High-strength Organic Wastewater Research Articles

PH-adjustment strategy for volatile fatty acid production from high-strength wastewater for biological nutrient removal.

Volatile fatty acid (VFA) production from three types of high-strength organic wastewater (cassava thin stillage, starch wastewater and yellow-wine processing wastewater) were compared. The results showed that cassava thin stillage was the most suitable substrate, based on its high specific VFA production (0.68 g chemical oxygen demand (COD)/g initial soluble chemical oxygen demand (SCOD)) and yield (0.72 g COD/g SCOD) as well as low nutrient content in the substrate and fermented liquid. The acid fermented cassava thin stillage was evaluated and compared with sodium acetate in a sequencing batch reactor system. Total nitrogen removal efficiency was higher with fermented cassava thin stillage than with the sodium acetate. The effects of pH and a pH-adjustment strategy on VFA production and composition were determined using cassava thin stillage. At an initial pH range of 7-11, a relatively high VFA concentration of about 9 g COD/L was obtained. The specific VFA production (g COD/g initial SCOD) increased from 0.27 to 0.47 to 0.67 at pH 8 and from 0.26 to 0.68 to 0.81 at pH 9 (initial pH, interval pH, and constant pH adjustment, respectively). The dominant VFA species changed significantly with the increasing frequency of the pH adjustment. Further studies will examine the metabolic pathways responsible for VFA composition.

Research Advances on the High-Strength Organic Wastewater Treatment

With the development of chemical and related industry, the quantity of high-strength organic wastewater is growing, which could cause a bigger threat to human health, so it becomes very urgent and essential to research and develop new applicable wastewater treatment technology. The treatment techniques of high-strength organic wastewater at home and abroad were summarized: physical and chemical methods, biological methods and the combined process. The technological process, characters and principle of every method were introduced. These wastewater treatment technologies have some advantages of completely mineralization and degradation of the pollutants, and low risk of secondary pollution. They also have many disadvantages of complex technological process and higher operating cost. Finally, the direction of the research on two-phase combined process was pointed out.

Oligosphaera ethanolica gen. nov., sp. nov., an anaerobic, carbohydrate-fermenting bacterium isolated from methanogenic sludge, and description of Oligosphaeria classis nov. in the phylum Lentisphaerae

A mesophilic, obligately anaerobic, carbohydrate-fermenting bacterium, designated 8KG-4(T), was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from salted vegetable production processes. Cells of strain 8KG-4(T) were non-motile, spherical and 0.7-1.5 µm in diameter (mean, 1.0 µm). Spore formation was not observed under any culture conditions tested. The strain grew optimally at 37 °C (range for growth 25-40 °C) and pH 7.0 (range, pH 6.5-7.5), and could grow fermentatively on glucose, ribose, xylose, galactose and sucrose. The main end products of glucose fermentation were acetate, ethanol and hydrogen. Organic acids, alcohols and amino acids were not utilized for growth. Yeast extract was not required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe(III) nitrilotriacetate were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.1 mol%. 16S rRNA gene sequence analysis revealed that the isolate represented a previously uncultured lineage at the subphylum level within the phylum Lentisphaerae known as 'WWE2 subgroup I'. The major cellular fatty acids were anteiso-C(15 : 0), iso-C(16 : 0), C(16 : 0) and anteiso-C(17 : 0). Respiratory quinones were not detected. The most abundant polar lipid of strain 8KG-4(T) was phosphatidylethanolamine. A novel genus and species, Oligosphaera ethanolica gen. nov., sp. nov., is proposed to accommodate strain 8KG-4(T) ( = JCM 17152(T) = DSM 24202(T) = CGMCC 1.5160(T)). In addition, we formally propose Oligosphaeria classis nov. and the subordinate taxa Oligosphaerales order nov. and Oligosphaeraceae fam. nov.

Effect of Carrier Materials in Inverse Anaerobic Fluidized Bed Reactor for Treating High Strength Organic Waste Water

This article explains that thermo cool, plastic beads, cork, teak wood and perlite were tried as carrier materials in the lab-scale reactor towards treating high strength organic wastewater by using inverse anaerobic fluidized bed reactor (IAFBR). Organic wastewater of great strength (molasses) is pronounced for its high chemical oxygen demand (COD) of 45,000 to 75,000 mg/l and low pH values of 4.3 to 5.3. The results of this study highlighted the selection, physical properties and performance of carrier materials on biomass retention. This study has also clearly indicated that perlite proves to be a suitable carrier material for high biomass retention and improvement of the reactor performances in a short time of operation.

