Heterogeneous Photocatalytic Disinfection of Wash Waters from the Fresh-Cut Vegetable Industry

2008 ◽  
Vol 71 (2) ◽  
pp. 286-292 ◽  
Author(s):  
MARÍA VICTORIA SELMA ◽  
ANA ALLENDE ◽  
FRANCISCO LÓPEZ-GÁLVEZ ◽  
MARÍA ÁNGELES CONESA ◽  
MARÍA ISABEL GIL
Keyword(s):  
Oxygen Demand ◽  
Physicochemical Characteristics ◽  
Heterogeneous Photocatalysis ◽  
Wash Water ◽  
Processing Plant ◽  
Photocatalytic Disinfection ◽  
Filtration System ◽  
Physico Chemical ◽  
Photocatalytic System ◽  
Fresh Cut

The effectiveness of photocatalytic disinfection for control of natural and potentially pathogenic microflora in wash waters used for fresh-cut vegetables was evaluated. Wash waters for lettuce, escarole, chicory, carrot, onion, and spinach from a fresh-cut vegetable processing plant were treated with a titanium dioxide (TiO2) photocatalytic system. The vegetable wash waters were impelled out with a pump at a flow rate of 1,000 liters/h and conducted through a stainless steel circuit to the filtration system to reach the TiO2 photocatalyst fiber, which was illuminated with a 40-W UV-C lamp. The microbial and physico-chemical qualities of the wash water were analyzed. Heterogeneous photocatalysis was an effective disinfection method, reducing counts of bacteria, molds, and yeasts. Most of the treated wash waters had total bacteria reductions of 4.1 ± 1.3 to 4.8 ± 0.4 log CFU/ml after 10 min of treatment when compared with untreated water. Higher decontamination efficacy was observed in carrot wash water (6.2 ± 0.1-log reductions), where turbidity and organic matter were lower than those in the wash waters for other vegetables. The tested heterogeneous photocatalytic system also was effective for reducing water turbidity, although chemical oxygen demand was unaffected after the treatments. The efficacy of the photocatalytic system for reducing microbial load depended on the physicochemical characteristics of the wash water, which depended on the vegetable being washed. The conclusions derived from this study illustrate that implementation of a heterogeneous photocatalytic system in the fresh-cut vegetable washing processes could allow the reuse of wash water.

Physico-chemical monitoring of biodegradation of furfural from oil industry effluents from the Arzew refinery (Oran) Algeria

2022 ◽  
Vol 11 (6) ◽  
pp. 667-675
Author(s):  
Amina-Afaf MOUFFAK
Keyword(s):  
Biological Treatment ◽  
Oxygen Demand ◽  
Oil Industry ◽  
Petroleum Products ◽  
Wash Water ◽  
Treatment Level ◽  
Chemical Monitoring ◽  
Pollution Problem ◽  
Physico Chemical ◽  
Direct Discharge

Furfural is one of the petroleum products posing a potential danger to the environment and human health. However, the decontamination of these pollutants released into the environment is primarily governed by biodegra-dation processes. This study is based on biodegradation kinetics at increasing concentrations of furfural by natural mixed culture in order to assess the potential of this process in the elimination of furfural from petrochemical effluents from the ARZEW refinery. This biodegradation was measured through physicochemical parameters such as pH, electrical conductivity, con-centration of hydrocarbons, the chemical oxygen demand (COD), biochemi-cal oxygen demand (BOD5) and the concentration of furfural. The results obtained show at a concentration of 250ppm of injected furfural: a decrease in pH 4.9 and an increase in other parameters (conductivity 3450 μS.cm-1, HC 102 mg / l; furfural 210 ppm, COD 327mg / l, BOD5 98mgO2 / l. The study findings indicated that the injection of these effluents with concentrations greater than 180 ppm leads to values of pH, EC, HC, Furfural, COD, BOD5 which do not comply with direct discharge standards and disrupt biological treatment. The high levels of furfural not only cause a pollution problem but can also disrupt the functioning of bacteria at the biological treatment level. Therefore, dilution with the filtration wash water before switching to biologi-cal treatment is recommended in order to reduce the concentrations below 180 ppm.

