Modern Tools and Methods of Water Treatment for Improving Living Standards

The United States drinking water public health protection goal is to provide water that meets all health-based standards to ninety-five percent of the population served by public drinking water supplies by 2005. In 2002, the level of compliance with some eighty-five health-based standards was ninety-four percent. This significant accomplishment has been achieved through strong regulation and technical support to drinking water supply systems. The engineering and risk management research program that supports drinking water regulation has developed the Drinking Water Contaminant Management Framework to organize research related to control of a contaminant or group of contaminants in drinking water. The recent lowering of the arsenic drinking water standard serves as a case study for application of the Framework. Emerging research areas include the use of DNA based analytical techniques to advance our understanding of microbial contaminants in drinking water and water security. Real-time monitoring techniques will require significant advancement before they can be relied upon to insure drinking water protection.

The geographical variation in atmospheric input fluxes of pollutants is of paramount importance for understanding the implications of atmospheric pollution. In regions with high levels of industrial and agricultural activity, the natural distribution of some pollutants could be affected by existing point sources of chemicals. Due to its geographic location and size, Canada offers opportunities for studying geographic variations in fluxes of airborne materials independently of local point sources. The sub-Arctic covers 53 percent of Canada and is very sparsely populated, hence most of Canada is not affected by point-source anthropogenic impacts. Most changes in loadings of contaminants reflect changes in regional atmospheric inputs. Some of the most convincing examples of this include synthetic organic compounds never used in the Arctic. To reconstruct histories of chemical contamination over the past 150 years, sedimentary records of 20 lakes have been examined. Fifty-four sediment cores collected from 1987 to 1993 were analyzed using Pb-210 (t_1/2=22.26 yr) and Cs-137 (t_1/2=30 yr) dating methods. A wide range of depositional characteristics including sedimentation rates, mixing depths, geochronologies of sedimentation, radionuclide inventories and fluxes were obtained. It was assumed that sediments from basins with no local industrial or domestic sources served as natural collecting systems recording the history of net inputs from the atmosphere. Since radionuclide inventories in the sediments are affected by physical, chemical and geological conditions, estimates of sediment focusing factors were made. Focusing factors were determined by dividing the measured excess Pb-210 flux in the core by the predicted atmospheric flux of excess Pb-210. The predicted flux values were determined experimentally from terrestrial soil profiles.

A heterotrophic plate count (HPC) is a measure of the total number of heterotrophic bacteria in a water sample. It does not indicate whether the bacteria are harmful or harmless to humans, but serves as an indicator of the cleanliness of the raw water and treatment processes. The most sensitive test uses the R2A agar and an incubation time of 7 days. Other media and shorter incubation times lead to lower counts. Whichever test is used, an incubation of 2–7 days makes the test clearly useless for operational decisions and intervention. Intentional or accidental contamination of a water supply must be determinable in minutes.

We have studied over the past three years several water sources, such as municipal water, bottled water, beach and pool water, and ballast water on ships. Using portable equipment, we have determined the ATP in the water sample by lysing the bacteria, adding luciferine/luciferase to develop light, and measuring the light emission in a luminometer. The test is not new and is described in Standard Methods. What is new is that the present test is more sensitive, the instrumentation fits on a clipboard, and the test can be done in the field at the location where the sample is taken. If the estimated HPC is high, a second step may be necessary to identify if there are pathogens in the water sample. A rapid test for E.coli O157:H7, Pseudomonas, and Legionella pneumophila has been developed using immunomagnetic separation. These tests take longer, but are still under an hour for each target bacterium. The detection of spores in the water sample is also possible. The essence of the method is that a contamination of bottled water with bacteria can be detected while the batch of bottled water is still on the shipping dock.

This paper deals with the choice of detector for organic pollution in wastewater. The AOX detector is characterized and explained in detail. These mobile analytical measuring tube systems were used during the inspection of wastewater treatment plants in a particular region and the results are compared with methodology based on microcalorimetry.

The main objective of this study was to further enhance the environmental protection by lowering the extend of environmentally harmful water treatment. Therefore, a comprehensive trial evaluation of the efficacy of the mixed-oxidant solutions produced from “activated water” in cooling tower biological control was conducted on two Midlands-based industrial sites.

Activated water (ECAL) is an electrochemically generated mixed-oxidant solution (MIOX). The ECAL replaced conventional oxidising biocides (chlorine and bromine) for cooling tower microbiological maintenance. A comprehensive sampling protocol was employed to evaluate the efficacy of activated water, against Legionellae and heterotrophic bacteria in four cooling towers, which were chosen as the most challenging applications. All of the cooling towers remained free from Legionellae throughout a twelve month evaluation period, despite the previously demonstrated presence of Legionellae in all four of the towers studied at levels well in excess of UK Health and Safety Commission (HSC) Approved Code of Practice and Guidance (ACOP) upper action limits. Levels of heterotrophic bacteria were controlled below Cadbury Trebor Bassett’s (CTB’s) and TIMET UK Ltd’s own limits of 10⁵ cfu/ml in all towers and below 10⁴ CFU/ml throughout the evaluation.

