Biochar amendment improves growth and the essential oil quality and quantity of peppermint (Mentha × piperita L.) grown under waste water and reduces environmental contamination from waste water disposal.

The reuse of waste water (WW) in agriculture is challenging as a potential strategy for sustainable agriculture development. However, its high content of heavy metals may cause damage to ecosystems. The property of biochar (BC) to minimize heavy metals accumulation into the soil was studied taking as a case study peppermint (Mentha x piperita L., Lamiaceae) irrigated with WW. Application of BC and WW, separately, promoted height, shoot number, crown diameter, internode length, leaf number, leaf length, leaf width, fresh (FW) and dry aerial parts weights (DW), root FW and root DW of peppermint. Also an increment in canopy diameter was observed. BC application considerably increased N, Mg, Mn, Fe and Zn, while WW increased N, P, K and Fe levels. Irrigation of peppermint with WW led to an increase of chlorophyll (Chl) a, Chl b, Chl a+b, carotenoids, anthocyanins, photosynthetic rate, transpiration, stomatal conductance, relative water content (RWC), and crop yield. On the other hand, BC application led to a decrease of Cd and Pb accumulation in plants. BC and WW application, separately, increased the essential oil content, the total phenol content, and the antioxidant capacity. Regardless of BC levels, irrigation of plants with WW decreased the percentage of menthone, menthofuran, isomenthone and pulegone in the essential oil, and increased the percentage of menthol and carvone. Similarly, BC application raised the percentage of menthol, and decreased that of pulegone. Overall, the application of BC in the culture medium is able to decrease the heavy metal concentration and improves the essential oil quality and quantity of peppermint under WW irrigation.

Treatment Effect of Ergocalciferol on Bone Metabolism Indexes and Parathyroid Hormone in Hemodialysis Patients.

INTRODUCTION: Vitamin D deficiency is a common problem in end-stage renal disease patients under hemodialysis. Both active and nutritional vitamin D supplementation have been recommended for its treatment. In this study we aimed to evaluate the effects of treatment with ergocalciferol on bone metabolism indexes in hemodialysis patients. MATERIALS AND METHODS: In a randomized controlled trial, 40 hemodialysis patients were randomly allocated to the intervention (n = 20) and placebo (n = 20) groups. During the study, 4 patients in the placebo and 1 in the intervention group were excluded. Patients received calcitriol, 0.25 mg/d, with ergocalciferol, 50 000 IU, or placebo weekly for 3 months. Serum levels of 25-hydroxyvitamin D, calcium, parathyroid hormone, and alkaline phosphatase were measured before and after treatment. RESULTS: 25-hydroxyvitamin D levels were significantly improved in the intervention group (12.00 ± 4.90 ng/mL versus 29.89 ± 9.48 ng/mL, P < .001), but the placebo group had no improvement (14.23 ± 7.62 ng/mL versus 13.87 ± 8.04 ng/mL, P > .05). There was no significant changes in serum calcium, parathyroid hormone, or alkaline phosphatase levels in each group. Eight patients (42.1%) in the intervention compared to zero cases in the placebo group had normal 25-hydroxyvitamin D levels after treatment (P = .004). No cases of hypercalcemia were seen in the studied patients. CONCLUSIONS: Treatment with ergocalciferol could significantly improve vitamin D deficiency with no significant effects of serum calcium or parathyroid hormone levels.