Marty Wanielista

Effect of Rejuvenation Methods on the Infiltration Rates of Pervious Concrete Pavements

Pervious concrete pavements in low-traffic urban areas such as parking lots reduce storm water runoff and also minimize water pollution. However, there are concerns about their expected clogging and consequential reduction of hydraulic performance in the long run. The pervious concrete pavements can be declogged using rejuvenation methods such as vacuum sweeping, or pressure washing, or a combination of both. This paper presents the results of our study that focused on the hydraulic performance of pervious concrete pavements. The study included field and laboratory investigations to evaluate the infiltration capacities of the pervious concrete cores and the underlying soils and the usefulness of rejuvenation methods in restoring their hydraulic performance. As a result of this research program, a new field test device, called the embedded ring infiltrometer, was developed for evaluating the infiltration rates of newly installed pervious concrete pavements. The results of this study indicate that the rejuvenation methods can substantially restore the performance of pervious concrete pavements for better management of storm water.

INTEGRATING NANOSCALE ZERO-VALENT IRON AND TITANIUM DIOXIDE FOR NUTRIENT REMOVAL IN STORMWATER SYSTEMS

Nutrients, such as nitrate, nitrite, and phosphorus, are common contaminants in many aquatic systems in the United States. Ammonia and nitrate are both regulated by the drinking water standards in the US primarily because excess levels of nitrate might cause methemoglobinemia. Phosphorus might become sources of the eutrophication problems associated with toxic algae in the freshwater bodies. Toxic algal blooms can cause severe acute and chronic public health problems. Chemical reduction of nitrate by using zero-valent iron started as early as 1964, and considerable research reports relating to this technology to nanomaterial were extensively reported in 1990s making the use of nanoscale zero-valent iron (NZVI) particles for nitrate removal become one of the most popular technologies in this field. The purpose of the present study was to examine the potential of integrating green sorption media, such as sawdust, limestone, tire crumb, and sand/silt, with two types of nanoparticles, including NZVI and Titanium Dioxide (TiO2), for nitrate removal in an engineering process. The study consists of running packed bed column tests followed by the addition of NZVI and TiO2 to improve nitrate and phosphorus removal efficiency. Preliminary results in this paper show that the potential and advanced study may support the creation of design criteria of stormwater and groundwater treatment systems for water reuse in the future.

Total Nitrogen Losses from Fertilized Turfs on Simulated Highway Slopes in Florida

AbstractFertilized highway slopes constitute nonpoint sources of nitrogenous nutrients that are degrading the surface water and groundwater resources. This paper presents the results of simulated rainfall experiments conducted on a plot-scale test bed (slope-adjustable) that was fully exposed to weather for closely representing the conditions of a fertilized turf-covered highway slope in Florida. Thirty-six tests were conducted on three slopes (25, 33, and 50%), simulating two rainfall intensities (12.5 and 25  mm/h). The soils used were fine sand (AASHTO A-3 class) and silty sand (AASHTO A-2-4 class). Following the local highway practices, the tests were conducted after compacting the soils and establishing Argentine Bahia turf over A-3 soils and Pensacola Bahia turf over A-2-4 soils. Two fertilizers were used: a quick release (QR) 10-10-10 and a slow release (SR) 16-0-8. Weather conditions varied considerably during the duration of the project, affecting soil moisture, soil—grass—nutrient interactions, ...

Cost benefit optimization of cistern volume and green roof area in the florida showcase green envirohome (FSGE)

Most water conservation and energy savings strategies for residential homes have higher first cost (more capital) than traditional spending. However, the added benefits of these greening strategies can outweigh the increase of initial capital cost at the end of the house life time. A cost-benefit optimization model was formulated to demonstrate the optimal design strategy with a typical Florida residential home (shingle and metal roofs) to synergistically integrate a green roof with gray water/stormwater reuse system. The objective of this model is to find the optimum green roof area without making the home cost more over a specific life time, such as 50 years, than a traditional one through energy saving and water conservation. We found out that when the energy savings was varied, the area of the green roof increased to an upper limit due to the irrigation requirement of the green roof. Due to the variability of the rainfall, a chance constraint was added to the model to address stormwater harvesting uncertainty. Research finding proved such a concept. As the risk level is varied, the area of green roof only changed by about 4.4% and 5.3% for the shingle and metal roofs respectively.

