混合固定化硝化菌和好氧反硝化菌处理焦化废水

对传统的聚乙烯醇(PVA)固定化方法进行了改进,试制了加入麦秸粉末的固定化球和以活性炭纤维膜为载体膜固定化细胞产品。混合固定化硝化细菌和好氧反硝化细菌对经过厌氧折流板反应器酸化后的焦化废水进行脱氮,焦化废水在厌氧折流板反应器中经过18 h的酸化后,pH在8.0左右,开始进入好氧槽进行脱氮。在有效容积为5 L好氧槽中经过12 h的曝气处理,加入麦秸粉末的固定化球对氨氮的去除率高达94.3%;纤维膜固定化细胞产品对氨氮的去除率为85%。整个脱氮过程无NO^-₂-N和NO^-₂-N的积累,实现了好氧条件下的同时硝化和反硝化。     

Simultaneous nitrification and denitrification with anoxic phosphorus uptake in a membrane bioreactor system.

The performance of an innovative membrane bioreactor (MBR) process using anoxic phosphorus uptake with nitrification and denitrification for the treatment of municipal wastewater with respect to operational performance and effluent quality is addressed in this paper. The system was operated at steady-state conditions with a synthetic acetate-based wastewater at a hydraulic retention time (HRT) of 12 hours and on degritted municipal wastewater at a total system HRT of 6 hours. The MBR system was able to achieve 99% biochemical oxygen demand (BOD), chemical oxygen demand (COD), and ammonia-nitrogen (NH4(+)-N); 98% total Kjeldahl nitrogen (TKN); and 97% phosphorus removal, producing effluent BOD, COD, NH4+-N, TKN, nitrate-nitrogen, nitrite-nitrogen, and phosphate-phosphorus of <3, 14, 0.2, 0.26, 5.8, 0.21, and <0.01 mg/L, respectively, at the 6-hour HRT. The comparison of the synthetic and municipal wastewater run is presented in this paper. Steady-state mass balance on municipal wastewater was performed to reveal some key features of the modified MBR system.     

Aerobic Treatment of a Nitrogen-Limited Chemical Process Waste water

Abstract

Nitrogen transformations and their effect on aerobic suspended growth treatment of an industrial wastewater were studied in three parallel bench-scale reactors operated at 5 "C at mean cell residence times (MCRT) of 15, 30, and 60 days. In normal process wastewater, the bulk of influent nitrogen was in organic form, and the fraction transformed was almost totally incorporated into synthesized biomass. Assimilative control by heterotrophs maintained ammonianitrogen levels below permitted effluent levels, and nitrification was not significant. Although volatile suspended solids had a nitrogen content of only 5% to 8%, effective organics removal was maintained, and total organic carbon and filtered daily average five-day biochemical oxygen demand (BODS) were below permitted effluent levels. A marked improvement in settleability and lower effluent total suspended solids was achieved by adding ammonia-nitrogen to the wastewater in excess of stoichiometric growth requirements.

During a batch production cycle of a cationic chemical, the ratio of nitrogen to chemical oxygen demand and the fraction of the total influent nitrogen in soluble form increased in the wastewater. Reactor effluent ammonia levels increased to above permit levels at all three MCRTs during treatment of wastewater containing cationic production effluents. The magnitude of ammonia increase was greater for longer MCRTs, suggesting that synthesis of cell mass was not capable of assimilating the increased ammonia supply under these non-steady conditions. The experimental results suggest several potential strategies for operating the aerobic process at the treatment facility, including adding nitrogen to improve settleability and discontinuing these additions when wastewater contains a high ratio of nitrogen to chemical oxygen demand and an elevated soluble nitrogen fraction     