scholarly journals Seasonal Variations in Physico-Chemical Characterstics of Tapi Estuary in Hazira Industrial Area

Our Nature ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 249-257 ◽  
Author(s):  
M Gadhia ◽  
R Surana ◽  
E Ansari
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Industrial Effluents ◽  
Total Solid ◽  
Industrial Area ◽  
Physicochemical Characteristics ◽  
Industrial Complex ◽  
Chemical Parameters ◽  
Physico Chemical

Present study was carried out to determine the important physico chemical parameters of water of Tapi estuary in Hazira industrial area. Tapi estuary receives the inputs of organic matter and nutrients coming from the domestic wastewater discharges from Surat City, a textile hub as well as industrial effluents from Hazira, a major industrial Complex of Gujarat, India. Uncontrolled discharges of domestic wastes and industrial effluents have affected the estuary. Present study was carried out from June - 2011 to May 2012 to study the impacts of uncontrolled discharges on physicochemical characteristics of water. Samples were collected monthly in the morning during low tide to determine the important physico chemical parameters Viz. Turbidity, conductivity, total solid, total dissolved solid, salinity, pH, dissolved oxygen, BOD, COD, Calcium, chloride, sodium , potassium and nutrients like nitrate, nitrite and phosphate. Dissolved oxygen was found extremely low during the study period. High biochemical oxygen demand (BOD) and Chemical Oxygen demand (COD) showed that the water quality of estuary has been affected by industrial and domestic effluents. DOI: http://dx.doi.org/10.3126/on.v10i1.7811

scholarly journals Fresh-cut Produce Wash Water Reuse Affects Water Quality and Packaged Product Quality and Microbial Growth in Romaine Lettuce

HortScience ◽  
2007 ◽  
Vol 42 (6) ◽  
pp. 1413-1419 ◽  
Author(s):  
Yaguang Luo
Keyword(s):  
Water Quality ◽  
Chemical Oxygen Demand ◽  
Product Quality ◽  
Water Reuse ◽  
Microbial Growth ◽  
Oxygen Demand ◽  
Wash Water ◽  
Clean Water ◽  
Romaine Lettuce ◽  
Fresh Cut

Washing is a critical step for maintaining quality and safety of fresh-cut produce during its preparation and is often the only measure taken to reduce microbial populations and remove tissue fluids. However, little is known about the effect of washing method on water quality or its consequence on microbial growth and finished product quality. This study was conducted to evaluate the effect of wash water reuse on changes in water quality and its subsequent effect on microbial growth and product quality of packaged fresh-cut Romaine lettuce (Lactuca sativa L.). Romaine lettuce leaves were sliced and washed in water with chemical oxygen demand levels ranging from 9.8 mg·L−1 (fresh water) to 1860.5 mg·L−1 (reused water) and product-to-water ratios of 1:20 and 1:150. The washed samples were dried and placed into packages prepared from films with an oxygen transmission rate of 8.0 pmol·s−1·m−2·Pa−1 and stored at 5 °C for 14 days. Microbial growth and product quality were monitored at days 0, 4, 8, 11, and 14 during storage. Results indicate that as the quantity of lettuce dipped in 40 L of water increased from 2.0 kg to 18.0 kg, water chemical oxygen demand increased from 124 mg·L−1 to 1721 mg·L−1 and biological oxygen demand increased from 140 mg·L−1 to 526 mg·L−1, whereas free and total chlorine levels declined from 151.5 mg·L−1 to 4.7 mg·L−1 and from 171 mg·L−1 to 31.5 mg·L−1, respectively. Thoroughly washed lettuce in clean water with a small product-to-water ratio had the least off-odor development. Samples without wash treatment and those washed with reused water had 0.8 to 1.6 log cfu·g−1 higher populations of lactic acid bacteria than those washed with clean water at the end of storage.