Nutrient and Pathogen Removal with an Innovative Passive Underground Drainfield for On-site Wastewater Treatment

When urban regions gradually expand due to regional development, centralized sewage collection, treatment, and disposal is often unavailable for both geographic and economic reasons. As a consequence, about a quarter of the residences in the United States relied on decentralized treatment of wastewater. Household wastewater contains high concentration of nutrients (mainly nitrogen and phosphorus), disease-causing organisms and viruses, and some toxic chemicals. Nation wide, wastewater effluent from on-site wastewater treatment (OWTS) can represent a large fraction of nutrient loads to groundwater aquifers. Phosphorus and nitrogen compounds are the most frequent measurements to indicate nutrient loadings. Some aquifers may discharge into springs or other surface waters adversely affecting public health. Hence, on-site wastewater effluent disposal has contributed significant adverse impacts to the dynamics of the natural environment. Nowadays, due to widespread septic tank failure, scientists, engineers, and manufacturers in the wastewater treatment industry have developed a wide range of alternative passive technologies designed to address increasing hydraulic loads, energy saving requirement, and water contamination by nutrients and pathogens in OWTS. This paper aims to present an innovative design of the underground drainfield with soil amendments (sorption media) in a pilot septic tank system. The new system located at the OWTS test center, University of Central Florida (UCF) was tested and proved costeffective in the initial test run in fall 2008.

In Situ Permeability Determination Device for Porous Pavement Systems

Porous pavement systems allow for the percolation of rainwater through the system to the underlying subsoil, which results in reduced runoff and pollutant transport. Several devices have been proposed and/or developed to determine the infiltration rates of the porous pavement systems. However, most of the devices only provide the infiltration rate of the pavement system surface layer, or are destructive techniques such as pavement coring for laboratory testing. The objective of this study was to develop and test the efficacy of a new testing device, called the embedded ring infiltrometer kit (ERIK), for field determination of the in situ permeability of porous pavement systems. The ERIK device provides a means to measure the pavement system’s surface course percolation rate as a maintenance indicator and the entire pavement system to evaluate a recovery time throughout the service life. Performance evaluation of the ERIK device showed good reproducibility with a coefficient of variation equal to 7% and repeatability at a 95% confidence interval. The results suggested that the ERIK device is a viable option for field determination of in situ permeability of porous pavements.

Nutrient and pathogen removal in a passive on-site sewage treatment and disposal system (OSTDS) with a recirculation filtration tank.

Groundwater contamination due to the nutrients from a septic tank system is a vital concern in environmental health. Active OSTDS also know as on-site wastewater treatment is dependent on the use of pump to sustain the aerobic condition in the process and promote the nitrification which might not be sustainable in terms of energy saving. Experiments have been conducted over the past three years to find a cost-effective, passive on-site wastewater treatment process to improve nutrient removal. The inclusion of recirculation sand filter (RSF) might be a suitable intermediate process to trigger the proper nitrification/denitrification process between the septic tank and the drain field. This option may be adopted for these existing traditional septic tank systems as a retrofit project. Yet the science question as to how effectively the nitrification and denitrification can be fostered in an RSF remains unclear. Three types of medium: fine sand, course sand, and green sorption media (i.e. denoted as options 1, 2 & 3 in this study) were used to assess the performance of the RSF. In particular, phosphorus removal from the wastewater was one of the key concerns, and the capability of using limestone for phosphorus removal was also investigated and confirmed. It can be concluded that fine sand with limestone mixture had better performance for nutrient removal if clogging issue can be overcome by using a grinder pump when dosing. On average, the septic tank and RSF system with fine sand removal efficiencies were: 60.54% ammonium, 49.48% total Kjehldahl nitrogen (TKN), 42.57% total nitrogen (TN), 92.06% soluble reactive phosphorus (SRP) and 87.16% total phosphorus (TP). The E. Coli removal efficiency by RSF was 99.9% in all cases. However, the addition of green sorption media is not favored due to insufficient hydraulic residence time (HRT). If the size of the RSF can be increased, the use of green sorption media in combination with limestone might be beneficial. Keyword: Wastewater treatment, Nutrient removal, Real-time PCR, Environmental health

