scholarly journals Improvement of the technological treatment scheme of iron-containing wastewater from etching operations

2021 ◽  
pp. 21-28
Author(s):  
Mykola Yatskov ◽  
Natalia Korchyk ◽  
Oksana Mysina ◽  
Nadia Budenkova

The aim of the research is to improve the technological scheme of treatment of iron-containing wastewater from etching operations by creating combined systems, including reagent wastewater treatment, their mutual neutralization, regeneration of etching solutions, deep post-treatment using a magnetic device. The main volume of wastewater is treated in centralized systems with partial return of water to the production process. Spent solutions from etching operations are subject to regeneration with return to the production process and partial dosing into the main wastewater stream from flushing operations. The consumption of commercial HCl is reduced by 50%. The use of hydrogen peroxide can increase the effect of extracting iron from etching solutions by 30% (total purification effect of 70%). Given that deep purification from iron-containing impurities is provided using a magnetic device, the possibilities of practical implementation of reverse osmosis to obtain "pure" water in centralized systems, which can be used for preparation of process solutions and in a mixture with technical water - for flushing operations, increase. In experimental and industrial conditions the expenses of reagents, their concentrations, dosing time are established

2021 ◽  
Vol 6 (3(62)) ◽  
pp. 21-26
Author(s):  
Mykola Yatskov ◽  
Natalia Korchyk ◽  
Oksana Mysina ◽  
Nadia Budenkova

The object of research is the methods of purification of iron-containing wastewater from etching operations, the subject of the study is spent technological solutions of etching and wastewater from the operations of washing enterprises of hardware products. Spent etching solutions are characterized as highly concentrated solutions, and wash water belongs to the category of concentrated solutions containing toxic impurities: heavy metal ions, acids, surfactants. The main problem in the etching area is the processing of used etching solutions. The most progressive creation of combined systems in which the bulk of wastewater is treated in centralized systems with partial return of water to the production process. With such wastewater treatment, the problem arises of reducing the total concentration of iron to less than 1 mg/l. That is why, in accordance with the requirements of environmental legislation on nature management, there is a need for deep additional treatment of such wastewater. The study used the methods of potentiometric titration and chemical deposition, as well as the method of photometric determination. Magnetic cleaning was studied in an experimental magnetic deposition apparatus. The paper presents the results of studies evaluating methods for purifying iron-containing wastewater from etching operations. Improvement is achieved by the creation of technological combined schemes for the purification of iron-containing wastewater, including a magnetic device as an auxiliary element. At the same time, the main volume of wastewater is treated in centralized systems with a partial return of water to the production process. Waste solutions from etching operations are subject to regeneration with return to the production process and partial dosage into the main wastewater stream from washing operations. Deep purification from iron-containing impurities using a magnetic device expands the possibilities of practical implementation of reverse osmosis to obtain «clean» water in centralized systems. This water is applicable for the preparation of process solutions and mixed with industrial water for flushing operations.


2018 ◽  
Vol 04 (02) ◽  
pp. 1750005 ◽  
Author(s):  
Oscar Zapata

Wastewater reuse constitutes an alternative supply source of water. It not only increases the amount of water available but also reduces water pollution. The benefits and costs of this practice, and the public perception of reuse are the focus of several studies. However, the evidence on industrial wastewater reuse at the firm level remains scant. This paper is aimed at filling this gap by presenting evidence on the determinants of both wastewater treatment and reuse practices in a developing country context. I use firm level data from the Survey on Firms’ Environmental Practices of Ecuador. My results show that wastewater management in general, and reuse in particular, are still limited practices in the industrial sector of the country. My results suggest that firm’s decisions to treat and reuse depends on long-term firm’s characteristics, such as annual investment, the nature of the production process and local conditions, as well as the scale of production and water consumption. Volumes of wastewater treated and reused depend positively on the amount of water used in the production process and the firm’s annual level of investment or expenditure. The cost of the practice only affects the volume treated. The results suggest that targeting water-intensive industry sectors and the costs of wastewater treatment can play an important role for a more sustainable use of water in the industrial sector of Ecuador.