DECOLOURIZATION AND COD REMOVAL OF WASEWATER FROM ETHANOL PRODUCTION PROCESS FROM MOLASSES BY COAGULANTION USING INORGANIC ALUM

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le
Keyword(s):  
Ethanol Production ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Biological Methods ◽  
Treatment Step ◽  
Main Material

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.

scholarly journals Application of Ozone and Oxygen to Reduce Chemical Oxygen Demand and Hydrogen Sulfide from a Recovered Paper Processing Plant

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Patricia A. Terry
Keyword(s):  
Hydrogen Sulfide ◽  
Chemical Oxygen Demand ◽  
Contact Time ◽  
Oxygen Demand ◽  
Gas Production ◽  
Injection System ◽  
Processing Plant ◽  
Short Contact Time ◽  
Production Of Hydrogen ◽  
Fox River

A pilot study was performed at the Fox River Fiber recovered paper processing company in DePere, Wisconsin, to determine the extent to which injection of oxygen and ozone could reduce the high chemical oxygen demand, COD, in the effluent and the effectiveness of the ozone/oxygen stream in suppressing production of hydrogen sulfide gas in downstream sewage lines. Adaptive Ozone Solutions, LLC, supplied the oxygen/ozone generation and injection system. Samples were analyzed both before and after oxygen/ozone injection. Hydrogen sulfide gas was continuously monitored at sewer stations downstream of Fox River Fiber. Results showed that with a very short contact time, effluent COD was reduced by over 15%. A simple kinetic model predicts that a contact time of fewer than 30 minutes could reduce COD by as much as 60%. In addition, downstream hydrogen sulfide gas production in the sewage mains was also better controlled, such that costly Bioxide applications could be reduced.

PHYSICO-CHEMICAL AND SOME HEAVY METALS CONCENTRATION ANALYSES ON THREE COMMON SPECIES OF FISH IN TUNGAN KAWO RESERVOIR KONTAGORA, NIGER STATE, NIGERIA

2021 ◽  
Vol 5 (1) ◽  
pp. 223-232
Author(s):  
Mohammed Jr. Kinta ◽  
A. V. Ayanwale ◽  
U. N. Keke ◽  
Y. I. Auta ◽  
B. S. Adama ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Oxygen Demand ◽  
Aquatic Organisms ◽  
Common Species ◽  
Human Consumption ◽  
Long Term Effects ◽  
Aquatic Life ◽  
Physico Chemical ◽  
Fish Samples

Developing countries like Nigeria are faced with increased in generation of domestic, industrial and agricultural wastes, with a large percentage moving. This study evaluates the physico-chemical and some heavy metals concentration in three common species of fish from Tungan Kawo reservoir Kontagora, Nigeria; using standard methods between (July 2018 – February 2019); at four different sampling stations of human activities on the water. Five heavy metals were evaluated (Lead, Copper, Manganese, Iron and Chromium) in the fish samples. Phosphate (0.4 – 2.5) mg/L, Nitrate (3.2 – 7.5) mg/L, Temperature (27 – 32.4) 0C, Dissolved Oxygen (2.4 – 5.2 mg/L), Conductivity (81 – 125 µS/cm), Biochemical Oxygen Demand (1.9 – 4.4 mg/L), Alkalinity (mg/L) and Total Dissolved Solids (117 – 198) ppm were within the standard for drinking water and survival of fish.  However, the pH (6.3 – 9.8) was above the standard for NIS and WHO drinking water but can support aquatic life. Iron (0.64 ± 0.072 mg/kg) was the most highly concentrated in Synodontis clarias while lead (0.01 ± 0.013 mg/kg) was the lowest in Oreochromis niloticus and Coptidon zillii (formerly Tilapia zillii. This current finding indicates that the water is safe for both aquatic life and domestic purpose but not suitable for direct human consumption without being properly treated. However, there is the need for regular monitoring of the heavy metals load in this water body and the aquatic organisms because of the long term effects

scholarly journals Evaluation of Physicochemical Characteristics of Surface Water from Orashi River, Rivers State, Southern Nigeria

2021 ◽  
Vol 8 (2) ◽  
pp. 105-122
Author(s):  
Onisogen Simeon Edori ◽  
Enize Simeon Edori
Keyword(s):  
Suspended Solids ◽  
Oxygen Demand ◽  
Physicochemical Characteristics ◽  
Total Dissolved Solids ◽  
Standard Laboratory ◽  
Mean Values ◽  
Drinking Purposes ◽  
The Mean ◽  
One Year ◽  
Rivers State

