High COD Concentration Research Articles

The treatment of Slaughterhouses wastewater by An Up Flow - Anaerobic Sludge Blanket (UASB) reactor.

Slaughterhouse wastewater is heavily polluted. It contains a high concentration of oil and grease, phosphorus, nitrogen, organic matter and suspended solids. The objective of the research is study the ability of slaughterhouses wastewater treatment by a UASB reactor and define the best hydraulic retention time (HRT). This research focuses on the treatment of slaughterhouse wastewater in Up Flow Anaerobic Sludge Blanket (UASB) reactor In these reactors, the polluted wastewater rises slowly which allows it to form a suspended sludge blanket. Granules of sludge gather on the surface and anaerobic bacteria is activated which feeds on the organic matter which exists in the liquid. The research includes a study of the effect of hydraulic retention time (HRT) on the efficiency of treatment in UASB reactors at a constant temperature of about 30±1°C. The experiments have illustrated that it is possible to achieve excellent removal efficiency for high concentrations of COD when the temperature of the wastewater is fixed at 30±1 °C. The removal efficiency fit with hydraulic retention times (HRTs) in UASB reactor, for the following values of HRTs:(6,12,18,24,30,36) hours, the removal efficiencies of COD were:(35.78%,48.93%,56.15%,71.3% ,76.33%,83.37%) respectively.

Removal of COD & NH3 from Produced Water using Modified Horizontal Subsurface Flow Constructed Wetlands (HSCW)

It is very common that COD and NH3 are found in Produced Water with elevated concentration. One proven technology that is capable in removing organic substances and nutrients, is Horizontal Subsurface Flow Constructed Wetland (HSCW). Based on characterization of produced water from one oil field in Indonesia, it was shown that COD and NH3 were found to exceed the threshold limit stated in Ministry of Environmental Decree no. 19 Year 2010. Modified HSCWs were developed in order to treat produced water containing high concentration of COD and NH3 and allowing anaerobic process to occur in the reactor. The HSCWs were planted by three different species; they were Sagittaria palaefolia (Jasmine Water), Scirpus grossus (Mensiang), and Typha latifolia (Walingi). Organic loading rates (OLRs) to the HSCWs reactor were varied from 7.2 to 72 gr COD/m2.day. It was found that HSCW planted with Typha latifolia had the highest removal efficiency for both COD and NH3 when the OLR was set at 14.4 gr COD/m2.day. Anaerobic bacteria were found in high number indicating that these bacteria involved actively in removing pollutants containing in produced water. However, further microbiology study should be performed in order to determine the role of anaerobic bacteria.

Study on the Short-term Treatment Technology of Landfill Leachate

Domestic garbage is mainly treated by sanitary landfill.The main characteristics of landfill leachate produced in the sanitary landfill process are high concentration of COD and BOD, high ammonia nitrogen content, high levels of refractory organics, heavy metal ions, poor biodegradability, unstable water quality, difficult handling and so on. If the treatment is not carried out, the environment will be severely damaged. According to the needs of the project, this paper proposes a set of short-term landfill leachate treatment process, which involves ozone oxidation, internal electrolytic oxidation technology, coagulation precipitation, deep oxidation of the chain reaction, microwave field catalytic oxidation, adsorption and other treatment processes. Eliminating the biochemical process, the entire process flow is relatively short, and the processing efficiency is high. And the use of PLC-based control system to achieve automatic control of landfill leachate treatment. Since the leachate water quality has a wide range of variation, the PID control method based on BP neural network adaptive control strategy is adopted to achieve on-line adjustment of PID control parameters. The final effluent water quality can meet the emission standards.

