Washing Wastewater Research Articles

Boundary flux modelling of ceramic tubular microfiltration towards fouling control and performance maximization for olive-oil washing wastewater treatment and revalorization

In the context of the Circular Economy concept, nowadays widely accepted as vital for present and future sustainable production, olive oil industry must be ready to evolve into a whole environmentally respectful process, and this irretrievable includes an adequate and tailored treatment of the effluents that are generated in olive mills, such as current two-phase olive-oil washing wastewater (OOWW). The treatment together with antioxidant fraction recovery by microfiltration (MF) is proposed in this research. In particular, the key operating input factors of MF for the treatment and valorization of OOWW were analyzed and modelled by the boundary flux theory. This permitted to achieve the prediction, maximization and control of the steady-state permeate flux of the membrane, critical for successful scale up of the process, reaching up to 10,596.5 L/h m² under appropriate operating conditions comprising pressure of 8.5 bar, tangential velocity of 4.2 L/min, raw pH0 equal to 5.13 and ambient temperature of 25 °C. These results highlight a reduction in energy consumption by running the MF process under ambient temperature and raw pH of the effluent, and this is the key to allow the cost-effectiveness of the proposed MF process at industrial scale in the olive mills.

Reclamation of actual automobile wash wastewater combined with energy recovery in 3D- microbial fuel cell packed with acid-activated multi walled carbon nanotubes coated anode

Microbial fuel cell (MFC) is a modern technique for treating industrial wastewater and converting the organic content to bioenergy. However, improvements and modifications of MFCs are necessary to overcome the internal resistance and improve the transfer process of electrons. Nanomaterials such as multi walled carbon nanotubes (MWCNTs) could be a promising material to be contributed in the MFCs modifications. In this study, two identically designed vertical flow packed bed dual chamber 3D-MFCs were constructed and operated in a continuous mode. Both MFCs were fueled with actual automobile wash wastewater (AWW) and inoculated with anaerobic aged sludge. One microbial fuel cell named as MFC1 was packed with graphite granules coated by pristine MWCNTs. The second MFC named as MFC2 was packed with graphite granules coated by acids-activated MWCNTs using a mixture of HCl, H2SO4, and HNO3 as a new approach for of MWCNTs activation. Removal efficiency of organic content and bioenergy generation were considered to evaluate the performance of the 3D-MFCs. The results revealed that the removal efficiency of the organic matters was relatively comparable in both 3D-MFCs. Maximum removal efficiency of COD was 87%±2.0 and 90%±1.1in MFC1 and MFC2, respectively. On the contrary, the power output in MFC2 was higher than its value in the MFC1. Maximum achieved power density was 332 mW/m3 and 462 mW/m3 in MFC and MFC2, respectively indicating the effect of acid activation on promoting the electrode conductivity. Sodium dodecyl sulfate (SDS) in addition to oil and grease (O&G) were found in considerable concentrations in the actual AWW. The removal of SDS and O&G was 87.3%±1.1 and 83% ±2.0 in MFC1, whereby, in MFC2 it was 99.99%±0.1 and 88%±1.7, respectively. The promising results potentially encourage the application of the suggested technique for automobile wash wastewater.

A compact, membrane-less, easy-to-use soil microbial fuel cell: Generating electricity from household rice washing wastewater

The soil microbial fuel cell (SMFC) is a potential technology for bioelectricity generation. An SMFC can convert chemical energy from organic compounds to electrical energy by utilizing exoelectrogenic bacteria existing in the soil. However, the conventional SMFC configuration is hard to set up and inconvenient to use. In addition, rice is one of the main staple foods worldwide, especially in Asia. Rice washing wastewater (RWW) contains various organic compounds with starch, minerals, and vitamins. In this study, a new design of a compact, portable, membrane-less SMFC is proposed. The SMFC is low-cost, easy-to-use, and can generate bioelectricity from abundant household RWW. The SMFC with double carbon-based anode and cathode electrodes was evaluated in muddy soil (total carbon (TC): 85,200 mg/kg, pH: 4.5, and electrical conductivity (EC): 1.36 dS/m) and sandy soil (TC: 1970 mg/kg, pH: 6.6, and EC: 0.01 dS/m) in an incubator at 30 ± 2 ℃. Household RWW was used as a carbon source to feed bacteria in the soil to power the SMFC. For comparison, a control experiment was also conducted, where only water was added to maintain the soil humidity. 15 mL of RWW or water was added to the SMFCs every 48 h. The result showed that when muddy soil was used, the maximum power density of the SMFC with RWW supplied was 485.2 mW/m2, which was 2.4 times higher than the controlled SMFC (202.9 mW/m2). When sandy soil was used, the SMFC with RWW supplied generated the maximum power density of 112 mW/m2, while that of the controlled SMFC was almost zero. These results imply that the proposed SMFC can operate in different types of soil and effectively generate bioelectricity from RWW.