Author(s):  
М.В. Кевбрина ◽  
А.М. Гаврилин ◽  
А.А. Пронин

Рассмотрен опыт внедрения современных технологий очистки сточных вод на очистных сооружениях г. Москвы, описаны технологические схемы для сооружений разной производительности. С конца 1990-х годов Инженерно-технологическим центром АО «Мосводоканал» проводились работы по разработке и внедрению современных технологий очистки сточных вод с удалением биогенных элементов. Поскольку состав сточных вод имеет отличия на разных очистных сооружениях, не удается «перенести» зарубежные технологии без изменения и адаптации, а иногда требуется разработка технологии «с нуля». Более чем за 20-летний период осуществлено поэтапное внедрение современных технологий на московских очистных сооружениях Южного Бутова и Зеленограда, блока удаления биогенных элементов Люберецких очистных сооружений (БУБЭ ЛОС), нового блока Курьяновских очистных сооружений (НКОС). В настоящее время идет реконструкция ЛОС (старый и новый блоки), планируется реконструкция старого блока КОС, в процессе реконструкции находятся очистные сооружения Троицкого и Новомосковского административных округов (ТиНАО) г. Москвы. Опыт АО «Мосводоканал» был использован при разработке справочника наилучших доступных технологий ИТС 10-2015. Разнообразие технологических решений позволяет обеспечить нормативное качество очистки для условий разных сооружений. The experience of introducing advanced technologies for wastewater treatment at the wastewater treatment facilities in Moscow is considered; process flow schemes for the structures of different capacities are described. Since the late 1990s, the Engineering and Technology Center of Mosvodokanal JSC has been working on the development and introduction of advanced wastewater treatment technologies with the removal of nutrients. Since the composition of wastewater differs at different treatment facilities, it is not possible to "transfer" foreign technologies without correction and adaptation; moreover, sometimes the development of technology "from square one" is required. For more than 20 years, a stepwise introduction of advanced technologies has been carried out at the Moscow treatment facilities of South Butovo and Zelenograd, at the nutrients removal block at the Lyuberetskie wastewater treatment facilities, at the new block of the Kurianovskie Wastewater Treatment Facilities. At present, the reconstruction of the Lyuberetskie Wastewater Treatment Facilities (old and new blocks) is underway, the reconstruction of the old part of the Kurianovskie Wastewater Treatment Facilities is planned, the treatment facilities of the Troitsk and Novomoskovsk administrative districts in Moscow have been under upgrade. The experience of Mosvodokanal JSC was used in the development of an ITS 10-2015 reference book of the best available technologies. A variety of process solutions provides for ensuring the standard quality of effluent for the conditions of different facilities.


Author(s):  
Xiaozheng Bian ◽  
Jianping Huang ◽  
Lin Qiu ◽  
Chunyan Ma ◽  
Danli Xi

Abstract A new type of polyvinylidene fluoride (PVDF)/polymethyl methacrylate (PMMA) hollow fiber membrane (HFM) with five bores was prepared. The effects of Polyvinylpyrrolidone (PVP), β-cyclodextrine (β-CD), Polyethylene Glycol (PEG) and Polysorbate 80 (Tween 80) and their combinations on the PVDF/PMMA five-bore HFMs were investigated. The performance and fouling characteristics of five-bore HFMs for dyeing wastewater treatment were evaluated. Results indicated that adding 5wt.% PVP could increase the porosity and water flux of the membrane but decrease the bovine serum albumin (BSA) rejection rate. Adding 5wt.% β-CD significantly improved the tensile and rejection of the HFMs without showing effect on the increase of water flux. The characteristic of the HFMs with different additives combinations proved that the mixture of 5wt.% PVP and 1wt.% β-CD obtained the best membrane performance, with a pure water flux of 427.9 L/ m2·h, a contact angle of 25°, and a rejection to bovine serum albumin (BSA) of 89.7%. The CODcr and UV254 removal rates of dyeing wastewater treatment were 61.10% and 50.41%, respectively. No breakage or leakage points were found after 120d operation showing the reliable mechanical properties. We set the operating flux to 55 L/m2·h and cross flow rate to 10% which can effectively control membrane fouling.