EFFECT OF ORGANIC LOADING RATE ON THE PERFORMANCE OF ANAEROBIC CO-DIGESTION DIGESTER TREATING FOOD WASTE AND SLUDGE WASTE

This research was carried out to evaluate the effect of organic loading rate to the performance of anaerobic co-digestion digester treating organic fraction of food waste (FW) and sludge waste (SW) from wastewater treatment plant. The experiment was conducted in two runs: Run S50, substrate contained 50 % of FW and 50 % of SW in term of volatile solid (VS) concentration; Run S100 (control run) contained 100 % SW in the influent substrate. The experiment was performed in a 3L working volume reactor at ambient temperature with three levels of organic loading rate (OLR) as 2; 4; 6 kgVS/m3/day, the duration of experiment was 18 days for each level of OLR. As results, the average of biogas production rate (BPR) at OLR 2;4;6 kgVS/m3/day,in Run S50 and Run S100 was 390 – 520; 860 – 1220; 1140 - 2440 ml/day and 160 – 300; 560 – 640; 700 - 1400 ml/day, respectively. The maximum methane yield (mlCH4/gVSadded/day) of organic loading rate 2; 4; 6 kgVS/m3/day was 118.96; 326.49; 628.20 for Run S50 and; 58.28; 160.27; 255.54 for Run S100, respectively. In conclusion, Run S50 always produced higher biogas production rate and higher methane yield at all 3 OLR levels. The higer OLR could enhance BPR and methane yield but at OLR 6 kgVS/m3/day made unstable performance and high concentration of COD in the effluent. Therefore, in this experimental conditions it has better operation at OLR under 6 kgVS/m3/day for the stable performance of reactors.

Microbial Fuel Cell (MFC) in treating spent caustic wastewater: Varies in Hydraulic Retention Time (HRT) and Mixed Liquor Suspended Solid (MLSS)

The performance of an anoxic-aerobic MFC reactor operated with spent caustic wastewater was studied at different HRT and MLSS. Spent caustic wastewater is the industrial wastewater with high COD concentration influenced by its high sulfur content, high salinity and high alkalinity. Little is known on the MFC capacity in treating spent caustic wastewater, therefore the present study employed spent caustic wastewater as the feed wastewater. The MFC performance was evaluated in terms of voltage production, COD and sulfide removal efficiency. The HRT range tested were 7 days, 8 days and 9 days whereas the MLSS range tested were 1500 mg/L, 2000 mg/L and 2500 mg/L. From the study, HRT of 9 days was the optimum HRT for the MFC operation with the highest COD and sulfide removal efficiency of 98% and 98.98% respectively. The removal efficiency increased with increasing HRT. In terms of voltage production, the highest achievable voltage was 82.1 mV obtained at HRT of 9 days. The overall energy production trend shows that energy production was increased with increasing HRT. For MLSS study, the optimum MLSS for the MFC operation was at 1500 mg/L with the highest COD removal and sulfide removal efficiency of 94.07% and 89.01% respectively. In terms of voltage production, the highest achievable voltage was 36.7 mV obtained at MLSS of 2500 mg/L.

Biological hydrogen production via dark fermentation by using a side-stream dynamic membrane bioreactor: Effect of substrate concentration

This study investigates the possibility of using dynamic membranes (DMs) as a solid-liquid separation medium for fermentative H2 production under mesophilic conditions. In particular, the fouling behaviour of DM and H2 production are studied in response to different influent COD concentrations (10–100 gCOD L−1). The results demonstrate that the influent feed concentration significantly affects the filtration behaviour of DM. In fact, the decrease in influent COD concentration determined an improvement of both DM permeability and solids separation. In addition, high influent COD concentration (above 30 g L−1) and resulting high organic loading rates, favoured the accumulation of volatile fatty acids (VFA), leading to the inhibition of bio-hydrogen production. The results, thus, demonstrated that stable DM filtration and H2 production can be achieved by operating the bench-scale anaerobic DM bioreactor at low influent COD concentration (10–30 g L−1) and at an HRT of approximately 1 d. However, stable DM was achieved applying rather low filtration fluxes (approximately 2 L m−2 h−1).

