Duckweed-based Wastewater Treatment Systems: Design Aspects and Integrated Reuse Options for Queensland Conditions

Point sources of wastewater pollution, including effluent from municipal sewage treatment plants and intensive livestock and processing industries, can contribute significantly to the degradation of receiving waters (Chambers et al. 1997; Productivity Commission 2004). This has led to increasingly stringent local wastewater discharge quotas (particularly regarding Nitrogen, Phosphorous and suspended solids), and many municipal authorities and industry managers are now faced with upgrading their existing treatment facilities in order to comply. However, with high construction, energy and maintenance expenses and increasing labour costs, traditional wastewater treatment systems are becoming an escalating financial burden for the communities and industries that operate them. This report was generated, in the first instance, for the Burdekin Shire Council to provide information on design aspects and parameters critical for developing duckweed-based wastewater treatment (DWT) in the Burdekin region. However, the information will be relevant to a range of wastewater sources throughout Queensland. This information has been collated from published literature and both overseas and local studies of pilot and full-scale DWT systems. This report also considers options to generate revenue from duckweed production (a significant feature of DWT), and provides specifications and component cost information (current at the time of publication) for a large-scale demonstration of an integrated DWT and fish production system.

Growth of Queensland Jatropha gossypifolia biotypes under varying water regimes

Bellyache bush (Jatropha gossypifolia L. (Euphorbiaceae)) is a serious weed of dry tropical regions of northern Australia, with the potential to spread over much of the tropical savannah. It is well adapted to the harsh conditions of the dry tropics, defoliating during the dry season and rapidly producing new leaves with the onset of the wet season. In this study we examined the growth and biomass allocation of the three Queensland biotypes Queensland Green, Queensland Bronze and Queensland Purple) under three water regimes (water-stressed, weekly watering and constant water). Bellyache bush plants have a high capacity to adjust to water stress. The impact of water stress was consistent across the three biotypes. Water stressed plants produced significantly less biomass compared to plants with constant water, increased their biomass allocation to the roots and increased biomass allocation to leaf material. Queensland Purple plants allocated more resources to roots and less to shoots than Queensland Green (Queensland Bronze being intermediate). Queensland Green produced less root biomass than the other two biotypes.

Fate of pathogen indicators in a domestic blend of food waste and wastewater through a two-stage anaerobic digestion system

Anaerobic digestion is a viable on-site treatment technology for rich organic waste streams such as food waste and blackwater. In contrast to large-scale municipal wastewater treatment plants which are typically located away from the community, the effluent from any type of on-site system is a potential pathogenic hazard because of the intimacy of the system to the community. The native concentrations of the pathogen indicators Escherichia coli, Clostridium perfringens and somatic coliphage were tracked for 30 days under stable operation (organic loading rate (OLR) = 1.8 kgCOD m(-3) day(-1), methane yield = 52% on a chemical oxygen demand (COD) basis) of a two-stage laboratory-scale digester treating a mixture of food waste and blackwater. E. coli numbers were reduced by a factor of 10(6.4) in the thermophilic stage, from 10(7.5+/-0.3) to 10(1.1+/-0.1) cfu 100 mL(-1), but regenerated by a factor of 10(4) in the mesophilic stage. Neither the thermophilic nor mesophilic stages had any significant impact on C. perfringens concentrations. Coliphage concentrations were reduced by a factor of 10(1.4) across the two stages. The study shows that anaerobic digestion only reduces pathogen counts marginally but that counts in effluent samples could be readily reduced to below detection limits by filtration through a 0.22 microm membrane, to investigate membrane filtration as a possible sanitation technique.

Brief for GSDR - Emerging Contaminants in urban stormwater: Challenges and perspectives for sustainable water use

Emerging contaminants (ECs) are chemical compounds commonly present in water. It is only recently that this family of compounds is being recognized as significant water pollutants (. ECs include a wide variety of chemicals such as pharmaceutical and personal care products (PPCPs), pesticides, hydrocarbons and hormones, among others, that once released into the environment exert adverse impacts on the human and wildlife endocrine system. Natural attenuation and conventional treatment processes are not capable of removing these micro-pollutants detected in wastewater influent and effluent and surface and drinking water. The main challenges related with presence of ECs in stormwater in the context of reuse are: a) Development of suitable laboratory test methodologies and protocols for ECs identification and quantification b) Identification of the sources of ECs in the urban environment; c) Understanding their impacts on human and/or ecosystem health; and d). Development of cost-effective removal technologies which are appropriate for large as well as small-scale application.

