Enhanced Biodegradation of Formaldehyde Using Aerobic Sequencing Batch Rotating Bed Bioreactor With and Without Stimulation by Hydrogen Peroxide

The removal of formaldehyde as a toxic substance from aqueous solutions is of particular importance. In this research, a sequencing batch rotating-bed bioreactor (SBRB) was used on a laboratory scale for biodegradation of formaldehyde from synthetic wastewater. The reactor was made of plexiglas with a cylindrical shape. Kaldnes media were placed in a rotating cylindrical basket in the reactor. The effects of formaldehyde concentration (500–1500 mg/L), hydraulic retention time (HRT) (8, 15, 24 hours), and injection of hydrogen peroxide (0.1-0.5 mM) on the performance of the reactor were investigated. The results showed that in the SBRB, at an HRT of 24 hours and an inlet formaldehyde concentration of 1000 mg/L, the removal efficiencies of formaldehyde and chemical oxygen demand (COD) were 99.2% and 92%, respectively, while without rotating the bed, the removal efficiency of formaldehyde and COD was found to be 95% and 83%, respectively. By adding hydrogen peroxide at a concentration of 0.3 mM and operation of the SBRB with an HRT of 8 hours and an inlet formaldehyde concentration of 1000 mg/L, an improvement in the removal efficiency of formaldehyde and COD (4% and 22%, respectively) was observed. Accordingly, SBRB stimulation with hydrogen peroxide could be considered as a high-performance process for the removal of formaldehyde and corresponding COD at a short HRT

Survey of crude oil toxicity component removal by adsorbtion with powdered activated carbon

زمینه و هدف: نفت خام ترکیبی بسیار پیچیده بوده که حاوی هزاران هیدروکربن با اثرات مضری مثل سرطان زایی و اثرات خونی می باشد. به دلیل حجم نسبتاً زیاد ورود آن به محیط های آبی، انجام تصفیه موثر روی پساب های حاوی نفت خام بسیار مهم می باشد. این مطالعه با هدف بررسی حذف ترکیبات عامل سمیت نفت خام در آب به وسیله جذب سطحی با کربن فعال پودری انجام شد. روش بررسی: در این مطالعه تجربی نمونه استاندارد قسمت محلول نفت خام با اختلاط یک قسمت نفت خام با 9 قسمت آب تهیه گردید. جهت آزمون سمیت از غلظت های مختلف قسمت محلول نفت خام و لارو ماهی قزل آلا استفاده شد. قبل و بعد از اضافه کردن 10، 20، 40 و 60 میلی گرم بر میلی لیتر کربن فعال پودری، آزمون سمیت و کربن آلی کل روی نمونه ها انجام گردید. غلضت کشنده 50 (LC50) نمونه ها توسط برنامه آماری پروبیت محاسبه شده و نتایج مورد تجزیه و تحلیل قرار گرفت. یافته ها: غلظت کشنده 50 محلول نفت خام قبل از استفاده از کربن فعال در زمان های 24، 48 و 96 ساعت به ترتیب 5/129، 5/69 و 6 به دست آمد. این غلظت با افزودن کربن فعال افزایش داشت که این افزایش وابسته به غلظت بود. به طوری که غلظت کشنده 50 96 ساعته بعد از اضافه کردن کربن فعال با غلظت های 10، 20، 40، 50، 60 میلی گرم بر لیتر به ترتیب 8/94، 6/106، 8/117، 3/138 و 5/181 میلی گرم بر لیتر اندازه گیری شد. مقادیر کربن آلی کل در غلظت های 0، 10، 20، 40، 50 و 60 میلی گرم بر لیتر کربن فعال به ترتیب 89/54، 81/44، 88/43، 16/38، 62/36 و 14/35 میلی گرم بر لیتر بود. نتیجه‌گیری: کربن فعال باعث کاهش سمیت و کربن آلی کل نمونه ها گردید. با افزایش میزان کربن فعال مورد استفاده، سمیت کاهش بیشتری را نشان داده اما کربن آلی کل با شدت سمیت کاهش نیافت. در صورت بروز حوادث و ورود نفت خام به منابع آب آشامیدنی استفاده از روش کربن فعال پودری می تواند مورد نظر قرار گیرد

Occurrence and Fate of Amoxicillin and Penicillin G Antibiotics in Hospital Wastewater Treatment Plants: A Case Study – Gonbad Kavous, Iran