Variations in methanogenic population structure under overloading of pre-acidified high-strength organic wastewaters

Methanogenic populations were quantitatively investigated in two separate anaerobic reactors, which received effluents from acidogenesis of either food waste-recycling wastewater or swine wastewater. Each set of the anaerobic digesters was operated under high organic loading rate (OLR) conditions (8.3–39.8 g chemical oxygen demand (COD)/L/d) with four different hydraulic retention times (10.4–3.0 days). Real-time PCR analysis demonstrated that the order Methanosarcinales was the most abundant (>55%) methanogenic group in the six runs with >50% COD removal, while the dominance (>70%) of Methanobacteriales was observed in the other two runs (<20% COD removal). Methanomicrobiales constituted a minor (<30%) population in all eight runs. The two reactors with relatively low performance were the only trials which contained less than 5 × 10 7 copies/mL of 16S rRNA gene of Methanosarcinales. These results imply that a minimum level of Methanosarcinales is important for achieving even moderate levels of process efficiency under high OLR.

The Molecular Characterization and Hydrogen Production of a New Species of Anaerobe in Wastewater Treatment Process for H&lt;sub&gt;2&lt;/sub&gt; Recovery

The isolation and identification of hydrogen production bacteria(HPB)with high yield and high evolution rate is an important foundation of fermented hydrogen production process by anaerobic digesting high strength organic wastewater. An improved Hungater rolling tubes technique and a plate method of culture bottle (PMCB) were employed to enumerate and isolate the anaerobes. The HPB-RL medium was designed specially for isolating and culturing anaerobic hydrogen bacteria. Culture temperature was at 37°C and 5.5 of pH. About 90 strains of bacteria were isolated, in which, a strain of the hydrogen producer with high yield and high evolution rate was isolated and named Rennanqi12. The isolates were straight rods, Grams positive, strictly anaerobic, no spore-forming bacteria, whole bacteria flagella, having capsule, 3~4 metachromatic granules. The strain of Rennanqi12 could produce hydrogen using molasses wastewater as the carbon resource. The isolate Rennanqi12 has the closest relationship with the strain C. cellulose for the 94% homology of 16S rDNA. The strain of Rennanqi12 might be a new species that belongs to a new genus. The amount of hydrogen-producing (YH2)is 1880.5ml/L medium and the maximum hydrogen-producing rate(QH2)is 28.2 mmol/g•(dry•cell)•h when R12 digested substrates were glucose.

Inhibition Kinetics of Phenolic Compounds in Aerobic Degradation of Organic Wastewaters

This study proposed a kinetic model for the aerobic degradation of high strength organic wastewaters with high concentrations of phenolic compounds. The model was based on the conventional Monod kinetic equation incorporating phenols' inhibition. Furthermore, a methodology for determining biokinetic constants was proposed. Olive-mill wastewater (OMWW) was used for the case study. The model and proposed methodology were fitted on the experimental data and it was proved that the aerobic degradation of OMWW was described satisfactorily. The following kinetic constants were determined: maximum specific substrate removal rate, 1.35 h(-1); minimum microorganisms decay rate, 0.01 h(-1); inhibition coefficient of phenolic compounds, 373 mg L(-1); half-saturation concentration in carbon units, 1004 mg L(-1); and decay acceleration coefficient of phenolic compounds, 231 mg L(-1). Finally, the biomass yield coefficient was found to be equal to 0.36. Thus, it was determined that the proposed methodology would be a useful tool for determining biokinetic constants of similar substrates.

