scholarly journals Toxicity reduction and biodegradability enhancement of cork processing wastewaters by ozonation

2013 ◽  
Vol 68 (10) ◽  
pp. 2214-2219 ◽  
Author(s):  
A. C. Gomes ◽  
L. Silva ◽  
R. Simões ◽  
N. Canto ◽  
A. Albuquerque
Keyword(s):  
Biological Treatment ◽  
Treatment Options ◽  
Oxygen Demand ◽  
Successful Implementation ◽  
Alkaline Ph ◽  
Acid Ph ◽  
Ozone Dose ◽  
Toxicity Reduction ◽  
High Oxidation ◽  
Pre Treatment

Biodegradability enhancement and detoxification of cork boiling wastewater (CBW) are required for the successful implementation of biological treatment options. We studied the possibility of achieving these goals through ozonation pre-treatment by experimenting on the effect of ozone dose and pH. The CBW used had a pH of 5.81, a chemical oxygen demand (COD) of 1,865 mg L−1, a biochemical oxygen demand (BOD5) of 498 mg L−1 and total phenol (TP) and tannin compounds concentrations of 523 and 399 mg L−1, respectively. The ozone doses ranged from 0.27 to 2.63 for the O3(applied)/COD0 ratios with samples at natural pH and set to 3.33 and 9.96. Ozonation allowed the BOD20/COD ratio (biodegradability index) to increase from 0.37 to 0.63 and a toxicity reduction from 3.08 to 1.24 TU (Microtox). The corresponding removals obtained were 15.2–62.0%, 38.4–83.2% and 56.7–92.1% for COD, TP and colour, respectively. The best outcome of ozonation pre-treatment requires O3(applied)/COD0 ratios over 1.5 and an acid pH. The increase of TP removals with ozone dose at acid pH led to biodegradability enhancement and CBW detoxification. However, for similar conditions the highest COD removals were obtained at alkaline pH due to the hydroxyl radicals’ high oxidation ability but lack of selectivity.

Influence of physico-chemical treatment on the subsequent biological process treating paper industry wastewater

2012 ◽  
Vol 66 (1) ◽  
pp. 217-223 ◽  
Author(s):  
Mouhamed el khames Saad ◽  
Younes Moussaoui ◽  
Asma Zaghbani ◽  
Imen Mosrati ◽  
Elimame Elaloui ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Chemical Treatment ◽  
Biological Treatment ◽  
Biological Process ◽  
Paper Industry ◽  
Oxygen Demand ◽  
Physico Chemical ◽  
Biodegradation Study ◽  
Pre Treatment ◽  
Industry Wastewater

The present paper presents the main results of the biodegradation study of paper industry wastewater through physico-chemical treatment. Indeed, around 60% of chemical oxygen demand (COD) removal can be achieved by electroflocculation treatment. Furthermore, a removal efficiency of the COD of almost 91% has been obtained by biological treatment, with activated amount of sludge for 24 h of culture. Concerning the physico-chemical pre-treatment of the untreated, filtered and electroflocculated rejection effluents, it has been investigated through the degradation curve of COD studies.

scholarly journals Performance of A-stage process treating combined municipal-industrial wastewater

2016 ◽  
Vol 75 (1) ◽  
pp. 228-238 ◽  
Author(s):  
Antoine Prandota Trzcinski ◽  
Chong Wang ◽  
Dongqing Zhang ◽  
Wui Seng Ang ◽  
Li Leonard Lin ◽  
...  
Keyword(s):  
Industrial Wastewater ◽  
Biological Treatment ◽  
Settling Tank ◽  
Oxygen Demand ◽  
Promising Alternative ◽  
High Loading Rate ◽  
Stage Process ◽  
Soluble Chemical Oxygen Demand ◽  
Overall Performance ◽  
Pre Treatment

