Pressure-controlled injection of guar gum stabilized microscale zerovalent iron for groundwater remediation.

The paper reports a pilot injection test of microsized zerovalent iron (mZVI) dispersed in a guar gum shear thinning solution. The test was performed in the framework of the EU research project AQUAREHAB in a site in Belgium contaminated by chlorinated aliphatic hydrocarbons (CAHs). The field application was aimed to overcome those critical aspects which hinder mZVI field injection, mainly due to the colloidal instability of ZVI-based suspensions. The iron slurry properties (iron particles size and concentration, polymeric stabilizer type and concentration, slurry viscosity) were designed in the laboratory based on several tests (reactivity tests towards contaminants, sedimentation tests and rheological measurements). The particles were delivered into the aquifer through an injection well specifically designed for controlled-pressure delivery (approximately 10 bars). The well characteristics and the critical pressure of the aquifer (i.e. the injection pressure above which fracturing occurs) were assessed via two innovative injection step rate tests, one performed with water and the other one with guar gum. Based on laboratory and field preliminary tests, a flow regime at the threshold between permeation and preferential flow was selected for mZVI delivery, as a compromise between the desired homogeneous distribution of the mZVI around the injection point (ensured by permeation flow) and the fast and effective injection of the slurry (guaranteed by high discharge rates and injection pressure, resulting in the generation of preferential flow paths). A monitoring setup was designed and installed for the real-time monitoring of relevant parameters during injection, and for a fast determination of the spatial mZVI distribution after injection via non-invasive magnetic susceptibility measurements.

[Clinical and immunologic aspects of chlamydial infections in infertile women]. / Klinicki i imunoloski aspekti hlamidijalnih infekcija kod infertilnih zena.

UNLABELLED: Chlamydia Trachomatis (CT) infection of the genital tract ranges from clinically severe to the silent subclinical forms of pelvic inflammatory diseases which can result in fallopian tubes obstruction and subsequent infertility. Our investigations: The serum antichlamydial antibodies of 30 infertile patients and the cultures of Chlamydia Trachomatis from specimens of endometrial biopsies were determined as well as HSG and laparoscopic examinations. METHODOLOGY: The evaluation of serum antichlamydial antibodies were measured by ELISA test. The endometrial specimens for culture of Chlamydia Trachomatis were collected transcervically from the uterine cavity. The statistical analyses were calculated on the basis of Student t test. RESULTS: Immunological determinations showed the presence of antichlamydial antibodies in 43.6%. The endometrial cultures yielded growth of CT (36.6%) and histological signs of chlamydial endometritis were also discovered. This study pointed to the positive correlation between the results of endometrial biopsies (cultures), immunological (serological) investigations and clinical examinations showing that the chlamydial infection reached the Fallopian tubes from the endometrium which could result in infertility.