Self-build packed-bed bioreactor for rapid and effective BOD estimation

This work demonstrated a simple, low-cost, rapid, and effective biochemical oxygen demand (BOD) estimation system based on a packed-bed bioreactor that can be easily self-built on-site at a particular wastewater treatment plant for continuous monitoring of the influent and effluent. The use of natural microbial consortium that were collected from the target wastewater and immobilized on a cheap porous carrier simply by adhesion resulted in an acceptable accuracy of over 95%. The newly developed semi-continuous operating mode with peak-type signals was shown to be able to continuously estimate BOD at a high flow rate to overcome the flow dependence of the oxygen electrode, limit clogging issues, enhance the response time, and lower the limit of detection. The resulting packed-bed bioreactors could work continuously for 22 h with a coefficient of variance (CoV) of only 1.8% or for 13 h a day for several days with a maximum CoV of 1.4% and their response was observed to be stable over 80 consecutive measurements. They exhibited stable responses at a wide pH range of 6.5–8.5, which is also the recommended range for aerobic wastewater treatment, emphasizing the greater ease of use of natural microorganisms for BOD estimation.

     

Chemical composition associated with different particle size fractions in municipal, industrial, and agricultural wastewaters

A more detailed characterization of particulate organic matter in wastewater streams is needed to improve solid-liquid separation and biological processes for wastewater treatment. The objective of this paper was to evaluate particle size distributions and the associated chemical composition for municipal, industrial, and agricultural waste streams. Most of the organic matter in these wastewaters was larger than a molecular weight of 10(3) amu and therefore would require extracellular hydrolysis before any bacterial metabolism. Particle size distributions were significantly different for the studied waste streams. In municipal wastewater, the organic matter was evenly distributed in all eight size fractions ranging from 10(3) amu up to 63 microm. The industrial and agricultural wastewaters, however, contained mainly soluble organic matter (<10(3) amu) and larger particles (>1.2 microm for the industrial and >10 microm for the agricultural waste) leaving a gap in the size range of large macromolecules and colloids. The relative protein and carbohydrate concentrations varied for the different size fractions compared to the measured chemical oxygen demand (COD) in the corresponding size fraction. Thus, the design of the solid-liquid separation at a treatment plant could be used to purposefully modify the overall chemical composition of the organic matter before further biological treatment. Particle size distributions will influence design and operation of biological nutrient removal processes such as denitrification or biological phosphorus removal that may be carbon limited if a large fraction of the organic matter is composed of large particles with slow hydrolysis rates. Measured particle size distributions for the different waste streams in this study (municipal, industrial, agricultural) were significantly different requiring specific approaches for treatment plant design.     

Advanced oxidation treatment of physico-chemically pre-treated olive mill industry effluent

In this study, the applicability of physico-chemical methods was investigated for the pre-treatment of the olive mill effluents prior to the discharge into the common sewerage ending with a municipal wastewater treatment plant. The samples were taken from an olive oil industry operated as three-phase process located in Turkey. Various pre-treatment methods including acid craking, polyelectrolyte and lime additions were applied. Advanced oxidation study using Fenton's process was also investigated following pre-treatment by acid cracking and cationic polyelectrolyte. Acid cracking alone gave satisfactory treatment efficiencies and polyelectrolite additions to the acid-cracked samples enhanced treatment efficiency. Since a complete treatment plant is available at the end of the sewer system, results indicated that the effluents of the investigated industry could be discharged into the municipal sewerage in the case of total chemical oxygen demand (COD_tot), suspended solid (SS) and volatile suspended solid (VSS) concentrations according to the Turkish Water Pollution Control Regulation after pre-treatment with 5 ppm anionic polyelectrolyte following acid cracking. The minimum COD_tot, SS and VSS removals were observed when raw wastewater was pre-treated with lime and the discharge standards to the municipal sewer system could not be met. Advanced oxidation with Fenton's process was applied after acid cracking and cationic polyelectrolyte treatment in order to investigate further reduction in chemical oxygen demand (COD) concentration for minimizing the influence of this industrial discharge on the existing municipal wastewater treatment plant. Results indicated that COD_tot removal increased up to 89% from 74% after Fenton's oxidation for the acid cracked samples in which cationic polyelectrolite (10 ppm) was added.     

