Fate of perfluoroalkyl and polyfluoroalkyl substances (PFAS) through two full-scale wastewater sludge incinerators.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are an emerging issue in wastewater treatment. High-temperature thermal processes, incineration being time-tested, offer the opportunity to destroy and change the composition of PFAS. The fate of PFAS has been documented through wastewater sludge incinerators, including a multiple hearth furnace (MHF) and a fluidized bed furnace (FBF). The dewatered wastewater sludge feedstock averaged 247- and 1280-µmol targeted PFAS per sample run in MHF and FBF feed, respectively. Stack emissions (reportable for all targeted PFAS from MHF only) averaged 5% of that value with shorter alkyl chain compounds comprising the majority of the targeted PFAS. Wet scrubber water streams accumulated nonpolar fluorinated organics from the furnace exhaust with an average of 0.740- and 0.114-mol F- per sample run, for the MHF and FBF, respectively. Simple alkane PFAS measured at the stack represented 0.5%-4.5% of the total estimated facility greenhouse gas emissions. PRACTITIONER POINTS: The MHF emitted six short chain PFAS from the stack, which were shorter alkyl chain compounds compared with sludge PFAS. The FBF did not consistently emit reportable PFAS from the stack, but contamination complicated the assessment. Five percent of the MHF sludge molar PFAS load was reported in the stack. MHF and FBF wet scrubber water streams accumulated nonpolar fluorinated organics from the furnace exhaust. Ultra-short volatile alkane PFAS measured at the stack represented 0.5%-4.5% of the estimated facility greenhouse gas emissions.

High-temperature technology survey and comparison among incineration, pyrolysis, and gasification systems for water resource recovery facilities.

Solids from wastewater treatment undergo processing to reduce mass, minimize pathogens, and condition the products for specific end uses. However, costs and contaminant concerns (e.g., per- and polyfluoroalkyl substances [PFAS]) challenge traditional landfill and land application practices. Incineration can overcome these issues but has become complicated due to evolving emissions regulations, and it suffers from poor public perception. These circumstances are driving the re-emergence of pyrolysis and gasification technologies. A survey of suppliers was conducted to document differences with technologies. Both offer advantages over incineration with tailored production of a carbon-rich solid, currently less stringent air emission requirements, and lower flue gas flows requiring treatment. However, incineration more simply combines drying and thermal processing into one reactor. Equipment costs provided favor pyrolysis and gasification at lower capacities but converge with incineration at higher capacities. Long-term operational experience will confirm technology competitiveness and elucidate whether pyrolysis and gasification warrant widespread adoption. PRACTITIONER POINTS: Pyrolysis and gasification systems are gaining traction in the wastewater industry with several full-scale installations operating, in construction, or design Several advantages, but some disadvantages, are considered in comparison with incineration Organic contaminants, including PFAS, will undergo transformation and potentially complete mineralization through each process.

Pyrolysis and gasification at water resource recovery facilities: Status of the industry.

Wastewater treatment generates solids requiring subsequent processing. Costs and contaminant concerns (e.g., per- and polyfluoroalkyl substances [PFAS]) are challenging widely used landfilling and land application practices. These circumstances are partly driving the re-emergence of pyrolysis and gasification technologies along with beneficial reuse prospects of the char solid residual. Previously, technologies experienced operational challenges leading to revised configurations, such as directly coupling a thermal oxidizer to the reactor to destroy tar forming compounds. This paper provides an overview of pyrolysis and gasification technologies, characteristics of the char product, air emission considerations, and potential fate of PFAS and other pollutants through the systems. Results from a survey of viable suppliers illustrate differences in commercially available options. Additional research is required to validate performance over the long-term operation and confirm contaminant fate, which will help determine whether resurging interest in pyrolysis and gasification warrants widespread adoption. PRACTITIONER POINTS: Pyrolysis and gasification systems are re-emerging in the wastewater industry. Direct coupling of thermal oxidizers and other modifications offered by contemporary systems aim to overcome past failures. Process conditions when coupled with a thermal oxidizer will likely destroy most organic contaminants, including PFAS, but requires additional research. Three full-scale facilities recently operated, several in construction or design that will provide operating experience for widespread technology adoption consideration.

Depression and Somatic Symptoms in a Non-Western Physician.

Because of the high prevalence and association of somatic symptoms in depression, a holistic treatment plan that also targets the associated somatic symptoms can be the cornerstone for such patients. In this paper, we present the case of a 53-year-old male physician with depression associated with the somatic symptoms of dysphagia. The initial failure in treating his swallowing defect led to the deterioration in his condition. Moreover, his unique history, complicated by multifactorial life stressors, also raises the attention that there are a variety of presentations of depression.

Per- and polyfluoroalkyl substances thermal destruction at water resource recovery facilities: A state of the science review.

Per- and polyfluoroalkyl substances (PFAS) are a recalcitrant group of chemicals and can be found throughout the environment. They often collect in wastewater systems with virtually no degradation prior to environmental discharge. Some PFAS partitions to solids captured in wastewater treatment which require further processing. Of all the commonly applied solids treatment technologies, incineration offers the only possibility to completely destroy PFAS. Little is known about the fate of PFAS through incineration, in particular, for the systems employed in water resource recovery facilities (WRRF). This review covers available research on the fate of PFAS through incineration systems with a focus on sewage sludge incinerators. This research indicates that at least some PFAS destruction will occur with incineration approaches used at WRRFs. Furthermore, PFAS in flue gas, ash, or water streams used for incinerator pollution control may be undetectable. Future research involving full-scale fate studies will provide insight on the efficacy of PFAS destruction through incineration and whether other compounds of concern are generated. PRACTITIONER POINTS: Thermal processing is the only commercial approach available to destroy PFAS. Thermal degradation conditions required for destruction of PFAS during incineration processes are discussed. Fate of PFAS through water resource recovery facility incineration technologies remains unclear. Other thermal technologies such as smoldering combustion, pyrolysis, gasification, and hydrothermal liquefaction provide promise but are in developmental phases.

Ictal aphasia: an unusual presentation of temporal lobe seizures.

Language disturbances during epileptic seizures are not uncommon, but isolated speech impairment is rare. We report a 67-year-old male with sudden onset of aphasia initially thought to be the result of an infarction of left middle cerebral artery territory. He had recurrent episodes of non-fluent, severely aphasic speech with intact comprehension as the primary manifestation, without other clinical seizure activity. After the administration of antiepileptic medication, his language returned to the baseline level. This case suggests that paroxysmal non-fluent aphasia can result from a seizure focus in the dominant temporal lobe. This is an important differential to be considered in patients with aphasia, which will assist in early diagnosis and treatment.

Breakeven costs for distributed advanced technology water-treatment systems.

Breakeven costs associated with the strategic distribution of advanced treatment units in a water supply network to manage network-derived water quality degradation were investigated. Disinfections by-product (DBP) formation was used as a representative water quality degradation parameter. A basic DBP formation model was used to predict that fraction of residential service population receiving water degraded below required quality levels within a hypothetical water utility service population. The costs of upgrading centralized treatment facilities to meet DBP water quality standards were estimated and then apportioned over that population fraction to estimate breakeven or equivalent cost allowances for an alternative distributed treatment approach. Breakeven costs for single-connection treatment units were calculated for a range of service populations. A sensitivity analysis of the impacts of various network parameters on breakeven costs revealed the existence of singularities--sudden shifts in optimal technology selection--resulting from relatively small variations in required treatment levels.