K. Miksch

Phytoremediation of explosives (TNT, RDX, HMX) by wild-type and transgenic plants

The large-scale production and processing of munitions has led to vast environmental pollution by the compounds TNT(2,4,6-trinitrotoluene), RDX(hexahydro-1,3,5-trinitro-1,3,5-triazine) and HMX(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine). Explosives contain these toxic and mutagenic xenobiotics, which are stable in the environment and recalcitrant to remediation. Certain technologies used thus far (incineration, adsorption, advanced oxidations processes, chemical reduction etc.) have not only been very expensive but also caused additional environmental problems. During recent decades, the most popular technologies have been biotechnological methods, such as phytoremediation, which is relatively cheap, environmentally friendly, and a highly accepted solution by society. The most promising of these technologies is the usage of genetically modified plants, which combines the ability of bacterial genes to detoxify compounds with the phytoremediation benefits of plants. This paper is a review related to the latest and most important achievements in the field of phytoremediation of water and soil contaminated with TNT, RDX and HMX.

Photocatalytic mineralization of humic acids with TiO2: Effect of pH, sulfate and chloride anions

Aims of the present work are to investigate the photomineralization of commercial humic acid in water solution.The effect of initial pH of solution and different anions (chloride, sulfate and mixture) on the photocatalytic degradation of HA with titanium dioxide in aqueous solution has been examined. The photocatalytic mineralization rate in alkaline solution is lower than in neutral and acidic solution. In our conditions no effect of chloride ions on the degradation rate is observed. The influence of the sulfate depends on its concentration in the solution. For a large concentration, we note a decrease of the mineralization rate.

R&D priorities in the field of sustainable remediation and purification of agro-industrial and municipal wastewater

This article was presented as a position paper during the Environmental Biotechnology and Microbiology Conference in Bologna, Italy in April 2012. It indicates major and emerging environmental biotechnology research and development (R&D) priorities for EU members in the field of sustainable remediation and purification of agro-industrial and municipal wastewater. The identified priorities are: anaerobic/aerobic microbial treatment, combination of photochemical and biological treatment, phytoremediation and algae-based remediation, as well as innovative technologies currently investigated, such as enzyme-based treatment, bioelectrochemical treatment and recovery of nutrients and reuse of cleaned water. State of the art, research needs and prospective development in these domains are crucially discussed. As a result, goals of the future development of bioremediation and purification processes are defined and the way to achieve them is proposed.

Influence of Calcium, Magnesium, and Iron Ions on Aerobic Granulation

In this study, we investigated the effect of different multivalent cations on granule formation. Previous experiments showed that formation of matrix EPS and their structure depend of the presence of divalent cations. This study indicates that trivalent cations are also playing an important role. However, the more compact granules were formed in the presence of all cations. The authors tried also to determine changes in proteomic profile of slime and tightly bound EPS. These results showed that matrix EPS is composed of a variety of large and complex proteins, but there are also small proteins, like for example, lectins. These small proteins have a role in the interaction between cells and exopolysaccharides and in granules formation.

Removal of analgesic drugs from the aquatic environment using photochemical methods.

The occurrence of analgesics in the environment can be explained by the fact that they are very popular and in common use, for example: to treat the symptoms of colds, aches and pains or for the treatment of painful diseases of rheumatic and non-rheumatic origin. Analgesic drugs are only partly removed from wastewater using the biological wastewater treatment processes. The photochemical methods are mentioned as a useful tool for the removal of analgesic medicines from the aquatic environment. The elimination of three analgesic drugs: diclofenac, naproxen and ibuprofen from the aquatic environment using UV- and UV/H(2)O(2)-processes was the aim of the study. All experiments were performed in the water with the presence and the absence of the urea as the main urine component. With the presence of urea the values of photo-oxidation rate constants (in the UV/H(2)O(2)-process) varied from 0.22 min(-1) (ibuprofen) to 0.39 min(-1) (diclofenac). The values of the photodegradation rate constants in the solution without urea (in the UV/H(2)O(2)-process) varied from 0.25 min(-1) (ibuprofen) to 0.45 min(-1) (diclofenac). The study showed that naproxen, ibuprofen and diclofenac may be effectively removed from the aquatic environment (e.g. from the urine) by means of photochemical methods.

Removal of diclofenac and sulfamethoxazole from synthetic municipal waste water in microcosm downflow constructed wetlands: Start-up results.

ABSTRACT The objectives of this study were to investigate the start-up removal of pharmaceutical compounds diclofenac and sulfamethoxazole in microcosm downflow constructed wetlands and their effect on the performance of the studied constructed wetlands, and also to assess the effect of plants on the removal of these compounds. The experimental system that was used in this 86-day experiment consisted of 24 columns filled up to 70 cm with predominantly sandy material. Four types of columns were used (six replicates) depending on the presence of plants (Phalaris arundinacea L. var. picta L.) and the presence of pharmaceutical compounds in the influent. The influent was synthetic municipal waste water to which a mixture of 5 mg/L of diclofenac and 5 mg/L of sulfamethoxazole was added. The observed removal of diclofenac was moderate (approx. 50%) and the removal of sulfamethoxazole was relatively low (24–30%). It was found that the removal of diclofenac and sulfamethoxazole was not affected by the vegetation. The presence of diclofenac and sulfamethoxazole in the influent had significant effect on the effluent concentration of N-NO3 and the water loss in the columns, which in both cases were lower than in the control columns. The scope for further research was discussed.