A biosorption column and a settling tank were operated for 6 months with combined municipal and industrial wastewaters (1 m3/hr) to study the effect of dissolved oxygen (DO) levels and Fe3+ dosage on removal efficiency of dissolved and suspended organics prior to biological treatment. High DO (>0.4 mg/L) were found to be detrimental for soluble chemical oxygen demand (COD) removals and iron dosing (up to 20 ppm) did not improve the overall performance. The system performed significantly better at high loading rate (>20 kg COD.m−3.d−1) where suspended solids and COD removals were greater than 80% and 60%, respectively. This is a significant improvement compared to the conventional primary sedimentation tank, and the process is a promising alternative for the pre-treatment of industrial wastewater.

scholarly journals Characteristics of greywater from different sources within households in a community in Durban, South Africa

2016 ◽  
Vol 7 (4) ◽  
pp. 520-528 ◽  
Author(s):  
B. F. Bakare ◽  
S. Mtsweni ◽  
S. Rathilal
Keyword(s):  
South Africa ◽  
Biological Treatment ◽  
Treatment Process ◽  
Oxygen Demand ◽  
Successful Implementation ◽  
Environment And Public Health ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Significant Difference ◽  
Different Sources

The reuse of greywater is steadily gaining importance in South Africa. Greywater contains pollutants that could have adverse effects on the environment and public health if the water is not treated before reuse. Successful implementation of any greywater treatment process depends largely on its characteristics in terms of the pollutant strength. This study investigated the physico-chemical characteristics of greywater from different sources within 75 households in a community in Durban, South Africa. The study was undertaken to create an understanding of greywater quality from different sources within and between households. Greywater samples were collected from the kitchen, laundry and bathing facilities within each of the households. The samples were analysed for: pH, conductivity, turbidity, total solids, chemical oxygen demand (COD) and biological oxygen demand (BOD). There was a significant difference in the parameters analysed between the greywater from the kitchen compared with the greywater from the bathtub/shower and laundry. It was also observed that the characteristics of greywater from the different households varied considerably. The characteristics of the greywater obtained in this study suggest that the greywater generated cannot be easily treatable using biological treatment processes and/or technologies due to the very low mean BOD : COD ratio (<0.5).

Suitability of ozone pre-treatment for amoxicillin wastewater

2013 ◽  
Vol 68 (11) ◽  
pp. 2492-2496 ◽  
Author(s):  
O. Lefebvre ◽  
X. Shi ◽  
J. G. Tein ◽  
H. Y. Ng
Keyword(s):  
Biochemical Oxygen Demand ◽  
Biological Treatment ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Biological Degradation ◽  
Reactor Performance ◽  
Pharmaceutical Wastewater ◽  
Pre Treatment ◽  
By Products

This study deals with the ozonation of amoxicillin in real pharmaceutical wastewater and its efficacy as a pre-treatment, prior to biological degradation by a mixed culture of bacteria in a sequencing batch reactor (SBR). An ozone utilization of 0.27 g/g-COD (chemical oxygen demand) lowered the pH of the wastewater to 6.6, reduced the specific ultraviolet absorption by 43% and increased the biochemical oxygen demand (BOD) concentration by 37%. The BOD:COD ratio became equal to 0.89, making the ozonated wastewater seemingly suitable for biological treatment; however, when the ozonated effluent was fed to the SBR, the reactor performance degraded, an effect which was attributed to ozonation by-products. In conclusion, ozonation might not be a suitable pre-treatment for pharmaceutical wastewater containing amoxicillin, and biotreatment with properly acclimated biomass may be a better option for treatment of such pharmaceutical wastewater.

Characterisation of medical-waste sterilisation-plant wastewater and a preliminary study of coagulation–flocculation treatment options

2010 ◽  
Vol 62 (2) ◽  
pp. 266-272 ◽  
Author(s):  
O. Özkan ◽  
H. Mıhçıokur ◽  
Ş. T. Azgın ◽  
Ö. Özdemir
Keyword(s):  
Ferric Chloride ◽  
Ph Value ◽  
Treatment Options ◽  
Oxygen Demand ◽  
Medical Waste ◽  
Municipal Sewage ◽  
Nitrogen And Phosphorus ◽  
Aluminium Sulfate ◽  
Coagulant Dosage ◽  
Pre Treatment