The results proved direct evidence of significant activity against biofilm bacteria, with biofilm removal beginning almost immediately after commissioning of the mixed oxidant treatment programme. The results obtained were significant and illustrated the following potential benefits for CTB and TIMET: (i) aggressive disinfection-elimination of biofilms, (ii) inactivation of pathogenic organisms including Legionella species, and nil or low aerobic bacterial counts, all without additional biocides; (iii) safe operation because only salt, water and power are used to generate the nonhazardous, mixed oxidant solution; (iv) liability exposure and associated management costs are reduced; (v) staff and community safety is improved, and costs for safe transportation, handling and storage of hypochlorite, chlorine dioxide or bromine are eliminated; (v) low maintenance-automated system requires only minimal operator attendance; (vi) cost competitive-low operating costs and no safety costs usually result in a lower lifecycle cost; (vii) potential to introduce technology to many other areas that are currently using consumable disinfection or CIP (cleaning in place) products with resultant cost and environmental impacts.

Polyester filters are produced and widely used in various countries for removal of dust from air. The process of filter production includes their treatment by acrylonitrilic emulsion for improving their mechanical characteristics. We have developed the technology of modification of polyester filters for production of ion-exchange and carbonic fibroid sorbents. The production of cation-exchange sorbents involved the treatment of ppolyester fibroid filters by a 20–25% solution of NH₂NH₂H₂O at 70–90°C and a 5% solution of NaOH at 40°C. Anion-exchange sorbents were made by treatment of cation-exchange sorbents with a 1–5% solution of polyethylenimine at ambient temperature. These new types of sorbents are used for the removal of radionuclides, heavy metal ions, and organic contaminants from wastewater and drinking water. We have investigated the main properties of these sorbents and their ability to remove ⁵⁷Co, ⁶⁰Co, ⁶⁵Zn, ⁸⁹Sr, ⁹⁰Sr, ¹³⁴Cs, ¹³⁷Cs, and other radionuclides, heavy metal ions (Zn, Ni, Cu, Sb, Pb, Cd, Cr, U, etc.), organic molecules M (pesticides, phenols, dioxins, benzene, toluene, etc.), radio-labeled organic molecules M-³²P, M-¹³¹I, M-⁹⁹Mo+^99mTc, M-¹⁴C, etc. The influence of pH and concentration of K⁺, Na⁺ and other ions on percentage removal, as well as the decrease of saturation capacity with increasing number of regenerations and other characteristics are described. The static exchange capacity is 1–2 meq/g for cationic sorbents and 0.5–1 meq/g for anionic sorbents. The capacity of the carbonic sorbents for removal of benzene is 100 mg/g. The developed sorbents are effective in removing low concentrations of contaminants from water (lower than 100–200 mg/L).

At present, newly developed ion-exchange and carbonic sorbents are used as drinking water filters and mini-systems for removing organic and inorganic contaminants. The sorbents described are also used for removing heavy metal ions from effluents from electroplating plants (Zn, Ni, Cd, Cr, Sb, Sn, etc.), match-producing plants (Zn, Cr, Sb, etc.), leather- and skin- treating plants (Cr), and

In-Situ Oxygen Curtain (iSOC™) is an ingenious oxygen delivery technology based on inVentures’ patented Gas inFusion™ technology - a unique method of infusing supersaturated levels of dissolved gas into liquids. At the heart of the iSOC™ is the proprietary structured polymer mass transfer device. A microporous hollow fiber provides an enormous surface area for mass transfer- in excess of 7000 m² per m³- and it is hydrophobic. Maintaining a gas at lower pressure than liquid ensures that ultra efficient mass transfer takes place without the formation of bubbles. When suspended in existing monitoring wells, the iSOC™ infuses high levels of oxygen into groundwater, without bubbles, and with a very low decay rate at atmospheric pressure. By simply connecting a regulated supply of compressed oxygen to a small diameter flexible tube leading to the iSOC™, high levels of supersaturated, nascent oxygen transfer takes place in the surrounding groundwater. For example, a regulated iSOC™ can infuse over a pound of dissolved oxygen per month at a supersaturated, bubbleless 70 ppm when the saturated depth is 20 feet, with resultant significantly increased oxygen concentration for bioremediation down gradient. Once oxygen is introduced into the groundwater, the laws of mass transport generally apply. The greatly enhanced level of dissolved oxygen in groundwater addresses dissolved-phase petroleum hydrocarbon contamination as well as sorbed material in the saturated, capillary fringe, and smear zones. The iSOC™ can create an enhanced O₂ curtain or barrier to prevent contamination migration or it can be used for the treatment of so-called “hot spots”.