One-year operation of 1000-L modularized microbial fuel cell for municipal wastewater treatment

This study constructed a 1000 L modularized MFC system, the largest volume so far, to treat practical municipal wastewater. This MFC system was operated under two different water flow connections in two municipal wastewater treatment plants (MWTP) for more than one year to test their treating abilities for wastewater with both low (average 80 mg L−1) and high initial COD concentration (average 250 mg L−1). The COD concentration in the effluent from the MFC system remained below 50 mg L−1 with a removal rate of 70–90%, which stably met the level A of the first class in discharge standard of pollutants for MWTP of China. A maximum power density of 125 W m−3 (7.58 W m−2) was generated when the MFC system was fed with artificial wastewater, while it lay in a range of 7–60 W m−3 (0.42–3.64 W m−2) when treating municipal wastewater. The energy recovery of 0.033 ± 0.005 kWh per m3 of municipal wastewater was achieved, with a hydraulic retention time (HRT) of 2 h.

Biosorption with autochthonous and allochthonous fungal biomasses for bioremediation and detoxification of landfill leachate

Landfill leachates are not adequately treated in traditional wastewater treatment plants, on account of their problematic peculiarities: i.e., dark colour, high concentration of recalcitrant pollutants and COD, and high toxicity. In this work, 19 biomasses (15 autochthonous and 4 allochthonous) were exploited in biosorption treatment for the remediation of a leachate (influent) and the effluent coming from the biological oxidation with activated sludge and nitrification–denitrification treatment. The effects of the initial pH, the biomass amount, and the medium for the biomass pre-culture were considered. The best configuration was: pH 5, 5 g L− 1 biomass cultivated on STY medium. Eventually, the two most effective biomasses, Cunninghamella bertholletiae MUT 2861 and Aspergillus fumigatus MUT 4050, were used in consecutive 2 h cycles in a batch biosorption experiment. The effectiveness of the treatment decreased in subsequent cycles in terms of decolourisation (31–15%). COD, Cl−, SO42−, total N, and toxicity were removed mainly in the second cycle of treatment (up to − 36, − 12, − 15, − 17 and − 49%, respectively). The results suggest that the effluent toxicity was basically due to uncoloured substances, which were mainly removed after coloured molecules.

STUDY ON THE GROWTH OF BACILLUS VELEZENSIS M2 AND APPLYING IT FOR TREATMENT OF THE CATTLE SLAUGHTERHOUSE WASTEWATER

Wastewater from cattle slaughterhouse usually contains high COD and total nitrogen concentration, which required to be treated properly in order to prevent pollution. Strain Bacillus velezensis M2 isolated from Thinh An slaughterhouse, has high ability to degrade organic pollutants rapidly and, therefore, it can be used to produce biological product for slaughterhouse wastewater treatment in large scale, thus reduce setting-up time of operation. In this study, we showed that the best conditions for Bacillus velezensis M2 to grow are NA medium, initial pH of 6.5, inoculum of 3 % (v/v), shaking of 200 rpm. For test in laboratory-scale of 500 ml flask, Bacillus velezensis M2 was induced in the cattle slaughterhouse water containing COD of 1260 mg/L and total nitrogen of 137 mg/L, shaking at 200 rpm, inoculum 3 %, after 12 hours the removal efficiency in COD and total nitrogen were 93.2 % and 83.5 %, respectively.

Identification of Important Parameter from Leachate Solid Waste Landfill on Water Quality, Case Study of Pesanggrahan River

Cipayung Landfill takes waste generation from Depok City approximately ± 750 tons/day of solid waste. The south and west boundaries of the landfill is Pesanggarahan River which 200m faraway. The objectives of this study are to indicate an important parameter which greatly affects the water quality of Pesanggrahan River and purpose the dynamic model for improving our understanding of the dynamic behavior that captures the interactions and feedbacks important parameter in river in order to identify and assess the effects of the treated leachate from final solid waste disposal activity as it responds to changes over time in the river. The high concentrations of BOD and COD are not the only cause significantly affect the quality of the pesanggrahan water, it also because the river has been contaminated in the upstream area. It need the water quality model to support the effectiveness calculation of activities for preventing a selected the pollutant sources the model should be developed for simulating and predicting the trend of water quality performance in Pesanggrahan River which can potentially be used by policy makers in strategic management to sustain river water quality as raw drinking water.

