The presence of nitrates and phosphorus in ground water is a worldwide problem. A septic tank with drainfield that is conventionally designed does not typically remove nitrogen in the form of nitrates. The main risks are in "Blue baby" syndrome and suspected carcinogenic effect of nitrates on humans and the nutrient enrichment of receiving waters. In some areas nitrate and phosphorus removal are essentially required. Thus the information in this report concentrates on using media in the drainfield for the removal of nitrogen and phosphorus. Extensive work has been conducted in the past few decades in order to find suitable media for denitrification with high selectivity towards nitrogen. Column experiments were conducted at the University of Central Florida to simulate the actual septic tank drainfield using mixes of fine sand. In one of the columns Sawdust and Tire Crumb were added to the Sand (STS) and in the other column Paper and Tire Crumb were added to the Sand (STP). Tire crumb was added as a carbon source required for better denitrification and for sorption. The columns were dosed daily using regular septic tank effluent and it was a continuous batch system. Samples were taken after a hydraulic retention time (HRT) of 24 hours and comparisons were made of the effluent with the influent to show percentage removal of nitrogen (nitrates, ammonia and total nitrogen), phosphorus (ortho-phosphorus and total phosphorus) and BOD. STS and STP columns showed more than 90% removal for all parameters (nitrates, ammonia, total nitrogen, ortho-phosphorus, total phosphorus, BOD). The results indicate that the investigated media blend (Black and GoldTM Nugget Mix) has the potential for successful application in full scale operations. It is recommended that Black and GoldTM Nugget Mix be used to achieve the required removal of the nutrients.

Nowadays people are more alert about conservation of water and water scarcity. The amount of usable water is decreasing due to unavailability of pure water for day to day use. Both surface and groundwater is contaminated by untreated wastewater discharged from improper onsite wastewater treatment system, nutrient laden agricultural runoff and increasing use of fertilizer in fields. This elevated nutrient level is increasing the maintenance and operation cost of water treatment plant. So it is an important task to remove those nutrients from wastewater and other water bodies by applying environmental friendly process. In the USA, about 25% homes are still depending on on-site wastewater treatment (OSWT) due to unavailability of centralized treatment process. In Florida, OSWT is managed by the Florida Department of Health (FDOH). By realizing the importance of water conservation, USEPA already determined the maximum contaminant level (MCL) for nitrate and nitrite in water bodies. Many researches are conducted to evaluate the performance of EPA recommended treatment process (i.e. traditional standard drain field) for OSWT. The UCF research group also performed an experiment to understand the efficiency of traditional standard drain field. At the same time the research group developed an innovative wastewater treatment process named B&G treatment bed as a comparison with traditional standard drain field. This paper mainly focuses on performance of these two treatment processes. The B&G is a novel treatment process by its functionality for nutrient removal. The process generally used a media mixture developed by the research group of UCF. This mixture will act as organic carbon source to support denitrification process while nitrification process does not demand such carbon source. Evan it is observed that this mixture can remove nutrient by physical-chemical process. The recirculation sand filter (RSF) of traditional drain field is also filled by another mixture of media. Both media mixtures are developed by batch experiment in UCF laboratory. The performance of the B&G is compared with the traditional treatment process practiced in USA. These media mixtures can be good supporting media for microorganisms' growth and development. All the major nitrogen and phosphorus species removal is observed by collecting sample in a weekly fashion. The pathogens removal efficiency is also observed. The sample is analyzed by a certified laboratory (i.e. Environmental Research and Design, ERD) in Orlando, Florida to maintain the best quality of this research. The presence of microorganisms is identified by using PCR. The B&G drainfield is very effective for removing both nitrogen and phosphorus species from wastewater. It is also very efficient to remove pathogens too. Standard drainfield is very effective for pathogen removal but it cannot remove nutrients effectively. Nitrate removal in B&G drainfield is well compared to standard drainfield.