Semi-specific Microbacterium phyllosphaerae-based microbial sensor for biochemical oxygen demand measurements in dairy wastewater

Although the long incubation time of biochemical oxygen demand (BOD₇) measurements has been addressed by the use of microbial biosensors, the resulting sensor-BOD values gained from the measurements with specific industrial wastewaters still underestimates the BOD value of such samples. This research aims to provide fast and more accurate BOD measurements in the dairy wastewater samples. Unlike municipal wastewater, wastewater from the dairy industry contains many substrates that are not easily accessible to a majority of microorganisms. Therefore, a bacterial culture, Microbacterium phyllosphaerae, isolated from dairy wastewater was used to construct a semi-specific microbial biosensor. A universal microbial biosensor based on Pseudomonas fluorescens, which has a wide substrate spectrum but is nonspecific to dairy wastewater, was used as a comparison. BOD biosensors were calibrated with OECD synthetic wastewater, and experiments with different synthetic and actual wastewater samples were carried out. Results show that the semi-specific M. phyllosphaerae-based microbial biosensor is more sensitive towards wastewaters that contain milk derivates and butter whey than the P. fluorescens-based biosensor. Although the M. phyllosphaerae biosensor underestimates the BOD₇ value of actual dairy wastewaters by 25–32 %, this bacterial culture is more suitable for BOD monitoring in dairy wastewater than P. fluorescens, which underestimated the same samples by 46–61 %.     

Environmental exposure of pharmaceuticals and musk fragrances in the Somes River before and after upgrading the municipal wastewater treatment plant Cluj-Napoca,Romania

Background, aim, and scope

Pharmaceutically active substances are a class of emerging contaminants, which has led to increasing concern about potential environmental risks. After excretion, substantial amounts of unchanged pharmaceuticals and their metabolites are discharged into domestic wastewaters. The absence of data on the environmental exposure in Eastern Europe is significant, since use patterns and volumes differ from country to country. In Romania, the majority of wastewater, from highly populated cities and industrial complex zones, is still discharged into surface waters without proper treatment or after inefficient treatment. In respect to this, it is important to determine the environmental occurrence and behavior of pharmaceuticals and personal care products (PPCPs) in wastewaters and surface waters. The objective of the present study was to investigate the occurrence of selected PPCPs during the transport in the Somes River by mass flow analysis before and after upgrading a municipal wastewater treatment plant (WWTP) in Cluj-Napoca, which serves 350,000 inhabitants and is the largest plant discharging into the Somes River. The concentrations of PPCPs at Cluj-Napoca can be correlated with the high population and a high number of hospitals located in the catchment area leading to higher mass flows. The results of this study are expected to provide information, with respect to the Romanian conditions, for environmental scientists, WWTP operators, and legal authorities. The data should support the improvement of existing WWTPs and implementation of new ones where necessary and, therefore, minimize the input of contaminants into ambient waters.

Materials and methods

The PPCPs were selected on the basis of consumption at the regional scale, reported aquatic toxicity, and the suitability of the gas chromatography/mass spectrometry (GC/MS) method for the determination of the compounds at trace levels. The studied PPCPs, caffeine (stimulant), carbamazepine (antiepileptic), pentoxifylline (anticoagulant), cyclophosphamide (cytostatic), ibuprofen (analgesic), and galaxolide (musk fragrance), were determined in samples of the Somes River. The analytes were enriched by solid-phase extraction and subsequently determined by GC/MS. Caffeine, pentoxifylline, and galaxolide were determined underivatized, whereas the acidic pharmaceuticals carbamazepine, cyclophosphamide, and ibuprofen were determined after derivatization with N-methyl-N-(trimethylsilyl)-trifluoroacetamide.

Results and discussion

The concentrations in the Somes River varied from below 10 ng/L up to 10 μg/L. A substantial decrease of the exposure in the Somes River could be observed due to the upgrade of the municipal WWTP in Cluj-Napoca. The loads in the river stretch between Cluj-Napoca and Dej (Somes Mic) varied strongly: caffeine (400–2,000 g/day), carbamazepine (78–213 g/day), galaxolide (140–684 g/day), ibuprofen (84–108 g/day). After the upgrade of the WWTP Cluj-Napoca, the concentrations in the Somes of caffeine, pentoxifylline, cyclophosphamide, galaxolide, and tonalide were significantly reduced (over 75%). One might be cautious comparing both studies because the relative efficiency of the WWTP’s removal of PPCP was not evaluated. However, the significantly lower concentrations of most compounds after the upgrade of the WWTP Cluj-Napoca allow one to infer that the technical measures at the source substantially reduced inputs of contaminants to the receiving river. Dej loads of the poorly biodegradable substance carbamazepine increased by a factor of 2–3 as a result of wastewater discharges into the river. The disproportionate increase in caffeine loads by a factor of 4 below Cluj-Napoca indicates inputs of untreated wastewater from the Somes Mare due to the discharge of untreated wastewater derived from Bistrita, Nasaud, and Beclean (115,000 inhabitants).

