effect of ph on the degradation of aqueous organophosphate (methylparathion) in wastewater by ozonation
نویسندگان
چکیده
degradation of o,o-dimethyl -o-4-nitrophenylphosphorothioate (methylparathion) by ozonation in aqueous solution was studied in a batch reactor under constant ozone dosage and variable ph conditions. the effectiveness of the process was estimated based on the degree of cod (chemical oxygen demand) reduction and conversion of methylparathion. it was observed that ozonation is more effective at alkaline reaction of medium than other conditions. the degree of methylparathion conversion achieved after 120 minutes of the process at ph 9 was 98% compared to 81% and 60% at ph 7 and 3, respectively. another parameter used to quantify the methylparathion during ozonation was the pseudo first order rate constant k (1/min). results showed that the rate constant of the process was approximately much higher at ph 9 compared to ph 7 and 3. a significant improvement in chemical oxygen demand removal was observed at ph above 7. at ph 9, the reduction in chemical oxygen demand at the end of the process reached 93%. the methylparathion degradation intermediate products were analyzed by gas chromatography–mass spectrometry (gc–ms). the main intermediate product was p-nitrophenol. the result of the study concludes that ozonation is an effective process for the treatment of organophosphate (methylparathion) contaminated wastewater.
منابع مشابه
effect of ph on the degradation of aqueous organophosphate (methylparathion) in wastewater by ozonation
degradation of o,o-dimethyl -o-4-nitrophenylphosphorothioate (methylparathion) by ozonation in aqueous solution was studied in a batch reactor under constant ozone dosage and variable ph conditions. the effectiveness of the process was estimated based on the degree of cod (chemical oxygen demand) reduction and conversion of methylparathion. it was observed that ozonation is more effective at a...
متن کاملthe effect of aqueous extract of garlic on formalin-induced pain in male rats
چکیده اثر عصاره آبی سیر بر درد ناشی از آزمون فرمالین در موش صحرایی نر به کوشش نرگس اسکندری روزبهانی زمینه و هدف: گیاه سیر از خانواده لیلیاسه و گونهallium sativum بومی آسیای میانه بوده و از دوران ،باستان تاکنون به خواص درمانی متفاوت آن مثل: کاهندگی قندخون، کلسترول خون، فشار خون، اثرات مفیدآن بر دستگاه قلبی عروقی و بیماریهای انعقادی خون، اثرات آنتی اکسیداتیو، درمان بیماریهای تنفسی وگوارشی، ا...
15 صفحه اولthe washback effect of discretepoint vs. integrative tests on the retention of content in knowledge tests
در این پایان نامه تاثیر دو نوع تست جزیی نگر و کلی نگر بر به یادسپاری محتوا ارزیابی شده که نتایج نشان دهندهکارایی تستهای کلی نگر بیشتر از سایر آزمونها است
15 صفحه اولthe effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)
cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...
the effect of e-64 on the developmental competence of sheep cocs during in vitro maturation
in the present study, the effect of e-64 at different concentrations (0.5, 1, 5 and 10 µm) added to (1) the ivm medium on oocyte nuclear maturation and developmental competence of ovine oocytes, and (2) to the ivc medium on embryonic development of ovine embryos were investigated.
the effect of learning strategies on the speaking ability of iranian students in the context of language institutes
the effect of learning strategies on the speaking ability of iranian students in the context of language institutes abstract language learning strategies are of the most important factors that help language learners to learn a foreign language and how they can deal with the four language skills specifically speaking skill effectively. acknowledging the great impact of learning strategies...
منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
international journal of environmental researchجلد ۶، شماره ۲، صفحات ۵۵۷-۵۶۴
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023