Advanced Treatment Unit Research Articles

Occurrence and profiling of multiple nitrosamines in source water and drinking water of China

The occurrence of multiple nitrosamines was investigated in 54 drinking water treatment plants (DWTPs) from 30 cities across major watersheds of China, and the formation potential (FP) and cancer risk of the dominant nitrosamines were studied for profiling purposes. The results showed that N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA) and N-nitrosodi-n-butylamine (NDBA) were the most abundant in DWTPs, and the concentrations in source water and finished water samples were not detected (ND) −53.6ng/L (NDMA), ND −68.5ng/L (NDEA), ND −48.2ng/L (NDBA). The frequencies of detection in source waters were 64.8%, 61.1% and 51.8%, and 57.4%, 53.7%, and 37% for finished waters, respectively. Further study indicated that the FPs of the three main nitrosamines during chloramination were higher than those during chlorination and in drinking water. The results of Principal Components Analysis (PCA) showed that ammonia was the most closely associated factor in nitrosamine formation in the investigated source water; however, there was no significant correlation between nitrosamine-FPs and the values of dominant water-quality parameters. The advanced treatment units (i.e., ozonation and biological activated carbon) used in DWTPs were able to control the nitrosamine-FPs effectively after disinfection. The target pollutants posed median and maximum cancer risks of 2.99×10−5 and 35.5×10−5 to the local populations due to their occurrence in drinking water.

Wetlands for Wastewater Treatment.

This paper provides a review of the treatment technologies, which utilize natural processes or passive components in wastewater treatment. In particular, this paper primarily focuses on wetland systems and their applications in wastewater treatment (as an advanced treatment unit or decentralized system), nutrient and pollutant removal (single and multiple pollutants, and metals), and emerging pollutant removal (pharmaceuticals). A summary of studies involving the plant (vegetation) effects, wetland design and modeling, hybrid and innovative systems, storm water treatment and pathogen removal is also included.

A Model of Optimising Activity in Emergency Hospitals’ MATUCC Type Divisions

The MATUCC (Monitoring and Advanced Treatment Units of Critical Cardiac patients) concept launched in 2010 by the Romanian Ministry of Health aims an increase of quality standards in coronary care in Romania. The MATUCC of Emergency County Hospital Pitesti was founded in 2013 in the current building. Learning from the experience of some prestigious hospitals, we conceived a new model of MATUCC, more appropriate to the new standard of care for the critical coronary patient in an Emergency Hospital. The present paper displays the new model created in our hospital, harmonized with regulatory authorities exigencies published in 2012, model that may be uptaken and adjusted for other Romanian hospitals. Keywords: MATUCC, new standard, emergency zonal hospital

Cathodic degradation of antibiotics: Characterization and pathway analysis

Antibiotics in wastewaters must be degraded to eliminate their antibacterial activity before discharging into the environment. A cathode can provide continuous electrons for the degradation of refractory pollutants, however the cathodic degradation feasibility, efficiency and pathway for different kinds of antibiotics is poorly understood. Here, we investigated the degradation of four antibiotics, namely nitrofurazone (NFZ), metronidazole (MNZ), chloramphenicol (CAP), and florfenicol (FLO) by a poised cathode in a dual chamber electrochemical reactor. The cyclic voltammetry preliminarily proved the feasibility of the cathodic degradation of these antibiotics. The cathodic reducibility of these antibiotics followed the order of NFZ > MNZ > CAP > FLO. A decreased phosphate buffered solution (PBS) concentration as low as 2 mM or utilization of NaCl buffer solution as catholyte had significant influence on antibiotics degradation rate and efficiency for CAP and FLO but not for NFZ and MNZ. PBS could be replaced by Na2CO3–NaHCO3 buffer solution as catholyte for the degradation of these antibiotics. Reductive dechlorination of CAP proceeded only after the reduction of the nitro group to aromatic amine. The composition of the degradation products depended on the cathode potential except for MNZ. The cathodic degradation process could eliminate the antibacterial activity of these antibiotics. The current study suggests that the electrochemical reduction could serve as a potential pretreatment or advanced treatment unit for the treatment of antibiotics containing wastewaters.