Reuse of treated sewage in Delhi city: Microbial evaluation of STPs and reuse options

Microbiological quality of the treated wastewater is an important parameter for its reuse. The data oil the Fecal Coliform (FC) and Fecal Streptococcus (FS) at different stages of treatment in the Sewage Treatment Plants (STPs) in Delhi watershed is not available, therefore in the present study microbial profiling of STPs was carried out to assess the effluent quality for present and future reuse options. This Study further evaluates the water quality profiles at different stages of treatment for 16 STPs in Delhi city. These STPs are based on conventional Activated Sludge Process (ASP), extended aeration, physical, chemical and biological treatment (BIOFORE), Trickling Filter and Oxidation Pond. The primary effluent quality produced from most of the STPs was suitable for Soil Aquifer Treatment (SAT). Extended Hydraulic Retention Time (HRT) as a result Of low inflow to the STPS Was responsible for high turbidity, COD and BODs removal. Conventional ASP based STPs achieved 1.66 log FC and 1.06 log FS removal. STPs with extended aeration treatment process produced better quality effluent with maximum 4 log order reduction in FC and FS levels. ``Kondli'' and ``Nilothi'' STPs employing ASP, produced better quality secondary effluent as compared to other STPs based oil similar treatment process. Oxidation Pond based STPs showed better FC and FS removals, whereas good physiochemical quality was achieved during the first half of the treatment. Based upon physical, chemical and microbiological removal efficiencies, actual integrated efficiency (IEa) of each STP was determined to evaluate its Suitability for reuse for irrigation purposes. Except Mehrauli'' and ``Oxidation Pond'', effluents from all other STPs require tertiary treatment for further reuse. Possible reuse options, depending Upon the geographical location, proximity of facilities of potential users based oil the beneficial uses, and sub-soil types, etc. for the Delhi city have been investigated, which include artificial groundwater recharge, aquaculture, horticulture and industrial uses Such as floor washing, boiler feed, and cooling towers, etc. (C) 2009 Elsevier B.V. All rights reserved.

Two ex situ fungal technologies to treat contaminated soil

Wood-degrading fungi are able to degrade a large range of recalcitrant pollutants which resemble the lignin biopolymer. This ability is attributed to the production of lignin-modifying enzymes, which are extracellular and non-specific. Despite the potential of fungi in bioremediation, there is still an understanding gap in terms of the technology. In this thesis, the feasibility of two ex situ fungal bioremediation methods to treat contaminated soil was evaluated. Treatment of polycyclic aromatic hydrocarbons (PAHs)-contaminated marsh soil was studied in a stirred slurry-phase reactor. Due to the salt content in marsh soil, fungi were screened for their halotolerance, and the white-rot fungi Lentinus tigrinus, Irpex lacteus and Bjerkandera adusta were selected for further studies. These fungi degraded 40 - 60% of a PAH mixture (phenanthrene, fluoranthene, pyrene and chrysene) in a slurry-phase reactor (100 ml) during 30 days of incubation. Thereafter, B. adusta was selected to scale-up and optimize the process in a 5 L reactor. Maximum degradation of dibenzothiophene (93%), fluoranthene (82%), pyrene (81%) and chrysene (83%) was achieved with the free mycelium inoculum of the highest initial biomass (2.2 g/l). In autoclaved soil, MnP was the most important enzyme involved in PAH degradation. In non-sterile soil, endogenous soil microbes together with B. adusta also degraded the PAHs extensively, suggesting a synergic action between soil microbes and the fungus. A fungal solid-phase cultivation method to pretreat contaminated sawmill soil with high organic matter content was developed to enhance the effectiveness of the subsequent soil combustion. In a preliminary screening of 146 fungal strains, 28 out of 52 fungi, which extensively colonized non-sterile contaminated soil, were litter-decomposing fungi. The 18 strains further selected were characterized by their production of lignin-modifying and hydrolytic enzymes, of which MnP and endo-1,4-β-glucanase were the main enzymes during cultivation on Scots pine (Pinus sylvestris) bark. Of the six fungi selected for further tests, Gymnopilus luteofolius, Phanerochaete velutina, and Stropharia rugosoannulata were the most active soil organic matter degraders. The results showed that a six-month pretreatment of sawmill soil would result in a 3.5 - 9.5% loss of organic matter, depending on the fungus applied. The pretreatment process was scaled-up for a 0.56 m3 reactor, in which perforated plastic tubes filled with S. rugosoannulata growing on pine bark were introduced into the soil. The fungal pretreatment resulted in a soil mass loss of 30.5 kg, which represents 10% of the original soil mass (308 kg). Despite the fact that Scots pine bark contains several antimicrobial compounds, it was a suitable substrate for fungal growth and promoter of the production of oxidative enzymes, as well as an excellent and cheap natural carrier of fungal mycelium. This thesis successfully developed two novel fungal ex situ bioremediation technologies and introduce new insights for their further full-scale application. Ex situ slurry-phase fungal reactors might be applied in cases when the soil has a high water content or when the contaminant bioavailability is low; for example, in wastewater treatment plants to remove pharmaceutical residues. Fungal solid-phase bioremediation is a promising remediation technology to ex situ or in situ treat contaminated soil.

