Effect of iron-loaded sludge biochar amendments on phytoremediation potential of Cr-contaminated soils by Leersia hexandra swartz.

In this study, the effect of iron-loaded sludge biochar (ISBC) with different amendment dosages (mass ratio of biochar to soil equal to 0, 0.01, 0.025 and 0.05) on the phytoremediation potential of Leersia hexandra swartz (L. hexandra) to Cr-contaminated soil was investigated. With increasing ISBC dosage from 0 to 0.05, plant height, aerial tissue biomass and root biomass increased from 15.70 cm, 0.152 g pot-1 and 0.058 g pot-1 to 24.33 cm, 0.304 g pot-1 and 0.125 g pot-1, respectively. Simultaneously, the Cr contents in aerial tissues and roots increased from 1039.68 mg kg-1 to 2427.87 mg kg-1 to 1526.57 mg kg-1 and 3242.62 mg kg-1, respectively. Thus, the corresponding bioenrichment factor (BCF), bioaccumulation factor (BAF), total phytoextraction (TPE) and translocation factor (TF) values were also increased from 10.52, 6.20, 0.158 mg pot-1 (aerial tissue)/0.140 mg pot-1 (roots) and 0.428 to 15.15, 9.42, 0.464 mg pot-1 (aerial tissue)/0.405 mg pot-1 (roots) and 0.471, respectively. The significant positive effect of ISBC amendment was primarily attributed to the following three aspects: 1) the root resistance index (RRI), tolerance index (TI) and growth toxicity index (GTI) of L. hexandra to Cr were increased from 100%, 100% and 0%-216.88%, 155.02% and 42.18%, respectively; 2) the bio-available Cr content in the soil was decreased from 1.89 mg L-1 to 1.48 mg L-1, while the corresponding TU (toxicity units) value was declined from 0.303 to 0.217; 3) the activities of urease, sucrase and alkaline phosphatase in soil were increased from 0.186 mg g-1, 1.40 mg g-1 and 0.156 mg g-1 to 0.242 mg g-1, 1.86 mg g-1 and 0.287 mg g-1, respectively. In summary, ISBC amendment was able to significantly improve the phytoremediation of Cr-contaminated soils by L. hexandra.

[Clinical comparison between micro-endoscopic discectomy (MED) and open discectomy for treatment of lumbar disc herniation].

OBJECTIVE: To compare between micro-endoscopic discectom) (MED) and open decompression discectomy, and assess the clinical value of MED. METHODS: Two hundreds and sixty-one cases who suffered from lumbar disc herniation had a retrospective study. One hundred and twenty-one of 261 patients were treated with MED including 72 male and 52 female with an average age of 37.6 years ranging 26 to 63, the segment of herniated discs were at L4.5 in 66 and at L5S1 in 58. The other 137 patients were treated with decompression by fenestration and discectomy including 66 male and 71 female with an average age of 44.5 years ranging 25 to 71, the segment of herniated discs were at L4.5 in 64 and at L5S1 in 73. MED was performed via a scopes. Open decompression discectomy was performed decompression by fenestration and discectomy. RESULTS: MED group were followed up for 14.5 months on average, the operative time was (85 +/- 15) minutes and blood loss was (50 +/- 10) ml, time of laying in bed after operation was (50 +/- 8) hours. Open decompression group were followed up for 15.5 months on average, operative time was (60 +/- 15) minutes and blood loss was (80 +/- 20) ml, time of laying bed after operation was (150 +/- 24) hours. MED group needed significantly less narcotic medication after operation than open decompression group. According to modified Macnab criteria, the results were excellent in 94, good in 25, fair in 5 in MED group and excellent in 101, good in 28, fair in 8 in open decompression group. CONCLUSION: As compared with open decompression group, MED offers a similar short-term clinical outcome, but with smaller incision, less tissue trauma and quicker recovery.