scholarly journals Studies on Biodegradation of Phenols and m -Cresols by Upflow Anaerobic Sludge Blanket and Aerobic Sequential Batch Reactor

2013 ◽  
Vol 10 (1) ◽  
pp. 39-46

Wastewaters from fossil fuel refining, pharmaceuticals, and pesticides are the main sources of phenolic compounds. Those with more complex structures are often more toxic than the simple phenol, and yet little is known about the treatment of wastewater containing a mixture of phenolic pollutants. . The present study was aimed at assessing the efficacy of UASB and SBR for the treatment of mixtures of phenolics compounds. The experiments were conducted in a laboratory scale UASB reactor, which had a volume of 1.414 l. A gas-liquid solid separator, GLSS was provided at the top of the reactor. The reactor was operated at constant HRT of 24 h throughout the study. The reactor was seeded with digested sewage sludge obtained from Okhla Sewage Treatment Plant, New Delhi, India. Initially the microbial culture was acclimatized to phenol concentration of 600 mg l-1 in UASB. Thereafter, different phenol: m-cresols ratio were introduced, 10:1, 4.5:1, 2.7:1, 1.75:1 and 1.2:1 and the performance of the reactor was evaluated under each case. The second experiment was conducted in a laboratory scale SBR reactor with a working volume of 1.4 l. The effluent was drawn from a volumetric exchange ratio of 50%. A fine bubble aerator in the bottom of the column was used to introduce air. The reactor was seeded with aerobic digested sludge obtained from Star Paper Mill, Saharanpur, UP, India. A constant HRT of 12h was kept throughout the study. Reactor was operated sequentially with fill, react, settle and draw periods for a cycle of 6h. In order to establish a viable biomass and minimize any potential toxic effects due to presence of phenolic compounds, the sludge was fed with phenol as batch culture up to 1000 mg l-1 concentration. After acclimatization, different phenol: m cresol ratio were introduced 6.5:1, 2:1, 1.1:1, 0.5:1 and the performance of the reactor was evaluated under each case. A start up period of 40 days was required to acclimatize the anaerobic bacterial at HRT of 24 hrs for phenol concentration of 200 mg l-1. UASB reactor successfully biodegraded phenol and m-cresol up to a maximum ratio (1.25:1) (300: 250 mg l-1) with 80% efficiency. A start up period of 30 days was required to acclimatize aerobic bacteria with phenol to concentration up to 1000 mg l-1 as batch culture. The maximum phenol and m-cresol up to (1.1: 1) (800: 700 mg l-1) was successfully treated with efficiency of 95% in SBR.The results indicates that anaerobic treatment by UASB and aerobic treatment by SBR can be successfully used for phenol/cresol mixture, representative of major substrates in chemical and petrochemical wastewater and the results shows proper acclimatization period is essential for the degradation of m - cresol and phenol. Moreover, SBR was found as a better alternative than UASB reactor as it is more efficient and higher concentration of m cresols can be successfully degraded.

2020 ◽  
Vol 21 (1) ◽  
pp. 31-39
Author(s):  
Zulkarnaini Zulkarnaini ◽  
Reri Afrianita ◽  
Ilham Hagi Putra