Wastewater from a medical-waste sterilisation plant (MWSP) contains unique pollutants and requires on-site treatment to prevent contamination of the municipal sewage system and receiving water bodies. Therefore, to meet the prescribed discharge standards and comply with the legal regulations, pre-treatment must be applied to MWSP wastewater. In this study, the capabilities of coagulation–flocculation processes were investigated for MWSP wastewater treatment. Processes using ferric chloride, ferrous sulfate and aluminium sulfate as coagulants were characterised. During the coagulation experiments, seven different coagulant dosages and four different pH values were evaluated to determine the optimum coagulant dosage and pH value. The highest removal efficiency of chemical oxygen demand (COD) was obtained using 300 mg/L of ferric chloride at pH 10. A COD removal of about 60% as well as considerable reductions in the amounts of suspended solids, nitrogen and phosphorus were realised.

scholarly journals A pilot-scale test on the treatment of biological pretreated leachate by the synergy of ozonation-biological treatment-catalytic ozonation

2020 ◽  
Vol 26 (4) ◽  
pp. 200349-0
Author(s):  
Yuanmei Chen ◽  
Yutang Xiao ◽  
Guanping Wang ◽  
Wei Shi ◽  
Linquan Sun ◽  
...  
Keyword(s):  
Biological Treatment ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Catalytic Ozonation ◽  
Test Results ◽  
Scale Test ◽  
Pre Treatment ◽  
Discharge Criteria ◽  
Pilot Scale Test

In this pilot-scale test, the ozonation-biological treatment-catalytic ozonation system was performed to treat complex organics and highly-concentrated total nitrogen (TN) in biological pretreated incineration leachate. The test results showed that the ratio of five-day biochemical oxygen demand (BOD5) / chemical oxygen demand (COD) increased from 0.059 to 0.237, which indicated that the concentration of biodegradable COD (CODbio) increased by ozonation pre-treatment process. In addition, the TN removal mainly occurred in anaerobic zone due to direct denitrification by the activated bacteria, which were domesticated through different influent ratio. Moreover, it was necessary to add catalytic ozonation process to reach higher direct effluent discharge criteria. After 60 days repeated debugging, the removal rate of COD and TN reached 88.5% and 98.2%, respectively. Finally, the total cost of this system was ￥ 6.65 /m<sup>3</sup> ($ 0.95 /m<sup>3</sup>), which was acceptable for the treatment of biological pretreated leachate. This pilot-scale test could provide some guiding information for the treatment of leachate containing highly-concentrated TN with low CODbio/N by the composite system.

Determination of the Size Distribution of Dissolved Organics in Effluents

1973 ◽  
Vol 8 (1) ◽  
pp. 1-15 ◽  
Author(s):  
L.A. Addie ◽  
K.L. Murphy ◽  
J.L. Robertson
Keyword(s):  
Size Distribution ◽  
Biological Treatment ◽  
Oxygen Demand ◽  
Molecular Size ◽  
Monitoring Systems ◽  
Clean Surface ◽  
Sephadex Column ◽  
Dissolved Organics ◽  
Molecular Size Distribution

Abstract The importance of removing the small amounts of residual organics is increasing as the sources of clean surface water decrease. Knowledge of the nature of these soluble residual organics will be needed in order to assess the type of treatment required for their removal. Residual organics in three different biological treatment plants were analyzed and compared. An attempt was made to characterize these organics by a molecular size distribution on a Sephadex column monitored by differential ultraviolet and refractive index detectors. The organic carbon and chemical oxygen demand of the fractions collected from the column was also determined. An investigation of some of the problems inherent in the monitoring systems was conducted.

