Biological Treatment Technologies Research Articles

Recent advances in brewery wastewater treatment; approaches for water reuse and energy recovery: a review

Brewery industry is one of the largest users of water and characterized by high levels of organic pollutants, and requires higher attention for remediation before discharge to the environment. This paper aims at providing a review of methods for treating brewery wastewater based implications using the state-of-the-art biological treatment technologies leading to water reuse and/or energy production. This could be linked to resource recovery as a sound and economic approach to alleviate fresh water scarcity and shortage of energy supply. In this review, the components of various bioreactors (i.e. membranes bioreactors, fluidized bed bioreactor and anaerobic bioreactors) and how efficiently these reactors can be utilized for treating and reuse of brewery wastewater are highlighted.

Hybrid anaerobic-aerobic biological treatment for real textile wastewater

In this study, working of hybrid anaerobic-aerobic biological treatment technology for real textile wastewater was investigated on the basis of system evaluation and optimization in two phases. In Phase I, system was optimized at laboratory scale on synthetic textile wastewater and later real textile wastewater was treated in Phase II. The study was conducted for 242 days in which industrial discharge coming from textile mill was collected and subjected to laboratory scale hybrid treatment. Activated sludge used in the process was obtained from full scale membrane bioreactor (MBR) plant and adapted to the synthetic and real textile wastewater using anaerobic process. Individual application of anaerobic treatment was found to be insufficient for the removal of COD, TKN and dyes. The proposed combine hybrid anaerobic-aerobic system was found to be effective in reporting removal efficiencies of 99.5% COD, 99.3% TKN, and 78.4% dyes. The anaerobic SBR added value to the hybrid system as it played a key role in improving treatment efficiency in addition to the production of sustainable energy source of biogas. Study shows that aerobic treatment is required to increase the treatment level by providing the final polishing to anaerobically treated effluent in order to reclaim water. The optimum HRT for hybrid anaerobic-aerobic system in treating real textile wastewater was found to be 54 h for maximum COD removal. The implication of this work is the industrial application of hybrid anaerobic-aerobic system for reuse of water in agricultural and industrial sectors.

Sewage sludge utilization for the municipality of Gdansk

In the municipal wastewater treatment plant in Gdansk a biological treatment technology allowing removing of nutrients was launched recently. This will result in increasing of the volume of sludge from 27.3 t d.m./d now to about 45 t d.m./d in the near future. The analysis of various possibilities of sludge utilization was made. It was concluded that incineration of the sludge seems to be the most promising method, while the possibilities of application of sludge in agriculture, forestry or to land reclamation are limited. Therefore it is suggested that 90% of sludge should be incinerated and the remaining 10% - stabilized with lime and applicated to land reclamation. The ahses generated during the incineration of sludge should be deposited at the municipal waste dump, with possible phosphorus extraction in the future.

Biochemical Treatment of Municipal Sewage in Northeast China in Winter

In view of the colder winter conditions in the north of China, and taking into account the high removal rate and low operating cost of biological wastewater treatment methods, which is the leading treatment process for organic wastewater. This paper selects the biological treatment technology to treat the urban sewage in Northeast China in winter. Temperature is one of the most important factors that affect microbial activity, therefore, in the application of wastewater biochemical treatment, the effect of sewage treatment is greatly affected by temperature. In order to solve the problem of low temperature, cold-resistant bacteria should be used to treat low-temperature domestic sewage. The result of this operation is that in the low temperature (10°C) sewage, the removal efficiency of COD with chilling resistant bacteria can reach more than 40%, and the adaptability to temperature change is also strong. Cold-tolerant microbial Complex flora has a good COD treatment ability under low temperature conditions, and has a good application prospect in low temperature domestic sewage biological treatment, the treatment of domestic sewage in Northeast China in winter can be carried out by the above methods.

The Role of the Anode Material in Selective Penicillin G Oxidation in Urine

AbstractIn this work, the removal of antibiotic penicillin G by electrolysis with boron doped diamond (BDD) and mixed metal oxide (MMO) anodes in urine media is evaluated. First, electrolysis in different water matrices (sulfate, chloride and urine) were carried out with diamond anodes to shed light on the contribution of mediated mechanisms. Results showed that penicillin G was completely removed by electrolysis for electric charges below 5 Ah dm−3, regardless of the water matrix and the current density applied (10‐100 mA cm−2). Then, the influence of the anode material was evaluated for the degradation of penicillin G in urine media. A complete removal of the antibiotic was attained, regardless of the tested anode material, although the BDD anode was found to be more efficient than MMO. Results also showed that, at the current charges in which the antibiotic is depleted, the removal of other organics was much lower and the formation of chlorates was negligible, especially operating at low current densities. Because of this selective oxidation of the pharmaceutical compound, electrolysis can be proposed to be used as a pre‐treatment technology for later and cheaper biological treatment.

