Intensive Tilapia Culture Units and its Application in an Integrated Lettuce Aquaponic Production Facility by Sami Samir Abdul Rahman A thesis submitted to the Graduate Faculty of Auburn University in partial fulfillment of the requirements for the Degree of Master of Science Auburn, Alabama December 13, 2010 Keywords: effluent wastewater, aquaponics, integrated, sustainable, hydroponic lettuce, nutrient assessment Copyright 2010 by Sami Samir Abdul Rahman Approved by Claude E. Boyd, Chair, Professor of Fisheries and Allied Aquacultures Jeff L. Sibley, Professor of Horticulture Jesse A. Chappell, Associate Professor of Fisheries and Allied Aquacultures Terrill R. Hanson, Associate Professor of Fisheries and Allied Aquacultures Abstract   In an intensive aquaculture project, effluent water characterization from three systems were evaluated (biofloc, polygyser and opposing flows). There were no differences in the mineral additions to the water per unit of feed while comparing the polygyser and opposing flow systems, both of which are bead bio-filter based systems. When both were compared to the biofloc system which lacks a bio-filter, the latter provided approximately 50 to 300% more mineral content in the water which varied based on the component discussed. This study suggests that the biofloc system provides a higher mineral content (and hence a higher nutrient value) for integrated applications such as a hydroponic grow bed. Characterizing the mineral content and feed nutrition value of effluent sludge indicates that the polygyser and opposing flow systems would be better than biofloc systems for organic fertilization purposes in an on land application due to a higher mineral value in the sludge since it had a longer time to mineralize. The proximate analysis trials showed that all three effluent sludge sources were a potentially excellent source of feed; they were not different and ranged around 17 to 24% crude protein among other variables tested. Lettuce trials showed that using settled fish water or unsettled fish water produced the same results and growth parameters. Lettuce grown in a commercial hydroponic solution produced better quality lettuce unless the fish effluent water being exchanged on a daily rate had nitrate, soluble phosphorus, potassium and calcium at 27 mg/L, 21 mg/L, 33 mg/L and 21 mg/L, respectively. It is only at these levels that the quality and growth of the lettuce produced by the fish effluent water was comparable to that of the commercially produced hydroponic lettuce. ii Tissue analysis of lettuce grown under three different treatments (fish effluent with solids, fish effluent without solids and commercial hydroponic solution) showed no differences, indicating that mineral uptake in lettuce was limited by the lowest mineral component found in the nutrient solution. iii Table of Contents Abstract ......................................................................................................................................... ii List of Tables ................................................................................................................................ v List of Figures .............................................................................................................................. vi Literature Review ........................................................................................................................ 1 Materials and Methods .............................................................................................................. 33 Results and Discussions ............................................................................................................ 40 Work Cited ................................................................................................................................ 72 Appendix A .............................................................................................................................. 80 Appendix B .............................................................................................................................. 84 iv List of Tables Table 1: Nutrient components resulting in the exchanged water / Kg of feed added / L / day in the evaluated Polygyser system. ................................................................................... 41 Table 2: Nutrient components resulting in the exchanged water / Kg of feed added / L / day in the evaluated opposing flow system. ............................................................................ 41 Table 3: Nutrient components resulting in the exchanged water / Kg of feed added / L / day in the evaluated bio-floc system........................................................................................ 42 Table 4: Effluent sludge quality of a polygyser system. ............................................................. 47 Table 5: Effluent sludge quality of an opposing flow system. ................................................... 48 Table 6: Effluent sludge quality of a bio-floc system. ................................................................ 48 Table 7: Proximate analysis of system sludge and other comparable feed ingredients ........................ 52 Table 8: Water quality parameters of an aquaculture trial on Lactuca sativa L. ‘Charles’. ........... 55 Table 9: Water quality parameters of an aquaculture trial on Lactuca sativa L. ‘Charles’. ........... 55 Table 10: Water quality parameters of an aquaculture trial on Lactuca sativa L. ‘Charles’. ......... 56 Table 11: Water quality parameters of an aquaculture trial on Lactuca sativa L. ‘Charles’. ......... 56 Table 12: Final growth indices, SPAD and weights of lettuce in trial 1 ............................................ 62 Table 13: Final growth indices, SPAD and weights of lettuce in trial 2 ............................................ 63 Table 14: Final growth indices, SPAD and weights of lettuce in trial 3 ............................................ 63 Table 15: Final growth indices, SPAD and weights of lettuce in trial 4 ............................................ 64 Table 16: Average lettuce tissue analysis trial 1 .............................................................................. 64 Table 17: Average lettuce tissue analysis trial 2 .............................................................................. 65 Table 18: Average lettuce tissue analysis trial 3 .............................................................................. 65 v Table 19: Average lettuce tissue analysis trial 4 .............................................................................. 66 vi List of Figures Fig. 1: Nitrite evaluation of effluent water in each system ............................................................... 42 Fig. 2: Nitrate evaluation of effluent water in each system ............................................................... 42 Fig. 3: Total Ammonia Nitrogen evaluation of effluent water in each system .................................... 43 Fig. 4: Soluble Reactive Phosphorus evaluation of effluent water in each system .............................. 43 Fig. 5: Potassium evaluation of effluent water in each system .......................................................... 43 Fig. 6: Total Hardness evaluation of effluent water in each system ................................................... 43 Fig. 7: Total Alkalinity evaluation of effluent water in each system.................................................. 43 Fig. 8: Calcium evaluation of effluent water in each system ............................................................. 43 Fig. 9: Electrical conductivity evaluation of effluent water in each system ..................................... 