The Characteristics of Community Wastewater Biological Treatment Processes in Taiwan

1986 ◽  
Vol 18 (7-8) ◽  
pp. 289-296
Author(s):  
C. F. Ouyang ◽  
T. J. Wan
Keyword(s):  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Field Investigation ◽  
Oxidation Ditch ◽  
Trickling Filter ◽  
Rotating Biological Contactor ◽  
Treatment Processes ◽  
Treatment Characteristics ◽  
Sludge Thickening

This study investigated and compared the treatment characteristics of three different kinds of biological wastewater treatment plants (including rotating biological contactor, trickling filter and oxidation ditch) which are currently operated in Taiwan. The field investigation of this study concentrated on the following items: the performance of biological oxygen demand (BOD) and suspended solids (SS) removal; the sludge yield rate of BOD removal; the settleability of sludge solids; the properties of sludge thickening; the power consumption and land area requirement per unit volume of wastewater. Finally, based on the results of the field investigation, a comparison of the treatment characteristics of the three different biological treatment processes was evaluated.

Savings with upgraded performance through improved activated sludge denitrification in the combined activated sludge–biofilter system of the Southpest Wastewater Treatment Plant

2008 ◽  
Vol 57 (8) ◽  
pp. 1287-1293 ◽  
Author(s):  
A. Jobbágy ◽  
G. M. Tardy ◽  
Gy. Palkó ◽  
A. Benáková ◽  
O. Krhutková ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Process Efficiency ◽  
Initial Value ◽  
Initial Profile ◽  
Biological Treatment System

The purpose of the experiments was to increase the rate of activated sludge denitrification in the combined biological treatment system of the Southpest Wastewater Treatment Plant in order to gain savings in cost and energy and improve process efficiency. Initial profile measurements revealed excess denitrification capacity of the preclarified wastewater. As a consequence, flow of nitrification filter effluent recirculated to the anoxic activated sludge basins was increased from 23,000 m3 d−1 to 42,288 m3 d−1 at an average preclarified influent flow of 64,843 m3 d−1, Both simulation studies and microbiological investigations suggested that activated sludge nitrification, achieved despite the low SRT (2–3 days), was initiated by the backseeding from the nitrification filters and facilitated by the decreased oxygen demand of the influent organics used for denitrification. With the improved activated sludge denitrification, methanol demand could be decreased to about half of the initial value. With the increased efficiency of the activated sludge pre-denitrification, plant effluent COD levels decreased from 40–70 mg l−1 to &lt; 30–45 mg l−1 due to the decreased likelihood of methanol overdosing in the denitrification filter

Alkali pre-treatment of Sorghum Moench for biogas production

2013 ◽  
Vol 67 (9) ◽  
Author(s):  
Karina Michalska ◽  
Stanisław Ledakowicz
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Total Phenolic ◽  
Methane Generation ◽  
Pre Treatment ◽  
Alkali Hydrolysis ◽  
Almost All

AbstractThis work studies the influence of the alkali pre-treatment of Sorghum Moench — a representative of energy crops used in biogas production. Solutions containing various concentrations of sodium hydroxide were used to achieve the highest degradation of lignocellulosic structures. The results obtained after chemical pre-treatment indicate that the use of NaOH leads to the removal of almost all lignin (over 99 % in the case of 5 mass % NaOH) from the biomass, which is a prerequisite for efficient anaerobic digestion. Several parameters, such as chemical oxygen demand, total organic carbon, total phenolic content, volatile fatty acids, and general nitrogen were determined in the hydrolysates thus obtained in order to define the most favourable conditions. The best results were obtained for the Sorghum treated with 5 mass % NaOH at 121°C for 30 min The hydrolysate thus achieved consisted of high total phenolic compounds concentration (ca. 4.7 g L−1) and chemical oxygen demand value (ca. 45 g L−1). Although single alkali hydrolysis causes total degradation of glucose, a combined chemical and enzymatic pre-treatment of Sorghum leads to the release of large amounts of this monosaccharide into the supernatant. This indicates that alkali pre-treatment does not lead to complete cellulose destruction. The high degradation of lignin structure in the first step of the pre-treatment rendered the remainder of the biomass available for enzymatic action. A comparison of the efficiency of biogas production from untreated Sorghum and Sorghum treated with the use of NaOH and enzymes shows that chemical hydrolysis improves the anaerobic digestion effectiveness and the combined pre-treatment could have great potential for methane generation.

Sign in / Sign up

Export Citation Format

Share Document