Improper Disposal of Waste Water and Masks during COVID-19, and the Associated Increased Cycle of Infection to Human Health in Developing Countries: A Case Study of Tanzania

Since COVID-19 was declared by the World Health Organization (WHO), wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution are being applied globally to reduce the transmission rate. This study was intended to investigate handling of after wash waste water and masks among Tanzanian residents on the COVID-19 pandemic after it has been, declared by the World Health Organization (WHO) that, wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution should be applied globally to reduce the transmission rate. The assessment of health care waste management in the facilities was conducted in all the 26 regions of Tanzania Mainland. A standardized checklist and tools were used to assess and monitor various aspects related to healthcare waste using open source software for collection (ODK). Data were analyzed using SPSS computer software. It has been indicated that before disposing the used mask, the best protocol is to spray 0.5% (5000 ppm) of chlorine disinfectant on the surface. In this study, about 46% consider used mask as normal municipal waste and 3% do not care they throw away the face masks in the street. Only 18% and 5% of reported to disposal as infectious and highly hazardous waste respectively. It is well documented that due to potential infectious disease like SARS-CoV-2, wastewater should be treated either on-site or conveyed off-site and treated in well-designed method or technology to kill the micro-organisms. The analysis revealed that majority of respondents (74.7%, 73.8%, 48.1% and 65% for healthcare center, district hospitals, regional hospitals and consultant hospitals respectively); dispose the waste in the open space. Continuous awareness creation programs about the negative impact of contaminated face masks and waste water on the health of individuals and introducing laws that can prohibit improper disposal are among the solutions that could help reduce the problem.

Recovery of Phenolic Compounds from Olive Oil Washing Wastewater by Adsorption/Desorption Process

Recovery of Phenolic Compounds from Olive Oil Washing Wastewater by Adsorption/Desorption Process

Fered-Fenton Treatment of Car Wash Wastewater Using Carbon Felt Cathode: Carbon Dissolution and Cathodic Corrosion

Fered-Fenton Treatment of Car Wash Wastewater Using Carbon Felt Cathode: Carbon Dissolution and Cathodic Corrosion

Treatment of vehicle wash wastewater by Fenton process and its recycling

A large number of vehicle wash centres are functioning in the state of Kerala, India and huge quantity of wastewater is generated at these service stations. Though, various treatment methods are available for the treatments of such wastewater, majority of the service stations do not have any treatment facility and the untreated wastewater is ultimately discharged off. This causes serious pollution problems. The aim of this study is to treat vehicle wash wastewater and make it reusable using Fenton process, an advanced oxidation process. Fenton process has already been proved to be effective in treating most wastewater. Wastewater samples were collected from a vehicle wash station in the city of Kochi, Kerala and characterization was done for various parameters. Factors affecting Fenton Process were identified and optimized by using Response Surface Methodology (RSM) for the percentage removal of turbidity, chemical oxygen demand (COD) and oil & grease. The results show that Fenton process effectively removes contaminants from vehicle wash wastewater making it fit for recycling.

An eco-friendly hybrid sonophotocatalytic approach to optimize carpet washing wastewater treatment

An eco-friendly hybrid sonophotocatalytic approach to optimize carpet washing wastewater treatment

Reuse of Mine and Ore Washing Wastewater in Scheelite Flotation Process to Protect Freshwater: Lab to Industrial Scale

Reuse of Mine and Ore Washing Wastewater in Scheelite Flotation Process to Protect Freshwater: Lab to Industrial Scale

Utilization of composite adsorbents for polycyclic aromatic hydrocarbons adsorption from vehicle wash wastewater and aqueous solutions

Utilization of composite adsorbents for polycyclic aromatic hydrocarbons adsorption from vehicle wash wastewater and aqueous solutions

Phytoremediation of Physico-chemical Parameters in Wastewater Effluents from Car Wash Bays in Yenagoa Metropolis, Nigeria