Enhanced treatment efficiency of an anaerobic sequencing batch reactor (ASBR) for cassava stillage with high solids content

Cassava stillage is a high strength organic wastewater with high suspended solids (SS) content. The efficiency of cassava stillage treatment using an anaerobic sequencing batch reactor (ASBR) was significantly enhanced by discharging settled sludge to maintain a lower sludge concentration (about 30 g/L) in the reactor. Three hydraulic retention times (HRTs), namely 10 d, 7.5 d, 5 d, were evaluated at this condition. The study demonstrated that at an HRT of 5 d and an organic loading rate (OLR) of 11.3 kg COD/(m(3) d), the total chemical oxygen demand (TCOD) and soluble COD (SCOD) removal efficiency can still be maintained at above 80%. The settleability of digested cassava stillage was improved significantly, and thus only a small amount of settled sludge needed to be discharged to maintain the sludge concentration in the reactor. Furthermore, the performance of ASBR operated at low and high sludge concentration (about 79.5 g/L without sludge discharged) was evaluated at an HRT of 5 d. The TCOD removal efficiency and SS in the effluent were 61% and 21.9 g/L respectively at high sludge concentration, while the values were 85.1% and 2.4 g/L at low sludge concentration. Therefore, low sludge concentration is recommended for ASBR treating cassava stillage at an HRT 5 d due to lower TCOD and SS in the effluent, which could facilitate post-treatment.

Comparative Analysis of Bacterial and Archaeal Communities in Methanogenic Sludge Granules from Upflow Anaerobic Sludge Blanket Reactors Treating Various Food-Processing, High-Strength Organic Wastewaters

A comprehensive survey of bacterial and archaeal community structures within granular sludges taken from twelve different types of full-scale, food-processing wastewater-treating, upflow anaerobic sludge blanket (UASB) reactors was performed with a 16S rRNA gene-based clone library method. In total, 1,282 bacterial 16S rRNA gene clones and 722 archaeal clones were analyzed, and their identities were determined by phylogenetic analyses. Overall, clones belonging to the bacterial phyla Proteobacteria (the class Deltaproteobacteria in particular), Firmicutes, Spirochaetes, and Bacteroidetes were observed in abundance within the bacterial clone libraries examined, indicating common bacterial denominators in such treatment systems. Within the domain Archaea, clones affiliated with the classes Methanomicrobia and Methanobacteria were found to be abundant in the archaeal libraries. In relation to features of reactor performance (such as chemical oxygen demand removal, fatty acid accumulation, and sludge bulking), possible representative phylotypes likely to be associated with process failures, such as sludge bulking and the accumulation of propionate, were found in comparative analyses of the distribution of phylotypes in the sludge libraries.

Acidibility established as a characteristic of high strength organic wastewater quality

Acidification processes of the alcohol wastewater on molasses and the sugar-peptone manual make-up water were studied to determine their acidification capability. The two types of wastewater were both diluted into serial gradient dilutions and acidified separately. The volatile fatty acids (VFAs) and were detected daily until acidification reached a maximum state. The degraded COD in each dilution, which were considered as degraded VFAs and analyzed. The ratio of the sum of produced VFAs and degraded VFAs to the initial COD of dilutions was defined as acidibility ( V/ C). It showed that within a large concentration extent, the V/ C values were consistent for different dilutions of each wastewater. Thus acidibility becomes a characteristic of high strength organic wastewater quality. The acidibility of the alcohol wastewater on molasses was analyzed to be 0.71, and the acidibility of sugar-peptone manual make-up water was 0.76. In a practicable view, it is meaningful to set up acidibility as a new water quality index, which can be used to guide the design of acidification technique in various high concentration organic wastewater treatment practices.

In Situ Detection and Quantification of Uncultured Members of the Phylum Nitrospirae Abundant in Methanogenic Wastewater Treatment Systems

In upflow anaerobic sludge blanket (UASB) reactors treating high-strength organic wastewaters, uncultured phylotypes belonging to the phylum Nitrospirae were assumed to play a key role in the treatment processes because of their high abundance as determined by 16S rRNA gene-based clone library analyses (Narihiro et al. (27)). A comparative nucleotide sequence analysis of the phylotypes, commonly found in anaerobic mesophilic sludges, revealed that these phylotypes formed a coherent clade at the family to genus levels with no cultured representatives. To determine the abundance and distribution in methanogenic waste/wastewater treatment sludges, 16S rRNA gene-based quantitative PCR measurements and 16S rRNA-targeted fluorescence in situ hybridization (FISH) were carried out. A specific gene primer/probe for the uncultured clade was developed and used for quantitative PCR and in situ detection of the targeted cells within the sludge granules. In all the six UASB sludges treating food-processing organic wastewaters, the phylotypes were detected at a range of 0.1 to 10.9% of total 16S rRNA genes. FISH revealed that the gene probe reacted with coccoid or irregular coccoid-like cells in the middle and inner layers of sludge granules of a UASB reactor, in which the Nitrospirae phylotypes were found in abundance by real-time PCR analyses.

