Chemical Synthesis-based Pharmaceutical Wastewater Research Articles

Roles of Fe-C amendment on sulfate-containing pharmaceutical wastewater anaerobic treatment: Microbial community and sulfur metabolism.

The effects of multiple two-phase anaerobic treatment involving acidification coupling Fe-C on sulfate-containing chemical synthesis-based pharmaceutical wastewater treatment were investigated. Fe-C was added as a filler with 25% vol. to acidogenic reactors for semi-continuous operation. The results suggested that Fe-C amendment promoted sulfate removal efficiency by 47.5% and shortened the reaction time by 50% in the acidogenic phase. With mitigation of sulfate inhibition, SCOD removal efficiency and methane production were further increased by 24.6% and 398% compared to direct raw wastewater anaerobic digestion, respectively, in methanogenic phase. The results of sulfate removal kinetics confirmed a 150% increase of removal rate in acidogenic phase. However, the apparent kinetic microbial sulfate removal constant without Fe-C amendment was maintained at approximately 0.06 h-1. The Fe-C amendment not only increased the relative abundance of Methanothrix and Desulfovibrio for sulfate reduction but also enriched unclassified_p__Chloroflexi and unclassified_c__Deltaproteobacteria for acidification. Metagenomic results indicated that Fe-C enhanced dissimilatory sulfate reduction and PAPS synthesis of assimilatory step. The hydrogen sulfide production through the 3-mercaptopyruvate to pyruvate pathways was also enhanced. Butyrate-oxidizing genes were increased synchronously to convert butyrate to acetate.

Preparation and Application of Sewage Sludge Bio-char/Zero Valent Iron (SSBC/ZVI) Composite for Improving the Biodegradability of a Real Chemical Synthesis-Based Pharmaceutical Wastewater

A new kind of micro-electrolysis filler sewage sludge biochar/zero valent iron (SSBC/ZVI) composite was prepared for a real chemical synthesis based pharmaceutical wastewater pretreatment for improving the biodegradation index (BI). The optimal operation condition of micro-electrolysis system was obtained at HRT of 2 h, the initial pH of 3.0 and filler dosage of 100 g/L, with COD removal rate of 30.5%. Characterization analysis of raw/used SSBC/ZVI filler and GC–MS analysis of raw/treated pharmaceutical wastewater were conducted to reveal the pollutant removal mechanisms by micro-electrolysis, and the results suggested that the pollutants removal was mainly attributed to the combination of reduction and oxidation, absorption of SSBC and flocculation of iron sludge. SSBC/ZVI exhibited relative high stability and excellent reusability for COD removal and BI improvement of real pharmaceutical wastewater after 4 runs. Moreover, the leaching tests of heavy metals (HMs) were conducted to investigate their release of the constituents in SS, and the results indicated that HMs leaching into the liquid from the filler was at a relative low level. This study provided new ideas of sewage sludge utilization for real wastewater pretreatment.

Comparison of three types of anaerobic granular sludge for treating pharmaceutical wastewater

Abstract Three types of anaerobic granular sludge for treating chemical synthesis-based pharmaceutical wastewater were compared: (1) an up-flow anaerobic sludge blanket (UASB) filled with polyvinyl alcohol (PVA) gel beads (UASB-PVA); (2) a UASB filled with traditional anaerobic granular sludge; and (3) a UASB filled with traditional anaerobic granular sludge and granular active carbon (UASB-GAC). The domestication times for the UASB-PVA, UASB, and UASB-GAC reactors were 30, 47, and 47 days, respectively. When the organic loading rate (OLR) was up to 7 kg chemical oxygen demand (COD)/(m3·d), the COD efficiency of the UASB-PVA, UASB, and UASB-GAC stayed in the range of 69% to 75% (deviation 1.8%), 46% to 69% (deviation 8.6%), and 61% to 73% (deviation 4.0%), respectively. The highest OLRs reached for the UASB-PVA, UASB, and UASB-GAC were 12, 7, and 8 kg COD/(m3·d), respectively. The performance of the UASB-PVA was the best of the three, the UASB-GAC was second, and the UASB was the worst. High-throughput pyrosequencing analysis showed that Levilinea, Syntrophorhabdus, Desulfovibrio and Acetobacterium were the dominant bacteria in the UASB-PVA, UASB, and UASB-GAC reactors’ granular sludge. The abundance and diversity of the microbial community in the UASB-PVA sludge were higher than for the UASB and UASB-GAC granular sludge.

