IWA Publishing in conjunction with the International Water Association’s Young Water Professionals is happy to announce a new initiative spotlighting the work of Young Water Professionals and showing how the work published in IWA Publishing Journals can be useful to those beginning their careers in the water sector.
Our second spotlight blog is on Ronald Zakhar, a PhD student and teacher at the Faculty of Chemical and Food Technology of Slovak University of Technology in Bratislava. Ronald was selected for this blog post after attending a YWP Conference. You can connect with Ronald on Facebook.
Ronald had access to our entire journal portfolio for one month, and picked out some interesting papers to discuss, read his thoughts below! A big thank you to Ronald for participating!
Hi, everyone! Let me introduce myself, my name is Ronald and I am a PhD student and teacher at the Faculty of Chemical and Food Technology of Slovak University of Technology in Bratislava. I graduated in 2014 as an environmental engineer and then started to work in a Danish water treatment company as a technologist. During this time I’ve learned a lot about the design and operation of different water treatment processes and technologies. I’ve made a lot of scale-up tests and also commissioned water technologies in different countries, like Slovakia, Czech republic, Hungary and Serbia. Mainly in Hungary and Serbia, there are some water resources contaminated by toxic arsenic, which is one of WHO’s 10 chemicals of major public health concern. In addition, arsenic contamination in drinking water is a major issue in the present world. In view of these facts I decided in 2017 to start my part-time PhD degree. In 2018 I became a full-time teacher at the Department of Environmental Engineering. My research topic is focused on arsenic removal from water and its impact on selected species of organisms. The goals of my dissertation thesis are: the comparison of different sorption materials for arsenic removal from water, modeling the adsorptive removal of arsenic, production of own sorption material, application of fluidised bed reactor in real water resource and study the impact of arsenic on different organisms.
Among the IWA Young Water Professionals I have a lot of good friends and like to meet them during different conferences and workshops. Two years ago I was awarded the best platform presentation at the 1st conference of the Young Water Professionals Czech Republic and last year for the best platform presentation at the 11th Eastern European Young Water Professionals Conference (EEYWP) in Prague. Thanks to these achievements I’ve decided to be part of the Organising commitee of the 12th EEYWP Conference in Riga and have accepted the offer from IWA Publishing to spend some time reading the research papers from IWAP journals. Let’s read!
Different technologies have been used and proposed to remove arsenic from aqueous media. Each technology has disadvantages and advantages, especially regarding efficiency and costs, which decide on implemented treatment. Therefore, I would like to recommend a published paper by Collivignarelli et al. (2019) in Water Practice & Technology, which is an analysis of four case studies where the problem of arsenic contamination in groundwater is faced with an approach that includes experimental activities at laboratory scale and/or pilot scale. In this paper the following studies were used: arsenic removal with naturally occurring Fe by the addition of an oxidizing agent (KMnO4) or a concentrated basic solution of MnO4– and AlO2–; then different experimental tests were carried out at laboratory scale in order to identify the best combination of treatments to be applied at full scale; the next case study followed by a full-scale upgrading for a drinking water treatment plant and the last case study investigated the performance of granular ferric oxide (GFO) with arsenic concentrations close to the regulatory limit. In addition, the monitoring results led to the implementation of the GFO filter at full scale.
Next, a very interesting research paper was published by Park et al. (2016) in Water Research, which focuses on a comparison of arsenic co-precipitation and adsorption by iron minerals, which occur in a natural mine stream. As we know, acid mine drainage causes severe environmental problems and usually can contained high concentrations of arsenic. This arsenic mine stream then can cause arsenic contamination in surface and groundwater. But Park et al. investigated that mine stream precipitate collected from real mine, contained high concentrations of arsenic, while water collected from the same site had negligible arsenic concentrations. This indicating natural attenuation of arsenic occurred in the mine stream. According to achieved results arsenic co-precipitation with iron mineral schwertmannite was the major mechanism of arsenic removal in the mine stream, followed by arsenic adsorption by goethite and arsenic coprecipitation with ferrihydrite. For this kind of research paper, I personally recommend also investigating the equilibrium and kinetic study of adsorption by batch experiments.
Nowadays there exists a growing interest in using low-cost methods and materials to remove arsenic from drinking water before it can cause significant contamination. One of these materials could be iron-chitosan composites (flakes and granules), which preparation and evaluation for arsenic removal from real life groundwater was published by Gupta et al. (2009) in Water Research. This material is biodegradable, biocompatible, and nontoxic, making its environment friendly. Removal of both arsenic from (III and V) was studied through adsorption at pH 7.0. The equilibrium data were described by the Langmuir adsorption model. Also anions which can cause serious interference in the adsorption behavior of arsenate/arsenite were studied. In addition the sorption–desorption studies by column reactor demonstrated the reusability of the adsorbent, which was successfully applied for the removal of total inorganic arsenic from arsenic contaminated real groundwater. The regeneration of adsorptive media for arsenic removal from groundwater was also published by Chen et al. (2015) in Water Research It can be said that the replacement cost accounts for around 80% of the systems total operational costs. So the onsite regeneration and reuse of the exhausted media is required. In Chen et al. research paper laboratory batch and column regeneration tests were conducted on six exhausted iron-based media products obtained from six full scale arsenic removal treatment systems. From the achieved results, it is observed that a 4% caustic (NaOH) solution can remove as high as 80% or more of the arsenic from iron-based exhausted media. Finaly the regenerated media could achieve arsenic removals somewhat similar to virgin media.
Some chemicals that are not commonly monitored have the potential to enter the environment and cause known or suspected adverse ecological and/or human health effects. Thats why I would like to recommend to my Young Water Professionals colleagues a review on emerging contaminants published by Petrie et al. (2015) in Water Research. This review identifies understudied areas of emerging contaminant research in wastewaters and the environment, and recommends a direction for future monitoring. Determination of fate and the removal of emerging contaminants during treatment processes, considering their likely implementation into the conventional WWTPs flow sheet, investigation of its impact on surrounding surface water, groundwater quality, in soil degradation, toxicity to terrestrial organisms and the potential uptake by plants and entry into the human food chain present the most discussed challenges in the research area.
Dear YWP colleagues, I hope that you liked my spotlight blog and that we will get the chance to meet each other at a future YWP workshop or conference!
See you!
Ronald Zakhar
ronald.zakhar [at] stuba.sk
Department of Environmental Engineering
Faculty of Chemical and Food Technology
Slovak University of Technology in Bratislava
List of referenced papers:
Comparison between experimental results of different technologies for arsenic removal from water intended for human consumption, Maria Cristina Collivignarelli, Silvestro Damiani and Sabrina Sorlini, Water Practice & Technology, (2019) 14 (4): 884–896.
Comparison of arsenic co-precipitation and adsorption by iron minerals and the mechanism of arsenic natural attenuation in a mine stream, Jin Hee Park, Young-Soo Han and Joo Sung Ahn, Water Research, (2016) 106: 295-303.
Preparation and evaluation of iron–chitosan composites for removal of As(III) and As(V) from arsenic contaminated real life groundwater, Anjali Gupta, Vivek Singh Chauhan and Nalini Sankararamakrishnan, Water Research, (2009) 43 (15):
3862-3870.
A review on emerging contaminants in wastewaters and the environment: Current knowledge, understudied areas and recommendations for future monitoring, Bruce Petrie, Ruth Barden and Barbara Kasprzyk-Horderna, Water Research, (2015) 72: 3-27.