Developing Methods to Characterize Cured-in-Place Pipe (CIPP)

Cured-in-place pipe (CIPP) is quickly growing as a method to repair aging water pipes. It’s an attractive option for states’ Departments of Transportation, as CIPP doesn’t require any long term or invasive construction. The exact composition of CIPP is poorly understood, even though CIPP leaching is assumed to be the cause of algal blooms, fish kills, and some human illnesses. The goal of this study was to develop methods to characterize what chemicals are present in uncured and cured CIPP resin and at what magnitude. An exhaust capture system was designed, and the condensate collected from this was extracted using dichloromethane and hexane. Additionally, a photoionization detector was used during field sampling to detect styrene, a major component of CIPP. Preliminary results indicate that the chemicals in the CIPP resin and the exhaust dispersion pattern are highly complex and require further study

Blast Furnace Slag Usage and Guidance for Indiana

The project goal was to better understand the extent of air-cooled blast furnace slag (ACBFS) usage for completed INDOT projects, factors that can influence slag leaching, review remediation strategies, and identify applications where future usage restrictions or sitting criteria are needed. A literature review of government documents, peer-review, and trade industry literature was conducted. The project team also conducted a site visit to an ACBFS storage facility and steel mill that generated the ACBFS and reviewed handling and testing procedures. The project team also contacted other state transportation agencies (IL, MD, MI, NY, OH) to determine the degree they incorporated ACBFS into their projects and if product performance tests were required. Results show that changes to Indiana test methods and acceptance criteria are warranted. Indiana Test Method 212 should be revised to extend the test duration, pH acceptance criterion, and add additional material acceptance criteria. Unbound ACBFS should be avoided for construction applications (1) where ground water could contact the material, (2) near environmentally sensitive and populated areas, (3) where a drainage system is not present. Additional work to improve the ability of INDOT to detect ACBFS that would cause short- or long-term chemical leaching problems could include (1) evaluating and optimizing stockpile sampling practices for representative sampling, (2) modifying ITM 212 to better predict worst-case leaching conditions and leachate quality, (3) conduct a head-to-head comparison of bench-scale and field-scale leaching results

Short-term Organic Carbon Release and Chlorine Disinfectant Decay for Cross-linked Polyethylene (PEX) Plumbing Pipes

The use of cross-linked polyethylene (PEX) plumbing pipes has grown in popularity for residential applications. However, PEX pipes can leach organic materials into water that can enable biofilm growth, cause off-tastes and -odors, and may react with disinfectants to form disinfection by-products (DBP). Varied manufacturing processes that are applied to create PEX pipes add to the complexity of understanding organic materials released. In this study, organic carbon release from three PEX pipe brands was monitored for up to five days using a series of stagnation periods. Seven stagnation periods of 1, 2, 4, 8, 24, 72, and 120 hours were conducted at 50 degrees Celsius with varying initial chlorine concentrations for a type A (PEX-a), type B (PEX-b), and type C (PEX-c) brand. Pipes were exposed to chlorinated tap water synthesized in the lab. Water exposed to these pipes was analyzed to determine total organic carbon (TOC), assimilable organic carbon (AOC), total chlorine, and free chlorine concentrations. Results show that all pipe brands had different chlorine decay rates and TOC concentrations. Chlorine residual decayed the slowest and fastest for PEX-A pipes and PEX-C pipes, respectively. Chlorine completely decayed in most pipes by 24 hours when the initial chlorine concentration was 2.0 mg/L. PEX-B leached the most amount of contaminants, with a TOC concentration that far exceeded 2.0 mg/L within 24 hours. AOC concentrations tended to increase over time for all pipes. Future work should include additional brands, aged PEX pipes, different flow conditions, temperatures, and longer stagnation periods

Indoor Premise Plumbing: The Relationship Between Water Stagnation, Chlorine Decay, and Total Organic Carbon Levels

Drinking water safety is critical to the health of populations worldwide, and modern plumbing infrastructure can influence drinking water chemical characteristics. Inside residential and commercial buildings however, water use and contact with different plumbing components can vary. For example, water can endure lengthy stagnation periods and residual disinfectant agents like chlorine can decay, leaving the water vulnerable to microbial growth. Plastic cross-linked polyethylene (PEX) pipes have become popular and have shown to influence water quality. While several studies have been carried out on chemical leaching from PEX piping, none were found that examined the role of pipe diameter in relation to chlorine disinfectant decay. The study goal was to better understand chlorine decay in PEX piping associated with stagnation and pipe diameter. Different diameters (3/4”, ½”) of the same brand of PEX pipe were first obtained and cleaned. PEX pipe were filled with a laboratory prepared synthetic water with about 2 mg/L as Cl2 at pH 7.3 and stagnated up to 3 days at 50°C temperature. Chlorine disinfectant level, pH, and total organic carbon concentration were characterized periodically. Results will be compared against water samples that were not exposed to PEX pipe for the same time period

Navigating the Academic Job Search for Environmental Engineers: Guidance for Job Seekers and Mentors