Natural Treatment and Onsite Processes

This paper provides a review of the treatment technologies, which utilize natural processes or passive components in wastewater treatment. The paper primarily focuses on wetland systems and their applications in wastewater treatment (as an advanced treatment unit or decentralized system), nutrient and pollutant removal (single and multiple pollutants, and metals), and emerging pollutant removal (pharmaceuticals). A summary of studies involving the plant (vegetation) effects, wetland design and modeling, hybrid and innovative systems, storm water treatment and other issues such as climate change and greenhouse gas emissions is also provided.

Natural Treatment and Onsite Processes

This paper provides a review of the treatment technologies which utilize natural processes or passive components in wastewater treatment. The paper primarily focuses on wetland systems and their applications in wastewater treatment (as an advanced treatment unit or decentralized system), nutrient and pollutant removal (single and multiple pollutants, and metals), and emerging pollutant removal (pharmaceuticals). A summary of studies involving the plant (vegetation) effects, wetland design and modeling, hybrid and innovative systems, storm water treatment, grass swales, bioretention and other issues involving climate change and greenhouse gas emissions is also provided.

Wastewater reclamation for various non-potable supplies and water quality control in a minimum-emission hydrologic cycle

In this study, we implemented an isolated decentralized water system with minimized wastewater discharge and maximized water reuse in water-deficient region. Dual quality wastewater reclamation and reuse system with parallel conventional treatment unit and advanced MBR treatment unit was built in which the reclaimed water with normal quality and high quality was produced, respectively. Based on maximum collection of the recollectable discharged water, the minimum-emission scheme characterized by high cycling rate of the limited water resource was formed and consequently all the nonpotable water consumption was covered by the reclaimed water. Environmental lakes integrated with multi-functions of quantity regulation and quality stabilization of the reclaimed water were introduced in the system configuration and stepwise use of the reclaimed water was observed successfully. As a result of the system operation, main pollutants were well removed and the quality of reclaimed water can reach the demands of various non potable reuse purposes. Water bodies on campus prove to be of good quality of surface water. The project accomplished the minimum emission of discharged water and maximum use efficiency of water resource. It was proven to be feasible based on the technical and economic evaluation. This study provided a model case for future urban development in the water-deficient regions.

Mechanical pre-treatment (MPT) – revitalised by MBR process

Since the mid-nineties membrane bioreactor (MBR) technology has been introduced to municipal wastewater treatment in Europe. The first MBR plants went into operation performing a conventional mechanical pre-treatment (MPT) without any advanced treatment units. After a short operation period, clogging caused by fibrous substances and hence module sludging was observed. Thus, MPT was upgraded introducing sieves. Several investigations had been carried out to determine the removal efficiency of different sieve units and entire MPT systems. Meanwhile experiences from long-term operation at different MBR sites indicate dependencies between different MPT units, especially between the aerated grit chamber/grease trap and the subsequent sieve unit. Usually the sieve is the final MPT unit and its performance depends on the performance of the upstream MPT units. This report describes and discusses results from a research project at MBR Kaarst-Nordkanal in Germany conducted in 2008 to 2010 by the Water Board of River Erft and the Department of Sanitary and Environmental Engineering. Main focus is addressed for the parameters SS (settable solids) and grease. One major experience is the confirmation of relevant interactions between the grit chamber and the downstream sieve unit. Stable operation of the grit chamber and grease trap is essential to achieve a constantly high removal performance of the sieve unit and therefore the entire MPT stage. In turn, negative impacts on the grit chamber performance from the return flow concept have to be avoided. Finally, it is shown that the appropriate two-dimensional sieve gap size should not go beyond 1 mm when operating hollow fibre membranes.

