Biological treatment and ultrafiltration of woodchip pre-hydrolysis liquor from dissolving pulp mills

2018 ◽  
Vol 33 (2) ◽  
pp. 358-364
Author(s):  
Tatiana Aurora Condezo Castro ◽  
Claudio Mudadu Silva ◽  
Jorge Luiz Colodette ◽  
Ann H. Mounteer
Keyword(s):  
Energy Demand ◽  
Biological Treatment ◽  
Black Liquor ◽  
Hydrothermal Process ◽  
Treatment Plant ◽  
Wood Chip ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Pulp Mills ◽  
Treated Effluent

Abstract Dissolving pulps could be considered as the future biorefineries, which normally generate liquor during the wood chip pre-hydrolysis (PHL). PHL has high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Mills do not have efficient means for disposal of PHL, being in general burned in the recovery boiler with a high cost due to its low consistency. The objectives of this work were to evaluate i) the biotreatability of PHL and the effects it would have on a kraft mill effluent biological treatment plant and ii) the use of ultrafiltration (UF) membrane to treat the PHL prior to biological treatment. PHL was generated into lab with a hydrothermal process and was mixed with kraft pulp mill effluent in different proportions and added to sequencing batch reactors (SBRs). The SBRs achieved high rates of COD removal (>75 %). However, treated effluent COD increased with the increase in PHL dose. This treatment using UF membranes reduced the COD load. Biotreatability of the UF permeate was higher than that of PHL. UF retentate, with 28 % of the volume and a much higher solids content than the initial PHL, would have a significantly lower evaporation energy demand if sent to the black liquor evaporators.

Mill case, simulation, and laboratory plant study of black liquor spill effects on a multiple stage biological treatment plantA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (5) ◽  
pp. 839-849 ◽  
Author(s):  
Maria Sandberg
Keyword(s):  
Biological Treatment ◽  
Black Liquor ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Short Term ◽  
Whole Plant ◽  
Term Trial ◽  
High Concentrations ◽  
Good Relation ◽  
The Impact

In this study, the impact of black liquor shocks on multiple stage biological treatment plant was studied. The tests were carried out in a lab scale plant and using a mathematical simulation model. The results showed good relation to a parallel situation at the Gruvön Mill. The MultiBio concept is persistent to short-term black liquor spills due to the design where the black liquor is diluted between every compartment. According to the lab scale trials, short-term shocks (5 and 10 h) of black liquor addition reduce bio activity in the first part of the MultiBio plant. Oxygen uptake rate and chemical oxygen demand (COD) degradation decreased during high concentrations of black liquor and increased when the black liquor concentration declined. Protozoas disappeared from compartments exposed to high concentrations of black liquor. A long-term trial encompassing 24 h of black liquor addition inhibited the COD reduction in the whole plant for several weeks.

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 < 30–45 mg l−1 due to the decreased likelihood of methanol overdosing in the denitrification filter

Purification of pulp mill condensates by an adsorptive process on activated carbon

Holzforschung ◽  
2019 ◽  
Vol 73 (6) ◽  
pp. 589-597 ◽  
Author(s):  
José A.F. Gamelas ◽  
Sofia M. Rebola ◽  
Margarita G. Evtyugina ◽  
Valdemar I. Esteves ◽  
Dmitry V. Evtuguin
Keyword(s):  
Activated Carbon ◽  
Volatile Compounds ◽  
Water Cycle ◽  
Black Liquor ◽  
Pulp Mill ◽  
Dimethyl Disulfide ◽  
Pulp Mills ◽  
Wide Range ◽  
New Process ◽  
Pseudo Second Order