The main sources of drinking water are often polluted by industrial and municipal chemicals. Water treatment plants reduce the concentrations of harmful chemicals in water to a safe level and mandatory disinfection renders water non-hazardous from a bacteriological standpoint. However, conventional water treatment technologies using chlorine result in formation of disinfectant by-products. They have been proved to be strongly carcinogenic. Additionally, water quality deteriorates through the distribution networks. This is due to reproduction and decay of different microorganisms inside the water mains. Thus, at the endpoints of water networks, the concentrations of trihalomethanes, surface-active substances, iron compounds, etc., may exceed the maximum permissible concentration (MPC) by several times, and those of heterotrophs — up to hundred times.

Contaminated water causes at least 80% of human diseases, therefore, innovative technologies for water treatment are urgently needed. There is also a worldwide demand for cost-effective means to prevent consumption of secondary contaminated tap water. Currently, the problem is being solved by manufacturing purified bottled water and by installing adsorption-filtering and osmotic systems. These systems are expensive both to operate and to maintain.

A novel bubble-film extraction system for water treatment is an alternative to the above-mentioned systems. The principle of the innovation is based on the following fact: inherent secondary produced surface-active water contaminants act as water cleaning agents during its treatment by the stream of air bubbles in a space of special geometry. This method has been shown to purify water by 10–100 times more economically than by filtering through charcoal. The quality of purified water satisfies the WHO requirements. Pilot scale bubble-film extraction water purifiers were produced and tested. The method can be applied for groundwater conditioning and wastewater post-purification. For advanced purification, very small amounts of special surface-active additives could be used to accelerate adsorption of pollutants to the interface and, hence, increase the degree of water purification. The additive serves as a disinfectant and additional carrier of contaminants such as bacteria, viruses, humic matter, iron and arsenic compounds, etc. The method could be used either in combination with conventional systems or instead of them.

The efficacy of using Ag⁺ and Cu²⁺ metal ions and colloidal Au combinations (within the limits of current drinking water regulations) for killing Typhoid-Paratyphoid, Legionella pneumophila, Salmonella, Vibrio cholerae asiaticea, Lamblia intestinalis, Cryptosporidium parvum, etc. has been examined. Tests carried out in various laboratories during 1998–2003 have shown the dependence of bacteria killing time on metal ion concentration, initial bacteria concentration, and the influence of the concentration of various ions (Cl⁻, SO₄²⁻, S^2–, Fe²⁺, Fe³⁺) on the disinfection process.

Water savings, reclamation and reuse in industry are topics of increasing economic interest due to increasing water scarcity and costs. For this reason, research and development activities within this topic is increasing, methods and tools for analyzing water savings and reuse possibilities are being developed, and solutions are being implemented.

This paper presents experience and results of water savings and reuse in industry exemplified by the textile industry. Textile processing is one of the largest and oldest industries worldwide and responsible for substantial resource consumption and pollution. The wet processing part of the industry, i.e. pre-treatment, dyeing, printing and finishing, is especially polluting and resource consuming in terms of water, energy and chemicals. It entails a vast variety of water consuming processes, and like in most industries, freshwater is used in all processes with almost no exceptions.

It was known for many years that fresh water is not needed by all processes taking place in textile wet treatment. However conservatism and consideration for product quality in the industry have until recently prevented substantial water reuse from breaking through in practice. A four year research program on industrial water reuse, however, recently resulted in a break-through of water reuse in the Danish textile industry: one polyester dyehouse has since 2001 successfully implemented direct water recycling, saving more than 40% of water required. Process Integration and water pinch techniques were used to identify the potentials and, combined with the company’s process insight, used to achieve the best system design for the reuse of water, energy and chemicals. Separation techniques like membrane filtration have been applied successfully to the process water used in wet processing in both cotton and polyester dyeing. Pilot scale demonstration plants have documented the technical feasibility of water reclamation by this technique, with payback periods of 1–3 years. This payback has, however, so far prevented full-scale implementation.

The study is focused on the possibilities for the development and practical application of preventive measures for optimization of galvanic wastewater treatment processes in Lithuania. The results of modernization of the wastewater treatment plant in JSC “Vilniaus Vingis” and optimization of the galvanic technological processes and reconstruction of the wastewater treatment plant in JSC “Vingriai” are presented.

The paper deals with the factors affecting the processes of nitrification and denitrification in wastewater treatment plants. The factors are e.g. sludge age, sludge load, retention period, temperature, pH, etc. The differences in efficiency of the nitrification and denitrification processes and energy demand are compared for a variety of types of wastewater treatment plant.