Monitoring bacterial and archaeal community shifts in a mesophilic anaerobic batch reactor treating a high-strength organic wastewater

Shifts in bacterial and archaeal communities, associated with changes in chemical profiles, were investigated in an anaerobic batch reactor treating dairy-processing wastewater prepared with whey permeate powder. The dynamics of bacterial and archaeal populations were monitored by quantitative real-time PCR and showed good agreement with the process data. A rapid increase in bacterial populations and a high rate of substrate fermentation were observed during the initial period. Growth and regrowth of archaeal populations occurred with biphasic production of methane, corresponding to the diauxic consumption of acetate and propionate. Bacterial community structure was examined by denaturing gel gradient electrophoresis (DGGE) targeting 16S rRNA genes. An Aeromonas-like organism was suggested to be mainly responsible for the rapid fermentation of carbohydrate during the initial period. Several band sequences closely related to the Clostridium species, capable of carbohydrate fermentation, lactate or ethanol fermentation, and/or homoacetogenesis, were also detected. Statistical analyses of the DGGE profiles showed that the bacterial community structure, as well as the process performance, varied with the incubation time. Our results demonstrated that the bacterial community shifted, reflecting the performance changes and, particularly, that a significant community shift corresponded to a considerable process event. This suggested that the diagnosis of an anaerobic digestion process could be possible by monitoring bacterial community shifts.

Performance of inverse anaerobic fluidized bed reactor for treating high strength organic wastewater during start-up phase

The aim of this work is to report on the physical characteristics of carrier material (perlite), biomass growth on the carrier material and the biogas production during an apparent steady state period in an inverse anaerobic fluidized bed reactor (IAFBR) for treating high strength organic wastewater. Before starting up the reactor, physical properties of the carrier material were determined. One millimeter diameter perlite particle is found to have a wet specific density of 295 kg/m 3 with specific surface area of 7.010 m 2/g. This material has provided a good surface for biomass attachment and development. The biofilm concentration (in terms of attached volatile solids (AVS)) attached to carrier material was found to be 0.66 g AVS/g solid. Most particles have been covered with a thin biofilm of uniform thickness. Once the inverse anaerobic fluidized bed system reached the steady state, the organic load was increased step wise by reducing hydraulic retention time (HRT) from 2 days to 0.16 day, while maintaining the constant feed of chemical oxygen demand (COD) concentration. This system has achieved 84% COD removal and reached the biogas production of 13.22 l/l/d at an organic loading rate (OLR) of 35 kg COD/m 3/d.

Evaluation of inverse anaerobic fluidized bed reactor for treating high strength organic wastewater

The aim of this work is to evaluate the feasibility of an inverse fluidized bed reactor for the anaerobic digestion of distillery effluent, with a carrier material that allows low energy requirements for fluidization, providing also a good surface for biomass attachment and development. Inverse fluidization particles having specific gravity less than one are carried out in the reactor. The carrier particles chosen for this study was perlite having specific surface area of 7.010 m 2/g and low energy requirements for fluidization. Before starting up the reactor, physical properties of the carrier material were determined. One millimeter diameter perlite particle is found to have a wet specific density of 295 kg/m 3. It was used for the treatment of distillery waste and performance studies were carried out for 65 days. Once the down flow anaerobic fluidized bed system reached the steady state, the organic load was increased step wise by reducing hydraulic retention time (HRT) from 2 days to 0.19 day, while maintaining the constant feed of chemical oxygen demand (COD) concentration. Most particles have been covered with a thin biofilm of uniform thickness. This system achieved 84% COD removal at an organic loading rate (OLR) of 35 kg COD/m 3/d.