Abstract In order to close the water cycle in pulp mills with condensates instead of fresh water, the malodorous/hazardous volatile compounds and colored substances have to be removed by appropriate efficient methods. In the present work, the condensate from the evaporation of black liquor (BL) from a kraft mill was purified by a batch adsorptive process by means of commercial activated carbon (AC). The effluent was found to contain a wide range of aromatic and organosulfur volatile compounds, including toluene, ethylguaicol, syringaldehyde, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), 2,3-dimethylthiophene, benzothiol and benzothiophene derivatives. Methanol was the major volatile organic component in the condensate (201 mg l−1), which was, however, poorly adsorbed on the AC surface. Aromatics and organosulfur contaminants were adsorbed almost completely in 2–5 min at 23°C under the optimized AC load (900 mg l−1). The treatment allowed the elimination of up to 99% of the obnoxious odor, color and turbidity of the condensate. The adsorption equilibrium followed the Langmuir model and the pseudo-second-order kinetics. The new process could be incorporated in the pulp mill with relatively low additional reagent costs.

Sensitivity of Effluent Variables in Activated Sludge Process

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
B Vivekanandan ◽  
K Jeyannathann ◽  
A. Seshagiri Rao
Keyword(s):  
Activated Sludge ◽  
Flow Rate ◽  
Oxygen Transfer Rate ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Maximum Flow ◽  
Activated Sludge Process ◽  
Flow Conditions ◽  
Treated Effluent ◽  
Influent Flow

Abstract The quality of a treated effluent changes when there is a sudden variation in the influent flow to the wastewater treatment plant during dry, rain, and storm weather conditions. In this study, various influent flow conditions in an activated sludge process are considered that affect the sensitivity of effluent variables such as chemical oxygen demand (COD), biological oxygen demand (BOD), nitrate nitrogen (SNO), ammonical nitrogen (SNH), and total nitrogen (TN) with respect to varying internal recycle flow rate (Qa), sludge recycle flow rate (Qr), sludge wastage flow rate (Qw) and oxygen transfer rate co-efficient of aerobic tanks (KLa(3,4,5)). The analysis has been carried out based on benchmark simulation model no.1 (BSM 1) plant layout which comprises of two models namely activated sludge model no.1 (ASM 1) and simple one dimensional (Simple 1-D) Takacs model. Based on the present analysis, it is observed that the changes in influent flow rate have larger impact on the effluent variables. This variation can be subdued by introducing additional tanks to smoothen the perturbations or using internal recycle rate from the fifth tank in order to maintain the flow around the optimal influent flow rate. The sludge wastage rate has a greater impact on all effluent variables except nitrogenous variables during maximum flow conditions.

scholarly journals Short investigation on occurrence and removal of semivolatiles during wastewater treatment processes

2021 ◽  
Vol 3 (2) ◽  
pp. 130-140
Author(s):  
Maria Diana Puiu ◽  
Keyword(s):  
Wastewater Treatment ◽  
Organic Contaminants ◽  
Biological Treatment ◽  
Organic Matter Content ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Matter Content ◽  
Physical Treatment ◽  
Dissolved Air Flotation ◽  
Treatment Processes

The food industry wastewater is known to present a high organic matter content, due to specific raw materials and processing activities. Even if these compounds are not directly toxic to the environment, high concentrations in effluents could represent a source of pollution as discharges of high biological oxygen demand may impact receiving river's ecosystems. Identifying the main organic contaminants in wastewater samples represents the first step in establishing the optimum treatment method. The sample analysis for the non-target compounds through the GC-MS technique highlights, along with other analytical parameters, the efficiency of the main physical and biological treatment steps of the middle-size Wastewater Treatment Plant (WWTP). Long-chain fatty acids and their esters were the main abundant classes of non-target identified compounds. The highest intensity detection signal was reached by n-hexadecanoic acid or palmitic acid, a component of palm oil, after the physical treatment processes with dissolved air flotation, and by 1-octadecanol after biological treatment.

scholarly journals Removal of Oxygen Demand and Acute Toxicity during Batch Biological Treatment of a Petroleum Refinery Effluent