Oxygen mass transfer and post-denitrification in a modified rotating drum biological contactor

A lab-scale rotating drum biological contactor (RDBC) was implemented and accessed concerning abiotic oxygen transfer rate and treatment capacity for domestic sewage. The dissolved oxygen (DO) transfer test showed that the rotational speed and the submergence level of drum greatly affected the DO in bulk liquid with the volumetric oxygen transfer coefficient KLa of 2.3-25.9 h−1, effectively achieving anaerobic/anoxic/aerobic conditions in the reactor. The post-denitrification process was proposed using the RDBC to degrade the synthetic nitrogen-containing sewage wastewater. When the hydraulic retention time was 16 h, the flow distribution ratio was 3:1 and the anoxic rotational speed was 6 rpm, the effluent NH4+-N and TN were 2.3 mg L−1 and 7.3 mg L−1 with the NH4+-N and TN removal efficiency of 94.1% and 80.9%, respectively. The Nitrosomonas europaea and Candidatus Kuenenia dominated in the anoxic carried-biofilm, indicating that the coexisting of aerobic and anaerobic ammonium oxidation bacteria enhanced the TN loss in the post-anoxic tank. This study provides an innovative non-aeration technology for biological wastewater treatment and has implications to simplify operation and save energy.

Issues on Existing Treatment Technologies and Possibility of Biological Treatment Technologies for 1,4－Dioxane-containing Industrial Wastewater

Issues on Existing Treatment Technologies and Possibility of Biological Treatment Technologies for 1,4－Dioxane-containing Industrial Wastewater

The influence of biochar and compost mixtures, water content, and gas flow rate, on the continuous adsorption of methane in a fixed bed column

Biofiltration is an excellent alternative for the treatment of diffuse emissions of methane (CH4) that cannot be treated by physical/chemical means or recovered for energy. Despite the advances on CH4 biological treatment technologies, they are limited by the low aqueous solubility of CH4 into the biofilm where CH4 mineralization occurs. In this study, the CH4 adsorption kinetics, adsorption capacity and transport behavior of CH4 was studied in batch experiments and in a fixed-bed column by varying the biochar and compost mixtures under 5-levels, 3 different water contents (dry, 15% and 30% water holding capacity), and 2 inlet flow rates. Experimental results were formally tested using analysis of variance (ANOVA) in order to draw objective conclusions based on statistical inference. As CH4 biofiltration requires water addition to maintain microbial activity, these results indicate adsorption capacity is not lost with water addition if biochar content is the dominant packing material. The Langmuir isotherm described the data best (R2 = 0.99). Maximum adsorption capacity by monolayer adsorption, or qmax, is relatively similar with or without the addition of water as long as the biochar component is the dominant material at 3.5 mg CH4/g medium for a 7:1 biochar: compost, v/v mixture. Empirical regression models for qo, kTh, (Thomas model) and τ and KYN (Yoon-Nelson model) were developed for the break through curves of CH4. The current work demonstrates the applicability of utilizing biochar, a relatively inexpensive adsorbent, can compensate for the low solubility of CH4 and overcome the rate-limiting step of mass transfer from the gas phase and into the methanotrophic biofilm. Further, biochar may be a reliable back-up system for CH4 storage especially for fluctuating inlet loads that may be encountered in industrial applications adsorbing up to 13 mg CH4/g biochar under dry conditions.

Nitrogen cycling during wastewater treatment.

Many wastewater treatment plants in the world do not remove reactive nitrogen from wastewater prior to release into the environment. Excess reactive nitrogen not only has a negative impact on human health, it also contributes to air and water pollution, and can cause complex ecosystems to collapse. In order to avoid the deleterious effects of excess reactive nitrogen in the environment, tertiary wastewater treatment practices that ensure the removal of reactive nitrogen species need to be implemented. Many wastewater treatment facilities rely on chemicals for tertiary treatment, however, biological nitrogen removal practices are much more environmentally friendly and cost effective. Therefore, interest in biological treatment is increasing. Biological approaches take advantage of specific groups of microorganisms involved in nitrogen cycling to remove reactive nitrogen from reactor systems by converting ammonia to nitrogen gas. Organisms known to be involved in this process include autotrophic ammonia-oxidizing bacteria, heterotrophic ammonia-oxidizing bacteria, ammonia-oxidizing archaea, anaerobic ammonia oxidizing bacteria (anammox), nitrite-oxidizing bacteria, complete ammonia oxidizers, and dissimilatory nitrate reducing microorganisms. For example, in nitrifying-denitrifying reactors, ammonia- and nitrite-oxidizing bacteria convert ammonia to nitrate and then denitrifying microorganisms reduce nitrate to nonreactive dinitrogen gas. Other nitrogen removal systems (anammox reactors) take advantage of anammox bacteria to convert ammonia to nitrogen gas using NO as an oxidant. A number of promising new biological treatment technologies are emerging and it is hoped that as the cost of these practices goes down more wastewater treatment plants will start to include a tertiary treatment step.