Treatment of chemical synthesis-based pharmaceutical wastewater in an ozonation-anaerobic membrane bioreactor (AnMBR) system

In this study, treatability of etodolac chemical synthesis wastewater from the pharmaceutical industry was investigated in a hybrid ozonation-Anaerobic Membrane Bioreactor (AnMBR) system. The AnMBR was successfully operated up to 7500mg/L of chemical oxygen demand (COD), but sulfite inhibition occurred at this loading. A pre-ozonation process was applied to overcome the problem of sulfite inhibition resulted from raw wastewater by decreasing the sulfite concentration through oxidation to sulphate. Furthermore, it was shown that this process was also effective obtaining high etodolac removal efficiencies up to 99%. Approximately 90% COD removal efficiency was achieved by the combined system. Extracellular polymeric substance (EPS) decreased in the conditions of long sludge retention time (SRT), hydraulic retention time (HRT) and low organic loading rate (OLR) values. Therefore, the granule size also decreased during the entire operation. Real-time polymerase chain reaction (Q-PCR) and fluorescent in situ hybridization (FISH) analyses revealed that high sulfite concentration affected the microbial population in the order of methanogens, acedogens and sulphate reducing bacteria (SRB).

UASB treatment of chemical synthesis-based pharmaceutical wastewater containing rich organic sulfur compounds and sulfate and associated microbial characteristics

• Successful application of UASB in treatment of rich organic S-bearing wastewater. • Sulfate in effluent was higher than influent at COD/SO 4 2− ratio of 8 and 5. • Conversely, sulfate in influent was higher than effluent at COD/SO 4 2− ratio of 1.5. • Archaea and bacterial community varied greatly with altered OLR. • Some species can be responsible for S release from organic sulfur compounds. The feasibility of treating of chemical synthesis-based pharmaceutical wastewater containing rich organic sulfur compounds and sulfate using an upflow anaerobic sludge blanket (UASB) was investigated. The initial COD/SO 4 2 − ratio of 8 in the wastewater varied from 5 to 1.5 after adding sulfate. Of interest that under the condition of COD/SO 4 2 − at 8 and 5, despite the simultaneous generation of sulfide and hydrogen sulfide, the sulfate concentration in the effluent was higher than in the influent. This is due to the sulfur release in the form of sulfate during the degradation of these organic sulfur compounds in this reactor. Conversely, at COD/SO 4 2 − of 1.5, influent sulfate was higher than effluent sulfate due to reduction of more sulfates in the reactor. At COD/SO 4 2 − of 8, for practical application, the optimum OLR was found to be 8 kg COD/m 3 /d, where a nearly 70% COD reduction occurred with biogas containing 63% methane. In this stage, the distribution of the archaea and bacterial community varied greatly with altered OLR (accompanied with prolonged operation time). Some species, such as Lysinibacillus sphaericus , Clostridium cellulovorans were expected to be partly responsible for S release from some organic sulfur compounds in the reactor. By increasing the sulfate loading at a COD/SO 4 2 − ratio up to 1.5 resulted in a light inhibition of methanogenesis due to the high sulfide concentration (1212 SO 4 2 − – S mg/L) with no obvious suppression of sulfidogenesis.

A novel application of anaerobic bio-entrapped membrane reactor for the treatment of chemical synthesis-based pharmaceutical wastewater