Solid inorganic peroxy compounds in environmental protection

Solid inorganic peroxy compounds in environmental protection The paper presents a solid inorganic peroxy compounds description (calcium peroxide, magnesium peroxide and sodium percarbonate) focused on the properties and environmental application, particularly for the degradation of polycyclic aromatic hydrocarbons (PAHs) and phenols in soil environment. Modern technological processes require the use of compounds that are safe for the environment, non-toxic, easily degradable to the products, which themselves have no adverse environmental effect. Peroxides, as the chemical compounds, produce an effect on the enzymatic activity of the environment into which they are introduced. A good indicator of the activity of soil, bottom sediment or activated sludge, may be the dehydrogenase activity, which is a reflection of the general physiological state of microorganisms. Peroxides can be applied both in a pure form, as well as in mixtures with certain other groups of compounds. To enhance their efficiency they can be mixed with nitrogen, phosphorus or potassium carrying compounds.

The effect of temperature on the efficiency of industrial wastewater nitrification and its (geno)toxicity

Abstract The paper deals with the problem of the determination of the effects of temperature on the efficiency of the nitrification process of industrial wastewater, as well as its toxicity to the test organisms. The study on nitrification efficiency was performed using wastewater from one of Polish chemical factories. The chemical factory produces nitrogen fertilizers and various chemicals. The investigated wastewater was taken from the influent to the industrial mechanical-biological wastewater treatment plant (WWTP). The WWTP guaranteed high removal efficiency of organic compounds defined as chemical oxygen demand (COD) but periodical failure of nitrification performance was noted in last years of the WWTP operation. The research aim was to establish the cause of recurring failures of nitrification process in the above mentioned WWTP. The tested wastewater was not acutely toxic to activated sludge microorganisms. However, the wastewater was genotoxic to activated sludge microorganisms and the genotoxicity was greater in winter than in spring time. Analysis of almost 3 years’ period of the WWTP operation data and laboratory batch tests showed that activated sludge from the WWTP under study is very sensitive to temperature changes and the nitrification efficiency collapses rapidly under 16°C. Additionally, it was calculated that in order to provide the stable nitrification, in winter period the sludge age (SRT) in the WWTP should be higher than 35 days.

Synergetic Toxic Effect of an Explosive Material Mixture in Soil

Explosives materials are stable in soil and recalcitrant to biodegradation. Different authors report that TNT (2,4,6-trinitrotoluene), RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) and HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) are toxic, but most investigations have been performed in artificial soil with individual substances. The aim of the presented research was to assess the toxicity of forest soil contaminated with these substances both individually as well in combinations of these substances. TNT was the most toxic substance. Although RDX and HMX did not have adverse effects on plants, these compounds did cause earthworm mortality, which has not been reported in earlier research. Synergistic effects of explosives mixture were observed.

Nanocoating with plant-derived pectins activates osteoblast response in vitro

A new strategy to improve osseointegration of implants is to stimulate adhesion of bone cells, bone matrix formation, and mineralization at the implant surface by modifying surface coating on the nanoscale level. Plant-derived pectins have been proposed as potential candidates for surface nanocoating of orthopedic and dental titanium implants due to 1) their osteogenic stimulation of osteoblasts to mineralize and 2) their ability to control pectin structural changes. The aim of this study was to evaluate in vitro the impact of the nanoscale plant-derived pectin Rhamnogalacturonan-I (RG-I) from potato on the osteogenic response of murine osteoblasts. RG-I from potato pulps was isolated, structurally modified, or left unmodified. Tissue culture plates were either coated with modified RG-I or unmodified RG-I or – as a control – left uncoated. The effect of nanocoating on mice osteoblast-like cells MC3T3-E1 and primary murine osteoblast with regard to proliferation, osteogenic response in terms of mineralization, and gene expression of Runt-related transcription factor 2 (Runx2), alkaline phosphate (Alpl), osteocalcin (Bglap), α-1 type I collagen (Col1a1), and receptor activator of NF-κB ligand (Rankl) were analyzed after 3, 7, 14, and 21 days, respectively. Nanocoating with pectin RG-Is increased proliferation and mineralization of MC3T3-E1 and primary osteoblast as compared to osteoblasts cultured without nanocoating. Moreover, osteogenic transcriptional response of osteoblasts was induced by nanocoating in terms of gene induction of Runx2, Alpl, Bglap, and Col1a1 in a time-dependent manner – of note – to the highest extent under the PA-coating condition. In contrast, Rankl expression was initially reduced by nanocoating in MC3T3-E1 or remained unaltered in primary osteoblast as compared to the uncoated controls. Our results showed that nanocoating of implants with modified RG-I beneficially 1) supports osteogenesis, 2) has the capacity to improve osseointegration of implants, and is therefore 3) a potential candidate for nanocoating of bone implants.