Establishing a decision-support system for eco-design of biological wastewater treatment: A case study of bioaugmented constructed wetland

Deep treatment is a common approach to enhance pollutant removal for biological wastewater treatment technologies (BWTTs), and life cycle assessment (LCA) holds substantial advantages to support process optimization. However, there lacks of LCA-based benchmarks that cover human-nature nexuses and stakeholder involvement, which limits the guidance and eco-design of BWTTs. This study proposed a decision-support system (DSS) by linking LCA with Water Quality Model and Conjoint Analysis. Three major findings were identified based on a demonstrative case (constructed wetland bioaugmented by dosing different microbial inocula): (1) Increasing bacterial intensities would achieve net environmental improvement, but it might not apply to all cases; (2) Making full use of natural self-purification capacity could partly replace the functions of BWTTs; (3) Stakeholders would concern aquatic environmental improvement when receiving river that had limited environmental capacity. Overall, the DSS provided a data-driven platform for screening options before determinations were made to constrain wastewater treatment sustainability.

Study on Growth Characteristics of Oily Sludge Degrading Bacteria

Regarding oily sludge, microbial treatment of oily sludge will be a future development trend. It will be of great significance to apply microbial degradation of oily sludge to practical engineering. However, there are still many problems and deficiencies in biological treatment technology, such as Screening and cultivation of petroleum-degrading bacteria, long treatment cycle, etc. The purpose of this study is to cultivate a more active petroleum-degrading bacterium, which is used in the best state for the degradation of oily sludge.

Agroindustrial Wastewater Treatment with Simultaneous Biodiesel Production in Attached Growth Systems Using a Mixed Microbial Culture

The use of cyanobacteria in biological wastewater treatment technologies can greatly reduce operation costs by combining wastewater bioremediation and production of lipid suitable as biodiesel feedstock. In this work, an attached growth system was employed to achieve the above-mentioned dual objective using a mixed microbial culture dominated by Leptolyngbya and Limnothrix species in diverse heterotrophic consortia. Kinetic experiments on different initial pollutant concentrations were carried out to determine the ability of the established culture to remove organic load (expressed by d-COD, dissolved-Chemical Oxygen Demand), N and P from agroindustrial wastewaters (dairy, winery and raisin). Biomass and oil productivity were determined. It was found that significant removal rates of nutrients were achieved in all the wastewaters examined, especially in that originated from winery in which the highest d-COD removal rate (up to 97.4%) was observed. The attached microbial biomass produced in winery wastewater contained 23.2% lipid/biomass, wt/wt, which was satisfying. The growth in the dairy wastewater yielded the highest attached biomass productivity (5.03 g m−2 day−1) followed by the mixed effluent of winery-raisin (4.12 g m−2 day−1) and the winery wastewater (3.08 g m−2 day−1). The produced microbial lipids contained high percentages of saturated and mono-unsaturated fatty acids (over 89% in total lipids) in all substrates examined. We conclude that the proposed attached growth photobioreactor system can be considered an effective wastewater treatment system that simultaneously produces microbial lipids suitable as biodiesel feedstock.

Application of unstructured kinetic models to predict microcystin biodegradation: Towards a practical approach for drinking water treatment

Biological drinking water treatment technologies offer a cost-effective and sustainable approach to mitigate microcystin (MC) toxins from harmful algal blooms. To effectively engineer these systems, an improved predictive understanding of the bacteria degrading these toxins is required. This study reports an initial comparison of several unstructured kinetic models to describe MC microbial metabolism by isolated degrading populations. Experimental data was acquired from the literature describing both MC removal and cell growth kinetics when MC was utilized as the primary carbon and energy source. A novel model-data calibration approach melding global single-objective, multi-objective, and Bayesian optimization in addition to a fully Bayesian approach to model selection and hypothesis testing were applied to identify and compare parameter and predictive uncertainties associated with each model structure. The results indicated that models incorporating mechanisms of enzyme-MC saturation, affinity, and cooperative binding interactions of a theoretical single, rate limiting reaction accurately and reliably predicted MC degradation and bacterial growth kinetics. Diverse growth characteristics were observed among MC degraders, including moderate to high maximum specific growth rates, very low to substantial affinities for MC, high yield of new biomass, and varying degrees of cooperative enzyme-MC binding. Model predictions suggest that low specific growth rates and MC removal rates of degraders are expected in practice, as MC concentrations in the environment are well below saturating levels for optimal growth. Overall, this study represents an initial step towards the development of a practical and comprehensive kinetic model to describe MC biodegradation in the environment.