Facile method to immobilize ZnO particles on glass spheres for the photocatalytic treatment of tannery wastewater

In order to apply the photocatalytic processes on a real scale for the treatment of industrial wastewaters, the use of slurry reactors employing suspended photocatalysts is not suitable due to the need for an uncomfortable and expensive separation phase of photocatalyst. To overcome this disadvantage, the photocatalyst particles must be immobilized on a transparent support: our work proposes, for this reason, a simple and cost effective method for the deposition of ZnO photocatalyst on glass spheres in order to formulate a structured photocatalyst effective in the treatment of aqueous solutions containing various organic dyes, commonly used in the tannery industries and in the treatment of a real wastewater at high COD content (11 g/L) coming from the refining unit of the tanning process. In particular, ZnO was immobilized on glass spheres (ZnO/GS) with a simple dip coating method, starting from zinc acetate aqueous solution, without using complexing agent and strong basic compounds. The optimization of ZnO amount on glass spheres was evaluated employing Acid Blue 7 dye, as model pollutant. In particular, it was found that best performances in terms of discoloration and mineralization of the target dye were obtained using the photocatalyst with a ZnO loading equal to 0.19 wt% (ZnO_ac1), prepared through only one dip-coating step. Moreover, the ZnO_ac1 photocatalyst can be easily separated from the reaction mixture, maintaining excellent photocatalytic activity and durability even after several reuse cycles. Finally, ZnO_ac1 showed a high photocatalytic activity in the treatment of the real wastewater, obtaining a COD removal equal to 70% after 180 min of UV light irradiation.

Performance of Anaerobic Baffled Reactor with Three Compartments in Removal of COD of Wastewater of Chilly Sauce

The objective in this study is to examine the performance of each compartment of the number of compartments of anaerobic baffled reactor (ABR) to the COD removal of the chilly sauce wastewater. Three-compartments of ABR were conducted in this experiment with the total volume of 60 l. ABR is very suitable for processing waste water with high content of COD. Wastewater conducted in this research is a degradable chilly sauce synthetic and high content of organic compounds. While the COD parameter is the main parameter to indicate the achievement of wastewater treatment plant. Stepwise in the research starting with the preparation of raw materials such as sample preparation of synthetic wastewater and preparation of activated sludge. Variable used is the time digestion in the ABR, sludge volume (50% and 70%), and initial COD concentrations (6000 – 14000 mg/L). The response is observed up to 7 days process. For a load of organic compounds, the first compartment has high degree of decomposition of organic compounds than 2nd and 3rd, it is shown that the COD removal the second and third compartment increase insignificantly compare the first compartment. As for the different height of the activated sludge indicated that for organic load of of 6170 mg/L up to 14265 mg/L, the first compartment has removal efficiency 79-73%, in the second compartment is 81-75%, 81-77% and third compartment.

Micro-Peat as a Potential Low-Cost Adsorbent Material for COD and NH<sub>3</sub>-N Removal

Micro-peat (M-P) was demonstrated in the present study as a potential low cost natural adsorbent for the removal of COD and ammoniacal nitrogen (NH3-N) from landfill leachate. A series of batch experiments were carried out under fixed conditions and the influence of mixture ratio was investigated. The characteristics of leachate were then determined. Results indicated that leachate is non-biodegradable with high concentration of COD (2739.06 mg/L), NH3-N (1765.34 mg/L) and BOD5/COD ratio (0.09). The optimum ratio for activated carbon (AC) and M-P in the removal of COD and NH3-N obtained were at 2.5:1.5 (87%) and 1.0:3.0 (65%) respectively. The low-cost natural adsorbent used in the present investigation is an attractive alternative to the conventional adsorbent (AC). Thus, M-P can be appropriated for use in leachate treatment that could be cost-effective due its local availability and adsorption property.

