High Strength Industrial Wastewater Research Articles

Treatment of High-Strength Animal Industrial Wastewater Using Photo-Assisted Fenton Oxidation Coupled to Photocatalytic Technology

Animal wastewater is one of the wastewaters that has a color and is difficult to treat because it contains a large amount of non-degradable organic materials. The photo-assisted Fenton oxidation technique was applied to treat animal wastewater, and the optimal conditions of chemical oxygen demands (COD) removal were analyzed according to changes in pH, ferrous ion, H2O2, and ultraviolet (UV) light intensity as a single experimental condition. Experimental results showed that, under the single-factor experimental conditions, the optimal conditions for degradation of animal wastewater were pH 3.5, Fe(II) 0.01 M, H2O2 0.1 M, light intensity 3.524 mW/m2. Under the optimal conditions, COD removal efficiency was 91%, sludge production was 2.5 mL from 100 mL of solution, color removal efficiency was 80%, and coliform removal efficiency was 99.5%.

Robustness of anammox granular sludge treating low-strength sewage under various shock loadings: Microbial mechanism and little N2O emission

With the increasing application of anammox for the treatment of high-strength industrial wastewater, application of anammox in municipal sewage has been gaining more attention. Sludge granulation in particular enhances the enrichment and retention of anammox bacteria in municipal sewage treatment systems. However, the performance of granular sludge under continuous and varying hydraulic loading shock remains little understood. In this study, the robustness of anammox granular sludge in treating low-strength municipal sewage under various shock loadings was investigated. Results showed that an upflow anaerobic sludge blanket (UASB) reactor with anammox granules performed well, with anammox specific activity up to 0.28 kg N/kg VSS/day and anti-loading shock capability up to 187.2 L/day during the 8-month testing period. The accumulation rate of N2O (<0.01 kg N/kg VSS/day) in the liquid phase was seven times higher than that of the gas phase, which could be mainly attributed to the incomplete denitrification and insufficient carbon source. However, only a small part of the produced N2O escaped into the atmosphere. High-throughput sequencing and molecular ecological network analyses also identified the bacterial diversity and community structure, indicating the potential resistance against loading shock. The composition and structural analyses showed that polysaccharides were an important functional component in the tightly bound extracellular polymeric substances (TB-EPS), which was the major EPS layer of anammox granules. Scanning electron microscopy (SEM) also showed that the gaps in between the anammox-clusters in the granules inhibit the flotation of the sludge and ensure efficient settling and retention of anammox granules.

Treatment of high strength industrial wastewater with membrane bioreactors for water reuse: Effect of pre-treatment with aerobic granular sludge on system performance and fouling tendency

In this study, the treatment of citrus wastewater with membrane bioreactors (MBRs) under different configurations was investigated for water reuse. In particular, one MBR and one aerobic granular sludge MBR (AGS + MBR) bench scale plants were operated for 60 days. The experimental campaign was divided into two periods. In Phase I, a conventional hollow fiber MBR was employed for the treatment of the raw high strength wastewater, whereas in Phase II a combination of in-series reactors (AGS + MBR) was adopted for the treatment of the high strength citrus wastewaterThe results demonstrated that both plant configurations enabled very high COD removal, with average values close to 99%. Respirometric batch tests revealed a considerable high metabolic activity of the biomass in both plant configurations, with higher values in the AGS + MBR. It was speculated that the MBR reactor was enriched in active biomass deriving from the erosion of the external granule layers in the upstream reactor. In terms of fouling tendency, higher resistance to filtration was observed in the AGS + MBR plant, also characterized by higher irremovable resistance increase compared to the MBR plant, that might severely affect the membrane service life.

Aerobic granulation technology: Laboratory studies to full scale practices

Abstract Aerobic Granulation Technology for treatment of wastewater is developed in last two decades. Aerobic Granules are special type of self-immobilization of microorganisms, without any surface medium for growth of microbial film. They have compact cores and have high diffusional confrontations to external particles and, hence have high acceptance of the toxic compounds to their integral cells. Most aerobic granules are large and have a compact core, and so are recommended for use in the biological treatment of high-strength industrial wastewaters. This technology requires small foot print, 25% of the area of conventional activated sludge setup and this process can reduce up to 50% on energy-costs. This paper reviews on start-ups, advances in aerobic granulation technology from laboratory studies to pilot scale and to its full-scale application for treatment of different types of domestic and industrial wastewater. Gaps in knowledge and new ideas for future work of aerobic granulation technology are also being discussed.

Special Issue on Wastewater Treatment and Reuse Technologies

Wastewater treatment allows for the safe disposal of municipal and industrial wastewater to protect public health and the ecosystem[...]

