Optimisation of bisphenol A removal from water using chemically modified pine bark and almond shell

The ability of pine bark and almond shells to remove bisphenol A (BPA) from aqueous solutions was evaluated. Samples of these traditional agro-forestry by-products were milled, sieved into different particle size fractions (0.10–0.15 and 1.5–2.0 mm) and submitted to two different types of treatment. Sorption experiments were conducted in a batch system at room temperature and natural pH. Sorption equilibrium was attained after 48 h for all systems under study. Bisphenol A was adsorbed more effectively on the smaller particles of the sorbents. Pine bark and almond shell pretreated with formaldehyde presented higher sorption efficiency (95%), followed by almond shell (87%) and pine bark (82%) washed with hot water. All the sorption isotherms were found to fit a Freundlich equation, with correlation coefficients (R ²) between 0.823 and 0.989. The sorption coefficient (K _F) ranged from 0.06 to 0.74 (mg^1?1/n ·L ^1/n ·g ^?1). These results indicate that utilisation of both materials as an alternative sorbent for the removal of bisphenol A from contaminated waters is promising because they are available in large amounts and have an acceptable cost–efficiency ratio when compared with traditional adsorbents.     

Opinions on railway trespassing of people living close to a railway line

A survey was designed to investigate opinions on railway trespassing of people living close to a railway line. The results showed that 89.2% of the respondents (n = 502) recalled that they had seen trespassing in their neighbourhood and, based on their observations, adults are the largest group trespassing. Overall, 68.9% of the respondents had personal experience of trespassing although 83.5% considered trespassing to be fairly or highly dangerous and 81.0% assumed it to be illegal. The respondents supported countermeasures such as building an underpass or fencing off the tracks, and only a few of them indicated that nothing could be done to resolve the problem. In addition, education in schools on the dangers of trespassing was suggested. These results allow practitioners and researchers to see the problem from a local perspective and thus develop a better understanding. This in turn helps design effective countermeasures.     

Unraveling the antibacterial mode of action of a clay from the Colombian Amazon

Natural antibacterial clays can inhibit growth of human pathogens; therefore, understanding the antibacterial mode of action may lead to new applications for health. The antibacterial modes of action have shown differences based on mineralogical constraints. Here we investigate a natural clay from the Colombian Amazon (AMZ) known to the Uitoto natives as a healing clay. The physical and chemical properties of the AMZ clay were compared to standard reference materials: smectite (SWy-1) and kaolinite (API #5) that represent the major minerals in AMZ. We tested model Gram-negative (Escherichia coli ATCC #25922) and Gram-positive (Bacillus subtilis ATCC #6633) bacteria to assess the clay’s antibacterial effectiveness against different bacterial types. The chemical and physical changes in the microbes were examined using bioimaging and mass spectrometry of clay digests and aqueous leachates. Results indicate that a single dose of AMZ clay (250 mg/mL) induced a 4–6 order of magnitude reduction in cell viability, unlike the reference clays that did not impact bacterial survival. AMZ clay possesses a relatively high specific surface area (51.23 m²/g) and much higher total surface area (278.82 m²/g) than the reference clays. In aqueous suspensions (50 mg clay/mL water), soluble metals are released and the minerals buffer fluid pH between 4.1 and 4.5. We propose that the clay facilitates chemical interactions detrimental to bacteria by absorbing nutrients (e.g., Mg, P) and potentially supplying metals (e.g., Al) toxic to bacteria. This study demonstrates that native traditional knowledge can direct scientific studies.     

Tracking traffic citations through court adjudications to posting to public driver records

Research has shown that one of the best predictors of a driver's future crash risk is the number of prior moving traffic violations (e.g., speeding). Public driver records are used by government and nongovernment users to assess drivers' future crash risks. However, the adequacy of such records may be compromised by deficient recordkeeping systems and by court-based diversion programs (e.g., probation before judgment, traffic school election) that allow drivers presumed guilty to avoid convictions in court and posting of the violations to their driver records. Using a case study approach in four jurisdictions in three states, citations issued for traffic violations were tracked through court adjudication to placement on driver records. Individual court case records and driver history records were reviewed. The percentages of citations issued that appeared on driver records were 58-87% for moving violations, 30-94% for driving while impaired (DWI), and 67-95% for occupant restraint violations. Diversion programs were a significant factor in two states, where 21% and 35% of moving violation citations resulted in diversions. Almost all court convictions in each jurisdiction were recorded on driver records, but few citations resulting in diversions were recorded. Thus, diversion programs in some jurisdictions substantially reduce the utility of public driver records as reliable indicators of prior traffic violations and future crash risks. Recordkeeping inefficiencies and errors were less important factors in this study.