Release of antibiotics to the environment as a result of wastewater effluent discharge is a cause for concern worldwide, as they pose a potential threat to  human health and the earth ecosystem. Penicillin and amoxicillin are widely used antibiotics. Despite their rapid hydrolysis in aqueous matrices, their  presence in the environment is widely investigated. The current study reported and analysed the current state of four hospital wastewater treatment  plants (WWTPs) in Gonbad Kavous, Iran, during 2019, from the perspective of amoxicillin and penicillin G removals. WWTPs were sampled at various  stages of the treatment process to determine at which stage the antibiotics are being removed. Concentrations of amoxicillin and penicillin G in raw  wastewater, analysed by HPLC, varied from 0.35 to 1.02 and 0.02–0.31 μgL−1, respectively. These values reduced in the final effluent, corresponding to  overall efficiency in removing the studied antibiotics of 20-60.5%. Anaerobic processes (i.e. septic tank) slightly outperformed aerobic biological processes  for both antibiotics’ removal, and penicillin G was removed more efficiently than amoxicillin. Effects of wastewater physicochemical properties,  including chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS) on antibiotics removal, were  also studied. Whereas statistically significant correlations were noticed between COD, amoxicillin and penicillin G removals, their decline showed no  correlation with TSS removal. Our study shows that despite the deployment of treatment plants, a considerable amount of antibiotics is released into  receiving water bodies, resulting in significant amounts of these pharmaceuticals entering the environment. There is abundant room for further progress  in the detection and quantification of pharmaceuticals and other emerging contaminants in hospital wastewaters and their metabolites and  biodegradation products.&nbsp

Fe2+/Persulfate / Clinoptilolite, catalytic oxidative treatment, as a cost effective process for Isocyanate and Meta Toluene Diamine Petrochemical unit wastewater

Background: Petrochemical wastewater from isocyanate units contains aromatic and hazardous compounds such as Diaminotoluenes, Mononitrotoluene, Dinitro-toluene, Nitro-phenol, Nitro-cresol. Persulfate and ferrous sulfate can produce sulfate radicals with strong standard oxidation potential. Clinoptilolite, a natural adsorbent; plus sulfate radicals can result in catalytic oxidation of these chemicals. The objective of this study is to evaluate the catalytic oxidation efficiency Fe2+/Persulfate/ Clinoptilolite and cost effectiveness of this process for treatment of petrochemical wastewater containing aromatics.Materials and methods: The effect of study variables including persulfate and ferrous sulfate concentrations, zeolite dosages, pH and oxidation time were investigated. The type and amount of aromatic compounds as well as COD and TSS removal efficiencies were determined. All procedures in study were conducted ethicallyResults: The COD and TSS removal efficiencies using catalytic oxidative treatment processes by Fe,Persulfate, Clinoptilolite were 96% and 95%, respectively. The corresponding COD and TSS removal efficiencies using Fe and Persulfate, without zeolite were 85% and 80%, respectively.Conclusion: The catalytic processes utilizing Fe2+/Persulfate/ Clinoptilolite demonstrates an excellent COD and TSS removal efficiency. Due to its natural nature, low cost compared to chemical oxidants, as well as improvements in the efficiency of advanced oxidation processes, Zeolite can be considered as anefficient and cost-effective alternative to upgrade the catalytic oxidative treatment

Comparison between conventional pump and adsorption sampling method with passive solid phase microextraction ( SPME ) sampling to investigate changes in the concentration of benzene, toluene , and xylene ( BTX ) in urban ambient air

Background and Aims: Besides toxic effects on human, animals and plants, aromatic hydrocarbons may also be effective in the formation of photochemical smog. The measurement of these hydrocarbons, therefore, play aprominent part in evaluating their health and environmental impacts. The purpose of this study was to compare pump and adsorption sampling method with solid phase microextraction (SPME) to investigate changes in theconcentration of benzene, toluene, and xylene (BTX).Materials and Methods: SPME samplers in sampling protective holders were placed in ambient air at a relatively high traffic routes for 5 days. Sampling was carried out in two seasons. Samples were analyzed at the end of sampling period. In addition, pump and adsorption sampling method was also used to measure the concentrations of benzene, toluene, and xylene. Ethical issues were all considered in conducting the study and citation.Results: The obtained results in solid phase microextraction sampling method were compared with those obtained using the conventional pump and adsorbent method. Correlation coefficients (R2) between these methods were 0.98, 0.9 and 0.95 for benzene, toluene, and xylene, respectively. The results obtained with pump and adsorption method showed a higher values in general.Conclusion: The comparison between obtained results with these methods indicates a relatively similar values. It may be concluded that SPME sampling method can also present reliable results for the measurement of benzene,toluene and xylene concentrations in the ambient air.Keywords: Passive sampling, SPME, Benzene, Toluene, XyleneFor downloading the full text please click here