Membrane integrated process for advanced treatment of high strength Opium Alkaloid wastewaters.

In this study, an integrated aerobic membrane bioreactor (MBR)-nanofiltration (NF) system has been applied for advanced treatment of Opium processing wastewaters to comply with strict discharge limits. Aerobic MBR treatment was successfully applied to high strength industrial wastewater. In aerobic MBR treatment, a non-fouling unique slot aeration system was designed using computational fluid dynamics techniques. The MBR was used to separate treated effluent from dispersed and non-settleable biomass. Respirometric modeling using MBR sludge indicated that the biomass exhibited similar kinetic parameters to that of municipal activated sludge systems. Aerobic MBR/NF treatment reduced chemical oxygen demand (COD) from 32,000 down to 2,500 and 130 mg/L, respectively. The MBR system provided complete removal of total inorganic nitrogen; however, nearly 50 mgN/L organic nitrogen remained in the permeate. Post NF treatment after MBR permeate reduced nitrogen below 20 mgN/L, providing nearly total color removal. In addition, a 90% removal in the conductivity parameter was reached with an integrated MBR/NF system. Finally, post NF application to MBR permeate was found not to be practical at higher pH due to low flux (3-4 L/m2/hour) with low recovery rates (30-40%). As the permeate pH lowered to 5.5, 75% of NF recovery was achieved at a flux of 15 L/m2/hour.

Lignin recovery and it effects quality of anaerobic treated palm oil mill effluent (AT-POME)

Lignin is one of the main structural polymers present in plant tissue. It can also be found as an isolated product of the pulp and paper industry. Palm oil mill effluent (POME) has been known as high strength industrial wastewater that is difficult to treat due to its large variety of inorganic and organic contents. The main purpose of this study is to recover soluble lignin from anaerobically treated palm oil mill effluent (AT-POME) and indirectly improves the quality of AT-POME. AT-POME was adjusted to different pH using different type of acids. Response Surface Methodology (RSM) was utilized to obtain the optimum operating parameters as well as to analyse the interaction between them. Model shows that 74.67 % of lignin can be recovered from AT-POME after 5 minutes reaction time using sulfuric acid (H2S04) at pH 5. Hence from the experiment, it was proved that simple pH adjustment could precipitate the soluble lignin from AT-POME.

Enhanced organics removal and partial desalination of high strength industrial wastewater with a multi-stage microbial desalination cell

Conventional microbial desalination cells (MDCs) extract organic energy from wastewater for in situ desalination of saline water, but cannot treat industrial wastewater containing high strength organics that may cause blocking in the thin membrane stack. In this study, a multi-stage MDC (M-MDC) was fabricated and operated for simultaneous treatment and desalination of diluted industrial wastewater. With wastewater (COD: 8723±456mg/L, conductivity: 24,612±772μS/cm) flowing serially from anode-1→cathode-1→anode-2→cathode-2, the maximum power density of the M-MDC reached 566.1mW/m2, with removal efficiencies of COD, TN, NH4+-N, and conductivity reaching 97.8%, 90.6%, 98.4%, and 31.6% respectively with addition of 1V external voltage. The high strength organics were significantly removed due to alternative anaerobic/oxic conditions, the nitrogen removal was enhanced by simultaneous electrical migration and biological nitrification/denitrification. Moreover, the addition of external voltage enhanced current generation (67.4±3.9mA), desalination efficiency, coulombic efficiency (14.1%), and organics removal in two anodes (47.3%), producing an effluent (COD <500mg/L, TN<15mg/L) qualified to be discharged into municipal wastewater pipe systems. These results indicated great potential of M-MDC to work as a pretreatment technology for high strength industrial wastewater.

Advanced treatment of sodium dithionite wastewater using the combination of coagulation, catalytic ozonation, and SBR

ABSTRACTA combined process of coagulation–catalytic ozonation–anaerobic sequencing batch reactor (ASBR)–SBR was developed at lab scale for treating a real sodium dithionite wastewater with an initial chemical oxygen demand (COD) of 21,760–22,450 mg/L. Catalytic ozonation with the prepared cerium oxide (CeO2)/granular activated carbon catalyst significantly enhances wastewater biodegradability and reduces wastewater microtoxicity. The results show that, under the optimum conditions, the removal efficiencies of COD and suspended solids are averagely 99.3% and 95.6%, respectively, and the quality of final effluent can meet the national discharge standard of China. The coagulation and ASBR processes remove a considerable proportion of organic matter, while the SBR plays an important role in post-polish of final effluent. The ecotoxicity of the wastewater is greatly reduced after undergoing the hybrid treatment. This work demonstrates that the hybrid system has the potential to be applied for the advanced treatment of high-strength industrial wastewater.