2002 ◽  
Vol 37 (2) ◽  
pp. 399-411 ◽  
Author(s):  
Brihas P. Sarathy ◽  
Preston M. Hoy ◽  
Sheldon J.B. Duff
Keyword(s):  
Biological Treatment ◽  
Petroleum Refinery ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Refinery Effluent ◽  
Second Stage ◽  
Batch Tests ◽  
Microtox Toxicity ◽  
Petroleum Refinery Effluent ◽  
Two Stages

Abstract A survey of the process streams at an operating petroleum refinery showed that desalting water from the crude and splitter units had the highest concentrations of pollutants, and accounted for approximately one-third of the BOD and COD of the combined effluent. Combined effluent (234 ± 62 mg BOD/L, 510 ± 0 mg COD/L, and Microtox EC50 4.9 ± 0.4%) was treated using a laboratory-scale batch biological reactor. Ninety-three percent of BOD and 77% of COD were removed over the first 24 hours of biological treatment. Acute (Microtox) toxicity was reduced in two discrete stages; the first coinciding with BOD and COD removal and the second stage occurring after BOD and COD had been removed. A final EC50 value of 27.8% was achieved in batch tests. The two stages of toxicity removal correspond quantitatively to the toxicity removal observed during secondary and tertiary biological treatment at the petroleum refinery's full-scale wastewater treatment plant.

Energy efficient aeration of wastewaters from the pulp and paper industry

2010 ◽  
Vol 62 (10) ◽  
pp. 2364-2371 ◽  
Author(s):  
M. Sandberg
Keyword(s):  
Oxygen Transfer ◽  
Biological Treatment ◽  
Bubble Column ◽  
Paper Industry ◽  
Electrical Power ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Paper Mills

More than 50% of the electrical power needed to treat pulp and paper industry effluents is used for aeration in biological treatment stages. A large share of the oxygen that passes through the wastewater is not consumed and will be found in the off-gas. Energy can be saved by aerating under conditions where the oxygen transfer is most efficient, for example at low concentrations of dissolved oxygen Consider the sludge as an energy source; electricity can be saved by avoiding sludge reduction through prolonged aeration. High oxygen transfer efficiency can be retained by using the oxygen consumption of biosolids. Quantified savings in the form of needed volumes of air while still achieving sufficient COD reduction are presented. The tests have been made in a bubble column with pulp mill process water and sludge from a biological treatment plant. These were supplemented with case studies at three pulp and paper mills.

Strategies for the reduction of Legionella in biological treatment systems

2016 ◽  
Vol 74 (4) ◽  
pp. 816-823 ◽  
Author(s):  
R. Nogueira ◽  
K.-U. Utecht ◽  
M. Exner ◽  
W. Verstraete ◽  
K.-H. Rosenwinkel
Keyword(s):  
Legionella Pneumophila ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Cooling System ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Micro Particles ◽  
Treated Effluent ◽  
Wastewater Stream ◽  
Insight Into

A community-wide outbreak of Legionnaire's disease occurred in Warstein, Germany, in August 2013. The epidemic strain, Legionella pneumophila Serogruppe 1, was isolated from an industrial wastewater stream entering the municipal wastewater treatment plant (WWTP) in Wartein, the WWTP itself, the river Wäster and air/water samples from an industrial cooling system 3 km downstream of the WWTP. The present study investigated the effect of physical–chemical disinfection methods on the reduction of the concentration of Legionella in the biological treatment and in the treated effluent entering the river Wäster. Additionally, to gain insight into the factors that promote the growth of Legionella in biological systems, growth experiments were made with different substrates and temperatures. The dosage rates of silver micro-particles, hydrogen peroxide, chlorine dioxide and ozone and pH stress to the activated sludge were not able to decrease the number of culturable Legionella spp. in the effluent. Nevertheless, the UV treatment of secondary treated effluent reduced Legionella spp. on average by 1.6–3.4 log units. Laboratory-scale experiments and full-scale measurements suggested that the aerobic treatment of warm wastewater (30–35 °C) rich in organic nitrogen (protein) is a possible source of Legionella infection.

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