Using a Subsurface Upflow Wetland for Nutrient and Pathogen Removal in an On-site Sewage Treatment and Disposal System

The conventional decentralized sewage collection, treatment, and disposal systems are no longer able to fully respond to the needs of handling removal of nutrients.. Without proper sorption and nitrification/denitrification, a large fraction of nutrient loads such as nitrogen and phosphorus flowing into aquatic system may adversely affect the water quality and public health. Constructed wetland, a cost-effective small-scale wastewater treatment system with low energy and maintenance requirements and operational costs, may well fit the current needs. A subsurface constructed wetland system as designed as a performance-based passive on-site sewage treatment and disposal system (OSTDS) was proved effective after receiving septic wastewater flow. With the aid of a suite of locally adapted and selected plant species, such an OSTDS was configured to handle 189 cubic meters per day (50 GPD) influent using green sorption media at the test center located on the main campus of University of Central Florida (UCF). During the test run, results indicate that wetland 1, which was planted with Canna, achieved the best removal efficiency of 97.1 %, 98.3 %, 99.98 % and near 100.0 % for TN, TP, fecal coli and E.Coli, respectively. Keyword: Wastewater treatment, Nutrient control, Ecological engineering, Sustainability engineering, Green Technology, Environmental health

Comparative Study of Two Standard Septic Tank Drain Fields Using Different Sand with Recirculation for Nutrient Removal

On-site Wastewater Treatment System (OWTS) using a septic tank followed by a recirculating sand filter (RSF) with effluent discharged to an unlined standard drain field is a typical performance-based treatment facility for nutrient removal. The type of effluent distribution in the standard drain field systems include gravity systems, low pressure dosed systems, drip irrigation systems, etc. The standard drain field that is constructed by a series of parallel, underground, perforated pipes allows the septic tank effluent to percolate into the surrounding soil in the vadose (unsaturated) zone where most of the residual nutrients may be assimilated. The inclusion of RSF may improve the nitrification to some extent so as to promote denitrification in the drain field. With such design, most residual nutrients in wastewater are expected to be consumed as the wastewater passes through the soil. This author’s aim of this paper is to present the effectivenss of RSF and a comparative study with these two different drain field sands for nutrient removal in vadose zone. They include astatula sand (i.e., citrus grove sand) and washed building sand, popular in Central Florida for drain field use. The use of a gene identification method is novel in supporting the biological removal. Research findings show that the performance of washed building sand and the astatula sand in terms of ultimate nutrient removal is about the same. Because astatula sand is less costly it can possibly be considered for replacement of the more expensive washed building sand.

MATERIAL CHARACTERIZATION AND REACTION KINETICS OF GREEN SORPTION MEDIA FOR NUTRIENTS REMOVAL

In water scarce areas throughout the world, stormwater and wastewater used as an alternative water supply have been put into practice to promote the sustainability of our water infrastructure. Also, in water rich areas, stormwater management and on-site wastewater treatment systems are highly susceptible to extremes in precipitation causing wide spread pollution problems. High nitrogen and phosphorus content in stormwater and wastewater effluents has impeded reuse potential and impacted ecosystem integrity and human health. Nitrate may be toxic and can cause human health problem such as methemoglobinemia, liver damage and even cancers. Phosphorus may trigger the eutrophication issues in fresh water bodies, which could result in toxic algae and endanger the source of drinking waters eventually. It aims to conduct the material characterization and examine the reaction kinetics of a selected recipe of green sorption media recycled from waste streams, such as sawdust and tire crumb, combined with sand/silt and limestone, for nutrient removal using packed bed column tests as a means. Pollutants of concern include ammonia, nitrate and ortho- phosphate. Application potential in stormwater management and wastewater treatment facilities was discussed in the context of sustainable systems engineering.