Pharmaceutical wastewaters are mainly generated by chemical-synthetic industries and usually contain high chemical oxygen demand (COD) and toxicity. A novel lab-scale anaerobic bio-entrapped membrane reactor (AnBEMR) packed with bio-ball carriers was constructed and compared with an anaerobic membrane bioreactor (AnMBR). The aims of this study are to investigate the treatment performances and evaluate the stability of the membrane filtration of the AnBEMR and AnMBR under the conditions of a high organic loading rate (OLR), ranging from 8.0 to 36.7kgCOD/m3d, and high total dissolved solids (TDS), ranging from 18,411 to 25,925mg/L, in the treatment of chemical synthetic-based pharmaceutical wastewater. Four different hydraulic retention times (HRTs) of 10.6, 14.1, 21.3, and 42.6h were studied. Total COD (TCOD) removal efficiency of the AnBEMR ranged from 36.7% to 50.8% at an OLR of 8.7±0.7kgCOD/m3d, while the highest OLR (34.0±2.7kgCOD/m3d) only led to TCOD removal efficiency of 10.1–20.7%. The AnBEMR achieved approximately 5–10% higher TCOD removal efficiency than the AnMBR. The influences of HRT and TDS (salinity) were also studied. The results show an increase of trans-membrane pressure (TMP) with decreasing HRT in both MBRs, where extracellular polymeric substances (EPS), soluble microbial products (SMP) and suspended biomass concentration were significantly higher at the shortest HRT of 10.6h, resulting in faster membrane fouling. Membrane fouling was improved in the AnBEMR (i.e., longer membrane filtration operating periods) due to the production of lower concentrations of EPS and SMP (protein and carbohydrate contents). Proteins, rather than carbohydrates, were the major component of EPS and SMP in both reactors. The study concludes that the application of the AnBEMR could achieve better treatment performance and reduced membrane fouling by producing lesser EPS, SMP, and suspended biomass concentration.

Automation Highlights from the Literature

Automation Highlights from the Literature

A Novel Application of Combined Bio-Technologies on Chemical Synthesis-Based Pharmaceutical Wastewater

This chemical synthesis-based pharmaceutical wastewater is treated by the process of hybrid hydrolysis acidification technique (HHAT) with anaerobic-low DO condition and the hybrid aerobic bio-technology consisted of alternate-flow biological reactor (ABR) and two-way-flow biological aerated filter (TBAF). The micro aerobic technology was employed in the HHAT and showed its advantages in refractory organic wastewater treatment. The largest plant in pharmaceutical wastewater treatment at home was built. The practice shows that the organics can be greatly removed and the effluent can reach the First Grade Discharge Standard which can be reclaimed with advanced treatment. The performance indicates that the combined bio-technologies are stable in pharmaceutical wastewater treatment.

A Novel Application of Combined Bio-Technologies on Chemical Synthesis-Based Pharmaceutical Wastewater

This chemical synthesis-based pharmaceutical wastewater is treated by the process of hybrid hydrolysis acidification technique (HHAT) with anaerobic-low DO condition and the hybrid aerobic bio-technology consisted of alternate-flow biological reactor (ABR) and two-way-flow biological aerated filter (TBAF). The micro aerobic technology was employed in the HHAT and showed its advantages in refractory organic wastewater treatment. The largest plant in pharmaceutical wastewater treatment at home was built. The practice shows that the organics can be greatly removed and the effluent can reach the First Grade Discharge Standard which can be reclaimed with advanced treatment. The performance indicates that the combined bio-technologies are stable in pharmaceutical wastewater treatment.

Simultaneous removal and evaluation of organic substrates and NH3-N by a novel combined process in treating chemical synthesis-based pharmaceutical wastewater

A full-scale novel combined anaerobic/micro-aerobic and two-stage aerobic biological process is used for the treatment of an actual chemical synthesis-based pharmaceutical wastewater containing amoxicillin. The anaerobic system is an up-flow anaerobic sludge blanket (UASB), the micro-aerobic system is a novel micro-aerobic hydrolysis acidification reactor (NHAR) and the two-stage aerobic process comprised cyclic activated sludge system (CASS) and biological contact oxidation tank (BCOT). The influent wastewater was high in COD, NH3-N varying daily 4016–13,093mg-CODL−1 and 156.4–650.2mg-NH3-NL−1, amoxicillin varying weekly between 69.1 and 105.4mg-amoxicillinL−1, respectively; Almost all the COD, NH3-N, amoxicillin were removed by the biological combined system, with removal percentages 97%, 93.4% and 97.2%, respectively, leaving around 104mg-CODL−1, 9.4mg-NH3-NL−1 and 2.6±0.8mg-amoxicillinL−1 in the final clarifier effluent. The performance evaluation of the wastewater treatment plant (WWTP) by mathematical statistic methods shown that at most of time effluent can meet the higher treatment discharge standard. In addition, the fate of amoxicillin in the full-scale WWTP and the amoxicillin removal rate of each different removal routes in UASB, NHAR, CASS, BCOT and final clarifier processes are investigated in this paper. The results show that biodegradation, adsorption and hydrolysis are the major mechanisms for amoxicillin removal.