Biological coupling process for treatment of toxic and refractory compounds in coal gasification wastewater

Coal gasification wastewater (CGW) contains a large number of toxic and refractory compounds, such as phenolic compounds and polycyclic and heterocyclic aromatic compounds. These toxic and refractory compounds are difficult to degrade if biological methods are the only ones used. In recent years, several novel biological coupling processes are used to treat CGW. In the study, this review attempts to offer a comprehensive summary regarding the biological coupling treatment technologies of CGW, including conventional biological processing arts, the combination of adsorption and biotechnology, biological enhancement technologies, co-metabolism technologies and the combination of advanced oxidation and biotechnology. Meanwhile, the treatment efficiency of different biological coupling processes was compared with each other. Co-metabolism and advanced oxidation with biotechnology are both highly effective and promising technologies for degrading toxic and refractory compounds. More research should be conducted on these two aspects in the future.

Effect of Aeration Rates and Filter Media Heights on the Performance of Pollutant Removal in an Up-Flow Biological Aerated Filter

The biological aerated filter (BAF) is an effective biological treatment technology which removes the pollutants in municipal wastewater secondary treatment. However, we still know little about the interaction between the pollutants removal and microbes within the BAF. In this study, we used an up-flow BAF (UBAF) reactor to investigate the relationships between the pollutants removal and microbial community structure at different aeration rates and filter media heights. The microbial community of biofilm was analyzed by Illumina pyrosequencing. Our results showed that the UBAF achieved a better removal efficiency of chemical oxygen demand (COD), NH4+-N, NO3−-N, and total phosphorus (TP) at an aeration rate of 65 L/h. In addition, the COD and NH4+-N removal mainly occurred at 0–25 cm height of filter media. The microbial community structure in the UBAF demonstrated that the relative abundance of the Planctomycetes and Comamonadaceae at 10 cm height of filter media were 11% and 48.1%, respectively, proportions significantly higher than those under others treatments. Finally, the changes in relative abundance of Proteobacteria, Planctomycetes, and Nitrospirae likely explained the mechanism of nitrogen and phosphorus removal. Our results showed that suitable conditions could enhance the microbial community structure to achieve a high pollutants removal in the UBAF.

Simulation study on comparison of algal treatment to conventional biological processes for greywater treatment

The reuse of greywater is a promising strategy to preserve fresh water resources for future generations. The main objective of the present study is to simulate three different biological treatment technologies (high rate algal pond (HRP), conventional activated sludge (AS) treatment and rotating biological contactors (RBC)) at varying pollutant loadings (low, medium and high-strength polluted greywater) and, then, compare the treatment efficiency of HRP treatment with both RBCs and AS process. All of the adopted technologies were found to produce effluents with satisfactory quality. RBC achieved higher removal of nitrate and phosphorus compared to the conventional AS treatment process, whereas sensitivity analyses reveal that the AS process reached the steady state condition faster than the RBC process. The removal efficiency for AS process was 100% for biochemical oxygen demand, while the total suspended solids and Escherichia coli concentrations were lower than 5 mg L−1 and 0.001 MPN 100-mL−1, respectively. Algal ponds treatment is effective but highly variable. However, it had additional benefits such as CO2 assimilation and biomass production. The treatment efficiency of algal system depended mainly on the mass concentrations of algae and flow rates. Algae mass concentration of 700 g m−3 and flow rate of 40 m3 d−1 achieved complete removal of the SBOD. The influence of operational parameters on the production of algal biomass was investigated and the higher CO2 fixation efficiency was achieved with the fraction of photoperiod as 0.8 and mass concentration of algae 1000 g m−3.

Management of municipal solid waste in Croatia: Analysis of current practices with performance benchmarking against other European Union member states.