Assessment of the Phytoremediation Potential of Salvinia minima Baker Compared to Spirodela polyrrhiza in High-strength Organic Wastewater

Salvinia minima combines several advantages for being used in aquatic phytoremediation. The objectives of this work were to compare the growth kinetics and productivity of S. minima and Spirodela polyrrhiza in high-strength synthetic organic wastewater (HSWW) and to evaluate the growth characteristics of S. minima in various culture media, including anaerobic effluents from pig wastewater (PWAE). It was found that the Relative Growth Rate (RGR) of S. minima was significantly higher (p < 0.05) compared to the RGR of S. polyrrhiza in Hutner Medium (HM) and in HSWW. Also, S. minima showed a 1.5 fold productivity and a 2.3 fold productivity, compared to S. polyrrhiza in HM and HSWW, respectively. Diauxic growth of S. minima was observed preferentially under pH control and there was a simultaneous consumption of two nitrogen sources. Productivity of S. minima was similar in pig waste anaerobic effluents (PWAE) and in HM without ammonium nitrate and amended with ammonium sulphate (MHM + AS), at an initial NH4 concentration of 35 mg l−1. Above this level, the productivity was found to decrease as the initial ammonium concentration increased, in both media. Growth was completely inhibited at 140 mg l−1 in the PWAE. In summary, S. minima is a better option than S. polyrrhiza for treating high-strength organic wastewater and lagoons should be operated at a maximum initial ammonium–nitrogen concentration of 70 mg l−1 and at a pH of 5.0 or 6.0. Likewise, the initial density should be maintained in the range of 7 to 15 g dw m−2.

A SIMPLE BUT EFFICIENT HIGH PERFORMANCE ANAEROBIC DIGESTER SYSTEM

A SIMPLE BUT EFFICIENT HIGH PERFORMANCE ANAEROBIC DIGESTER SYSTEMA new and radically different anaerobic digester called the BioTerminator has been developed using plug flow hydraulics that achieves remarkable and unprecedented solids destruction efficiencies. It is designed to digest biological solids from wastewater treatment plants and treat high-strength organic wastewaters from industrial operations. The recently introduced commercial version of this...Author(s)Clyde BurnettA. Paul TognaAndrew BohnerYonghua YangNsobiari WarmateP.M. Paul SuttonSourceProceedings of the Water Environment FederationSubjectSession 23: Special InterestDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2007ISSN1938-6478SICI1938-6478(20070101)2007:3L.1290;1-DOI10.2175/193864707787975769Volume / Issue2007 / 3Content sourceResiduals and Biosolids ConferenceFirst / last page(s)1290 - 1297Copyright2007Word count196

Development of combined biological technology for treatment of high-strength organic wastewater and results of case studies

Our study group has developed a unique combined biological technology to treat high-strength organic wastewaters from the industries of dyestuff, pharmaceutical, chemical engineering and zymolysis by using the principles of anaerobic ecological niche and bio-phase separation. The study obtained five national invention patents and eight patent equipments. This technology contains four kernel processes - two-phase anaerobic-aerobic process, hydrolysis-acidification-oxidation process, UASBAF-oxidation process, and internal cycling-hydrolysis-oxidation process. Fifteen pilot projects were accomplished in the basins of Tai Lake, Huai River, Liao River and Songhua River, and their total capital investment reached 185.214 million Yuan (RMB). Compared to conventional wastewater treatment technology, the innovative technology is more cost-effective for high-strength organic wastewater treatment, can save capital investment by 15% – 30%, lessen land usage by 20% to 40% and decrease the operating cost by 10% to 25%. The operating cost of treatment per cubic meter industrial wastewater could be below 0.6 to 1.4 Yuan (RMB).

Multivariate Online Monitoring of a Full-Scale Biological Anaerobic Filter Process Using Kernel-Based Algorithms.