Water samples were collected from four different stations bimonthly from the Orashi River for a period of one year. The samples were collected from the shores of selected communities along the Engenni axis of the river. The samples were treated and analyzed according to standard laboratory and analytical procedures for water physicochemical parameters. The parameters examined were pH, Salinity, chlorides (Cl-), Conductivity, total dissolved solids (TDS), total suspended solids (TSS) turbidity, temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrates (NO3-), sulphate (SO42-) and phosphates (PO43-). The results showed that the mean values of the evaluated parameters were; pH (6.91±0.11), salinity (9.79±0.27 mg/L), Cl (6.25±0.25 mg/L), conductivity (29.66±1.20 µS/cm), TDS (17.66±2.08 mg/L), TSS (16.83±1.15 mg/L), turbidity (11.84±1.50 mg/L), temperature (28.16±0.12 oC), DO (5.91±0.18 mg/L), BOD (7.30±0.60 mg/L), COD (9.41±0.70 mg/L), NO3- (3.42±0.27 mg/L), SO42- (1.15±0.56 mg/L) and PO43- (15.65±5.76 mg/L). The results of the different parameters showed that all of them fall within the WHO acceptable limit except turbidity, DO and BOD that were not within the recommended range, then COD and phosphates that were either within or above the recommended values at different instances. Based on the findings of this work, the water may not be particularly suitable for drinking purposes, but can be used for other household functions that do not require consumption and also for irrigation. Keywords: water, physicochemical property, human activity, environment, contamination

scholarly journals Physicochemical Characteristics of the Okomu Wetland, Edo State, Nigeria

2020 ◽  
Vol 4 (2) ◽  
pp. 398-410
Author(s):  
A.E. Ogbeibu ◽  
S.I Ehiorobo
Keyword(s):  
Physicochemical Parameters ◽  
Forest Canopy ◽  
Oxygen Demand ◽  
Water Quality Assessment ◽  
Organic Pollution ◽  
Physicochemical Characteristics ◽  
Water Bodies ◽  
Temporary Ponds ◽  
Forested Wetland ◽  
Sampling Protocols

Water quality assessment was carried out within the 202 km2 Okomu National Park located within the 1,082km2Okomu Forest Reserve between January 2017 and December 2018. Water sampling was carried in ten compartments of approximately 1.6km2 each, covering Ponds, Stream and River, based on easy accessibility. No such study has been carried out for the Okomu Wetlands in the past three decades. Sampling protocols, laboratory analysis and quality control/quality assurance measures followed standard procedures. All physicochemical parameters showed significant (P < 0.001) spatial variations. The maximum and minimum values obtained for physicochemical parameters of the Okomu Wetland are 23.6 and 38.0°C air temperature; 21.0 – 38°C water temperature; 0.15 – 1.02m water level; 16.7 – 150.7mg/l total dissolved Solids (TDS); 0.5 – 18.8mg/l total suspended Solids (TSS); 0.2 – 14.8mg/l turbidity; 40. 0 – 307.4µS/cm electrical conductivity (EC); 4.4 – 6.7 pH; 0.02 – 0.14mg/l salinity; 0.7 – 5.5mg/l dissolve oxygen (DO); 0.5 – 3.8mg/l biochemical oxygen demand (BOD); 1.5 – 120.2mg/l chemical oxygen demand (COD); 23.8 – 593.6mg/l bicarbonates (HCO3); 69.9 – 245.3mg/l Chlorine (Cl); 0.02 – 0.59mg/l nitrite (NO2); 0.11 – 2.34mg/l nitrate (NO3); 0.04 – 2.11mg/l ammonium-nitrogen (NH4N); 0.05 – 2.96mg/l sulphate (SO4); 0.09 – 9.2mg/l phosphorus (P); 0.20 – 2.72mg/l sodium (Na), 0.03 – 1.32mg/l potassium (K); 0.88 – 5.88mg/l calcium (Ca); 0.13 – 3.1mg/l magnesium (Mg); 5.8 – 18.9mg/l iron (Fe); 0.04 – 1.1mg/l manganese (Mn); 0.02 – 0.09mg/l copper (Cu); 0.93 – 6.0mg/l zinc (Zn); 0.01 – 2.9mg/l lead (Pb); 0.01 – 0.18mg/l cadmium (Cd); 0.06 – 4.0mg/l chromium (Cr); 0.01 – 0.15mg/l nickel (Ni); 0.01 – 11mg/l vanadium (V). Air and water temperatures were mostly influenced by forest canopy cover. pH levels indicate that the water bodies within the forested wetland are slightly acidic. Higher DO values were recorded in the Arhakhuan Stream and Okomu River (Agekpukpu and Iron bridge) than in the temporary ponds. BOD levels of greater than 1mg/l were observed which is indicative of slight levels of organic pollution. Higher concentrations of TDS, TSS, turbidity, EC, Colour, HCO3, NH4N, NO2, NO3, P, Na, K, Ca Mg and heavy metals were recorded in the temporary ponds than in the Stream and River. Research on water bodies within wetlands should be carried out routinely in order to monitor changes in the water conditions that could occur overtime whether natural or anthropogenic. This becomes even more pertinent in the light of glaring impacts of climate change and increasing environmental modifications.

