No abstract

Two of the main drawbacks to be overcome before full scale implementation of boron-doped diamond electro-oxidation were addressed in this work; its energy consumption and hazard of formation of chlorinated organics. This was framed within a study in which the technical and economic feasibility of BDD electro-oxidation of landfill leachate was evaluated at pilot scale. On one hand, its technical feasibility was assessed based on COD and NH(4)(+) removal, allowing the selection of the operation conditions that provide optimal energy efficiency, and special attention was paid to the risk of formation of undesired by-products such as nitrite, nitrate ions and trihalomethanes. On the other hand, treatment costs were estimated based on energy consumption required to reach the disposal limits to natural watercourses established by legislation. The results were compared with those of other commonly used AOPs. Under the operating conditions studied, the concentration of COD decreased below the disposal limit (160 mg L(-1)) and ammonia concentration reached values as low as 30 mg L(-1). The energy consumption needed was estimated at 54 kWh/m(3) and the formation of chlorination by-products appeared to be low as the maximum total trihalomethane concentration detected was 432 microg/L.

No abstract

Guánica Bay, located in southwestern Puerto Rico, has suffered oil spills and other pollution discharges since the 1960s. Previous research showed elevated concentrations of polychlorinated biphenyls (PCBs) in coral reef and sediment. This research examined PCB concentrations in sediment and fish. Sediment and fish sampling in the bay was facilitated by community members. This study identified the second highest reported PCB level (129,300 ng/g) in sediment in the United States. Fish samples also showed elevated concentrations (1,623ng/g to 3,768 ng/g), which were higher than the thresholds of safe levels of PCBs in fish for human consumption. The alarmingly high concentration of PCBs calls for proactive community engagement to bring awareness about contamination of the bay and more extensive sampling to test for the concentration PCBs in seafood and the people of Guánica. This study also underscores the value of the involvement of local communities during sampling design aimed at identifying hot spots of contaminants.

Background. Brasilia, the capital of Brazil, currently has the largest dumpsite of the Americas at Estrutural, with over 30 million tons of waste accumulated. Recyclable waste collectors are a group of workers who, in addition to having a low socioeconomic status and residing in vulnerable areas, work sorting garbage in inadequate and unsanitary areas. This profession puts individuals at risk, resulting in death, mutilation, and disease for workers. Objectives. The aim of this study was to understand the effects of waste on recyclable collectors, along with their perceptions of associated risks. Methods. A qualitative study was conducted, using interviews with 34 participants at Estrutural. Results. Collectors were exposed to several hazards, including biological, physical, and more extreme hazards (e.g. being run over by waste trucks). Personal protective equipment was not adequately used, exposing recyclable collectors to injury. Accidents included cuts, burns, skin lesions, eyes lesions, and arm, leg, head, feet, and hand injuries and amputations. Often, homecare remedies and collected medical waste (e.g. pain killers) were used on these injuries instead of seeking out proper medical care. Conclusions. Recyclable collectors were aware of occupational hazards, but lacked education on the risks and consequences associated with exposure to medical hazards. Moreover, Brazil recently formally closed all dumpsites, complicating this issue. The findings of the present study confirm the need to address these hazards to provide a safe working environment for waste pickers. Participant Consent. Obtained Ethics Approval. This study was approved by the Research and Ethics Committee of the Health School of Brasília University under Opinion n. 1.517.670/2016. Competing Interests. The authors declare no competing financial interests.