Multivariate statistical process control such as principal component analysis (PCA) and partial least squares (PLS) has been effectively utilized to analyze large databases accumulated in industrial plants in order to improve process performance and product quality. However, because both PCA and PLS are basically linear methods, nonlinearity in most chemical and biological processes is still a significant problem for their practical applications. Kernel-based algorithms are potentially very efficient for monitoring process disturbances and predicting key quality variables of nonlinear processes by mapping an original input space into a high-dimensional feature space. Nonlinear data structure in the original space is most likely to be linear at the high-dimensional feature space. Kernel-based methods essentially require only linear algebra, making them as simple as linear multivariate projection methods, and can handle a wide range of nonlinearities because of their ability to use different kernel functions. In this work, kernel-based algorithms such as kernel PCA (KPCA) and kernel PLS (KPLS) are applied to a full-scale biological anaerobic filter process treating highstrength organic wastewater in a petrochemical plant. KPCA is applied to detect process disturbances in real-time and KPLS to predict inferentially key process variables in the anaerobic filter process. The proposed kernel-based approaches could effectively capture the nonlinear relationship in the process variables and show far better performance in process monitoring and prediction of quality variables compared to the conventional PCA and PLS methods.

Diversity, Localization, and Physiological Properties of Filamentous Microbes Belonging to Chloroflexi Subphylum I in Mesophilic and Thermophilic Methanogenic Sludge Granules

We previously reported that the thermophilic filamentous anaerobe Anaerolinea thermophila, which is the first cultured representative of subphylum I of the bacterial phylum Chloroflexi, not only was one of the predominant constituents of thermophilic sludge granules but also was a causative agent of filamentous sludge bulking in a thermophilic (55 degrees C) upflow anaerobic sludge blanket (UASB) reactor in which high-strength organic wastewater was treated (Y. Sekiguchi, H. Takahashi, Y. Kamagata, A. Ohashi, and H. Harada, Appl. Environ. Microbiol. 67:5740-5749, 2001). To further elucidate the ecology and function of Anaerolinea-type filamentous microbes in UASB sludge granules, we surveyed the diversity, distribution, and physiological properties of Chloroflexi subphylum I microbes residing in UASB granules. Five different types of mesophilic and thermophilic UASB sludge were used to analyze the Chloroflexi subphylum I populations. 16S rRNA gene cloning-based analyses using a 16S rRNA gene-targeted Chloroflexi-specific PCR primer set revealed that all clonal sequences were affiliated with the Chloroflexi subphylum I group and that a number of different phylotypes were present in each clone library, suggesting the ubiquity and vast genetic diversity of these populations in UASB sludge granules. Subsequent fluorescence in situ hybridization (FISH) of the three different types of mesophilic sludge granules using a Chloroflexi-specific probe suggested that all probe-reactive cells had a filamentous morphology and were widely distributed within the sludge granules. The FISH observations also indicated that the Chloroflexi subphylum I bacteria were not always the predominant populations within mesophilic sludge granules, in contrast to thermophilic sludge granules. We isolated two mesophilic strains and one thermophilic strain belonging to the Chloroflexi subphylum I group. The physiological properties of these isolates suggested that these populations may contribute to the degradation of carbohydrates and other cellular components, such as amino acids, in the bioreactors.

Optimized operational parameters of a pilot scale membrane bioreactor for high-strength organic wastewater treatment

Abstract A pilot-scale test was conducted in a submerged membrane bioreactor (SMBR) for 452 days to treat high-strength traditional Chinese medicine wastewater from two-phase anaerobic digest effluent. This study focuses on the effects of operational parameters on effluent quality of a SMBR. The parameters include shorter hydraulic retention time (HRT), higher influent COD concentration, higher COD loading rate and mixed liquor suspended solids (MLSS). The experimental results demonstrated that when HRT was 5 h and the influent COD was less than 3000 mg L−1, the effluent quality of the SMBR evaluated from its COD content (CODfilt) could meet the accepted Chinese standards for water reclamation; when HRT was 3.2 h and the influent COD was less than 3000 mg L −1, or HRT was 5 h and the influent COD fluctuated between 3000 and 6000 mg L−1, the effluent quality of the SMBR could meet the normal Chinese discharged standard. Statistical analyses showed that CODfilt correlated positively with the COD loading rate. It correlated negatively with the MLSS for MLSS values between 7543 and 13 694 mg L−1. When MLSS was >13 694 mg L−1 it correlated positively with CODfilt. Based on experimental values from SMBR and on values predicted by a simulation model generated using the back propagation neural network (BPNN) theory, the optimum operational parameters for the treatment of a high-strength TCM wastewater were as follows: HRT was 5 h, SRT was 100 day, COD loading rate was