Qualitative and Quantitative Analysis of the Inorganic Materials Changes with Time in the Stages of the Wastewater Treatment Plant

Due to the importance of the inorganic materials removal from wastewater, experimental and analytical study to the concentration change with time of these materials became essential. In this work, experimental analyses were performed to investigate the concentration changes of inorganic compounds during stages of activated sludge wastewater treatment plants at different sites in Jordan. The aim of this research is to examine the performance of the plants in treating pollutants and inorganic materials, and verify the quantitative and qualitative changes with time. Samples from the treatment stages were monthly taken and analyzed in the laboratory along a period of one year. The concentration changes of the inorganic solids in wastewater passing through treatment stages and aeration tank were recorded. Results show that the conventional treatment of the wastewater within different conditions in the year is not effective to decrease the concentrations of the inorganic compounds. Based on these results, we recommend adding tertiary advanced treatment unit in order to get acceptable water quality allowable to be reused for different purposes.

Comparing removal of trace organic compounds and assimilable organic carbon (AOC) at advanced and traditional water treatment plants

Stability of drinking water can be indicated by the assimilable organic carbon (AOC). This AOC value represents the regrowth capacity of microorganisms and has large impacts on the quality of drinking water in a distribution system. With respect to the effectiveness of traditional and advanced processing methods in removing trace organic compounds (including TOC, DOC, UV(254), and AOC) from water, experimental results indicate that the removal rate of AOC at the Cheng Ching Lake water treatment plant (which utilizes advanced water treatment processes, and is hereinafter referred to as CCLWTP) is 54%, while the removal rate of AOC at the Gong Yuan water treatment plant (which uses traditional water treatment processes, and is hereinafter referred to as GYWTP) is 36%. In advanced water treatment units, new coagulation-sedimentation processes, rapid filters, and biological activated carbon filters can effectively remove AOC, total organic carbon (TOC), and dissolved organic carbon (DOC). In traditional water treatment units, coagulation-sedimentation processes are most effective in removing AOC. Simulation results and calculations made using the AutoNet method indicate that TOC, TDS, NH(3)-N, and NO(3)-N should be regularly monitored in the CCLWTP, and that TOC, temperature, and NH(3)-N should be regularly monitored in the GYWTP.

Current situation of urban wastewater treatment plants in megacity Istanbul

Within the framework of a European Union-funded project, a comprehensive questionnaire has been prepared and a survey has been realized among the already existing urban wastewater treatment plants of the country with the aim of investigating the reuse possibility of treated effluents. This study forming one of the project milestones, aimed at putting forth the existing situation of the urban wastewater treatment plants of the Greater Metropolitan Istanbul which is one of the most crowded cities of the world. The current situation revealed that as the city has scarce available land and is surrounded by sea, primary treatment is favored. Some of the plants own biological treatment units where the effluents comply with the discharge to receiving water standards. Most of the plants serve to populations over 100 000 and face operational problems such as lack of automation, clogging of pipes, old-fashioned equipment and working over-capacities. The Water and Sewerage Administration of Istanbul (ISKI) has to supply high quality drinking water to the inhabitants of the city and is responsible for the treatment of the urban wastewater. ISKI has started to initiate not only secondary but also advanced biological treatment units to the already existing plants and urges the companies in charge of their construction to operate the plants for 20 years.

Breakeven costs for distributed advanced technology water-treatment systems

Breakeven costs associated with the strategic distribution of advanced treatment units in a water supply network to manage network-derived water quality degradation were investigated. Disinfections by-product (DBP) formation was used as a representative water quality degradation parameter. A basic DBP formation model was used to predict that fraction of residential service population receiving water degraded below required quality levels within a hypothetical water utility service population. The costs of upgrading centralized treatment facilities to meet DBP water quality standards were estimated and then apportioned over that population fraction to estimate breakeven or equivalent cost allowances for an alternative distributed treatment approach. Breakeven costs for single-connection treatment units were calculated for a range of service populations. A sensitivity analysis of the impacts of various network parameters on breakeven costs revealed the existence of singularities—sudden shifts in optimal technology selection—resulting from relatively small variations in required treatment levels.