44 Fig. 10: Total suspended solids evaluation of effluent water in each system .................................. 44 Fig. 11: Evaluation of total N in sludge from each system. ........................................................ 49 Fig. 12: Evaluation of total P in sludge from each system. ........................................................ 49 Fig. 13: Evaluation of total K in sludge from each system. ........................................................ 49 Fig. 14: Evaluation of total nitrate in sludge from each system. ................................................ 49 Fig. 15: Evaluation of total ammonia in sludge from each system. ............................................ 49 Fig. 16: Evaluation of total calcium in sludge from each system. .............................................. 49 Fig. 17: Evaluation of total EC in sludge from each system. ..................................................... 50 Fig. 18: Evaluation of total pH in sludge from each system. ...................................................... 50 Fig. 19: Evaluation of total moisture content in sludge from each system. ................................ 50 vii Fig. 20: Evaluation of total mineral matter in sludge from each system. ................................... 50 Fig. 21: Average value of critical nutrient (nitrate, SRP, K and Ca) over the period of 4 trials within treatment A (bio-floc effluence with solids). ...................................................... 58 Fig. 22: Average value of critical nutrient (nitrate, SRP, K and Ca) over the period of 4 trials within treatment B (bio-floc effluence without solids). ................................................. 58 Fig. 23: Average value of critical nutrient (nitrate, SRP, K and Ca) over the period of 4 trials within treatment C (commercial hydroponic solution). ................................................. 59 Fig. 24: Graphical representation of average growth indices of the first grown out trial of Lactuca sativa L. ‘Charles’ under three treatments ........................................................................... 66 Fig. 25: Graphical representation of average growth indices of the second grown out trial of Lactuca sativa L. ‘Charles’ under three treatments ........................................................................... 66 Fig. 26: Graphical representation of average growth indices of the third grown out trial of Lactuca sativa L. ‘Charles’ under three treatments ........................................................................... 67 Fig. 27: Graphical representation of average growth indices of the fourth grown out trial of Lactuca sativa L. ‘Charles’ under three treatments ........................................................................... 67 Fig. 28: Graphical representation of average tissue analysis of Lactuca sativa L. ‘Charles’ produced during trial 1. .................................................................................................................... 67 Fig. 29: Graphical representation of average tissue analysis of Lactuca sativa L. ‘Charles’ produced during trial 2. .................................................................................................................... 68 Fig. 30: Graphical representation of average tissue analysis of Lactuca sativa L. ‘Charles’ produced during trial 3. ................................................................................................................... 68 Fig. 31: Graphical representation of average tissue analysis of Lactuca sativa L. ‘Charles’ produced during trial 4. ................................................................................................................... 68 Fig. 32: Trial 1 Comparison of Lactuca sativa L. ‘Charles’ under three different treatments ............. 80 Fig. 33: Trial 2 Comparison of Lactuca sativa L. ‘Charles’ under three different treatments .............. 81 Fig. 34: Trial 3 Comparison of Lactuca sativa L. ‘Charles’ under three different treatments .............. 82 Fig. 35: Trial 4 Comparison of Lactuca sativa L. ‘Charles’ under three different treatments .............. 83 viii LITERATURE REVIEW Aquaculture Aquaculture is defined as the production of living organisms in water which encompasses both plants and animals in fresh, marine or brackish water (Jasper, 1992). The products from aquaculture are usually targeted for food and fiber, but as the industry has developed products suited for the ornamental, pharmaceutical and medical industries have resulted. Different systems of aquaculture are segregated based on their levels of intensity ranging from extensive systems where human input is minimal, followed by semi-intensive and then intensive systems where man has the upper hand in controlling both water quality and availability of food (Brown, et al., 1986). Within the aquaculture industry, production units can be divided into open and closed (or water reuse) systems. Open systems take water in from one point and discharge it at another; hence they use the water once. Closed systems involve reusing the water and only adding new water to the system when water is lost. Closed culture units often have a series of filtration and processing components that help maintain water quality (Berghage, et al., 1999). Aquaculture is poised to provide more than one third of the world demand of fish, shellfish and other marine organisms, but concerns over the negative environmental impact of aquaculture have been brewing. The issues range from mangrove destruction in the case of shrimp production to sea bed pollution in case of large scale off shore aquaculture (Wurts, 2000). One of the key issues of concern is the effluents produced in such systems. Each type of system differs in effluent quality based on production capacity, and effluents are a major concern 1 because they often are discharged in canals, creeks, rivers or seas. Currently, the industry is developing guidelines and technological innovations to tackle environmental issues by implementing practices to lessen pollution loads and to make use of aquaculture waste in an economical and beneficial way (EPA, 1980). Tank Culture Tank culture is one of the intensive ways of producing fish. The quantity of fish per unit volume in tank culture is many times greater than in pond culture. Tank culture systems are efficient because of their lower requirements of land as well as water resources (Rakocy and Mcginty, 1989). The higher productivity level in tank culture is achieved by aerating the water, providing complete feeds, exchanging the water partially or continuously, as well as removing wastes and amending certain water parameters when needed (Schonbeck et al., 1991). A distinction should be made between tank culture systems that discard the water after it goes through the culture units (flow through systems) and those that filter and recycle water (re- circulating systems) (Rakocy, 2002). Tank culture of tilapia or other species offers several advantages compared to cage or pond culture. Disrupting breeding at high stocking densities allows both sexes to reach marketable size in a shorter period of time due to lack of energy expenditure on reproductive development. The fish stocking density and the environmental parameters in re-circulating units can be managed to a high degree to achieve maximum production levels (Shaw and Cantliffe, 2003). Tank culture has also made it possible for tilapia and other fish species to be grown beyond their normal geographical range by maintaining them in environmentally controlled structures keeping in mind that all tank culture systems are not in greenhouses. The filtration systems that accompany re-circulation systems are complex and expensive and backup systems 2