scholarly journals Efficient Malathion Removal in Constructed Wetlands Coupled to UV/H2O2 Pretreatment

2020 ◽  
Vol 10 (15) ◽  
pp. 5306
Author(s):  
Cinthia I. G. Cedillo-Herrera ◽  
Adriana Roé-Sosa ◽  
Aurora M. Pat-Espadas ◽  
Karina Ramírez ◽  
Jaime Rochín-Medina ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Hybrid System ◽  
Flow Reactor ◽  
Irradiation Time ◽  
Treatment Plant ◽  
Optimal Operation ◽  
Second Stage ◽  
Toc Removal ◽  
Central Composite ◽  
H2o2 Pretreatment

Intensive agriculture has led to the increasing application of pesticides, such as malathion, thus generating large volumes of untreated cropland wastewater (CropWW). In this work, a hybrid system constructed wetlands (CW) coupled in continuous with an optimized UV/H2O2 pretreatment was evaluated for the efficient removal of malathion contained in CropWW. In the first stage, 90 min UV irradiation time (UV IR) and 65 mM hydrogen peroxide (H2O2) were identified as optimal operation parameters through a central composite design. The second stage consisted of CW planted with Phragmites australis collected from the agricultural discharge area and operated as a piston flow reactor. Furthermore, CW hydraulic residence times (HRT) of 1, 2 and 3 days, including hydraulic coupling, were evaluated. The removal efficiencies obtained in the first stage (UV/H2O2) were 94 ± 2.5% of malathion and 45 ± 2.5% of total organic carbon (TOC). In stage two (CW) 65 ± 9.6% TOC removal was achieved during the first 17 days, from which around 24% was associated to the biosorption of malathion byproducts. Subsequently, and until the operation ends, CW removed about 80% of TOC for 2 and 3 days HRT, with no significant differences (p > 0.2), which is higher than those reported in several studies involving only advanced oxidation processes (AOP) with UV IR times above 240 min and even for systems using catalysts. The results obtained indicate that the system UV/H2O2-CW is a technically suitable option for the treatment of CropWW with a high content of malathion mainly found in developing countries. Moreover, the hybrid system proposed also represent significant reduction in the size of the treatment plant.

Performance of hybrid small wastewater treatment system consisting of jet mixed separator and rotating biological contactor

1997 ◽  
Vol 35 (6) ◽  
pp. 63-70 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Yoshihiko Iwasaki
Keyword(s):  
Wastewater Treatment ◽  
Electric Power ◽  
Hybrid System ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Treatment System ◽  
Municipal Wastewater Treatment ◽  
Wastewater Treatment System ◽  
Pre Treatment ◽  
Organic Particles

This paper describes a pilot plant study on the performance of a hybrid small municipal wastewater treatment system consisting of a jet mixed separator(JMS) and upgraded RBC. The JMS was used as a pre-treatment of the RBC instead of the primary clarifier. The treatment capacity of the system was fixed at 100 m3/d, corresponding to the hydraulic loading to the RBC of 117 L/m2/d. The effluent from the grid chamber at a municipal wastewater treatment plant was fed into the hybrid system. The RBC was operated using the electric power produced by a solar electric generation panel with a surface area of 8 m2 under enough sunlight. In order to reduce the organic loading to the RBC, polyaluminium chloride(PAC) was added to the JMS influent to remove the colloidal and suspended organic particles. At the operational condition where the A1 dosage and hydraulic retention time of the JMS were fixed at 5 g/m3 and 45 min., respectively, the average effluent water quality of hybrid system was as follows: TOC=8 g/m3, Total BOD=8 g/m3, SS=8 g/m3, Turbidity=6 TU, NH4-N=7 g/m3, T-P=0.5 g/m3. In this operating condition, electric power consumption of the RBC for treating unit volume of wastewater is only 0.07 KWH/m3.

Nitrogen removal from digester supernatant via nitrite - SBR or SHARON?