scholarly journals STUDY OF PHYSICOCHEMICAL CHARACTERISTICS OF BIRD VALLEY’S QUARRY WATER PCMC, MAHARASHTRA

2021 ◽  
Vol 6 (2) ◽  
pp. 18-24
Author(s):  
Shashikala Kokcha ◽  
Harsha Chatrath
Keyword(s):  
Seasonal Variations ◽  
Water Samples ◽  
Physicochemical Characteristics ◽  
Point Of View ◽  
Present Condition ◽  
Chemical Parameters ◽  
Standard Methods ◽  
Drinking Purposes ◽  
Physico Chemical ◽  
Methods And Techniques

Purpose of the study: The purpose of this study is to make sure that the Bird valley’s quarry water is suitable for drinking purposes or not and to monitor the seasonal variations in the physico-chemical parameters of this quarry water. Methodology: Water samples from the quarry were collected in clean and sterilized polyethylene bottles. Water samples were collected from different points and mixed together to get an integrated sample. Some of the selected physico-chemical parameters of the quarry water have been analyzed. Results were compared with standard limits of IS: 10500-2012. All the parameters were analyzed in the laboratory by using standard methods and techniques. Main Findings: As per the obtained results this quarry water contains a very large number of Coliforms detected in the months of September and December and in June month Coliform count was 33 CFU/ml. This overall result for coliform is making this quarry water unfit for domestic purposes. Applications of this study: This study helps us to understand the current condition of this quarry water and also enables us to know whether the quarry water is fit for drinking purposes. It also enables us to know whether this quarry water can be used for domestic purposes after the treatment. Novelty/Originality of this study: Bird valley’s quarry water has not been analyzed from this point of view till date. This study will help us to understand the present condition of the water.

scholarly journals SEASONAL VARIATIONS OF THE ZAPADNA MORAVA RIVER WATER QUALITY

2021 ◽  
Author(s):  
Nebojša Đ. Pantelic ◽  
◽  
Jana S. Štrbacki ◽  
Goran Markovic ◽  
Jelena B. Popovic-Đorđevic ◽  
...  
Keyword(s):  
Surface Water ◽  
Oxygen Demand ◽  
Nutrient Content ◽  
Ammonium Ion ◽  
Polluted Water ◽  
Chemical Parameters ◽  
Chemical Status ◽  
Physico Chemical ◽  
Morava River

The water samples collected from four localities of the middle course of the Zapadna Morava River during 2020 were analyzed via the selected physico-chemical parameters with the aim to estimate the quality of surface water. According to the results of selected physico-chemical parameters (pH, conductivity, dissolved oxygen, chemical oxygen demand, biochemical oxygen demand), analyzed surface water show a good chemical status, while the values of nutrient content (nitrate, nitrite, ammonium ion, total phosphorus) indicated the poor chemical status especially at the locality 4 probably due to the outflow of wastewater from the city of Čačak as well as from the influence of the polluted water of the Čemernica River.

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