Development of a high-rate submerged anaerobic membrane bioreactor

ABSTRACTTypically, anaerobic membrane bioreactors are operated at an organic loading rate (OLR) less than 10 kg chemical oxygen demand (COD)/m3 d. This paper discusses the development and performance of a high-rate submerged anaerobic membrane bioreactor (SAnMBR) for a high-strength synthetic industrial wastewater treatment. An OLR as high as 41 kg COD/m3 d was achieved with excellent COD removal efficiency (>99%). The membrane was operated at constant fluxes (9.4–9.9 ± 0.5 L/m2 h) and the change in trans-membrane pressure (TMP) was monitored to characterize the membrane performance. The results showed a low TMP (<5 kPa) under steady-state operation with only biogas sparging and relaxation as control strategy for over 300 days, implying no significant fouling was developed. Inorganic fouling was the dominant fouling mechanism occurred at the end of the study. The results suggest that the newly developed SAnMBR configuration can treat high-strength wastewater at lower capital expenditure while still providing superior effluent quality for water reuse or system closure.

Biological Nitrogen Removal From High-Strength Industrial Wastewater

Biological Nitrogen Removal From High-Strength Industrial Wastewater

Electricity Production and Characterization of High-Strength Industrial Wastewaters in Microbial Fuel Cell.

Microbial fuel cells (MFCs) convert electrochemical energy into electrical energy immediately and have a big potential usage for the same time wastewater treatment and energy recovery via electro-active microorganisms. However, MFCs must be efficiently optimized due to its limitations such as high cost and low power production. Finding new materials to increase the cell performance and reduce cost for MFC anodes is mandatory. In the first step of this study, different inoculation sludges such as anaerobic gum industry wastewater, anaerobic brewery wastewater and anaerobic phosphate were tested, and MFC that was set up with anaerobic gum industry wastewater inoculation sludge exhibited the highest performance. In the second step of this study, various wastewaters such as chocolate industry, gum industry and slaughterhouse industry were investigated for anode bacteria sources. Several electrochemical techniques have been employed to elucidate how wastewaters affect the MFCs' performance. Among all the mentioned wastewaters, the best performance was achieved by the MFCs fed with slaughterhouse wastewater; this device produced a maximum power density of 267mW·m-2.

RETRACTED: Acetate-triggered granular sludge floatation in methanogenic bioreactors

Methanogenic granular sludge from anaerobic bioreactors plays a primary role in treatment of various high-strength industrial wastewaters. The common problem of sludge floatation can lead to washout of granules from the reactor and severely affect reactor performance. However, an understanding of the specific key trigger-factors and appropriate control strategies for granular sludge floatation remains elusive. In this study, the concentration of acetate, rather than that of other volatile fatty acids (VFAs, i.e. propionate and butyrate) and granular sludge properties, was identified to be positively, linearly correlated with the amount of floating granules. The number of floating granules on propionate (18±6) or butyrate-containing (34±13) wastewater was comparable with that of non-VFA control wastewater (30.5±7.5), and much lower than that of acetate-containing wastewater (80.5±10.5). A scenario of excessive acetate-triggered granular sludge floatation is proposed based on these results as well as on the microbial community profile and spatial distribution, porous structure of granules, and impacts of operational parameters. Two new strategies, acetate-depletion and co-substrate addition, effectively reduced the number of floating granules by 28.5% and 51.6%, respectively. These results deepen our understanding of granular sludge floatation in methanogenic bioreactors and provide effective strategies to control sludge floatation.

Potential of using non-inoculated self-aerated immobilized biomass reactor for post-treatment of upflow anaerobic staged reactor treating high strength industrial wastewater

BACKGROUND Cake industry produces a heavily polluted wastewater that is characterized by high amounts of suspended solids, lipids, chemical oxygen demand (COD), biochemical oxygen demand (BOD5) and nitrogen components. In this study, assessment the efficiency of non-inoculated self-aerated immobilized biomass (SAIB) reactor for post-treatment of the anaerobic effluent of cake processing wastewater was extensively investigated. RESULTS The reactor was operated at different hydraulic retention times (HRTs) and sludge residence times (SRTs). CODt and CODs removal efficiencies increased from 50 ± 15.2 to 61.8 ± 20.7% and from 51.6 ± 9.3 to 60 ± 17.8% at increasing the HRT from 2.5 to 5.0 h, respectively. Maximum nitrification efficiency and biomass concentration of 67% ± 3.1% and 39.8 gVS/ Lsponge was obtained at an SRT of 42 days. The results of the empirical model showed a good agreement between predicted and experimental values. Ammonium oxidizing bacteria (AOB) was dominated and represented 0.14% at the middle zone of the reactor where the dissolved oxygen is sufficient for growth of nitrifiers. CONCLUSION The innovative (SAIB) reactor was able to treat cake wastewater with high content of carbon and lipids in comparison with the other conventional technologies. The efficiency of the reactor was contingent mainly on HRT, SRT, VSS/TSS ratio, F/M ratio and CODp/CODt ratio.