ABSTRACTAnammox process is a more practical alternative in biological nitrogen removal compared to conventional nitrification-denitrification processes. This process conducted at the optimum temperature of 370C. Indonesia, as a tropical country, has the potential for the application of anammox processes to remove nitrogen in wastewater. The purpose of this study was to analyze the efficiency of nitrogen removal in the anammox process using the Up-Flow Anaerobic Sludge Blanket (UASB) reactor at ambient temperature with variations in the hydraulic retention time (HRT) of 24 hours and 12 hours, at the laboratory scale. Samples are measured twice a week using a UV-Vis spectrophotometer. As a seeding sludge for start-up, the reactor was inoculated with granular anammox bacteria genus Candidatus Brocadia. At the stable operation, the ratio of ΔNO2--N:ΔNH4+-N and ΔNO3--N:ΔNH4+-N approach the stoichiometry of the anammox process were 1.20 and 0.21, respectively. The performance of nitrogen removal with 24-hour HRT obtained a maximum nitrogen removal rate (NRR) of 0.113 kg-N/m3.d with nitrogen loading rate (NLR) 0.14 kg-N/m3.d, and at 12-hour HRT, maximum NRR  of 0.196 kg-N/m3.d with NLR 0,28 kg-N/m3.d. Ammonium Conversion Efficiency (ACE) and Nitrogen Removal Efficiency (NRE) maximum for HRT 24 hours were 82% and 77%, respectively while HRT 12 hours were 72% and 68%, respectively. The anammox process operated stably in the tropical temperature with a temperature range of 23-280C on a laboratory scale using the UASB reactor.Keywords: anammox, nitrogen, temperature, tropical, uasb.ABSTRAKProses anammox menjadi alternatif yang lebih efektif dalam penyisihan nitrogen secara biologi dibandingkan dengan proses konvensional nitrifikasi-denitrifikasi. Proses ini berlangsung optimum pada suhu 370C. Indonesia sebagai negara tropis memiliki potensi untuk aplikasi proses anammox untuk menghilangkan nitrogen pada air limbah. Penelitian ini bertujuan untuk menganalisis efesiensi penyisihan nitrogen pada proses anammox menggunakan Up-Flow Anaerobic Sludge Blanket (UASB) reaktor pada suhu ambien dengan variasi Waktu Tinggal Hidrolik (WTH) 24 jam dan 12 jam, pada skala laboratorium. Sampel diukur dua kali setiap minggu menggunakan spektrofotometer UV-Vis. Sebagai seeding sludge (lumpur biakan) untuk start-up (memulai) reaktor digunakan bakteri anammox genus Candidatus Brocadia berbentuk granular. Berdasarkan hasil pengukuran, didapatkan nilai rasio ΔNO2--N:ΔNH4+-N dan ΔNO3--N:ΔNH4+-N mendekati stoikiometri proses anammox yaitu 1,20 dan 0,21. Kinerja penyisihan nitrogen dengan WTH 24 jam didapatkan nilai tingkat penyisihan nitrogen (TPyN ) maksimum 0,113 kg-N/m3.h pada tingkat pemuatan nitrogen (TPN) 0,14 kg-N/m3.h, dan WTH 12 jam nilai TPyN  maksimum 0,196 kg-N/m3.h pada TPN 0,28 kg-N/m3.h. Nilai efisiensi konversi amonia (EKA) dan efisiensi penyisihan nitrogen (EPN) maksimum pada WTH 24 jam berturut-turut adalah 82% dan 77%, sedangkan pada WTH 12 jam berturut-turut adalah 72% dan 68%. Penelitian membuktikan bahwa proses anammox dapat berlangsung stabil pada daerah tropis dengan suhu terukur 21-290C pada skala laboratorium menggunakan UASB reaktor. Kata kunci: Anammox, nitrogen, temperatur, tropis, uasb.


1997 ◽  
Vol 35 (8) ◽  
pp. 247-253 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau ◽  
Denis W. C. Chung

The effects of nine common aromatic pollutants from chemical industry on the bioactivity of anaerobic granules were examined. The granules were obtained from an upflow anaerobic sludge blanket (UASB) reactor treating wastewater containing colloidal starch. The specific methanogenic activities (SMA) of granules were measured at 37°C in serum vials using 3000 mg/l of colloidal starch as substrate, plus individual pollutants at various concentrations. The toxicity was expressed by the IR50 and IC50 values, i.e. the toxicant/biomass ratio and concentration at which levels the granules exhibited only 50% of their original bioactivities. Results showed that in general the granules exhibited mild resistance to toxicity of aromatic pollutants, probably due to the granules' layered microstructure. The toxicities, which were dependent on the nature of chemical functional group, of the aromatic pollutants were in the following descending order: cresols > phenol > hydroxyphenols/phthalate > benzoate. There was only marginal difference between the toxicity of the steric isomers. For the seven phenolic pollutants, the more hydrophobic the functional group the higher the toxicity. The granules' resistance to toxicity suggested the plausibility of anaerobic treatment of wastewater from the chemical industry.


2021 ◽  
Vol 13 (15) ◽  
pp. 8620
Author(s):  
Sanaz Salehi ◽  
Kourosh Abdollahi ◽  
Reza Panahi ◽  
Nejat Rahmanian ◽  
Mozaffar Shakeri ◽  
...  

Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.


Author(s):  
MARTHA N. CHOLLOM ◽  
SUDESH RATHILAL ◽  
FEROZ M. SWALAHA ◽  
BABATUNDE F. BAKARE ◽  
EMMANUEL KWEINOR TETTEH

1992 ◽  
Vol 26 (3-4) ◽  
pp. 877-886 ◽  
Author(s):  
T. Ohtsuki ◽  
M. Watanabe ◽  
Y. Miyaji

Two start-up methods of thermophilic UASB reactor were investigated for fast start-ups; one utilized micro-carrier as an initial support material and the other used intact mesophilic UASB granules as an initial seed. With both methods thermophilic granules having high activity were obtained in less than 3 months, even with acidified wastewater. Maximum sludge load for VFA substrate and sugar substrate were 3.2 and 0.9 kgCOD/kgVSS/day, respectively. Pre-acidogenesis was indispensable for high-performance treatment of sugar-containing substrate. It was proven that with a two-phase system sludge load could be raised to 3.0 kgCOD/kgVSS/day for sugar containing wastewaters. Some features of obtained sludge were examined, including maximum substrate utilizing activities, temperature dependence, pH dependence, and activity deterioration under lower loading conditions.


1992 ◽  
Vol 37 (1) ◽  
pp. 130-135 ◽  
Author(s):  
Jules B. van Lier ◽  
Katja C. F. Grolle ◽  
Alfons J. M. Stams ◽  
Everly Conway de Macario ◽  
Gatze Lettinga

1990 ◽  
Vol 22 (9) ◽  
pp. 167-174 ◽  
Author(s):  
S. S. Cheng ◽  
J. J. Lay ◽  
Y. T. Wei ◽  
M. H. Wu ◽  
G. D. Roam ◽  
...  