Surface water pollution through the discharge of untreated wastewater is on the increase globally. Efforts made using conventional techniques had not yielded the needed results. This study was conducted to determine the effectiveness of some native aquatic plants for the removal of some physico–chemical parameters from car wash wastewater effluents in Yenagoa metropolis. The plants used for this study were lemna minor, nymphaea nouchalli, pistia-stratiotes, eichhornia crassipes and ceratophyllum demersum; while the physico-chemical parameters investigated in this study include pH, DO, COD, BOD5, NO3, PO4 and turbidity. The wastewater samples collected from car wash bays were analysed to determine the level of the physico-chemical parameters concentrations using standard methods. The experiment was conducted in a green house for 42 days retention period. The results indicated that the cultured plants reduced the physico-chemical parameters to a minimum level, except DO, which increased in concentration. Therefore, they are considered good bioremediators of the parameters under review and the bioremediation potentials of the plants are in the order of P. stratiotes > L. minor > E. crassipes > N. nouchalli> C. demersum. It is therefore recommended that these plants should be used to treat wastewater effluents based on the investigated physico-chemical parameters.

Important Parameters of Ceramic Membranes Derived from Oasis Waste and Its Application for Car Wash Wastewater Treatment

The purpose of this study is to find the best parameters, which are the oasis waste concentration, molding pressure, and sintering temperature for the fabrication of ceramic membrane to be used in the treatment of car wash wastewater. These membranes were prepared from clay and oasis waste using the semidry-pressing process. Characterization of these membranes was done by the determination of their porosity, contact angle, and shrinkage. Following the experiments, we notice that when the oasis waste concentration goes from 8% to 22%, the membranes become more hydrophilic. The same evolution is observed when the sintering temperature and molding pressure increase from 700 to 900°C, and eight to 12 bars, respectively. Moreover, membrane porosity increases with the increase of sintering temperature and oasis waste concentration by 14.6% and 49.3%, respectively. In addition, permeate flux is proportional to the oasis waste concentration and the sintering temperature. The highest flux increase is 62.2% for the case of 15% of oasis waste concentration, while a drop of 23.8% for permeate flux is recorded with the rise of molding pressure. After determining the membrane specific volume, which complies with the Tunisian standards NT.106.002, the best experimental parameters for the membrane fabrication are found to be: (i) 22% of oasis waste concentration, (ii) 800°C for sintering temperature, and (iii) Eight bars for molding pressure. After 30 minutes of the experimentation of wastewater treatment of car wash using the best membrane, an oil rejection of 93% and permeate flux of 116× 10-6 m3/m²s could be achieved.

The Potential of Tofu Liquid Waste and Rice Washing Wastewater as Cheap Growth Media for Trichoderma sp.

The tofu processing industry in Indonesia is massively increasing. The increasing activity of tofu production causes the disposal of tofu industrial waste to the environment to be higher as well. This condition is exacerbated by the fact that generally, the tofu industry producers do not have their appropriate tofu waste management system. The liquid waste generated from the tofu processing industry will be discharged directly into the waterways. Additionally, people in Indonesia generally use rice as their staple food. The rice washing process produces washing wastewater which is usually discharged into the environment directly. The disposal of these wastes raises the environmental pollution rate. Also, the tofu liquid waste and rice washing water contain some nutrients such as proteins, fats, carbohydrates, and vitamins. The presence of these nutrients will increase the population of pathogenic microbes in the environment. Thus, in this study, the authors discussed the potential of tofu wastewater and rice washing wastewater as alternative media for the growth of Trichoderma sp. Trichoderma sp. is an antagonistic fungus that can be used as a biocontrol agent for farmers. The use of waste as an alternative medium reduces the mass production and propagation cost of biological agents. In this study, this isolate was cultivated in tofu liquid waste and rice washing wastewater by adding a carbon source. Based on the research conducted, it was known that the average conidial density of Trichoderma sp. cultivated in tofu liquid waste was 2.9 x 106, while the conidial density of Trichoderma sp. cultivated in alternative rice washing wastewater was only 1.6 x 106. The growth of this isolate in tofu liquid waste was higher than rice washing water. It indicated that tofu liquid waste potentially to be used as a cheap alternative growth medium for Trichoderma sp.

