Reagent-free electrokinetic remediation coupled with anode oxidation for the treatment of phenanthrene polluted soil.

Electrokinetic in-situ chemical oxidation (EK-ISCO) has attracted much attention during remediation of organic contaminated soil. Oxidants in EK-ISCO brings high cost and negative effects on soil physicochemical properties. In this study, a novel approach of combined electrokinetic treatment and anode oxidation was investigated to remediate phenanthrene polluted soils without adding oxidants. The fabricated Ti4O7 acted as anode, and could generate •OH at the rate of 9.31 × 10-7 mol h-1 at current 5.10 mA cm-2 through direct H2O electrolysis. Electro-osmotic flow (EOF) was used to transport phenanthrene to anode for the subsequent degradation. Sandy soil, fluvo-aquic soil and red soil were selected as typical soil samples, because pH and buffer capacity were two important factors affecting the direction of EOF. Strategies were developed to regulate the direction of EOF, including adding CEM membrane, maintaining soil pH at 3.5-4.0 and mixing solution from anode and cathode chambers. After treatment, more than 81.9% of phenanthrene was removed without adding any oxidants, and the remediated soil had low toxicity for Lolium perenne growth based on 3-d cultivation results. The results indicated that EK-AO had the advantage of less energy consumption and superior environmental friendliness than traditional EK-ISCO.

Enhanced soil washing process for the remediation of PBDEs/Pb/Cd-contaminated electronic waste site with carboxymethyl chitosan in a sunflower oil-water solvent system and microbial augmentation.

An innovative ex situ soil washing technology was developed to remediate polybrominated diphenyl ethers (PBDEs) and heavy metals in an electronic waste site. Elevated temperature (50 °C) in combination with ultrasonication (40 kHz, 20 min) at 5.0 mL L(-1) sunflower oil and 2.5 g L(-1) carboxymethyl chitosan were found to be effective in extracting mixed pollutants from soil. After two successive washing cycles, the removal efficiency rates for total PBDEs, BDE28, BDE47, BDE209, Pb, and Cd were approximately 94.1, 93.4, 94.3, 99.1, 89.3, and 92.7 %, respectively. Treating the second washed soil with PBDE-degrading bacteria (Rhodococcus sp. strain RHA1) inoculation and nutrient addition for 3 months led to maximum biodegradation rates of 37.3, 52.6, 23.9, and 1.3 % of the remaining total PBDEs, BDE28, BDE47, BDE209, respectively. After the combined treatment, the microbiological functions of washed soil was partially restored, as indicated by a significant increase in the counts, biomass C, N, and functioning diversity of soil microorganisms (p < 0.05), and the residual PBDEs and heavy metals mainly existed as very slow desorbing fractions and residual fractions, as evaluated by Tenax extraction combined with a first-three-compartment model and sequential extraction with metal stability indices (I R and U ts). Additionally, the secondary environmental risk of mixed contaminants in the remediated soil was limited. Therefore, the proposed combined cleanup strategy is an environment-friendly technology that is important for risk assessment and management in mixed-contaminated sites.

[Study on effects of Tripterygium wilfordii polycoride in resisting macrophage inflammation and regulating inflammation via TLR4/NF-κB].

To investigate the effect of Tripterygium wilfordii polycoride (TWP) on LPS-induced macrophage inflammatory response, particularly the inhibitory effect on inflammatory factors TNF-α and IL-1ß and the regulatory effect on inflammation via TLR4/NF-κB. The MTT method was adopted to test the effects of tested drugs, TWP, dexamethasone (DXM) and azathioprine (AZA) on cell growth to define the appropriate concentration. LPS was used to induce the inflammatory reaction in mouse RAW264. 7 cell lines. The Elisa kit was adopted to test the release level of TNF-α and IL-1ß. The Western blotting was applied to test the protein expressions of TNF-α and IL-1ß. The RT-PCR was adopted to test the expressions of TLR4 and NF-κB. According to the results, TWP could inhibit the release of macrophage inflammatory factors TNF-α and IL-1ß in a dose dependent manner. All of TWP groups showed a weaker efficacy than that of the DXM group. But the TWP high dose group revealed a better effect on TNF-α and equal effect on IL-1ß compared with the AZA group. TWP show an equal or better effect in down-regulating TLR4 and NF-κB p65 expressions in a dose dependent manner than DXM and AZA. In conclusion, TWP could inhibit TLR4 and NF-κB p65, which may be related to the down-regulation of TLR4 and NF-κB p65 receptor expressions.

[Intervention Effect of Modified Dachengqi Decoction on Intestinal Mucosal Barrier of Severe Acute Pancreatitis Model Rats].

