Dorota Papciak

The use of activated carbons for removing organic matter from groundwater

Abstract The article presents research results of the introduction of powdery activated carbon to the existing technological system of the groundwater treatment stations in a laboratory, pilot plant and technical scale. The aim of the research was to reduce the content of organic compounds found in the treated water, which create toxic organic chlorine compounds (THM) after disinfection with chlorine. Nine types of powdery active carbons were tested in laboratory scale. The top two were selected for further study. Pilot plant scale research was carried out for the filter model using CWZ-30 and Norit Sa Super carbon. Reduction of the organic matter in relation to the existing content in the treated water reached about 30%. Research in technical scale using CWZ-30 carbon showed a lesser efficiency with respect to laboratory and pilot-plant scale studies. The organic matter decreased by 15%. Since filtration is the last process before the individual disinfection, an alternative solution is proposed, i.e. the second stage of filtration with a granular activated carbon bed, operating in combined sorption and biodegradation processes. The results of tests carried out in pilot scale were fully satisfactory with the effectiveness of 70–100%.

THE USE OF BIOFILTRATION PROCESS TO REMOVE ORGANIC MATTER FROM GROUNDWATER

The article describes the research on the removal of organic matter from natural underground water using biofiltration process. The study was carried out in semi-technical scale on a model filter composed of activated carbon WD-extra. The development of biological activity in a biosorption bed, as well as observations on the relationship between the processes of sorption and biodegradation was evaluated based on the Eberhardt, Madsen, Sontheimer (EMS) test. Leading operation control parameters of biologically active carbon filter BAF included: change of TOC content, dissolved oxygen and permanganate index. To evaluate the colonization of granular carbon determination of ATP value was used. The presence of the biofilm was found by observation using light and scanning microscopes. The organic compounds in the water taken were adsorbed 100% and 70% biodegradable. The combination of sorption process with biodegradation until depletion of activated carbon adsorption capacity allowed in the initial phase of coalbed work for the removal of organic matter in approx. 100%. Formation of biofilm at the right time allowed to extend the filtration cycle and helped lower the TOC by 70%, i.e. from 10 mg C/l to 3–4 mg C/l.

STUDYING MICROBIOLOGY OF RAIN WATER FOR OF THEIR USE IN ECONOMY

Growing areas of sealed surfaces, rising water needs due to industry development, increasing populations, and climatic changes affect precipitation patterns and form a vision of the future in which meteoric water storage may become almost an obligatory activity. The aim of this paper was to identify the amounts and, to some degree, the quality of microorganisms present in rainwater collected from different types of rooftops of utility buildings in the spring-summer season. Apart from the classic culture plate method complemented by flow cytometry. The results of performed analyses explicitly show that rainwater collected from rooftops and directly from air prove to be microbially contaminated to a substantial degree, which includes pathogenic coliforms and faecal streptococci. Waters collected after dry periods also contained bacteria like Clostridium perfingens. The findings rule out the possibility of using rainwater collected from roof surfaces of utility buildings before its treatment.

Using Ion Exchange Process in Removal of Selected Organic Pollution from Aqueous Solutions

Surfactant and phenol were removed using AMBERLITE IRA 900 Cl ion-exchange resin, which is a strong alkali. In the process, the tests were carried out under non-flow conditions, the effect of contact time and ionite dose on the surfactant and phenol exchange was determined. The tests under the through-flow conditions were realized in three consecutive cycles, preceded by regeneration and rinsing. The obtained results served for determination of ionexchange capabilities of the studied ionite. The usable ion-exchange capabilities of the resin obtained after the second and third ionite operation cycle were lower by about 10% (surfactant) and 14.29–17.86% (phenol) than those after the first cycle. It shows that the process of sorption occurred simultaneously with the ion-exchange process.

Adsorption of Phenol from Water on Natural Minerals

Phenol and its derivatives (chlorophenol, nitrophenol, methylphenol, cresol etc.) belong to highly toxic contaminants, and their occurrence in industrial and municipal sewage as well as in groundwater carries a high threat to the environment and human health. Elimination of such contaminants is one of the major challenges in solving the global environmental problems. Implementation of pro-ecological methods of water treatment is associated with the use of natural, cheap and unprocessed materials, with the possibility of their repeated use. The article presents the results of the studies on the use of powdery adsorbents for the removal of phenol from aqueous solutions. The following natural minerals were used: attapulgite – Abso’net Superior Special (ASS) and alganite – Abso’net Multisorb (AM). Tests were performed under non-flowing conditions, in series, depending on the type and dose of adsorbents. Tests were conducted on a model solution of phenol with the initial concentration of C0 = 20 mg /dm 3, at the temp. of 20° C. Alganite mineral (AM) proved to be effective in adsorption of phenol. Maximum adsorption capacity P = 0.21 g/g, was obtained for a dose 10 mg/dm3. Almost complete removal of phenol (99.9%) was obtained for a dose of 500 mg/dm3. For natural attapulgite – Abso’net Superior Special (ASS) the maximum adsorption capacity (at a dose 5 mg/dm3) amounted to P = 0.15 g/g. The efficiency of phenol removal at the level 99% was obtained at a dose of 1000 mg/dm3).

APPLICATION OF POWDERY ACTIVATED CARBONS FOR REMOVAL IBUPROFEN FROM WATER

The paper presents the results of studies on the use of adsorptive properties of selected powdered activated carbons (Norit SA Super and Carbopol MB5) for removal of ibuprofen from water. The tests were performed on non-flow conditions, series depending on the type and dose of powdered adsorbents. The research was carried out on a model solution of ibuprofen at initial concentration C0 = 20 mg/dm 3, at 20 °C. Froundlich and Langmuir adsorption isotherms were used. Lagergrene kinetic models (PFO) and Ho (PSO) were used to describe adsorption kinetics. Both carbons exhibited a higher affinity for the adsorbent at pH above 7. Norit SA Super was a better adsorbent, for which, the highest adsorption capacity q = 0.448 g/g was achieved with dose D = 35 mg/dm3. The effectiveness of adsorption (decrease of ibuprofen in water) was 78%. The total removal of ibuprofen was obtained for a dose of carbon D = 200 mg/ dm3. With respect to Carbopol, the highest adsorption capacity (q = 0.353 g/g) was achieved at a dose of 30 mg/dm3, resulting in a 53% efficiency. Studies have shown that both tested powdered activated carbons have contributed to effective cleaning of aqueous solutions containing ibuprofen.

Analysis of chemical stability of tap water in terms of required level of technological safety

Abstract The main goal of this work is to show the new approach to determining safety technological levels (SLs) in terms of water quality and its chemical stability, as well as issues of water corrosion properties in water distribution systems (WDSs), due to the fact that water supply pipes are prone to corrosion. In the paper the methodology of determining the risk associated with threat to technical infrastructure was considered. The concept was studied on the basis of real operational data from the water treatment plant. The probability of exceeding the individual parameters for WTPI is slightly larger than for WTPII, which means that this water treatment process may cause lack of chemical stability in the water supply network. Operators should anticipate in the process of designing water distribution system, using proper materials, as to ensure an adequate level of safety from the water source to the water recipient. It should be noted that it is necessary to adjust the material of internal installation of water supply networks to the parameters of the water. At present, there are no correlations between the designing step and water parameters. It was concluded that to protect the water supply infrastructure, which belongs to critical infrastructure, water company should put more emphasis on distribution of stable water that has not potentially corrosion properties. Some suggestions were made for the protection of WDS and to ensure safety of system functioning and long-term usability of water pipes.