Conclusions

The relative contribution of treated and untreated wastewater in surface water might be assessed by measuring chemical markers. Recalcitrant pharmaceuticals like carbamazepine are suitable as chemical markers for estimating the relative contribution of wastewater in surface water. The easily degradable caffeine might be a good indicator for raw sewage and hardly treated wastewaters.

Recommendations and perspectives

Municipal WWTPs have the potential of a significant contribution in reducing the load of contaminants to ambient waters. The efficiency of the wastewater treatment in Cluj-Napoca improved considerably after the upgrade of the WWTP. Therefore, it is crucial that several WWTPs must be implemented or improved in the Somes Valley Watershed in order to reduce the discharge of contaminants in the Somes River from these point sources.

     

Advanced oxidation treatment of physico-chemically pre-treated olive mill industry effluent

In this study, the applicability of physico-chemical methods was investigated for the pre-treatment of the olive mill effluents prior to the discharge into the common sewerage ending with a municipal wastewater treatment plant. The samples were taken from an olive oil industry operated as three-phase process located in Turkey. Various pre-treatment methods including acid craking, polyelectrolyte and lime additions were applied. Advanced oxidation study using Fenton's process was also investigated following pre-treatment by acid cracking and cationic polyelectrolyte. Acid cracking alone gave satisfactory treatment efficiencies and polyelectrolite additions to the acid-cracked samples enhanced treatment efficiency. Since a complete treatment plant is available at the end of the sewer system, results indicated that the effluents of the investigated industry could be discharged into the municipal sewerage in the case of total chemical oxygen demand (COD(tot)), suspended solid (SS) and volatile suspended solid (VSS) concentrations according to the Turkish Water Pollution Control Regulation after pre-treatment with 5 ppm anionic polyelectrolyte following acid cracking. The minimum COD(tot), SS and VSS removals were observed when raw wastewater was pre-treated with lime and the discharge standards to the municipal sewer system could not be met. Advanced oxidation with Fenton's process was applied after acid cracking and cationic polyelectrolyte treatment in order to investigate further reduction in chemical oxygen demand (COD) concentration for minimizing the influence of this industrial discharge on the existing municipal wastewater treatment plant. Results indicated that COD(tot) removal increased up to 89% from 74% after Fenton's oxidation for the acid cracked samples in which cationic polyelectrolite (10 ppm) was added.     

固定化微生物技术及其在重金属废水处理中的应用

固定化微生物技术是一种有效的废水生物处理技术.较为全面地介绍了其定义、分类及载体选择.全面系统地介绍了固定化微生物(主要是菌类和藻类)技术近年来在重金属废水处理中的应用现状,分析认为,固定化微生物技术对于处理含各种重金属离子的废水均有很广阔的应用前景,并对今后的研究方向做了探讨.     

固定化微生物技术及其在重金属废水处理中的应用

固定化微生物技术是一种有效的废水生物处理技术。较为全面地介绍了其定义、分类及载体选择。全面系统地介绍了固定化微生物（主要是菌类和藻类）技术近年来在重金属废水处理中的应用现状，分析认为，固定化微生物技术对于处理含各种重金属离子的废水均有很广阔的应用前景，并对今后的研究方向做了探讨。     

Improvement of solar photo-Fenton by extracts of amazonian fruits for the degradation of pharmaceuticals in municipal wastewater