Combination of Electrochemical Processes with Membrane Bioreactors for Wastewater Treatment and Fouling Control: A Review

This paper provides a critical review about the integration of electrochemical processes into membrane bioreactors (MBR) in order to understand the influence of these processes on wastewater treatment performance and membrane fouling control. The integration can be realized either in an internal or an external configuration. Electrically enhanced membrane bioreactors or electro membrane bioreactors (eMBRs) combine biodegradation, electrochemical and membrane filtration processes into one system providing higher effluent quality as compared to conventional MBRs and activated sludge plants. Furthermore, electrochemical processes, such as electrocoagulation, electrophoresis and electroosmosis, help to mitigate deposition of foulants into the membrane and enhance sludge dewaterability by controlling the morphological properties and mobility of the colloidal particles and bulk liquid. Intermittent application of minute electric field has proven to reduce energy consumption and operational cost as well as minimize the negative effect of direct current field on microbial activity which are some of the main concerns in eMBR technology. The present review discusses important design considerations of eMBR, its advantages as well as its applications to different types of wastewater. It also presents several challenges that need to be addressed for future development of this hybrid technology which include treatment of high strength industrial wastewater and removal of emerging contaminants, optimization study, cost benefit analysis and the possible combination with microbial electrolysis cell for biohydrogen production.

Effect of by-pass and effluent recirculation on nitrogen removal in hybrid constructed wetlands for domestic and industrial wastewater treatment

Hybrid constructed wetlands (CWs) including subsurface horizontal flow (HF) and vertical flow (VF) steps look for effective nitrification and denitrification through the combination of anaerobic/anoxic and aerobic conditions. Several CW configurations including several configurations of single pass systems (HF + HF, VF + VF, VF + HF), the Bp(VF + HF) arrangement (with feeding by-pass) and the R(HF + VF) system (with effluent recirculation) were tested treating synthetic domestic wastewater. Two HF/VF area ratios (AR) were tested for the VF + HF and Bp(VF + HF) systems. In addition, a R(VF + VF) system was tested for the treatment of a high strength industrial wastewater. The percentage removal of TSS, COD and BOD5 was usually higher than 95% in all systems. The single pass systems showed TN removal below the threshold of 50% and low removal rates (0.6–1.2 g TN/m2 d), except the VF + VF system which reached 63% and 3.5 g TN/m2 d removal but only at high loading rates. Bp(VF + HF) systems required by-pass ratios of 40–50% and increased TN removal rates to approximately 50–60% in a sustainable manner. Removal rates depended on the AR value, increasing from 1.6 (AR 2.0) to 5.2 g TN/m2 d (AR 0.5), both working with synthetic domestic wastewater. On real domestic wastewater the Bp (VF + HF) (AR 0.5 and 30% by-pass) reached 2.5 g TN/m2 d removal rate. Effluent recirculation significantly improved the TN removal efficiency and rate. The R(HF + VF) system showed stable TN removals of approximately 80% at loading rates ranging from 2 to 8 g TN/m2 d. High TN removal rates (up to 73% TN and 8.4 g TN/m2 d) were also obtained for the R(VF + VF) system treating industrial wastewater.

Performance and microbial community composition in a long-term sequential anaerobic-aerobic bioreactor operation treating coking wastewater.