2003 ◽  
Vol 48 (8) ◽  
pp. 9-18 ◽  
Author(s):  
C. Fux ◽  
K. Lange ◽  
A. Faessler ◽  
P. Huber ◽  
B. Grueniger ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Flow Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Full Scale ◽  
Municipal Wastewater Treatment ◽  
Nitrite Oxidation ◽  
High Concentrations ◽  
Nitrite Nitrate ◽  
Sharon Process

Separate biological elimination of nitrogen from the digester supernatant of a municipal wastewater treatment plant (WWTP) was investigated in pilot and full-scale plants. Denitrification mainly via nitrite was achieved in a sequencing batch reactor (SBR) and a continuous flow reactor (CSTR or SHARON). Suppression of nitrite oxidation in the SBR was feasible at short aerobic/anaerobic intervals allowing for immediate denitrification of the produced nitrite. Nitrate production could also be stopped by exposing the biomass to anaerobic conditions for 11 days. Temporarily high concentrations (up to 80 gNH3-Nm-3) of free ammonia could not be considered as the major reason for inhibiting nitrite oxidation. In a full-scale SBR plant 90% of the nitrogen load was denitrified in a total hydraulic retention time (HRT) of 1.6 days and with a sludge age between 15 and 20 days. Ethanol and methanol were used for denitrification. The specific average substrate consumption was 2.2 gCODdosedg-1Nremoved with an effective biomass yield of 0.2 gCODbiomassg-1CODdosed. No dosing with base was required. In the SHARON process full nitrogen elimination was achieved only with a total HRT greater than 4 days at 29°C. The overall costs were estimated at €1.4 kg-1Nremoved for the SBR and €1.63 kg-1Nremoved in SHARON mode, respectively. The SHARON process is simple in operation (CSTR) but the tank volume has to be significantly greater than in SBR.

BIOLOGICAL TREATABILITY OF AMINE LADEN REFINERY WASTEWATER

1994 ◽  
Vol 30 (3) ◽  
pp. 21-28 ◽  
Author(s):  
Nyuk-Min Chong
Keyword(s):  
Activated Sludge ◽  
Biological Treatment ◽  
Flow Reactor ◽  
Treatment Plant ◽  
Petroleum Products ◽  
System Stability ◽  
Refinery Wastewater ◽  
Continuous Flow Reactor ◽  
Biological Treatability

Mono- and Di- hydroxyl amines are used in the desulfuration processes for refined petroleum products. The refinery wastewater treatment plant may be shocked by amine laden wastewater periodically, bringing operation difficulties to the biological treatment units. Data on the treatability, shock load behaviour and on long term system stability of biological treatment of amines are therefore required. Shake-flask test results showed that pure diethanol amine and diisopropanol amines have characteristics of persistent compounds. Each of the two compounds has a prolonged lag time when first inoculated with indigenous activated sludge. Acclimated activated sludge in a continuous flow reactor treated a feed of ethanol amine with a 93 percent COD removal and a 98 percent nitrification, but the system was unstable because amine caused a bulking sludge. By physical retention of the activated sludge, 550 mg/l influent COD of amines was treated to m1 average 50 mg/l effluent COD. Sludge yield was approximately 0.26 mg MLSS per mg COD. The activated sludge system withstood a chm1ge of feed to a real refinery wastewater laden with the; amine. A mean cell residence time above five (5) days should be maintained for safe treatment of; amine.

scholarly journals Rapid and Mild Synthesis of Au-NHC Complexes in a Simple Two-Phase Flow Reactor

2021 ◽  
Author(s):  
Helgi Freyr Jónsson ◽  
Anne Fiksdahl ◽  
Andrew Harvie
Keyword(s):  
Two Phase Flow ◽  
Flow Reactor ◽  
Direct Synthesis ◽  
Phase Flow ◽  
Rapid Synthesis ◽  
Two Phase ◽  
Second Stage ◽  
Mild Conditions ◽  
Common Problems