Extracts of copoazu (Theobroma gramdiflorum), canangucha (Maurita Flexuosa), and coffee (Coffea arabica) were explored as enhancers of the solar photo-Fenton process to eliminate acetaminophen, sulfamethoxazole, carbamazepine, and diclofenac in raw municipal wastewater. The process, at pH 6.2 and 5 mg L^?1 of iron without the presence of extracts, had a very limited action (~35% of the pollutants degradation at 90 min of treatment) due to the iron precipitation. Interestingly, the extract addition increased the soluble iron forms, but only copoazu extract improved the pollutant degradation (~95% of elimination at 20 min of the process action). The copoazu extract components acted as natural complexing agents, maintaining the soluble iron up to 2 mg L^?1 even after 90 min and, consequently, enhancing the pollutant degradation. The effect of copoazu extract dose on the process performance was also assessed, finding that an iron:polyphenols (from the copoazu extract) at a molar ratio equal to 1:0.16 was the most favorable condition. Then, the process improved by copoazu extract was applied to raw municipal wastewater. Remarkably, the process led to ~90% of total pharmaceuticals degradation at 20 min of treatment. This work evidenced the feasibility of amazonian fruit extracts to improve the solar photo-Fenton process to degrade pharmaceuticals in aqueous matrices at near-neutral pH.

     

固定化微生物技术在印染废水处理方面的研究进展

从固定化方法、固定化载体以及固定化微生物的选择等方面全面系统地介绍了固定化微生物技术处理印染废水的研究进展及应用现状,并展望了固定化微生物技术应用前景。     

固定化解脂耶氏酵母间歇式处理油脂废水研究

固定化解脂耶氏酵母菌(Yarrowia lipolytica)在气升式反应器中处理色拉油浓度为2 000 mg/L、COD为3 000 mg/L的高COD油脂废水。结果表明,固定化菌对废水的最佳处理时间为6 d,可间歇式处理9批次高COD油脂废水,重复处理废水后,其对油脂的降解均在85%以上,对COD的降解在70%以上,降解后的排出水pH稳定在3.6~3.8。且处理动力学方程属于一级生化方程。结果进一步表明,固定化解脂耶氏酵母菌在气升式反应器中适于处理高COD含油脂的污水。     

Methane Emissions from Domestic Waste Management Facilities in Jordan—Applicability of IPCC Methodology

ABSTRACT

In this paper, methane emissions from municipal wastewater treatment plants and municipal solid waste (MSW) landfills in Jordan for 1994 have been estimated using the methodology developed by the Intergovernmental Panel on Climate Change (IPCC). For this purpose, the 14 domestic wastewater treatment plants in the country were surveyed. Generation rates and characterization of MSW components as well as dumping and landfilling practices were surveyed in order to estimate 1994 CH₄ emissions from these sites. Locally available waste statistics were used in cases where those of the IPCC guidelines were not representative of Jordan's statistics.

Methane emissions from domestic wastewater in Jordan were estimated at 4.66 gigagrams (Gg). Total 1994 CH₄ emissions from MSW management facilities in Jordan are estimated at 371.76 Gg—351.12 Gg (94.45%) from sanitary landfills, 19.83 Gg (5.33%) from MSW open dumps, and 0.81 Gg (0.22%) from raw sewage-water dumping ponds. Uncertainties associated with these estimations are presented.     

Anaerobic treatment of slaughterhouse wastewater: a review

This article presents a review of anaerobic treatment technologies to treat slaughterhouse wastewater including its advantages and disadvantages. Physico-chemical characteristics and biochemical methane potential (BMP) of slaughterhouse wastewater are addressed. Various anaerobic treatment technologies are presented with the related operating parameters, viz., hydraulic retention time (HRT), organic loading rate (OLR), upflow velocity (V_up), and biogas yield vis-a-vis treatment efficiency in terms of chemical oxygen demand (COD). In addition, various factors that affect the anaerobic treatment of slaughterhouse wastewater such as high oil & grease (O & G) concentration in influent, inhibitors, volatile fatty acids (VFAs), and the loading rate are also addressed. The literature review indicated that the slaughterhouse wastewater can be treated effectively by employing any anaerobic treatment technologies at OLRs up to 5 kg COD/m³.d with more than 80% COD removal efficiency without experiencing operational problems. Anaerobic hybrid reactors (AHRs) were found the most effective among various reviewed technologies because of their ability to operate at higher OLRs (8 to 20 kg COD/m³.d) and lower HRTs (8 to 12 hrs).