During the last two years,twenty-seven bioreactors of upflow anaerobic sludge blanket(UASB) process were constructed and operated well to treat 3,300 m3/day of winery wastewater in six winery plants in Taiwan. Each UASB reactor was installed with an internal filter and a side-armed sludge settler to separate gas-liquid-solid effectively in 127 m3 of reactor volume.These six plants established good performance of UASB process with different organic loadings depending on different characteristics of the winery wastewater. Start-up performance of the modified UASB process in four winery plants was investigated.Bioactivity of anaerobic sludge in each UASB was evaluated by means of Biochemical Methane Potential (BMP)test. Biokinetics of Monod and Haldane models were employed to interpret the different sludge characteristics in terms of gas production rate. Scanning electronic microscopy also showed different morphology of sludge granules in three UASB systems.


2018 ◽  
Vol 7 (2) ◽  
pp. 1 ◽  
Author(s):  
Ryland Cairns ◽  
Paul Mead

With a greater push to achieve waste management and renewable energy targets technologies such as anaerobic digestion (AD) have increased in popularity. One such technology option is the Upflow Anaerobic Sludge Blanket (UASB) reactor, these have been shown to be a particularly robust option for high strength organic wastewaters, such as those generated by the malted ingredient manufacturing industry. Despite their effectiveness they are reported to have lengthy and complex start ups due to the range of physiochemical and biological interactions influencing sludge blanket stability. This process can be sped up by seeding the plant from sludge from similar plants, however this is not always possible. This paper aims to investigate the start up of a full-scale mesophilic UASB treating malted ingredient wastewater that was initially seeded with a granular sludge treating dairy wastewater. Operational performance during the first 75 days of start up was comparable to that of a fully established plant with a COD removal efficiency in excess of 81.89% and a biogas methane concentration greater than 57.24%. During this period the plant remained operationally robust with the Organic Loading Rates (OLR) exuding the greatest influence on plant performance. Similar to operations during stable conditions key operational parameters such as HRT times, temperatures and pH did not exert a strong influence on the plant. 


2004 ◽  
Vol 50 (8) ◽  
pp. 185-192
Author(s):  
S. Karnchanawong ◽  
T. Sawangpanyangkura

The objective of this study was to investigate the performance of the upflow anaerobic sludge blanket (UASB) reactor as the pretreatment system for silk-dyeing wastewater. Two laboratory-scale UASB reactors, with working volume of 15.59 l, were used during May 1998 to June 1999. The actual wastewater was diluted to reduce ammonium ion toxicity on anaerobic bacteria. The experiments were conducted at the organic loading rates (OLRs) of 0.52, 1.01, 1.04, 1.54 and 2.56 kgCOD/(m3.d), treating only wastewater generated from the acid-dye process of mixed-species raw silk. It took approximately 41/2 months to reach the steady-state conditions. It was found that the COD removal was in the ranges of 74.1-85.3% , except at OLR 2.56 kgCOD/(m3.d) where efficiency significantly dropped to 55.2%. The apparent color removal was in the similar trend as COD. During the study periods, wastewater input had various color shades while the effluent generally looked pale yellowish. The methane generation rates ranged from 0.18-0.31 m3/kg COD removed, with methane composition 81.0-88.1% in biogas. The average granule size in the sludge bed had slowly increased to 0.73 mm in the last experiment. It can be concluded that the UASB reactor is suitable as a pretreatment system for silk-dyeing wastewater. An OLR of 1 kgCOD/(m3.d) and an influent concentration diluted to 2,600 mgCOD/l are suggested while COD and apparent color removal efficiency of 80% and 70%, respectively, can be expected.


1999 ◽  
Vol 40 (8) ◽  
pp. 57-62 ◽  
Author(s):  
A. Pun˜al ◽  
J. M. Lema

The start-up and optimisation of a 380 m3 UASB reactor (Up-flow Anaerobic Sludge Blanket) treating wastewater from a fish-canning factory was carried out. At the beginning of the operation the Organic Loading Rate (OLR) was 1 kg COD/m3·d. Then, the load was gradually increased in steps of 50% OLR until the final capacity of the system (4 kg COD/m3·d) was achieved. Wastewater characteristics were highly dependent on the canned product (mussel, tuna, sardines, etc.). In spite of that, a stable operation working at a hydraulic retention time (HRT) of 2 days was maintained. Total Alkalinity (TA) always presented values higher than 3 g CaCO3/l, while the IA/TA ratio (Intermediate Alalinity/Total Alkalinity) was always maintained lower than 0.3. In order to improve granulation conditions, upward velocities from 0.5 to 0.8 m/h were applied. The highest values caused the washout of non-granulated biomass from the reactor, optimum operation being achieved at an upward velocity of 0.7 m/h.


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