Yearly Archives: 2016

Abstract:
In the field of remediation it has also become more common to combine two complimentary remediation technologies to present the best technical and economic approach to a given site. This article will examine the use of In Situ Chemical Oxidation (ISCO) utilising RemOx® L ISCO Reagent (sodium permanganate) for source area treatment used in combination with biostimulation for enhanced reductive dechlorination utilizing CAP18 ME® Anaerobic Bioremediation Product for polishing of the source area and treatment of the lower concentration downgradient plume at an industrial dry cleaning facility. The site is a closed industrial dry cleaning facility that is surrounded by both commercial and residential areas. Over the course of the facilities operation, the soil and groundwater at the site became contaminated with tetrachloroethylene (PCE) and trichloroethylene (TCE) which are common chlorinated dry cleaning agents.

Abstract:
The most preferred method of stabilization of sewage sludge is composting. It is apparently a simple process aimed at stabilization of organic matter – ripening, destruction of pathogenic organisms, production of an environmental friendly material which can be sold or used as fertilizer. To reach the above aims the sludge has to be mixed with structural materials in suitable proportion to obtain a C:N ratio of about 25:1. In practice, the most often used structural materials contain cellulose (i.e. wooden chips, sawdust, bark, straw, leaf litter, other vegetal wastes). The present study presents several composting experiments performed using as raw materials dewatered anaerobic digested sludge from a municipal WWTP, two different vegetal wastes (wood chips, straws, vine shoots) in different proportions and water in order to ensure a 50 to 70% humidity. The experiments were performed using aerated heap method; the heap is arranged on a porous layer, which is periodically aerated by a blower. Composting process evolution was verified during the whole period of 3 months of experimentation by online measurement of temperature, periodic pH and humidity monitoring and by weekly microscopic observations. The quality of the obtained compost was good, similar to commercial products used for pot-flowers, with heavy metal concentrations below the limits imposed by 344/2004 Order.

Abstract:
A sample of anaerobically digested sludge from an operation for municipal wastewater treatment in Bulgaria was characterized by relatively high contents of some heavy metals (mainly of iron, zinc, copper, manganese and chromium) and of some organochemical pollutants (mainly polyaromatic hydrocarbons and oil products). Some microorganisms which are indicators for the faecal pollution of the waters being treated such as Escherihia coli, Enterococcus faecalis and Streptococcus faecalis, were found in the samples, as well as some pathogenic microorganisms (related to the genus Clostridium) and eggs of helminths. The objective of this study was not only to remove the toxic pollutants from the activated sludge in connection with the relevant sanitary requirements but also to use the pretreated sludge as an amendment in agriculture and, having in mind the contents and the current prices of some heavy metals present in the activated sludge before treatment, to use it as a source of these metals. Copper and zinc were the most promising in this respect. Different treatment techniques were tested to achieve the objective mentioned above. The best results were obtained with sludge sample initially subjected to autoclaving and then leached by a mixed culture of moderately thermophilic chemolithotrophic bacteria. The addition of iron ions (mainly in the ferric state) and sulphuric acid from outside at the start of the leaching facilitated the growth of bacteria and the solubilization of metals. Leaching at 50 oC and an initial solid content of 20 % in the suspension resulted in high extractions of copper (98.8 %) and zinc (95.7 %) within 120 hours. The dissolved metals were selectively recovered from the pregnant leach solution by means of solvent extraction plus electrowining. The residual treated sludge contained no toxic chemical and biological pollutants in concentrations higher than the relevant permissible levels. At the same time, the bioassimilable forms of C, N, P, K and some essential microelements were still present in sufficient concentrations for utilization in agriculture.

Abstract:
To sustain healthy life in harmony with nature, it is extremely important to develop materials and processes that minimize a harmful influence on the environment. The feasibility of sludge recycling in the ceramic manufacture was evaluated through laboratory testing. Such residues have similar chemical and mineralogical composition with the raw mixture of the green ceramic body used in construction. Several ceramic masses with clay, sand and various proportion of sludge have been synthesized and then characterized by their physical-mechanical properties. The fineness of the clay, the main component of the green ceramic body, has been considered for every raw mixture. The proportion of the sludge waste addition depends of the clay fineness and the sintering capacity also, increases with the clay fineness. Ceramic properties, especially porosity, water adsorption and mechanical properties in the presence of small amounts of sludge have insignificant changes. The introduction of such waste into building ceramic matrix (bricks, tiles and plates) has a very good perspective.