     

Evaluation of removal efficiency for acute toxicity and genotoxicity on zebrafish in anoxic–oxic process from selected municipal wastewater treatment plants

The anoxic–oxic (A/O) process has been extensively applied for simultaneous removal of organic contaminants and nitrogen in wastewater treatment. However, very little is known about its ability to remove toxic materials. Municipal wastewater contains various kinds of pollutants, some of which have recalcitrant genotoxicity and may cause potential threat to environment, and even can lead to extinction of many species. In this study, we have selected three municipal wastewater treatment plants (WWTPs) employing anoxic–oxic (A/O) process to evaluate their ability to remove acute toxicity and genotoxicity of wastewater. Mortality rate of zebrafish (Danio rerio) was used to evaluate acute toxicity, while micronucleus (MN) and comet assays were used to detect genotoxicity. Results showed that in this process the acute toxicity was completely removed as the treatment proceeded along with decrease in chemical oxygen demand (COD) (<50 mg L^?1) in the effluent. However, in these treatment processes the genotoxicity was not significantly reduced, but an increase in genotoxicity was observed. Both MN and comet assays showed similar results. The eliminated effluent may pose genotoxic threaten although its COD level has met the Chinese Sewage Discharge Standard. This study suggests that further treatment of the wastewater is required after the A/O process to remove the genotoxicity and minimize the ecotoxicological risk.     

Autonomous mobile platform for monitoring air emissions from industrial and municipal wastewater ponds

Significant amounts of volatile organic compounds and greenhouse gases are generated from wastewater lagoons and tailings ponds in Alberta, Canada. Accurate measurements of these air pollutants and greenhouse gases are needed to support management and regulatory decisions. A mobile platform was developed to measure air emissions from tailings pond in the oil sands region of Alberta. The mobile platform was tested in 2015 in a municipal wastewater treatment lagoon. With a flux chamber and a CO₂/CH₄ sensor on board, the mobile platform was able to measure CO₂ and CH₄ emissions over two days at two different locations in the pond. Flux emission rates of CO₂ and CH₄ that were measured over the study period suggest the presence of aerobic and anaerobic zones in the wastewater treatment lagoon. The study demonstrated the capabilities of the mobile platform in measuring fugitive air emissions and identified the potential for the applications in air and water quality monitoring programs.

Implications: The Mobile Platform demonstrated in this study has the ability to measure greenhouse gas (GHG) emissions from fugitive sources such as municipal wastewater lagoons. This technology can be used to measure emission fluxes from tailings ponds with better detection of spatial and temporal variations of fugitive emissions. Additional air and water sampling equipment could be added to the mobile platform for a broad range of air and water quality studies in the oil sands region of Alberta.     

Pilot-scale biopesticide production by Bacillus thuringiensis subsp. kurstaki using starch industry wastewater as raw material

Pilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (K_La) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material.     

TiO2/β-SiC foam-structured photoreactor for continuous wastewater treatment

Introduction

This study of photocatalytic degradation of wastewater was carried out in alveolar cell ??-SiC foam-structured photocatalytic reactors working in a recirculation mode. The immobilization of TiO2 on ??-SiC foams was efficiently obtained through a sol?Cgel technique in acidic conditions.

Discussion

In order to optimize degradation yields obtained by the foam-structured prototype reactor for the photocatalytic water treatment, the operating conditions of the photoreactor have been investigated and the efficiency of the process was evaluated by measuring the photocatalytic degradation of Diuron (3-(3,4-dichlorophenyl)-1,1-dimethyl-urea)) under UV irradiation. Kinetic studies were carried out by investigating the influence of different parameters controlling the reaction (TiO2 loading and ??-SiC foam cell size). The ageing of TiO2/??-SiC foam photocatalytic materials and the mineralization (TOC, Cl?, NO3? and NH4+) of Diuron were investigated.