Chloroplastic glutamine synthetase from normal and water stressed safflower (Carthamus tinctorius L.) leaves

The chloroplastic isoform of glutamine synthetase (GS(2), EC 6.3.1.2) from normal and water stressed safflower (Carthamus tinctorius L. cv.A-300) leaves has been purified to apparent electrophoretic homogeneity by a procedure involving anion-exchange, hydrophobic and size-exclusion chromatography followed by electroelution of the protein from preparative polyacrylamide gels. The observed molecular weight of the native protein varied from 305-330 kDa depending on the sizing column employed. The native protein is composed of 44 kDa subunits. Under conditions of saturating ammonium and at ATP levels of 0.1-10 mM, double-reciprocal plots with respect to glutamate are biphasic and concave downward at high concentrations of the varied substrate for normal enzyme but are linear for enzyme from water-stressed plants. Under subsaturating ATP levels, K-Glu is over 18-fold lower for enzyme from stressed leaves. The K-m, (ATP) varies with Mg2+ levels in the assay mixture. Double-reciprocal plots of initial velocity with respect to ATP at changing fixed levels of NH4+ are linear for normal enzyme but are curved upwards for enzyme from stressed leaves. Initial velocity data of 1/v vs. 1/ammonium for the enzyme from both the sources are non-linear (curved upwards) when ATP is saturating. At subsaturating ATP levels, the data are linear for normal enzyme but are still non-linear for the enzyme from stressed leaves. The results obtained suggest positively cooperative binding of NH4+ A V-max(/2) value of 3.6 mM for Mg2+ was obtained at 5 mM ATP. The isoelectric point of the native protein from normal and stressed leaves was determined to be, respectively, 5.6 and 6.1. The mixed competitive and competitive inhibitors, methionine sulfoximine and ADP and K-i values of 0.086 mM (0.017 for the enzyme from stressed leaves) and 2.15 mM (1.70 for the enzyme from stressed leaves), respectively. Enzyme from stressed leaves is not inhibited by 5 mM proline. The observed kinetic constants of GS(2) from normal and water stressed safflower seedlings are discussed in relation to the known water-stress tolerance of this crop plant.

Euglena sp as a suitable source of lipids for potential use as biofuel and sustainable wastewater treatment

Prolific algal growth in sewage ponds with high organic loads in the tropical regions can provide cost-effective and efficient wastewater treatment and biofuel production. This work examines the ability of Euglena sp. growing in wastewater ponds for biofuel production and treatment of wastewater. The algae were isolated from the sewage treatment plants and were tested for their nutrient removal capability. Compared to other algae, Euglena sp. showed faster growth rates with high biomass density at elevated concentrations of ammonium nitrogen (NH4-N) and organic carbon (C). Profuse growth of these species was observed in untreated wastewaters with a mean specific growth rate (mu) of 0.28 day(-1) and biomass productivities of 132 mg L-1 day(-1). The algae cultured within a short period of 8 days resulted in the 98 % removal of NH4-N, 93 % of total nitrogen 85 % of ortho-phosphate, 66 % of total phosphate and 92 % total organic carbon. Euglenoids achieved a maximum lipid content of 24.6 % (w/w) with a biomass density of 1.24 g L-1 (dry wt.). Fourier transform infrared spectra showed clear transitions in biochemical compositions with increased lipid/protein ratio at the end of the culture. Gas chromatography and mass spectrometry indicated the presence of high contents of palmitic, linolenic and linoleic acids (46, 23 and 22 %, respectively), adding to the biodiesel quality. Good lipid content (comprised quality fatty acids), efficient nutrient uptake and profuse biomass productivity make the Euglena sp. as a viable source for biofuel production in wastewaters.