The European Commission has adopted a very ambitious circular economy package and has consequently revised many legislative proposals on waste. The new targets include achieving a recycling rate of 65% by 2030 and imposing a cap on landfilled waste to no more than 10% (as a percentage of weight). Using available European and national databases on municipal solid waste indicators, we have analysed municipal solid waste production trends for Croatia and have benchmarked the indicators against other EU member states and EU averages. Our analysis points out that the production of municipal solid waste has steadily risen over the last two decades. Although Croatia produces a relatively low amount of municipal solid waste compared with other EU countries and EU averages, gross domestic product adjusted waste production reveals that for every euro of gross domestic product Croatia produces substantial amounts of municipal solid waste. As a matter of fact, among all the EU member states, only Bulgaria had a worse performance than Croatia. Regarding recycling rates, Croatia recycles 15% of its municipal solid waste and incinerates approximately 3% (by weight). The rest (82% by weight) is currently being landfilled. Regarding the treatment of waste, Croatia has implemented mechanical-biological treatment technology, but our analysis reveals that the initial number of mechanical-biological treatment plants will likely have to be scaled down taking into consideration the new EU waste management targets.

Biological and chemical treatment technologies for waste amines from CO2 capture plants

Amine-based carbon dioxide capture is the most mature technology for reducing flue gas CO2 emissions. It has been postulated and observed during commercialisation of this technology that significant quantities of waste amines are produced. Further industrial implementation of this technology requires adequate disposal or valorisation options for this waste. This review presents an analysis of seven biological and chemical technologies for waste amine amelioration or valorisation. Of these, the biological treatments are identified as being more mature for industrial application with the capacity for marketable product generation. Slow speed is the main drawback of the biological processes but this does not hinder their commercial viability. Using waste amine for NOx reduction in power stations is a secondary option, where it seems probable that the amount of waste amine generated in the CO2 capture plant is sufficient to fulfil the DeNOx requirements of the flue gas. This route, however, requires investigation into the impact of waste amine impurities on the power station and the CO2 capture plant operations.

Upaya Optimasi Kinerja Melalui Basic Design Revitalisasi Pada Instalasi Pengolahan Air Limbah (IPAL) Cisirung, Bandung Selatan

Berkaitan dengan upaya restorasi dan Pengendalian Pencemaran Air (PPA) yang masuk ke Sungai Citarum bagian hulu, kegiatan revitalisasi IPAL Cisirung dilakukan untuk meningkatkan kapasitas IPAL Cisirung agar kinerjanya menjadi lebih optimal. IPAL Cisirung dibangun dengan teknologi pengolahan air limbah secara fisika, kimia dan biologi. Kegiatan ini dilakukan dengan melakukan survei lapangan dan pengujian sampel di laboratorium. Debit air limbah saat ini yang masuk ke IPAL Cisirung sebesar 206,10 L/detik. Tujuan dari kegiatan ini adalah untuk membuat basic design revitalisasi IPAL Cisirung sebagai acuan Detail Engineering Design (DED) dengan kapasitas perencanaan sebesar 350 L/detik. Pengambilan sampel air dilakukan berdasarkan gambaran unit pengolahan yang harus direvitalisasi, yakni bak ekualisasi, outlet bak pengendap I, dan bak pengendap II. Hasil uji penelitian di laboratorium secara kimiawi menunjukan kondisi optimum kekeruhan adalah 28,6 NTU. Revitalisasi unit pengolahan biologi dirancang menggunakan teknologi Moving Bed Biofilm Reactor (MBBR). Keuntungan teknologi MBBR adalah sangat efektif dalam mereduksi COD sebesar 85%, mereduksi nitrogen melalui proses nitrifikasi dan mampu menyerap TSS atau MLSS sebanyak 2400 mg/L.

Engaging multiple weighting approaches and Conjoint Analysis to extend results acceptance of life cycle assessment in biological wastewater treatment technologies

Environmental impacts of biological wastewater treatment technologies (BWTTs) can be evaluated by life cycle assessment (LCA). However, very few efforts have been made to expand the ranges of results acceptance and promote stakeholders to participate in the results analysis. To facilitate the evaluation reaching more wide and deep understanding, this study proposed to employ multiple weighting methods and the Conjoint Analysis. To investigate the feasibility, an illustrative case of a bioaugmented constructed wetland was carried out. Weighting results indicated that appropriate improvement strategies could be obtained from synthesizing the similarities and differences of LCA results due to different weighting methods employed. Meanwhile, application of Conjoint Analysis was conducive to the communication between LCA practitioners and BWTTs stakeholders. In a simulated decision-situation, this study found that the decision-making process of stakeholders could be clearly derived to indicate how stakeholders would take trade-offs and make choices based on analyzing LCA outcome.