Simultaneous desalination and ammonia recovery using microbial electrolysis desalination and chemical-production cell: A feasibility study of alkaline soil washing wastewater

The high concentrations of ions and ammonia nitrogen (NH3−N) in soil washing wastewater can remarkably affect ecosystem balance. This study aims to prove the feasibility of using alkaline soil washing wastewater as inlet water of microbial electrolysis desalination and chemical-production cell (MEDCC) to desalinate and recover NH3-N, from the views of performance and mechanism. The system could obtain desalination, and NH3-N removal efficiencies of 73 ± 7% and 85 ± 3%, respectively, within 12 h at the maximum current density of 9.8 ± 0.1 A/m2. Importantly, 82.5% of the removed NH3-N could be recovered in the form of NH3·H2O. The addition of electrochemically active bacteria in the anode chamber of MEDCC improved desalination and NH3-N recovery efficiencies by strengthing electric field. Bioenergy provided 58% of the total energy consumption, forming an energy-saving method for soil washing wastewater treatment. Alkalization pretreatment and acid immersion could reduce precipitation from membranes to improve desalination performance and reduce energy consumption. From the standpoint of the mechanism of desalination and NH3-N recovery, the MEDCC is expected to have the potential to simultaneously complete desalination and NH3-N recovery in alkaline wastewater with low energy consumption.

The effectiveness of anode variations for electrocoagulation and its application for laundry wastewater treatment

Since Diponegoro University moved its campus to the Tembalang area, it has been full of issues of decreasing groundwater quality and aesthetic decline caused by laundry wastewater and washing and toilet wastewater which has growing rapidly along with the growth of boarding houses in the Tembalang area. This will have an impact on the health quality of the people who live in the Tembalang area. This study aims to reduce the content of dissolved organic matter in laundry wastewater and bath wash also bath, wash and toilet wastewater. The method chosen was the electrocoagulation method, using 2 different electrodes. The electrodes chosen are aluminum metal and ferrous metal (as anode) and carbon (as cathode). With the electrocoagulation method using aluminum electrodes (as anode) and carbon (as a cathode) the amount of organic material that could be removed was 60.1%. Meanwhile, with ferrous metal (as anode) and carbon (as cathode) the amount of organic material that can be removed is smaller, namely 52.2%. The addition of 100 ppm NaCl solution and 100 ppm Na2SO4 solution was able to increase the efficiency of organic matter removal by 1.8-2.5%.

Pollutant removal from mining processing wastewater by electrochemical method

<p>Discharging wastewater from industries without any treatment causes environmental pollution and endangers biotic life. In this study, pollutant removal by electrocoagulation (EC) process was investigated using wastewater of the ore processing plant (magnesite crushing and screening plant). In the EC process, iron-iron and copper-copper electrodes were used in parallel in the reactor. Chemical oxygen demand (COD), Sulphate, Chromium (VI), Nickel, Zinc, Magnesium, and Total Suspended Solids (TSS) removals were investigated in the EC process of mineral processing industry wastewater with the iron electrode. These pollutants were calculated as %97.6, %95.1, %98.2, %98.1, %97.8, %88.2, and %98.9, respectively. COD, Sulphate, Chromium (VI), Nickel, Zinc, Magnesium, and TSS removals in the EC process of mineral processing industry wastewater with the copper electrode are %92.8, %94.9, %99.5, %98.7, %96.1, %91.6, and %96.9 respectively. It has been observed that high removal efficiency can be achieved by using the electrocoagulation process in the treatment of ore washing wastewater resulting from the crushing and screening processes in the Chrome Magnesite processing plant.</p>

Hybrid process of combined soil washing and selective adsorption to treat Cs-contaminated soil

The decommissioning of old nuclear power plants is a worldwide issue and the removal of radioactive materials from soil is challenging. In this study, we proposed a hybrid process that combines soil washing for extraction and selective adsorption for Cs-containing washing wastewater to treat cesium (Cs+)-contaminated soil. To extract Cs+ from the soil, various extracting agents were evaluated including cationic salts (CaCl2, BaCl2, KCl, and NH4Cl), organic/inorganic acids (EDTA, oxalic acid, HCl, and HNO3), and a base (NaOH). In addition, the combination of cationic salts and acids was investigated to enhance the overall extraction of Cs+ from soil. Potassium ions (K+) showed the highest removal of Cs+ (about 60%). The operating parameters of extracting agent concentration, reaction time, and solid/liquid (S/L) ratio required to desorb Cs+ from the soil were determined to be 0.1 M, 10 min, and 1/10, respectively. To enhance the overall extraction of Cs+ from soil, a three step multi-extraction process was proposed and approximately 99% of Cs+ was extracted by the multi-extraction process. The extracted Cs+ in the aqueous solution was mostly adsorbed onto the synthesized and the adsorbent removed Cs+ selectively even in the presence of a high concentration of K+ (about 99%). This result shows the effectiveness of the hybrid process of extraction and selective adsorption. The technique proposed is expected to reduce greatly the amount of radioactive waste to be disposed of permanently.