The combined anaerobic-aerobic biosystem is assumed to consume less energy for the treatment of high strength industrial wastewater. In this study, pollutant removal performance and microbial diversity were assessed in a long-term (over 300days) bench-scale sequential anaerobic-aerobic bioreactor treating coking wastewater. Anaerobic treatment removed one third of the chemical oxygen demand (COD) and more than half of the phenols with hydraulic retention time (HRT) of 42h, while the combined system with total HRT of 114h removed 81.8, 85.6, 99.9, 98.2, and 85.4% of COD, total organic carbon (TOC), total phenols, thiocyanate, and cyanide, respectively. Two-dimensional gas chromatography with time-of-flight mass spectrometry showed complete removal of phenol derivatives and nitrogenous heterocyclic compounds (NHCs) via the combined system, with the anaerobic process alone contributing 58.4 and 58.6% removal on average, respectively. Microbial activity in the bioreactors was examined by 454 pyrosequencing of the bacterial, archaeal, and fungal communities. Proteobacteria (61.2-93.4%), particularly Betaproteobacteria (34.4-70.1%), was the dominant bacterial group. Ottowia (14.1-46.7%), Soehngenia (3.0-8.2%), and Corynebacterium (0.9-12.0%), which are comprised of phenol-degrading and hydrolytic bacteria, were the most abundant genera in the anaerobic sludge, whereas Thiobacillus (6.6-43.6%), Diaphorobacter (5.1-13.0%), and Comamonas (0.2-11.1%) were the major degraders of phenol, thiocyanate, and NHCs in the aerobic sludge. Despite the low density of fungi, phenol degrading oleaginous yeast Trichosporon was abundant in the aerobic sludge. This study demonstrated the feasibility and optimization of less energy intensive treatment and the potential association between abundant bacterial groups and biodegradation of key pollutants in coking wastewater.

Treating anaerobic sequencing batch reactor effluent with electrically conducting ultrafiltration and nanofiltration membranes for fouling control

The anaerobic treatment of industrial wastewater has attracted a significant amount of interest. However, excessive fouling complicates the treatment of anaerobic reactor effluent with membranes, which limits the application of membranes as a tertiary treatment. Here, we use an anaerobic sequencing batch reactor coupled to electrically conducting ultrafiltration and nanofiltration membranes to treat high-strength industrial wastewater containing high concentrations of benzyl alcohol, a commercial paint stripper. We demonstrate that an anaerobic process can be used successfully to degrade this contaminant. We also show that the application of negative electrical potential to the ultrafiltration membrane surface prevents membrane fouling and allows for higher operational fluxes during the treatment of complex wastewater streams. The application of positive potential to the membrane surface increases membrane fouling, as well as hindering the cleaning and recovery of the nanofiltration membranes. Overall, our experimental results demonstrate the feasibility of using electrically conducting membranes to prevent membrane fouling during the treatment of anaerobic reactor effluent at high operational fluxes.

The close relation between Lactococcus and Methanosaeta is a keystone for stable methane production from molasses wastewater in a UASB reactor.

The up-flow anaerobic sludge blanket (UASB) reactor is a promising method for the treatment of high-strength industrial wastewaters due to advantage of its high treatment capacity and settleable suspended biomass retention. Molasses wastewater as a sugar-rich waste is one of the most valuable raw material for bioenergy production due to its high organic strength and bioavailability. Interpretation for complex interactions of microbial community structures and operational parameters can help to establish stable biogas production. RNA-based approach for biogas production systems is recommended for analysis of functionally active community members which are significantly underestimated. In this study, methane production and active microbial community were characterized in an UASB reactor using molasses wastewater as feedstock. The UASB reactor achieved a stable process performance at an organic loading rate of 1.7~13.8-g chemical oxygen demand (COD,·L(-1) day(-1); 87-95 % COD removal efficiencies), and the maximum methane production rate was 4.01 L-CH4·at 13.8 g-COD L(-1) day(-1). Lactococcus and Methanosaeta were comprised up to 84 and 80 % of the active bacterial and archaeal communities, respectively. Network analysis of reactor performance and microbial community revealed that Lactococcus and Methanosaeta were network hub nodes and positively correlated each other. In addition, they were positively correlated with methane production and organic loading rate, and they shared the other microbial hub nodes as neighbors. The results indicate that the close association between Lactococcus and Methanosaeta is responsible for the stable production of methane in the UASB reactor using molasses wastewater.

Effect of organic matter to nitrogen ratio on membrane bioreactor performance

Effect of chemical oxygen demand (COD) to nitrogen (COD:N) ratio in feed on the performance of aerobic membrane bioreactor (MBR) for treating a synthetic high-strength industrial waste water containing glucose was studied for over 370 days. The widely recommended nutrients ratio (COD:N:P = 100:5:1) is not necessary for aerobic biological industrial waste water treatment. An increased COD:N ratio from 100:5 to 100:2.5 and 100:1.8 had a limited impact on COD removal efficiency and further led to a significant improvement in membrane performance, a reduced sludge yield, and improved effluent quality in terms of residual nutrients. An increased COD:N ratio will benefit the industrial waste water treatment using MBRs by reducing membrane fouling and sludge yield, saving chemical costs, and reducing secondary pollution by nutrients addition. Optimization of nutrients usage should be conducted for specific industrial waste water streams.