Students and postdoctoral associates interested in tenure-track environmental engineering positions have limited resources to aid them. The Student Services Committee (SSC) of the Association of Environmental Engineering and Science Professors (AEESP) organized a workshop to fill some of the need. Newly hired faculty and experienced search committee and department chairs shared information on how to create competitive applications. Students and postdoctoral associates were also provided with individualized feedback on their faculty application packages. Survey data were collected for all participants, and these data are presented in this paper along with tips shared during the workshop and information collected from the literature. The objective of this paper is to share that information (1) to inform applicants (students and postdoctoral associates) about the academic job search process, and (2) to inform mentors about how to mentor applicants. Survey responses revealed that participants felt they learned valuable information about the job search process. They found the personalized feedback on application packages to be the most helpful activity; other mentors are encouraged to provide similar personalized feedback. A wiki website component included in the workshop was effective at engaging the participants and helped broaden the impact beyond the workshop attendees. Key lessons learned by comparing workshop results with literature were the importance of fit, the unique diversity of environmental engineering, mentoring and networking, Ph.D. planning sessions, being informed, and becoming a more skilled candidate. The recommendations presented in this paper can be used by students, postdoctoral associates, and their mentors to facilitate the candidate’s path toward academia

Lack of Data for Predicting Storm Water Pollutant Removal by Post-Construction Best Management Practices

The project objective was to conduct a detailed literature review of storm water pollutants and mitigation technologies and synthesize the information so that INDOT can implement project results into standards. Because it is a municipal separate storm sewer system (MS4), INDOT is required to minimize storm water pollution. A literature review was carried-out to gauge pollutants examined by other transportation agencies, the pollutant’s relevance to Indiana roadways, and the effectiveness of storm water pollution minimization best management practices (BMP). A cost benefit analysis was also conducted for a few BMP devices used in Indiana. Results showed that a variety of databases contained BMP testing studies and the same type of BMP may not perform similarly at different sites. Some BMPs can also generate pollutants. Very little BMP design, cost, and performance data were obtained during this study from INDOT and municipalities contacted due to the organizations being unable to access it. Manufacturer self-reported BMP device performance data found was not corroborated by independent device testing data. Reliance on manufacturer reported data greatly overestimated the device’s cost benefit; field validated device performance data are needed. Based on project results INDOT should consider (1) establishing agency-wide procedures to begin collecting pertinent storm water BMP information from ongoing and planned projects, (2) surveying which and how many BMPs are under INDOT control, (3) applying caution when estimating BMP performance based on manufacturer reported data or BMP performance data from other parts of the U.S., (4) conducting a field investigation to determine pollutant removal effectiveness for select BMPs

Doxycycline pharmacokinetics in the absence of renal function

Doxycycline pharmacokinetics in the absence of renal function. Doxycycline is a new tetracycline that is now in widespread clinical use. It differs from the other tetracycline drugs in many important respects including small daily dosage schedules, essentially complete upper gastrointestinal absorption and excretory characteristics that are independent of renal function. Our studies demonstrate that in anephric patients and patients with varying degrees of renal function the plasma t½ of biologically active doxycycline is not significantly extended and that in such a clinical situation the usual therapeutic regimen of the drug is necessary. Clearance rate of the compound from the systemic circulation by hemodialysis is only 10ml/min or less. In addition, our investigations identify the importance of the nonhepatic gastrointestinal pathway of elimination of doxycycline from the systemic circulation. Doxycycline therefore appears to be unique among the tetracyclines in that it may be utilized as a drug of choice for the therapy of systemic infections when a tetracycline compound is indicated in the clinical setting of impaired renal function.Pharmacocinétique de la doxycycline en l'absence de fonction rénale. La doxycycline est une nouvelle tétracycline dont l'usage clinique est maintenant largement répandu. Elle diffère des autres tétracyclines à plusieurs égards importants parmi lesquels la faible posologie quotidienne, l'absorption totale dans la partie haute du tractus digestif et des modalités d'excrétion indépendantes de la fonction rénale. Notre travail démontre que chez les sujets anéphriques et les malades atteints d'insuffisance rénale de sévérité variable la demie vie de la doxycycline biologiquement active n'est pas significativement allongée et que dans ces situations cliniques les modalités thérapeutiques habituelles sont nécessaires. La clearance du composé observée au cours de l'hémodialyse est égale ou inférieure à 10 ml/min. De surcroît nos travaux identifient l'importance de la voie d'élimination hépatique non intestinale de la doxycycline. La doxycycline apparaît donc être unique parmi les tétracyclines en ce sens qu'elle peut être utilisée comme une drogue de choix pour le traitment des infections systémiques quand une tétracycline est indiquée et qu'il existe une altération de la fonction rénale

Mechanisms of lysine-induced acute renal failure in rats

Mechanisms of lysine-induced acute renal failure in rats. We have previously found that lysine produces acute renal failure in rats. To define the acute effects of lysine, rats given lysine at 8.9 mg/kg/min, i.v. for 4.5 hr were compared with control rats receiving equiosmolar dextrose. Systemic blood pressure was stable in both groups. Mean intratubular pressure, inulin clearance (CIn), and renal blood flow were determined at 45-min intervals. Intratubular pressures measured with a servonulling micropressure device were elevated by 90 min in lysine-treated animals, with tubular heterogeneity, while pressures in dextrose-treated rats were normal and homogeneous. By 135 min CIn in lysine-treated rats was 45% of CIn in dextrose rats. Urine output fell in ly sine-treated rats. Renal blood flow determined by flow probe remained normal in ly sine-treated rats through 135 min and did not decline significantly until 180 min. Significant dilatation of surface tubules was documented by intravital microscopy beginning at 90 min in lysine-treated rats. The sequence of elevated intratubular pressure and tubular dilatation, followed by decreased CIn, and then by decreased renal blood flow suggests that lysine produces acute renal failure primarily through tubular obstruction. The tubular obstruction is followed later by an increase in renal vascular resistance