On-site wastewater treatment and reuses in Japan

On-site wastewater treatment poses a challenging problem for engineers. It requires a balance of appropriate levels of technology and the operational complexity necessary to obtain high-quality effluent together with adequate reliability and simplicity to accommodate infrequent maintenance and monitoring. This review covers how these issues have been addressed in on-site wastewater treatment in Japan (termed johkasou). On-site systems in Japan range from outmoded designs that discharge grey water directly into the environment to advanced treatment units in high-density areas that produce reclaimed water on-site. Japan is a world leader in membrane technologies that have led to the development of on-site wastewater treatment units capable of water-reclamation quality effluent. Alternative ideas being pursued for on-site technologies also include separate waste stream collection, which would provide for more efficient treatment and reuse. Night soil treatment plants, where sludge from on-site systems is treated, are also distinctive to Japan, serving 37 million people. Japan has governmental regulations in place to ensure routine inspections of on-site units; furthermore, subsidies are available to reduce the cost of on-site systems for building owners. Lessons learned in on-site wastewater treatment in Japan have applications worldwide, from regions where water is scarce, to high-density areas in developing countries that currently lack sewer infrastructures.

Treatment of landfill leachate - high tech or low tech? A case study

At the sanitary landfill of the city of Penzberg (Germany), two diverse approaches to leachate treatment were studied as parts of a three-stage treatment concept. The performance of a simple aerobic pond was compared to that of an advanced multistage treatment unit, the latter comprising a membrane biological reactor and a two-stage activated carbon filter. For 274 days of the year (75%) the pond was able to provide sufficient treatment even under cold weather conditions. For temperatures lower than 5 degrees C, a higher biomass content and temporal storage of the raw leachate (e.g. increasing hydraulic retention time) could close the gap of insufficient treatment. In contrast, the advanced treatment system could only accomplish limited treatment capabilities due to insufficient maintenance, low loading conditions and deficient coordination between the individual treatment steps. As a result, degradation rates were low and operational problems frequent. Limits for Ntot were exceeded regularly (Ntot,e = 60-70 mg/L), throughput broke down and excessive nitrite production occurred (NO2-Ne = 10 mg/L) as a result of microbial activity inside the activated carbon filters. This case study clearly suggests aerobic ponds as an appropriate solution for the treatment of landfill leachate in areas where operational independence is essential.

Advanced treatment of swine wastewater by electrodialysis with a tubular ion exchange membrane

ABSTRACTTo remove the excess nitrogen and phosphorus in swine wastewater, an electrodialysis technique was applied to an advanced treatment method. The laboratory‐scale swine wastewater treatment system constructed for the present study consisted of an activated sludge process, as the main treatment unit, and electrodialysis, as an advanced treatment unit. This system was operated for 200 days and the processing performance was evaluated. By electrodialysis, approximately 99% of NO3– and PO43– in the activated sludge‐treated water (AT solution) was removed during operation. Furthermore, electrodialysis decreased the color density of the AT solution at a rate of 58%. The advanced treatment of swine wastewater by electrodialysis proved to be an efficient technique to remove excess nitrogen and phosphorus, and decrease color density.

"Forward psychiatry" in the military: its origins and effectiveness.

"Forward psychiatry" was devised in World War I for the treatment of shell shock and today is the standard intervention for combat stress reaction. It relied on three principles: proximity to battle, immediacy, and expectation of recovery, subsequently given the acronym "PIE." Both US and UK forces belatedly reintroduced PIE methods during World War II to return servicemen to active duty and made confident claims for its efficacy. Advanced treatment units also appeared to have minimized psychiatric battle casualties during Korean and Vietnamese Wars. Evaluations of its use by Israeli forces in the Lebanon conflict showed higher return-to-duty rates than at base hospitals. A reexamination of these examples suggests that reported outcomes tended to exaggerate its effectiveness both as a treatment for acute stress reaction and as a prophylaxis for chronic disorders such as PTSD. It remains uncertain who is being served by the intervention: whether it is the individual soldier or the needs of the military.