Improving the efficiencies of simultaneous organic substance and nitrogen removal in a multi-stage loop membrane bioreactor-based PWWTP using an on-line Knowledge-Based Expert System

The results of the use of an expert system (ES) to control a novel multi-stage loop membrane bioreactor (MLMBR) for the simultaneous removal of organic substances and nutrients are reported. The study was conducted at a bench-scale plant for the purpose of meeting new discharge standards (GB21904-2008) for the treatment of chemical synthesis-based pharmaceutical wastewater (1200–9600 mg/L COD, 500–2500 mg/L BOD 5, 50–200 mg/L NH 4 +-N and 105–400 mg/L TN in the influent water) by developing a distributed control system. The system allows various expert operational approaches to be deployed with the goal of minimizing organic substances and nitrogen levels in the outlet while using the minimum amount of energy. The proposed distributed control system, which is supervised by a Knowledge-Based Expert System (KBES) constructed with G2 (a tool for expert system development) and a back propagation BP artificial neural network, permits the on-line implementation of every operating strategy of the experimental system. A support vector machine (SVM) is applied to achieve pattern recognition. A set of experiments involving variable sludge retention time (SRT), hydraulic retention time (HRT) and dissolved oxygen (DO) was carried out. Using the proposed system, the amounts of COD, TN and NH 4 +-N in the effluent decreased by 55%, 62% and 38%, respectively, compared to the usual operating conditions. These improvements were achieved with little energy cost because the performance of the treatment plant was optimized using operating rules implemented in real time.

Wastewater Treatment from Antibiotics Plant

Upflow anaerobic sludge blanket (UASB) reactors have been widely used for treatment of industrial wastewater. In this study, performance of a lab-scale up-flow anaerobic sludge blanket (UASB) reactor, treating a chemical synthesis-based pharmaceutical wastewater, was evaluated under different operating conditions. A (P.E) pipe with a diameter of 250 mm and total height of 120 cm and effective height of 100 cm with approximate volume of 49 liter was used as a reactor. The loading rates on reactor were increased in steps to assess the maximum loading capacity of the reactor to study the performance of reactor at different loading rates. The COD concentrations used in the present investigation ranges between 1850 mg/L to 15170 mg/L. The performance of the reactor up to 10.81 kg COD/m3.d was evaluated and the hydraulic retention times were examined. During this study, which lasted for 120 days, the temperature of the wastewater entering the reactor ranged from 30 to 35 o C and no heat exchanger was used. Finally the removal ratio of COD with hydraulic retention time of 33.7 hours and organic loading rate of 10.81 kg COD/m3.day were 54 percent respectively.

A novel application of TPAD–MBR system to the pilot treatment of chemical synthesis-based pharmaceutical wastewater

A pilot-scale test was conducted with a two-phase anaerobic digestion (TPAD) system and a subsequential membrane bioreactor (MBR) treating chemical synthesis-based pharmaceutical wastewater. The TPAD system comprised a continuous stirred tank reactor (CSTR) and an upflow anaerobic sludge blanket-anaerobic filter (UASBAF), working as the acidogenic and methanogenic phases, respectively. The wastewater was high in COD, varying daily between 5789 and 58,792 mg L −1, with a wide range of pH from 4.3 to 7.2. The wastewater was pumped at a fixed flow rate of 1 m 3 h −1 through the CSTR, the UASBAF and the MBR in series, resulting in respective HRTs of 12, 55 and 5 h. Almost all the COD was removed by the TPAD–MBR system, leaving a COD of around 40 mg L −1 in the MBR effluent. The pH of the MBR effluent was found in a narrow range of 6.8–7.6, indicating that the MBR effluent can be directly discharged into natural waters. A model, built on the back propagation neural network (BPNN) theory and linear regression techniques, was developed for the simulation of TPAD–MBR system performance in the biodegradation of chemical synthesis-based pharmaceutical wastewater. The model well fitted the laboratory data, and was able to simulate the removal of COD.