B Cells and T Cells Abnormalities in Patients With Selective IgA Deficiency

BACKGROUND: Selective IgA deficiency (SIgAD) is the most prevalent inborn errors of immunity with almost unknown etiology. This study aimed to investigate the clinical diagnostic and prognostic values of lymphocyte subsets and function in symptomatic SIgAD patients. METHODS: A total of 30 available SIgAD patients from the Iranian registry and 30 age-sex-matched healthy controls were included in the present study. We analyzed B and T cell peripheral subsets and T cell proliferation assay by flow cytometry in SIgAD patients with mild and severe clinical phenotypes. RESULTS: Our results indicated a significant increase in naïve and transitional B cells and a strong decrease in marginal zone-like and switched memory B-cells in SIgAD patients. We found that naïve and central memory CD4 CONCLUSION: SIgAD patients have varied cellular and humoral deficiencies. Therefore, T cell and B cell assessment might help in better understanding the heterogeneous pathogenesis and prognosis estimation of the disease

بررسی امکان بازیابی آهن از لجن تصفیه‌خانه آب با استفاده از آسیاب سیاره‌ای و فرایند هضم اسیدی

 Background and Aims: Both the number of water treatment plants and their sludge volume increases by population. Considering the presence of high amounts of valuable coagulants in water treatment plant sludge, it’s recovery and reuse is sought to be one of the practical and cost effective solutions for sludge management in water treatment plants.Materials and Methods: Iron sludge was collected from the sludge dryer bed of Jalaliyeh water treatment plant in Tehran. A planetary mill device was used to prepare samples and to investigate the effect of mechanochemical process on sludge recovery as an Iron based coagulant. XRD, XRF, TEM، MP-AES tests were performed on the sludge sample before and after the mechanochemical process. Ethical considerations were observed in all stages of the study.Results: The results of this study showed that the use of a planetary mill leads to more recovery of iron, so that at 1 N acid concentration, iron recovery increases from 23.5% in the unmilled sludge sample to 60.5% in the milled sludge. Phase and chemical structure changes of sludge after planetary mill were clearly visible in XRD analysis.Conclusion: The results showed that by combining mechanochemical and acid digestion, it is possible to significantly improve ferric chloride recovery in terms of acid consumption and final product quality; so that the iron based final product could be used for industrial wastewater treatment.   زمینه و اهداف: با افزایش جمعیت تعداد تصفیه‌خانه های آب و حجم لجن تولیدی حاصل از آن‌ها هم زیاد می‌شود. با توجه به وجود مقادیر بالایی ازمواد منعقد‌کننده در آن، بازیابی و استفاده مجدد از لجن تصفیه‌خانه آب یکی از راهکارهای عملیاتی و مقرون به صرفه جهت  مدیریت لجن تصفیه‌خانه آب است. مواد و روش‌ها: لجن آهن از بستر لجن خشک‌کن تصفیه‌خانه آب جلالیه تهران جمع‌آوری شد. از دستگاه آسیاب سیاره‌ای به منظور بررسی تعیین اثر فرایند مکانوشیمیایی بر بازیابی آهن از لجن تصفیه‌خانه آب استفاده شد. تست‌های تکمیلی XRD، XRF، TEM، MP-AES از نمونه لجن تصفیه‌خانه آب قبل و بعد از فرایند مکانوشیمیایی گرفته شد. ملاحظات اخلاقی در تمام مراحل اجرای مطالعه رعایت شد. یافته‌ها: نتایج این تحقیق نشان داد که استفاده از آسیاب سیاره‌ای باعث بازیابی بیشتر آهن می‌شود. به طوری که با استفاده از اسید 1 نرمال میزان بازیابی آهن از 23/5% در نمونه لجن آسیاب نشده به 60/5% در نمونه لجن آسیاب شده، می‌رسد. در نتایج XRD تغییر فاز و ساختار شیمیایی لجن بعد از آسیاب سیاره‌ای کاملا مشهود بود. نتیجه‌گیری: نتایج این مطالعه نشان داد که استفاده از دو روش، مکانوشیمیایی و هضم اسیدی با هم می‌توان شرایط بازیابی کلروفریک را از نظر میزان اسید مصرفی و کیفیت محصول نهایی تا حد قابل توجهی بهبود داد و در صنعت تصفیه فاضلاب صنعتی استفاده کرد.