<p>We describe a simple two-phase flow reactor which allows for the efficient and rapid synthesis of several Au(I)-NHC complexes under mild conditions, with minimal workup, and avoiding common problems with decomposition to Au(0). An optional second stage allows for direct synthesis of Au(III)-NHC complexes, without isolation of the Au(I)-NHC intermediate.</p>

scholarly journals Optimization of Waste Cooking Oil’s FFA as Biodiesel Feedstock

Teknomekanik ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 14-21
Author(s):  
Sri Rizki Putri Primandari ◽  
Andril Arafat ◽  
Harumi Veny
Keyword(s):  
Irradiation Time ◽  
Control Variable ◽  
Waste Cooking Oil ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Cooking Oil ◽  
Biodiesel Feedstock ◽  
Temperature Irradiation ◽  
Acid Esterification ◽  
Central Composite

Waste cooking oil has high Free Fatty Acid (FFA). It affected on decreasing a biodiesel production. FFA reduction is one of important processes in biodiesel production from waste cooking oil. Thus, this study aimed to examine the optimum condition in FFA reduction. The process is assisted by using ultrasonic irradiation on acid esterification. Variables of the process are acid concentration, molar ratio of methanol and oil, and irradiation time. Meanwhile temperature irradiation on 45oC is a control variable. Process optimization is conducted by Response Surface Methodology (RSM) with Central Composite Design (CCD). The optimum conditions of response were 7.22:1 (methanol to oil molar ratio), 0.92% wt H2SO4, 26.04 minutes (irradiation time), and 45oC (irradiation temperature). Ultrasonic system reduced FFA significantly compared to conventional method.

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.

scholarly journals Effectiveness of wastewater treatment from the fruit and vegetable industry in the vertical flow-type constructed wetlands

2018 ◽  
Vol 44 ◽  
pp. 00149 ◽  
Author(s):  
Monika Puchlik
Keyword(s):  
Wastewater Treatment ◽  
Organic Compounds ◽  
Constructed Wetlands ◽  
Total Nitrogen ◽  
Organic Substance ◽  
Treatment Plant ◽  
Phosphorus Compounds ◽  
Vertical Flow ◽  
Fruit And Vegetable ◽  
Nitrogen And Phosphorus

The purpose of the work was to determine the effectiveness of wastewater treatment from the fruit and vegetable industry in constructed wetlands supported by a bio-preparation. An increase in the efficiency of organic substance purification expressed as BOD5 and COD by 8% in deposit with the addition of bio-preparation in relation to the control bed (without the addition of bio-preparation), was found. The efficiency of the total suspension, total nitrogen and total phosphorus increased respectively by 19.5%, 10%, and 27% in relation to the bed without addition of bio-preparation. Constructed wetlands treatment plant ensures high removal of organic compounds expressed as BOD5 and COD, as well as guarantees reduction in the concentration of nitrogen and phosphorus compounds.

Selection of the surface water treatment technology – a full-scale technological investigation

2014 ◽  
Vol 71 (4) ◽  
pp. 638-644 ◽  
Author(s):  
Alina Pruss
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Full Scale ◽  
Treatment Technology ◽  
Surface Water Treatment ◽  
Second Stage ◽  
Third Stage ◽  
Water Treatment Technology

A technological investigation was carried out over a period of 2 years to evaluate surface water treatment technology. The study was performed in Poland, in three stages. From November 2011 to July 2012, for the first stage, flow tests with a capacity of 0.1–1.5 m3/h were performed simultaneously in three types of technical installations differing by coagulation modules. The outcome of the first stage was the choice of the technology for further investigation. The second stage was performed between September 2012 and March 2013 on a full-scale water treatment plant. Three large technical installations, operated in parallel, were analysed: coagulation with sludge flotation, micro-sand ballasted coagulation with sedimentation, coagulation with sedimentation and sludge recirculation. The capacity of the installations ranged from 10 to 40 m3/h. The third stage was also performed in a full-scale water treatment plant and was aimed at optimising the selected technology. This article presents the results of the second stage of the full-scale investigation. The critical treatment process, for the analysed water, was the coagulation in an acidic environment (6.5 &lt; pH &lt; 7.0) carried out in a system with rapid mixing, a flocculation chamber, preliminary separation of coagulation products, and removal of residual suspended solids through filtration.