Instability in an amorphous In-Ga-Zn-O field effect transistor upon water exposure

The instability of an amorphous indium-gallium-zinc oxide (IGZO) field effect transistor is investigated upon water treatment. Electrical characteristics are measured before, immediately after and a few days after water treatment in ambient as well as in vacuum conditions. It is observed that after a few days of water exposure an IGZO field effect transistor (FET) shows relatively more stable behaviour as compared to before exposure. Transfer characteristics are found to shift negatively after immediate water exposure and in vacuum. More interestingly, after water exposure the off current is found to decrease by 1-2 orders of magnitude and remains stable even after 15 d of water exposure in ambient as well as in vacuum, whereas the on current more or less remains the same. An x-ray photoelectron spectroscopic study is carried out to investigate the qualitative and quantitative analysis of IGZO upon water exposure. The changes in the FET parameters are evaluated and attributed to the formation of excess oxygen vacancies and changes in the electronic structure of the IGZO bulk channel and at the IGZO/SiO2 interface, which can further lead to the formation of subgap states. An attempt is made to distinguish which parameters of the FET are affected by the changes in the electronic structure of the IGZO bulk channel and at the IGZO/SiO2 interface separately.

Deepwater shorelines

Research has proven that Shoreline Erosion is caused by excess water contained within the shore face. This Research presents an opportunity to control erosion by managing the near shore water table. Our Research on Bogue Banks North Carolina suggests that our buildings and other impervious surfaces collect and concentrate water from storm rain runoff into the surface water table and within the critical beach front water exit point. Presently our Potable Fresh Water is supplied from deep wells located beneath an impervious layer of Marl. After our use, the Waste water is drained into the Surface Aquifer, the combined waste and storm rain water raises the Surface Aquifer water table and produces Erosion. The Deep Aquifers presently supplying our Potable Water have an unknown recharge rate, with increasing reports of Salt Water intrusion. We believe our Vital Fresh water supply system should be modified to supply Reverse Osmosis treatment plants from shallow wells. This will lower the Surface Water Table. These Shallow wells, either horizontal or vertical, might be located within the beach front, adjacent to high erosion risk properties. Beach Drains and Reverse Osmosis Water systems are new and proven technologies. By combining these technologies we can reduce or reverse Shore Erosion, ensure a safe Potable Water supply, reduce requirements for periodic beach nourishment, reduce taxes and protect our property well into the Future. (PDF contains 5 pages)

The significance of sedimentation and sediments to phytoplankton growth in drinking-water reservoirs

In the mesotrophic-eutrophic Saidenbach Reservoir in Saxony, the nanoplankton and cyanobacteria have increased at the expense of diatom dominance, due to a doubling of the external phosphorus load in the last 15 years. However, the phosphorus sedimentation flux is still very high (up to 80% of the input), corresponding to more than 2 g m2 d-1 in terms of dry weight. There is a strong correlation between the abundance of diatoms in the euphotic zone and their sedimentation flux (with a delay of about 2 weeks). Only about 25% of the deposited material could be clearly attributed to plankton biomass; the remainder resulted from flocculation and precipitation processes or directly from the inflow of clay minerals. The ash content of the deposited material was high (73%). Thus the sedimentation flux can be considered to operate as an internal water-treatment/oligotrophication process within the lake. The neighbouring Neunzehnhain Reservoir still has a very clear water with a transparency up to 18 m depth. Though the sediment was not much lower than Saidenbach sediment in total phosphorus and total numbers of bacteria, sulphide was always absent and the ratio of Fe 2+ to Fe 3+ was very low in the upper (0- 5 cm) layer. Thus the external and internal phosphorus loads do not attain the critical level necessary to induce a ”phosphorus - phytoplankton” feedback loop.

Tastes and odours in potable water:perception versus reality

Tastes and odours are amongst the few water quality standards immediately apparent to a consumer and, as a result, account for most consumer complaints about water quality. Although taste and odour problems can arise from a great many sources, from an operational point of view they are either ”predictable” or ”unpredictable”. The former - which include problems related to actinomycete and algal growth - have a tendency to occur in certain types of water under certain combinations of conditions, whereas the latter - typically chemical spills - can occur anywhere. Long-term control is one option for predictable problems, although biomanipulation on a large scale has had utile success. Detection and avoidance is a more practicable option for both predictable and unpredictable problems, particularly if the distribution network can be serviced from other sources. Where these are not feasible, then water treatment, typically using activated carbon, is possible. In general there is a reasonable understanding of what compounds cause taste and odour problems, and how to treat these. An efficient taste and odour control programme therefore relies ultimately on good management of existing resources. However, a number of problems lie outside the remit of water supply companies and will require more fundamental regulation of activities in the catchment.

Analytical method development for the uptake study of different organic pollutants by crops cultivated in compost-amended soils

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Gestão de resíduos químicos em laboratório universitário. Estudo de caso: Laboratório de Engenharia Sanitária, Faculdade de Engenharia UERJ.