Constructed wetland treatment of source separated washing wastewater in rural areas of southern China

China's toilet modernization has enabled thousands of villages to separate their feces and urines from the greywater or washing wastewater. Human feces and urine are usually used as raw materials for fertilizers, but the lack of understanding of discharge characteristics of washing wastewater in China rural areas affects the development of treatment technology and the reuse of treated water. In this study, a village in the lower reaches of the Yangtze River was selected to investigate the discharge characteristics of washing wastewater, and four kinds of subsurface constructed wetlands were used for treatment and reuse. The results showed that the production of washing wastewater in rural aeras was 59–232 L/(cap .d), with an average of 121 L/(cap .d). The bathing wastewater contributed the highest proportion of 46.19%. COD was identified as the key pollutants with average concentration of 337 mg/L. Compared with domestic wastewater, the concentrations of TN and TP were much lower with the average of 11.1 mg/L and 0.6 mg/L respectively. After treated by the constructed wetland with ceramsite, volcanic rock and anthracite as composite substrate, the effluent water met the requirements of paddy field crop irrigation, and the removal rates of COD, TN and TP achieved 61.5%, 68.8% and 70.5% respectively. Wetland plants and modular design had significant positive effects on the removal of nitrogen and phosphorous, but little effect on COD removal. The fecal coliforms in the effluent were all lower than 4.0 lg (MPN/L) in the four constructed wetlands, indicating they were not the limiting factors for irrigation reuse.

A Column Study on The Efficiency and Reusability of Kapok Fibre as Car Wash Wastewater Treatment

The car washing industry which consumes large amount of water produces Car Wash Wastewater (CWW) which were likely to exceeds the standard set in both Malaysia’s and Singapore’s regulation. Kapok Fibre (KF) is a natural adsorbing material which have large lumen and low density is believed to be able to act as an adsorbent to manage the CWW. This study was done to determine the characteristic of KF and CWW and investigate the efficiency of KF in treating CWW along with the reusability of KF through a column study with Organic Loading Rate (OLR) of 12.41g COD/L.day. The CWW contains a certain concentration of Chemical Oxygen Demand (COD, Oil and Grease (O&G), and Anionic Surfactant (AS) though the interaction between KF and AS is novel. KF found out to has the capability in removing COD, O&G, and AS up to 88.37%, 100%, and 83.8% respectively. However, in reusability experiment there is limitation to KF in which by exceeding the operation time to 600 minutes of treatment, the efficiency in removing COD, O&G, and AS were found to drop to 62.02%, 75%, and 55% respectively. This shows that KF could be an avant-garde, low-cost sustainable treatment to treat CWW instead of the conventional high cost and complex operating system.

Two-phase olive-oil washing wastewater treatment plus phenolic fraction recovery by novel ion exchange resins process modelling and optimization

This research was focused on the modelling and optimization of an environmentally friendly procedure to recover added-value polyphenols (TPhs) from two-phase olive-oil washing wastewaters (OOWW) by ion exchange (IE) resins and simultaneously permit the treatment of this effluent. The reason is the need of olive mills to evolve into a whole environmentally friendly conception to upgrade this ancestral industry, comprising the management of the by-produced effluents. Key operating factors of Dowex 21KXLT® strong-base and Dowex66® weak-base resins were studied, modelled and optimized by statistical multifactorial analysis. Optimal resin amount between 140 and 146 and 114–146 gresin/LOOWW, T from 20 to 25 °C, pH0 between 6.5 and 8.2 and 4.7–7.1 and 60 vs. 25 min contact time were determined for the strong-base and weak-base resins. Final phenols concentration uptake of 60.8% vs. 83.3% plus 55.8% vs. 53.7% COD removal supported major efficacy of the selected weak-base resin. In addition, the process could be directly driven with raw OOWW exiting the mills’ vertical centrifuges upon unmodified pH0 nor T. The high added-value concentrated pool of antioxidant phenols could render feasible the industrial scale-up, and the treated effluent could be now driven to biological treatment given the high removal of TPhs preventing biomass inhibition, or partially discharged.