Colour removal from biologically treated textile dyeing wastewater with natural and novel pre-hydrolysed coagulants

In this paper, natural (chitosan and starch) and novel pre-hydrolysed coagulants (PACl, PAFC, PFS and PFC) were performed with coagulant aid for colour removal from a biologically treated textile wastewater including multiple dyes (indigo and reactive). According to the experimental results, optimum coagulant dosages which provide the best colour removal for PACl, PAFCl, PFS (%10) and PFCl (%10), were determined as 80 mg/L, 10 mg/L, 3 mg/L and 40 mg/L, respectively, at pH 4 and pH 6,98 (natural pH of studied wastewater, pHnww). Maximum colour removal was determined as 97% for PAFCl, minimum removal was 23% for PFCl at pH 4, while it was calculated as 75% and 52% at pHnww. COD removal was observed as 45% at pH 4 and 55% at pHnww for maximum colour removal. Sludge production rate was measured as 71 kg/d while this rate was found as 60 kg/d at pHnww. On the other hand colour removal efficiencies were determined in the range of 55-88% at pHnww and pH 3 for chitosan while it was calculated as 52% for starch at pHnww and pH 9. According to the results, PAFCl and chitosan were found as the best coagulants for colour removal of investigated textile wastewater. According to the economic analysis results, the best colour effiency were found as 97% with PAFCl and the second best colour removal were found as 88% with Chitosan. Due to lower sludge production than PAFCl and lower chemical costs; Chitosan can be considered as a reasonable alternative for this wastewater. © 2018, Turkish Chemical Society. All rights reserved.This paper was produced by associated with a Msc. Thesis titled as ‘Determination of the best available coagulation/flocculation technologies for colour removal from a treated textile industrial wastewater originated from the processes including indigo fabric washing together with cotton fabric dyeing’ funded by the Scientific Research Council of Namık Kemal University via Grant No. NKU BAP.00.17.YL.14.0

The effect of COVID-19 on development of hair and nail disorders: a Turkish multicenter, controlled study

© 2022 the International Society of Dermatology.Background: A broad spectrum of skin diseases, including hair and nails, can be directly or indirectly triggered by COVID-19. It is aimed to examine the type and frequency of hair and nail disorders after COVID-19 infection. Methods: This is a multicenter study conducted on consecutive 2171 post-COVID-19 patients. Patients who developed hair and nail disorders and did not develop hair and nail disorders were recruited as subject and control groups. The type and frequency of hair and nail disorders were examined. Results: The rate of the previous admission in hospital due to COVID-19 was statistically significantly more common in patients who developed hair loss after getting infected with COVID-19 (P < 0.001). Telogen effluvium (85%) was the most common hair loss type followed by worsening of androgenetic alopecia (7%) after COVID-19 infection. The mean stress scores during and after getting infected with COVID-19 were 6.88 ± 2.77 and 3.64 ± 3.04, respectively, in the hair loss group and were 5.77 ± 3.18 and 2.81 ± 2.84, respectively, in the control group (P < 0.001, P < 0.001). The frequency of recurrent COVID-19 was statistically significantly higher in men with severe androgenetic alopecia (Grades 4–7 HNS) (P = 0.012; Odds ratio: 2.931 [1.222–7.027]). The most common nail disorders were leukonychia, onycholysis, Beau's lines, onychomadesis, and onychoschisis, respectively. The symptoms of COVID-19 were statistically significantly more common in patients having nail disorders after getting infected with COVID-19 when compared to the control group (P < 0.05). Conclusion: The development of both nail and hair disorders after COVID-19 seems to be related to a history of severe COVID-19