Investigation of Acorn fruit Ash Efficiency in Cadmium Removal from Aqueous Solutions: Adsorption Isotherm and Kinetic Studies

Background: Heavy metals are known as significant pollutants because of toxicity and nonbiodegradable characteristics. Cadmium is one of the heavy metals that have carcinogen potential. So, this study carried out in order to investigate the acorn fruit ash efficiency in cadmium removal from aqueous solutions. Methods: This study was done in the batch laboratory conditions. In this study, the effect of different parameters including pH, contact time, adsorbent dose, and initial cadmium concentration were evaluated. The Langmuir, Freundlich and Temkin isotherm models were used for analysis of the equilibrium isotherm. Adsorption kinetics of cadmium by different models were also investigated. The measurement of residual cadmium in the samples was determined by atomic absorption spectrophotometry at 228.8 nm. The SPSS-16 software was used for analysis of data. Results: According to the results, the maximum adsorption capacity of cadmium was 9.29 mg/g at pH=7 and 8 g/L adsorbent dose. The removal efficiency was increased with increasing contact time and decreased with increasing of cadmium initial concentration. Investigation of achieving data showed that the adsorption process followed better by Freundlich isotherm and the pseudo-second order kinetic. Conclusions: According to the results of this study, it could be concluded that the acorn fruit ash had high ability in cadmium adsorption and could be used as a cheap adsorbent in the removal of cadmium

Enhancing anaerobic digestion of automotive paint sludge through biochar addition

The reduction of traditional fuel sources and the unpredictability of the global economy have led to a push for renewable energy alternatives. Waste recycling can significantly reduce greenhouse gas emissions. In this study, the effects of different proportions of biochar on the efficiency of mesophilic anaerobic digestion of automotive paint sludge were investigated over a period of one month. A combination of paint sludge and anaerobic sludge in a ratio of three to one was used, and biochar was added to the anaerobic digestion reactor in two different amounts of 10 and 26 g/l, with a control sample without biochar. The cumulative volume of biogas produced at the end of the one-month experiment was recorded for three samples: the control sample (without biochar), the second sample (with 2 g of biochar), and the third sample (with 5.2 g of biochar). The volumes of biogas produced were 300, 380, and 530 ml, respectively. Additionally, the COD reduction rates were 25%, 33%, and 48%, and the VS decrement rates were 21%, 27%, and 43%, respectively. The findings showed that adding biochar to the anaerobic digestion reactor containing automotive paint sludge increased biogas production. Additionally, gas chromatography results for an optimal sample of biogas extracted from the anaerobic digestion reactor indicated the presence of about 50% methane gas. These results highlight the potential for utilizing biochar in anaerobic digestion processes to improve renewable energy production and waste management

Biodegradability improvement of composting leachate by sulfate radical-advanced oxidation process followed by aerobic and anaerobic treatmentcomparison of biodegradability improvement of composting leachate by sulfate radical-advanced oxidation process for aerobic and anaerobic treatment

Aims: Comparing to strong traditional oxidation, the persulfate and sulfate radicals was characterized by relatively low cost and easy application. The present study aimed to investigate the performance of sulfate radical-based advanced oxidation process (SR-AOP) for pretreatment of compost leachate in order to improvement of its biodegradability. Materials and Methods: The sulfate radicals was used for pretreatment of compost leachate in the batch reactor followed by aerobic and anaerobic biological reactors. Results: the results of combination of SR-AOP with biological treatment showed that BOD5/COD ratio was increase. However, the different trend was observed in COD removal by sequencing batch reactor (SBR) and anaerobic sequencing batch reactor (ASBR). Comparing to SR-AOP with ASBR, the SR-AOP with SBR substantially improved final COD removal efficiency up to 70%. Although pretreatment of compost leachate with the SR-AOP clearly improved the BOD5/COD ratio of entering raw leachate into ASBR (from 0.4 to 0.65), but, the COD removal efficiency was ranging between 25% and 27%. Conclusion: Based on the results, it can be concluded that the BOD5/COD ratio cannot be suggested as biodegradability improvement indicator without considerations of changing of substrate nature during pretreatment