Some fundamentals and applications of electrochemical systems containing 3—dimensional electrode systems with dynamic matrix, fluidized beds, consisting of particles possessing different conductivity, namely: nonconductive (glass or plastics), conductive (metal granules), semi-conductive (various carbon materials) and ion conductive (ion exchangers) are discussed. The principles of control of electrochemical processes in particulate beds are formulated. The advantages of the fluidised beds are demonstrated by application to water management.

Nowadays, more than 100 constructed wetlands are in operation in Poland. Most of them are one-stage wetland systems with horizontal subsurface flows. Such constructed wetlands ensure efficient removal of organic matter (BOD₅, COD_Cr) and suspended solids, but the efficiency of removal of nitrogen compounds in many cases is insufficient. In the period from 1995 to 2003, measurements of removal of contaminations in 11 household pilot units and 4 community plants equipped with one-stage horizontal flow beds, as well as in 4 community plants equipped with hybrid reed wetland systems composed of HF-CW (constructed wetlands with horizontal flow) and VF-CW (constructed wetlands with vertical flow) filters, were carried out. It was found that sufficient removal of organic matter (70–90 %) took place in the HF filters. The removal of nitrogen took place in VF beds and HF beds (denitrification) applied as a second and third stage of primary hybrid treatment. The removal of nitrogen was limited by the efficiency of the nitrification process in VF beds in wetland systems.

Limited capacity for renewal of ground and surface water and increasing demands from agriculture, industry and domestic users affect the quantity and quality of water resources. The links between the provision of clean water, sanitation and good health are so strong that protection and management of water becomes an indirect primary health protection issue. To prevent and overcome the variety of water-related health risks, implementation of various activities that include general environmental protection, development of water management systems, permanent water quality monitoring and control, and improvement of standards and legislature, are needed. Croatia has a long history of legislation that controls the quality of water. Both drinking water and surface waters are constantly monitored according to the existing laws and regulations. The legislation and implementation of various mechanisms of water protection as a tool for health protection are described.

Bulgaria is among the Central and East European countries applying for membership in the European Union. One of the priority objectives of the country is getting into compliance with the EU legislation within the shortest possible time. This paper is focused on water protection and water quality management. The description of the current status on the discharge and treatment of urban and industrial wastewater is based on information from the inventory of urban wastewater treatment plants (WWTP) and the sewage network prepared for implementation of the EU Directive 91/271/EEC concerning urban wastewater treatment. The total amount of wastewater discharged into water bodies is 878,555,000 m³ per year. The population connected to the urban collection system is 66.8%. The public sewerage discharges treated in urban wastewater treatment plants are 76%. There are 61 operational WWTP in Bulgaria. Some of them are completed, and others need additional measures for extension, reconstruction and modernization, since they operate below their designed capacity. In 1999, the National Program for priority construction of urban WWTP for settlements with over 10,000 equivalent inhabitants in Bulgaria was developed. The objective of the programme is to establish the priorities for construction of urban WWTP for all populated areas in the country with over 10,000 equivalent inhabitants, as well as the national short-term priorities until the year 2006. In 2003, the Implementation Programme for Directive 91/271/EEC concerning urban wastewater treatment has been developed. Identification of “sensitive areas” was conducted for all rivers in Bulgaria. Criteria for the construction of collection systems and WWTP are presented.

After more than 40 years of communist rule, Romania experienced a major regime change in 1989. Since it began its economic transition in 1990, Romania has taken a hesitant approach to reforms, and sought to protect vested interests and minimize the social costs associated with the transformation to a market economy. This strategy failed to produce sustainable gains in either economic or social conditions, and the costs have been higher than if a bolder approach to structural transformation had been adopted at the outset. Romania continued to face deepening economic recession, rising unemployment, and mounting problems stemming from lack of sufficient restructuring. In the first years of transition to a market economy, many industrial plants in Romania strongly diminished their production, this reduction ranging from 30 up to 80 %. The surviving plants will increase their production in the future. From an ecological point of view, the reduction of industrial production levels lead to a smaller number of pollution sources and smaller quantities of emitted pollutants. The transition period has represented, for the environment in Romania, a break in its fight with industrial pollution. This truce will be ended soon, and the only help for the environment will remain pollution prevention.

The emergent water plants Juncus effusus and Typha latifolia are studied as phytoremediants in constructed wetlands. Degradation of some toxic organic pollutants in the rhizosphere of plants may be followed by biochemical shifts in the surface lipids formation and change in their functions. The total fatty acid composition of surface lipids of these species was studied. An unusual composition of fatty acids and typical heavy isotopic discrimination for C₃-plants have been detected. The possible role of some lipid components in the protective functions of plant organism is discussed.