Remediation of cadmium-contaminated coastal saline-alkaline soil by Spartina alterniflora derived biochar.

Following oil extraction in the wetland of the Yellow River Delta, heavy metal contamination of coastal saline-alkaline soil, especially with cadmium (Cd), has become a serious environmental problem in some regions. Biochar application has been proposed to remedy Cd-contaminated soil, but the remediation effect is related to preparation conditions of biochar (e.g., pyrolysis temperature and raw material) and soil properties. The invasive plant, Spartina alterniflora, produces a high amount of biomass, making it suitable for biochar production in coastal China. We investigated the effect of S. alterniflora-derived biochar (SDB) pyrolyzed at four temperatures (350, 450, 550, and 650 °C) crossed with three addition ratios (1, 5, and 10%) and control on Cd contamination of coastal saline-alkaline soil. Pyrolysis temperature affected pH, surface area, and functional groups of SDB. SDB markedly improved soil pH and soil organic matter, but the degree of improvement was affected by pyrolysis temperature and addition ratio. SDB significantly altered available Cd content in soil, but reduced it only at low pyrolysis temperatures (350 and 450 °C). Available Cd content had a positive correlation with soil pH (R2 = 0.298, P < 0.01), but was not related to salinity and soil organic matter content. Thus, SDB pyrolyzed at 350 °C with 5% addition was optimal for passivating Cd in coastal saline-alkaline soil, since available Cd content in soil decreased mostly (by 26.9%). These findings act as a reference for the development of an application strategy for SDB to ameliorate Cd-contaminated coastal saline-alkaline soil.

Long-Term Follow-Up of the Fellow Eye in Patients Undergoing Surgery on One Eye for Treating Myopic Traction Maculopathy.

Objective. To observe the fellow eye in patients undergoing surgery on one eye for treating myopic traction maculopathy. Methods. 99 fellow eyes of consecutive patients who underwent unilateral surgery to treat MTM were retrospectively evaluated. All patients underwent thorough ophthalmologic examinations, including age, gender, duration of follow-up, refraction, axial length, intraocular pressure, lens status, presence/absence of a staphyloma, and best-corrected visual acuity (BCVA). Fundus photographs and SD-OCT images were obtained. When feasible, MP-1 microperimetry was performed to evaluate macular sensitivity and fixation stability. Results. At an average follow-up time of 24.7 months, 7% fellow eyes exhibited partial or complete MTM resolution, 68% stabilized, and 25% exhibited progression of MTM. Of the 38 eyes with "normal" macular structure on initial examination, 11% exhibited disease progression. The difference in progression rates in Groups 2, 3, and 4 was statistically significant. Refraction, axial length, the frequency of a posterior staphyloma, chorioretinal atrophy, initial BCVA, final BCVA, and retinal sensitivity all differed significantly among Groups 1-4. Conclusions. Long axial length, chorioretinal atrophy, a posterior staphyloma, and anterior traction contribute to MTM development. Patients with high myopia and unilateral MTM require regular OCT monitoring of the fellow eye to assess progression to myopic pre-MTM. For cases exhibiting one or more potential risk factors, early surgical intervention may maximize the visual outcomes.