Abstract:
The paper presents some relevant aspects related to the influence of pollution matrix specific to the groundwater supplies, upon the treatment technologies applied in order to remove the inorganic nitrogen – based compounds (ammonium, nitrite, nitrate ions). The main association of ammonium (NH4+) with inorganic/organic pollutants in groundwater are, as follows:  NH4+ and metallic ions (Mn  Fe);  NH4+ and sulphur derivatives (S2-, S2O32-, SO32-);  NH4+ and nitrite/nitrate ions (NO2-/ NO3-);  NH4+ and natural organic matter (NOM – THMs precursors) in the presence of bromide ion (Br-). Also, the concentration levels of nitrogen – based compounds and associated pollutants are very important in the selection of suitable treatment procedures, including the succession of treatment steps. The treatment technologies developed for NH4+ and NO3- ions removal from groundwater supplies have as specific steps: breakpoint chlorination (NH4+) or biological nitrification (NH4+) and denitrification (NO2-/ NO3-) processes. Among the main problems specific for the most applied technology at industrial level for NH4+  oxidizable pollutants removal (one step chlorination), are mentioned:  low treatment efficiency (NH4+, S2-);  generation of trihalometanes (THMs), especially brominated ones, with unpleasant consequence upon the treated water quality, which is not proper for human consumption.

Abstract:
The wastewater results from different foods industry are generally characterized by a high organic load, far above limits discharge referred to legislation. In particular the wastewater results from different technological phases of milk industry processing, contain high quantities of organic compounds, especially proteins (caseine, β-lactoglobuline, α-lactalbumine, serumalbumine, immunoglobuline), lipide (mono, di and triacilglicerides, free fat acids, phospholipids) and disaccharides class (especially lactose). In the treatment processes, the membrane techniques – microfiltration, ultrafiltration, reverse osmosis – are frequently used for their advantages: are continuous processes, the energetic consumption is very low, not implies temperature and phase changes, not uses chemicals adjuvant, occur in modular equipment. The paper present the experimental results obtained in the ultrafiltration process of a wastewater from milk industry processing- washing the reactors from production of yoghurt. The aim of the experiments was to studied the correlation between the membrane characteristics and the reduction of the organic compounds from the wastewater. 2 composite ultrafiltration membranes were used, polysulphone-polyaniline types, different by monomer used on policondensation chemical reaction in porous structure of the base polymer. The experimental setup that has been used was the KMS Laboratory Cell CF-1 (Koch-Membrane – Germany) ensuring a tangential flow mode in separated process. The following indicators were analyzed from the water samples (the feed wastewater, the permeate and the concentrate): TOC, BOD, COD, total nitrogen, protein contents, conductivity. In the same time were studied the hydrodynamic, electroconductive and structural characteristics of the membranes. Relevant in these experiments were: – reduction the proteine contents in permeate to 42% – higher reduction of the DOC contents in permeate to 92% The BOD/COD ratio in the permeate samples was above 0,3, which indicate the remanent biodegradable characteristics. In this case its possible to introduce the water on the biological treatment setup improving their performances.

Abstract:
The low-pressure system, also known as vacuum system or vacuum sewer system contains closed pipeline networks without manholes. Vacuum sewer systems are essentially mechanized systems of wastewater transport. Unlike typical gravity sewers, it uses differential air pressure to transport the wastewater and all the sewer mains are under vacuum (under negative pressure). The high transport velocity of the air/water-mixture in the vacuum pipelines prevents sediments. An outlet of wastewater is excluded due to the vacuum occurring inside the system. The system is more economical and efficient compared to the classical gravitational sewage network. Normally the drainage procedure serves as a collection of wastewater in separate systems. Though, vacuum sewer line may be laid in the same trench together with water supply lines and storm water drainage according to the German guideline DWA-A 116-1. In this case, there shall be no physical connections between a public or private potable water supply system and a sewer. The vacuum technology is a special drainage procedure which might – under certain circumstances – be considerably cheaper than the conventional gravity lines sewage system. Investments costs can be considerably lower in comparison with other drainage procedures.

Abstract:
The technology for processing waste plant material for their further use as food or dietary products “Lignin-Cellulose Sorbents” and functional foods “CELISORB” was developed. It was studied the organoleptic and physicochemical parameters of these materials and was shown that they were promising materials for use in medicine and food industry as (entero)sorbents, antioxidants and dietary supplements, which could solve many problems of internal ecology of organism (endoecology) and health of people. Integrated radiometric, laboratory and clinical research were carried out. Clinical studies were done to assess the therapeutic and decorporative efficacy relative to 137Cs for children aged 7-17 residing in territories contaminated with radionuclides.