Preliminary Study of Contamination Wastewater on Environment in Slaughterhouse of Merauke City

The purpose of this research is to know the contamination of waste water that happened in slaughterhouse (RPH) city of merauke. Data were obtained based on surveys and field observations and the sample used was RPH water waste each in repeat as many as 6 replications. Data analysis was done descriptively by comparing the result obtained with the standard of quality which have been determined. The results showed that the contamination of waste water all exceeded the quality standard except at pH value. The ALT content of wastewater in RPH 2790 x 104 and contains E. Coli and Salmonella microbes. The high content of BOD, COD, TTS, Ammonia and microbial contamination is thought to be due to the absence of wastewater treatment installation (IPAL) at RPH in accordance with the standard. Proper handling of ammonia waste can reduce the amount of carbon in the atmosphere.

Recent development in sanitary landfilling and landfill leachate treatment in Malaysia

The main issue in landfilling in developing countries is the management of leachate. Leachate is rich in organic compounds, ammonia, heavy metals, and other hazardous chemicals. COD, colour, and NH3-N, are among the problematic parameters that are difficult to be completely removed. The treatments depend on leachate characteristics, operation and capital costs, and regulations. The development of holistic solutions to leachate-related problems has been widely promoted. Multiple-stage treatments in the form of physical, biological, chemical, and combination methods are always necessary. This paper discusses issues on landfill technology and recent techniques for the treatment of the leachate. The low biodegradability and high COD, colour, and NH3-N content of leachate treatment peculiar to semi-aerobic landfills in developing countries, especially in Malaysia, is described. Some of the challenging issues in overall leachate treatment processes are also elucidated.

Treatment of Rural Wastewater Using a Spiral Fiber Based Salinity-Persistent Sequencing Batch Biofilm Reactor

Differing from municipal wastewater, rural wastewater in salinization areas is characterized with arbitrary discharge and high concentration of salt, COD, nitrogen and phosphorus, which would cause severe deterioration of rivers and lakes. To overcome the limits of traditional biological processes, a spiral fiber based salinity-persistent Sequencing Biofilm Batch Reactor (SBBR) was developed and investigated with synthetic rural wastewater (COD = 500 mg/L, NH4+-N = 50 mg/L, TP = 6 mg/L) under different salinity (0.0–10.0 g/L of NaCl). Results indicated that a quick start-up could be achieved in 15 days, along with sufficient biomass up to 7275 mg/L. During operating period, the removal of COD, NH4+-N, TN was almost not disturbed by salt varying from 0.0 to 10.0 g/L with stable efficiency reaching 92%, 82% and 80%, respectively. Although TP could be removed at high efficiency of 90% in low salinity conditions (from 0.0 to 5.0 g/L of NaCl), it was seriously inhibited due to nitrite accumulation and reduction of Phosphorus Accumulating Organisms (PAOs) after addition of 10.0 g/L of salt. The behavior proposed in this study will provide theoretical foundation and guidance for application of SBBR in saline rural wastewater treatment.

Low Temperature Start-up of Coating Wastewater Treatment Works

The purpose of this paper was to realize rapid start-up of coating wastewater treatment works under low temperature. Thermal insulation treatment was carried out to the pool wall and pool top of the reactor, heating equipment was arranged to ensure that the reactor can provide appropriate temperature conditions for the inoculated sludge, the amount of influent water was reasonably controlled to ensure that microorganisms have appropriate proportion of nutrient elements, and the effluent water of the reactor was continuously detected and the biophase of the sludge was continuously observed. The practice results showed that the reactor ran stably, and the effluent water met the requirements on quality of washing water and boiler make-up water in Urban Wastewater Reclamation and Reuse Industrial Water Quality (GB/T 19923-2005). The coating wastewater has a complex composition, a high COD content and poor biodegradability (Sun et al., 2009; Zhang and Li, 2009; Dong et al., 2013) as it contains a large amount of residual acrylic resin, amino resin, nitrocellulose film-forming agent, water-soluble dye colorants, brighteners, surfactants and other additives. The present works processed the coating wastewater by adopting a process of coagulation-hydrolytic acidification-contact oxidation-sand filtration-activated carbon adsorption. When the project started, the local maximum temperature was about 0 ˚C and the average temperature was -5 ˚C, which was not suitable for the growth of microorganisms. The present works adopted rock wool covered insulation, electric heating system configuration and other measures to ensure successful start-up of the hydrolytic acidification pond and contact oxidation pond.

