Are iron chelates suitable to perform photo-Fenton at neutral pH for secondary effluent treatment?

There have been concerns about which iron chelate is most suitable for application in the photo-Fenton process as well as the fate of these chelates after application. In this study, five chelating agents, i.e. citric acid (CA), oxalic acid (OA), ethylenediamine disuccinic acid (EDDS), ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), representing the most used iron chelates were assessed for suitability of application in homogeneous photo-Fenton-like process at pH of 7. The efficiency of the iron chelates were assessed in the disinfection of secondary effluent. The results for the disinfection and bacteria regrowth followed the order EDTA>OA>NTA>CA>OA. All the iron chelates were observed to have increased the COD of the effluent with EDDS having the highest COD contribution. The ability of the chelates to remove aromaticity was measured by the UV254 measurement. The efficiency of the chelates to remove aromaticity decreased in the order CA>EDDS>NTA>CA>OA. To determine the fate of the chelates, toxicity tests were conducted on the chelates before and after irradiation and the results revealed a decrease in toxicity after photoirradiation, implying the chelates were degraded and the products/intermediates produced were of less toxicity as compared to the parent compounds.

A review on the use of chelating agents as an alternative to promote photo-Fenton at neutral pH: Current trends, knowledge gap and future studies.

In this review, we have critically examined the alternatives to conventional photo-Fenton process such as the strategies to perform it in circumneutral pH in the so-called photo-Fenton like process. They include iron chelation, iron replacement with another metal and use of iron immobilized on surfaces of solid materials, use of iron oxides, among others. The use of such strategies can be employed to overcome the challenges identified in conventional photo-Fenton, moreover, advantages and drawback of each technique must be clarified and the recent achievements should be shared with the scientific community. The use of a chelating agent to make iron soluble at circumneutral pH presents many advantages when compared to other current techniques. However, the correct understanding of the chelating process, complex activity and the complex resistance along with the mechanism of radical production should be taken into account to prepare an effective photo-Fenton with complexed iron. The review also identifies the current trends in chelate assisted photo-Fenton process and the unexplored areas in this field of study. A discussion about the environmental and safety issues in the application of these methods, with emphasis to the Fe chelation strategy, was also considered with detailed review over the past ten years.

Salivary gland tumour of the lip: report of two cases and literature review.

BACKGROUND: Salivary gland tumours (SGT'S) are uncommon. The minor glands are dispersed throughout the upper aerodigestive submucosa including the lip. OBJECTIVE: To present two case reports of salivary gland tumour of the upper lip and highlight its diagnostic and therapeutic challenges. CASE REPORTS: A 50-year-old female farmer presented with a two year history of swelling of the upper lip and the histology revealed a pleomorphic adenoma of the minor salivary gland. She was offered a wide excision which resulted in a huge upper lip defect managed by a two staged lip switch ABBE flap. The second patient, a 40-year-old female teacher presented with a 10 year history of a left sided upper lip swelling. Histology revealed pleomorphic adenoma. She was offered an excision with no evidence of recurrence after 26 months of follow up. CONCLUSION: Salivary gland tumours should be considered as a differential diagnosis of tumours of the lip: Early presentation is advocated as late presentation with advanced tumour presents diagnostic and therapeutic challenges.

[Adrenal cortex carcinoma: diagnosis, therapy and course in 10 cases]. / Das Nebennierenrindenkarzinom: Diagnostik, Therapie und Verlauf in zehn Fällen.

Data from ten cases with carcinoma of the adrenal cortex, diagnosed between 1981 and 1988, have been extensively reevaluated. Six patients suffered from a hormonally active tumor with proven clinical and laboratory signs of hypercortisolism and/or hyperandrogenism. Female patients dominated the cohort (eight of ten). No preference for particular age (35 to 64, mean 52) or lateralisation of the tumor was recognisable. In all cases signs for endocrinopathy and/or tumor disease lead to investigative intervention. Nonspecific symptoms like pain, reduction of weight and fatigue were registered most frequently. In three patients an abdominal tumor was palpable. Investigation of hormone levels and imaging procedures (sonography and CT scan) assured correct diagnosis in all cases. Since prior to operation metastases have been detected in five cases and in eight cases capsular invasion was proven histologically only, one patient was free of tumor after operation but developed hepatic metastases later on. Altogether nine of ten patients developed metastases later on. Seven of the patients died from the perioperative period up to 8.4 +/- 8.15 months. Mean survival of all patients was 20.5 +/- 24.5 months. Histological grading and assessment of anaplasia did not correlate with either survival or tumor stage. None of the patients presented with tumor stage I according to the TNM system by MacFarlane (55). All four patients with advanced disease in stage IV died within the first year after operation. Eight patients were treated with 1 to 6 g of the adrenolytic o,p'DDD (mitotane, Lysodren). In one of these cases, a sonographically documented remission lasting for over eight years was observed. A second patient with anaplastic carcinoma showed a reduction of the size of pulmonary metastases under continuous therapy with o,p'DDD and a cyclic polychemotherapy. After the latter was discontinued, the course was progressive.