OBJECTIVE: To study the effect of Modified Dachengqi Decoction (MDD) as whole course therapy on mediators of inflammation in severe acute pancreatitis (SAP) model rats, and to compare interventional advantages over intestinal mucosal barrier (IMB) of SAP rats between whole course therapy of MDD and early stage therapy of MDD. METHODS: Totally 190 SD rats were divided into five groups according to random digit table, i.e., the sham-operation group, the model group, the octreotide (OT) group, the early stage MDD treatment group, the whole course MDD treatment group, 38 in each group. SAP models were established with retrograde injection of 5% sodium taurocholate into the pancreaticobiliary duct. Three hours after modeling normal saline (NS) was administered to rats in the sham-operation group and the model group by gastrogavage, once per 12 h.1.35 µg/100 g OT was subcutaneously injected to rats in the OT group, once every 8 h. 0.4 mL/100 g MDD was administered to rats in the early stage MDD treatment group, and 6 h later changed to NS (once per 12 h).0.4 mL/100 g MDD was administered to rats in the whole course MDD treatment group, once every 12 h. The accumulative survival rate and morphological manifestations of pancreas and small intestine were observed under microscope 48 h after modeling. Pathologic scores of the pancreas and small intestine were conducted at 4, 6, 24, and 48 h after modeling. Contents of serum amylase (AMY), alanine transaminase (ALT), and TNF-α were also detected. The expression of high mobility group box protein 1 (HMGB1) in the small intestine tissue was also detected by Western blot. The positive rate of bacterial translocation in mesenteric lymph nodes (MLNs) was observed within 48 h. Correlations between serum TNF-α or HMGB1 in small intestinal tissue and pathological scores of the pancreas or the small intestine were analyzed. RESULTS: The accumulative survival rate was 100. 0% in the sham-operation group, 79. 2% in the whole course MDD treatment group, 70. 8% in the OT group, 45. 8% in the early stage MDD treatment group, and 37.5% in the model group. At 6 h after modeling, pathological scores decreased more in the whole course MDD treatment group, the early stage MDD treatment group, the OT group than in the model group (P < 0.05). At 24 and 48 h after modeling, pathological scores of the pancreas and the small intestine decreased more in the whole course MDD treatment group and the OT group than in the early stage MDD treatment group (P <0. 05). At 6, 24, and 48 h after modeling, serum contents of AMY and ALT both decreased more in the whole course MDD treatment group, the early stage MDD treatment group, the OT group than in the model group (P < 0.05). At 48 h after modeling serum contents of AMY and ALT both decreased more in the whole course MDD treatment group and the OT group than in the early stage MDD treatment group (P < 0.05). At 6 h after modeling serum TNF-α levels decreased more in the whole course MDD treatment group, the early stage MDD treatment group, the OT group than in the model group (P < 0.05). At 6, 24, and 48 h after modeling the level of HMGB1 in the small intestinal tissue decreased more in the whole course MDD treatment group, the early stage MDD treatment group, the OT group than in the model group (P < 0.05). Of them, HMGB1 levels at 24 and 48 h were lower in the whole course MDD treatment group and the OT group than in the early stage MDD treatment group (P < 0.05). The number of MLNs bacterial translocation at 48 h after modeling was lower in the whole course MDD treatment group and the OT group than in the early stage MDD treatment group and the model group (P < 0.05). Serum TNF-α contents within 6 h were positively correlated with pathological scores of pancreas (r = 0.579, P < 0.01). ROC curve showed that serum TNF-α contents could predict the severity of SAP (ROC = 0.990, 95% Cl: 0.971 to 1.000). HMGB1 in the small intestine was positively correlated with pathological scores of the small intestine (r = 0.620, P < 0.01). CONCLUSIONS: Early stage use of MDD could effectively reduce the release of TNF-α, while whole course use of MDD could effectively inhibit the expression of HMGB1. The latter could preferably attenuate injuries of the pancreas and the small intestine, lower MLNs bacterial translocation, and elevate the survival rate.

Electrokinetic delivery of persulfate to remediate PCBs polluted soils: effect of injection spot.

Persulfate-based in situ chemical oxidation (ISCO) is a promising technique for the remediation of organic compounds contaminated soils. Electrokinetics (EK) provides an alternative method to deliver oxidants into the target zones especially in low permeable-soil. In this study, the flexibility of delivering persulfate by EK to remediate polychlorinated biphenyls (PCBs) polluted soil was investigated. 20% (w/w) of persulfate was injected at the anode, cathode and both electrodes to examine its transport behaviors under electrical field, and the effect of field inversion process was also evaluated. The results showed that high dosage of persulfate could be delivered into S4 section (near cathode) by electroosmosis when persulfate was injected from anode, 30.8% of PCBs was removed from the soil, and the formed hydroxyl precipitation near the cathode during EK process impeded the transportation of persulfate. In contrast, only 18.9% of PCBs was removed with the injection of persulfate from cathode, although the breakthrough of persulfate into the anode reservoir was observed. These results indicated that the electroosmotic flow is more effective for the transportation of persulfate into soil. The addition of persulfate from both electrodes did not significantly facilitate the PCBs oxidation as well as the treatment of electrical field reversion, the reinforced negative depolarization function occurring in the cathode at high current consumed most of the oxidant. Furthermore, it was found that strong acid condition near the anode favored the oxidation of PCBs by persulfate and the degradation of PCBs was in consistent with the oxidation of Soil TOC in EK/persulfate system.