Removal of organics from wastewater using a novel biological hybrid system

2001 ◽  
Vol 43 (1) ◽  
pp. 321-326 ◽  
Author(s):  
H. A. Al-Sharekh ◽  
M. F. Hamoda
Keyword(s):  
Activated Sludge ◽  
Hybrid System ◽  
Treatment Plant ◽  
Minor Effect ◽  
Loading Rates ◽  
Innovative System ◽  
The Mean ◽  
Percentage Removal ◽  
Removal Efficiencies ◽  
A Minor

This paper summarizes the results obtained using the hybrid aerated submerged fixed-film (HASFF) process. HASFF is an innovative system comprising a four-compartment reactor having an array of fixed ceramic plates maintained under diffused aeration to support attached biomass, with activated sludge recycle to promote suspended growth in the reactor. Wastewater from a municipal treatment plant was fed to the reactor and its activated sludge was used for recycling in the hybrid system. Four pilot units were operated in the plant at various hydraulic retention times, HRTs (2, 4, 6 and 8 h), using primary-settled wastewater under organic loading rates up to 0.7 g BOD/gMLTVS · d. Data obtained showed that the overall BOD percentage removal efficiencies were consistently above 94.0% at all HRTs including the 2 hours while the COD percentage removal efficiencies ranged between 65.7–76%. The effluent's mean filtered BOD concentration ranged between 4.5–7.5 mg/l whereas the mean filtered COD concentration ranged between 70.0–89.6 mg/l. Increasing the hydraulic loading rate by four-folds from 0.08 to 0.32 m3/m2 · d had a minor effect on the unit's BOD and COD percentage removal efficiencies indicating a robust biological process that is resilient to hydraulic shock loads, thereby offering a viable upgrading option.

Dosing ratios for reduced bromate formation by dissolved ozone dosing

2005 ◽  
Vol 5 (5) ◽  
pp. 35-40
Author(s):  
A.W.C. van der Helm ◽  
P.W.M.H. Smeets ◽  
E.T. Baars ◽  
L.C. Rietveld ◽  
J.C. van Dijk
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Water Flow ◽  
Flow Reactor ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Limiting Factor ◽  
Drinking Water Treatment Plant ◽  
Side Stream

Bromate formation experiments were carried out in a 100 l/h bench-scale dissolved ozone plug flow reactor (DOPFR) with natural filtered water from the drinking water treatment plant Leiduin of Amsterdam Water Supply at gross ozone dosages of 0.7–3.4 mg/l. In the DOPFR, ozone is dosed by intensively mixing a dissolved ozone water flow (side stream) with a test water flow (mainstream). The side stream is pre-treated to remove bromide and DOC and to lower the pH. For full-scale application of the DOPFR concept, it is most cost effective to apply the smallest possible side stream. This research is done to establish the effect of decreasing the ratio of the dissolved ozone side stream to the mainstream from 1:10 to 1:25, by increasing the ozone concentration and decreasing the flow of the side stream. The results show that the dosing ratio has no influence on the bromate formation in the ozone dosing range of 0.7–1.4 mg/l. The gross ozone dosages that are currently applied at the drinking water treatment plant Leiduin are 0.8–1.0 mg/l. This means that for application of dissolved ozone dosing at Leiduin the amount of ozone that can be dissolved in the side stream will be the limiting factor for the minimal flow of the dissolved ozone side stream.

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