Anaerobic treatment of a chemical synthesis-based pharmaceutical wastewater in a hybrid upflow anaerobic sludge blanket reactor

In this study, performance of a lab-scale hybrid up-flow anaerobic sludge blanket (UASB) reactor, treating a chemical synthesis-based pharmaceutical wastewater, was evaluated under different operating conditions. This study consisted of two experimental stages: first, acclimation to the pharmaceutical wastewater and second, determination of maximum loading capacity of the hybrid UASB reactor. Initially, the carbon source in the reactor feed came entirely from glucose, applied at an organic loading rate (OLR) 1 kg COD/m 3 d. The OLR was gradually step increased to 3 kg COD/m 3 d at which point the feed to the hybrid UASB reactor was progressively modified by introducing the pharmaceutical wastewater in blends with glucose, so that the wastewater contributed approximately 10%, 30%, 70%, and ultimately, 100% of the carbon (COD) to be treated. At the acclimation OLR of 3 kg COD/m 3 d the hydraulic retention time (HRT) was 2 days. During this period of feed modification, the COD removal efficiencies of the anaerobic reactor were 99%, 96%, 91% and 85%, and specific methanogenic activities (SMA) were measured as 240, 230, 205 and 231 ml CH 4/g TVS d, respectively. Following the acclimation period, the hybrid UASB reactor was fed with 100% (w/v) pharmaceutical wastewater up to an OLR of 9 kg COD/m 3 d in order to determine the maximum loading capacity achievable before reactor failure. At this OLR, the COD removal efficiency was 28%, and the SMA was measured as 170 ml CH 4/g TVS d. The hybrid UASB reactor was found to be far more effective at an OLR of 8 kg COD/m 3 d with a COD removal efficiency of 72%. At this point, SMA value was 200 ml CH 4/g TVS d. It was concluded that the hybrid UASB reactor could be a suitable alternative for the treatment of chemical synthesis-based pharmaceutical wastewater.

Determination of optimum operating conditions of an acidification reactor treating a chemical synthesis-based pharmaceutical wastewater

In this study, the optimum operating conditions of a lab-scale completely stirred acidogenic reactor treating a chemical synthesis-based pharmaceutical wastewater were determined. Individual effects of hydraulic retention time (HRT), organic loading rate (OLR) and pH on the degree of acidification were investigated at a mesophilic temperature (35 ± 1 °C), for HRT in the range 8–24 h, OLR up to 14 kg COD/m 3 d and pH in the range of 5.0–6.3. A maximum acidification level of 44% and COD removal efficiency of 13%, were obtained at an OLR of 13 kg COD/m 3 d at pH of 5.5 ± 0.1 with an HRT of 12 h. Under these conditions, acetic, propionic and n-butyric acids were found to be predominant volatile fatty acids in the acidogenic reactor.

Effect of Wastewater Composition on Methanogenic Activity in an Anaerobic Reactor

In this study, effects of a chemical synthesis-based pharmaceutical wastewater on activity of acetoclastic methanogens within a lab-scale anaerobic completely stirred tank reactor (CSTR) were investigated. The CSTR was initially fed with glucose and loaded up to an organic loading rate of 6 kg COD m−3 d−1 at which 92% soluble COD removal efficiency was achieved. Acetoclastic methanogenic activity was found to be 336 mL CH4 gTVS−1 d−1. The CSTR was then, fed with several dilutions of preaerated wastewater with glucose at 10% wt v−1, 30% wt v−1, and 70% wt v−1 ratios and followed by 100% wt v−1 preaerated wastewater. In the latter, 71% soluble COD removal efficiency was obtained and a maximum acetoclastic methanogenic activity was 166 mL CH4 gTVS−1 d−1. Finally, raw wastewater diluted with preaerated wastewater was fed into the CSTR in increasing ratios of 10–60% wt v−1. Total failure of anaerobic reactor was observed at 60% wt v−1 raw wastewater fed. The study was, therefore, discontinued due to poor acetoclastic methanogenic activity of reactor sludge which was totally distorted.