Discussion on Wastewater Treatment Process of Coal Chemical Industry

Coal chemical wastewater has such characteristics as high concentration of oil, ammonia nitrogen and COD. In this paper, treatment process of coal chemical industry is described mainly, such as pretreatment process, biochemical treatment process and polishing process. Through the recovery of phenol and ammonia and the treatment of wastewater from abroad, the new technology of wastewater treatment in coal chemical industry was expounded. Finally, The development of coal chemical wastewater treatment technology is prospected, and the pretreatment technology is emphasized. According to the diversification and utilization of water, zero discharge of coal chemical wastewater will be fulfilled.

Microbial transcript and metabolome analysis uncover discrepant metabolic pathways in autotrophic and mixotrophic anammox consortia

The ability of anammox bacteria to utilize organic matter has drawn extensive attention. However, the metabolic discrepancies between autotrophic and mixotrophic anammox consortia need to be further explored. Here, microbial transcript and metabolomic analysis were conducted for the samples harvested in the reactors and batch assays to investigate the phenotype discrepancies and intrinsic causes in autotrophic and mixotrophic anammox consortia. Results showed that metabolically active community structures did not show significant difference between autotrophic and mixotrophic anammox consortia (C/N = 0.3). Changes in the metabolic state were the main cause for those discrepancies in virtue of the added acetate oxidized via the acetyl-CoA pathway by mixotrophic anammox bacteria. At C/N ratio of 0.3, anammox activity was obviously promoted compared to that in the autotrophic condition, due to higher levels of NADH and NAD+, as well as ATP consumption. Mixotrophic anammox consortia were found to yield more biomass, resulting from enhanced purine, pyrimidine, and putrescine synthetic pathways for regulating bacterial growth. Up-regulated amino sugar and nucleotide sugar metabolism pathways participating in regulating more extracellular polysaccharides secreted by mixotrophic anammox consortia. In adverse environment with higher COD concentration, more extracellular proteins were produced by anammox consortia to protect themselves and amino acids also accumulated in the cell. This study provides useful information to catch the optimal metabolism way of anammox consortia and accelerate anammox bacterial cultivation or reactor startup for wastewater treatment.

Hot wastewater recovery by using ceramic membrane ultrafiltration and its reusability in textile industry

Ceramic membrane filtration is a viable option for recovery of hot discharges due to their high mechanical, chemical and thermal durability. Recovery of hot discharges in textile industry with this method has not been studied in detail previously. In this study, the potential recovery of hot textile wastewater discharges was assessed in situ taking into consideration the amount, pollutant content and costs of the water. Samples were selected from potential recovery points according to wastewater amount, temperature and accessibility and were evaluated using laboratory scale ceramic membrane filtration with four different MWCO (300 kDa, 50 kDa, 15 kDa and 3 kDa) membrane sizes. The pollutant size distribution correlated with removal efficiency of the method and the highest pollutant removal efficiency was achieved with the 3 kDa ceramic membrane. However, the mixed hot wastewater and disperse printing washing baths mix permeate from the 3 kDa membrane had high COD and TOC contents and was not optimal for reuse without additional treatment. The printing washing baths hot discharges mix was the most appropriate option for reuse with 67 ± 12 mg COD/L, 21 ± 4 mg TOC/L and 23 ± 7.7 mg CaCO3/L Total Hardness values which could be reused in dense dyeing and printing baths washing after 3 kDa ceramic membrane ultrafiltration. In order to define the fouling mechanism, resistance-in-series model was used and physically removable resistance was the main contributor to overall fouling.With this method, not only the reuse requirements will be met but also 22% of total water consumption may be reused and thus wastewater, energy and water related expenses may be reduced significantly in textile industry.