Ao longo da história do homem, as universidades têm exercido um papel fundamental na geração de conhecimentos e tecnologias com o fim maior de melhorar a qualidade de vida de nossa sociedade. Em contrapartida, além de produzir os benefícios oriundos da aplicação dos conhecimentos e tecnologias, as pesquisas científicas produzem também diversos tipos de resíduos potencialmente poluidores e tóxicos os quais não estão sendo descartados e tratados corretamente. A falta de políticas institucionais de gerenciamento de resíduos nas universidades além de proporcionar a poluição dos corpos receptores de seus efluentes, a deterioração das tubulações coletoras de esgoto e, danos a eficiência das estações de tratamento de esgoto, também contribui para a geração de um passivo ambiental nas universidades, os quais são acumulados anualmente à espera de tratamento adequado em precárias condições de armazenamento. Dentro deste cenário, o presente estudo visa caracterizar e avaliar o gerenciamento dos resíduos químicos do Laboratório de Engenharia Sanitária (LES) da Universidade do Estado do Rio de Janeiro (UERJ). Quanto aos meios, foram realizadas pesquisas bibliográficas, eletrônicas e documentais, assim como entrevistas com os principais atores do gerenciamento dos resíduos no laboratório foco deste estudo. O estudo revela que o gerenciamento dos resíduos gerados em tal laboratório é realizado de maneira incipiente. As metodologias utilizadas em todas as etapas do gerenciamento, desde a geração dos resíduos até a destinação final dos mesmos carecem de melhorias para também a melhora da qualidade ambiental das atividades de pesquisa e de ensino do laboratório. Além da inexistência de normas internas para a padronização e controle do processo de gerenciamento, o laboratório também carece de estrutura física e financeira para a adequação do processo. A partir do diagnóstico deste cenário, foi possível o reconhecimento de riscos relacionados às características dos reagentes químicos somados as condicionantes ambientais do laboratório, mais especificamente, às condicionantes presentes no local do armazenamento dos resíduos. Tais riscos possuem a natureza de riscos químicos, físicos, toxicidade e riscos de explosão. Ainda na caracterização deste cenário, foi possível o reconhecimento do não cumprimento de legislações pertinentes ao tema. Conclui-se que, de maneira geral, as universidades carecem de investimentos na temática de gestão ambiental nas políticas institucionais e dia-a-dia das universidades. O laboratório em questão também não foge a esta realidade e, por tal razão, também carece de investimentos financeiros, investimentos em treinamento e investimentos na estruturas físicas para todos estes darem suporte a implantação de um gerenciamento de resíduos eficiente e consistente.

Avaliação de desempenho para estações de tratamento de efluentes industriais.

O processo produtivo industrial pode gerar uma grande quantidade de efluentes líquidos. Esses efluentes, quando não tratados, podem poluir o solo e a água, podendo causar grande impacto ambiental. Nesse sentido é imprescindível que todas as indústrias que geram efluentes líquidos possuam uma estação de tratamento. Porém, para que a estação esteja permanentemente funcionando de acordo com seu objetivo, essa deve ser rotineiramente avaliada. Dessa forma, a avaliação de desempenho para Estação de Tratamento de Efluentes Industriais (ETEI) se torna uma ferramenta importante para a manutenção da eficiência da estação, pois se justifica por procurar pontos vulneráveis da planta de tratamento fornecendo os subsídios necessários à elaboração do diagnóstico e projetos de adequação dos sistemas, permitindo que os efluentes tratados fiquem em conformidade com as exigências estabelecidas pela legislação ambiental. Neste trabalho, foi elaborada uma proposta metodológica, formada por um roteiro, composto por níveis de questionamentos, que auxilia o avaliador na análise de desempenho da ETEI. Complementando esse roteiro foram elaboradas algumas listas de verificação que contribuem para guiar o avaliador em suas análises. Na elaboração das listas, manuais desenvolvidos em diversos países foram considerados. As listas de verificação incluem perguntas para a avaliação dos dados gerais da indústria, para seu Sistema de Gestão Ambiental (SGA) e para alguns sistemas e unidades operacionais da estação de tratamento. Para exemplificar um dos níveis de questionamento do roteiro foi incluído um estudo de caso, no qual o afluente e o efluente de uma indústria mineradora foram avaliados através da técnica estatística multivariada Análise de Componentes Principais (ACP), para demonstração do desempenho da estação de tratamento. O resultado da avaliação realizada demonstrou um bom desempenho da ETEI em tratar os efluentes líquidos. Espera-se, portanto, que este trabalho seja útil para a avaliação de desempenho em plantas de tratamento de efluentes industriais.