2020 ◽  
Vol 2 (1) ◽  
pp. 53-73
Author(s):  
Liron Friedman ◽  
Hadas Mamane ◽  
Kartik Chandran ◽  
Martin Jekel ◽  
Haim Cikurel ◽  
...  

Tertiary wastewater treatment could provide a reliable source of water for reuse. Amongst these types of wastewater treatment, deep-bed filtration of secondary effluents can effectively remove particles and organic matter; however, NH4+ and NO2− are not easily removed. This study examined the feasibility of stimulating microbial activity using hydrogen peroxide (H2O2) as a bio-specific and clean oxygen source that leaves no residuals in the water and is advantageous upon aeration due to the solubility limitations of the oxygen. The performance of a pilot bio-filtration system at a filtration velocity of 5–6 m/h, was enhanced by the addition of H2O2 for particle, organic matter, NH4+, and NO2− removal. Hydrogen peroxide provided the oxygen demand for full nitrification. As a result, influent concentrations of 4.2 ± 2.5 mg/L N-NH4+ and 0.65 ± 0.4 mg/L N-NO2 were removed during the short hydraulic residence time (HRT). In comparison, filtration without H2O2 addition only removed up to 0.6 mg/L N-NH4+ and almost no N-NO2−. A DNA metagenome analysis of the functional genes of the media biomass reflected a significant potential for simultaneous nitrification and denitrification activity. It is hypothesized that the low biodegradability of the organic carbon and H2O2 addition stimulated oxygen utilization in favor of nitrification, followed by the enhancement of anoxic activity.


2019 ◽  
Vol 11 (21) ◽  
pp. 5906
Author(s):  
Shoulong Xu ◽  
Qifan Wu ◽  
Xiaogang Li ◽  
Feng Yuan ◽  
Liangying Tu

The radiation impact on the environment from naturally-occurring radioactive materials in zircon sand is an important issue for zirconium product manufacturing enterprises. In this paper, a typical oxychloride production enterprise has been taken as an example to study the radiation effect and environmental pollution during the whole production process. The transfer and enrichment of radionuclides in zircon sand was studied by analyzing their concentrations in samples, such as products and wastes, which were sampled from every studied workshop, so that the dose rate in the environment and typical facility surfaces of each workshop could be measured. The study results show that the transfer and enrichment of radionuclides occur mainly in workshops of acidification, dissolution, concentration and crystallization. Silicon slag adsorbed some radionuclides, but most of the radionuclides in raw materials are transferred and enriched in waste acid by the concentration and crystallization process. Sludge and wastewater still contain a large quantity of radionuclides after treatment by wastewater treatment plants. This results in a significant increase in U-238 and Th-232 concentrations in river water near the main outlet. The average effective dose of all employees in the studied enterprises was 0.94 mSv, and workers from the wastewater treatment plants had the largest annual effective dose at 11 mSv.


1999 ◽  
Vol 39 (10-11) ◽  
pp. 9-16 ◽  
Author(s):  
Hong-Ying Hu ◽  
Naohiro Goto ◽  
Koichi Fujie

The present study aims to present basic concepts to minimize the emissions from industrial production processes. Strategies and methodologies to analyze emissions from various production processes, to establish a so called negative flow sheet and to reduce the emissions from those processes by refining and/or replacing the present production process with an alternative process are discussed. Preliminary evaluation and management systems of the materials used in the production process based on characteristics such as microbial and physico-chemical treatabilities are proposed as well. The relationship between the removal efficiency of dissolved organic carbon in the five-days BOD test and that in a laboratory scale submerged biofilter with continuous operation is suggested to evaluate the biological removability of organic pollutants contained in wastewater. A novel concept to select the appropriate treatment process of an industrial wastewater based on properties such as the molecular size and biodegradability of the pollutants contained in that wastewater is also proposed. To give basic information for the minimization of energy consumption in wastewater treatment, various biological wastewater treatment processes are compared from the view point of power economy.


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