Floor Washing Research Articles

Effluent quality and reuse potential of wastewater treated in constructed wetlands in Southern Brazil

ABSTRACT The main objective of this study was to evaluate the quality and reuse potential of treated effluents by constructed wetlands (CW) systems utilized for decentralized wastewater treatment in urban and rural scenarios in southern Brazil. The assessment, based on Brazilian discharge standards and wastewater reuse guidelines, revealed a close link between treatment efficiency and technological configurations, considering diverse inlet wastewater sources. Most CW treated effluents complied with regulatory standards for disposal, prompting the exploration of reuse scenarios in urban and agricultural settings. However, the study underscores the imperative for rigorous disinfection due to the limited microbiological removal capacity of CW. Overall, the research emphasizes the adaptability and resilience of CW in treating diverse wastewater compositions, highlighting their pivotal role in advancing circular economy principles within sanitation services. Importantly, the findings suggest significant potential for treated wastewater reuse in both urban and agricultural settings. Urban applications, including toilet flushing, floor washing, and garden irrigation, prove feasible for CW systems situated in residential and commercial buildings. Meanwhile, rural CW systems demonstrate suitability for reclaimed water directed toward crop fertigation, tailored to the specific needs and irrigation methods of various crops.

Water reuse in the food processing industries: A review on pressure-driven membrane processes as reconditioning treatments

Establishing general rules for short wastewater recycling loops in the food industries is a challenging task. This work provides an overview on water consumption, effluent discharge and the main water consuming unit operations in this sector. Pressure-driven membrane processes as treatment technologies will be focused on and nanofiltration and reverse osmosis appear unavoidable. An original synthesis of the membranes used, the best operating conditions and the corresponding performances are broken down by food sector and by effluent load. Recycling is mostly proposed for floor washing, heating/cooling, vessel pre-cleaning, even though criteria for potable water are not fulfilled. Water of a quality which is sufficient for recycling can be obtained with a single membrane treatment stage only when weakly concentrated (COD <1 g/L) non-fat effluents are concerned, originating from flushing, bottle washing or rinsing water after vegetable peeling. This critical review can be used as a guideline for recycling projects and points to the remaining challenges and improvements to be made.

Use of rain water in floor washing and garden irrigation: a case study

The socioeconomic context brought by the COVID-19 pandemic and the war in Ukraine, caused a crisis in the world economy. Faced with this situation of inflation and the rise of the dollar, access to basic items such as water and cooking gas has become an obstacle for the needy population. There are alternatives to overcome water scarcity, and one of them is the use of water harvesting systems with low-cost technologies, which facilitate replication in environments that do not have a water distribution network, allowing the economically disadvantaged population access the water. This work analyzes the use of rainwater in garden irrigation and floor washing in a public building. The case study was carried out at the Civil Court and Consumer Relations Court in Camaragibe, PE. The rainfall index and the history of water consumption were analyzed, as well as the analysis of rainwater in the study region. Reservoir simulations and economic analysis were performed using the NETUNO software. The economic simulation resulted in the value of R$3,000.00 (three thousand reais), and a payback time of 5 years. After analyzing the simulations and the results of the rainwater samples, as well as complying with the requirements of the ABNT 15527/2019 standard, it can be inferred that the implementation of rainwater harvesting for non-potable use is feasible.Keywords: Harvesting rainwater. Sustainability. Low cost technology.

Economic analysis of crossbred (Landrace × Desi) pig reared under different floor space allowances

Present experiment was conducted to study the relative economics of crossbred (Landrace×Desi) pigs with thirty six crossbred barrows reared under 3 different floor space allowances (n=12 each) having group size of 4 pigs/pen. One group (TIS) was provided floor space as per Indian Standards (0.9, 1.35 and 1.8 m2/pig for weaner, grower and finisher stages, respectively) specifications, while other two groups with 33% (T2/3) and 50% (T1/2) reduced floor space allowances. Only covered floor area was provided for all the groups. Different parameters analyzed during the study involved growth, feed conversion efficiency, requirement of water and labour for floor washing, and some other economic variables. Pigs were reared up to 28 weeks of age. Relative economics of pig rearing for three floor space allocation groups was calculated using partial budget analysis. Major performance traits, i.e. average daily gain (ADG) and feed conversion efficiency (FCE) did not differ significantly among the groups. Although body weights of T2/3 and T1/2 groups were marginally higher than TIS group. In contrary to minor savings of labour, large quantity of water was saved in T1/2 and T2/3 groups (805.4 liters/pig and 400.1 liters/pig, respectively) than TIS group between weaner and finisher stages. Additionally, input costs of ₹` 145 and ` ₹ 96 per pig was saved by providing floor space as per T1/2 and T2/3 groups, respectively than TIS group. It can be concluded that economic gains were maximum in 50% floor space reduction group without adverse effect on performance traits of crossbred pigs.

Quality of water produced by air conditioning equipment for non-potable purposes

Air conditioner is an equipment which is present in most buildings around the world, either serving to provide greater thermal comfort to its users, or as part of industrial processes. This equipment while in operation produces water from the condensation of the air in contact with its coil, which has the potential to be used for non-potable purposes within the buildings. This study aims to evaluate the quality of condensate water from air conditioners for non-potable purposes. Water collection was carried out in the water harvesting system of a hospital type building located in the city of Recife-PE, Brazil. The applied methodology analyzed the physicochemical parameters that include: pH, color, odor, turbidity, electrical conductivity, total dissolved solids, ammonia, nitrite, nitrate, alkalinities, total hardness, carbonate hardness, non-carbonate hardness, chloride, sulfate, carbonate, bicarbonate, calcium, magnesium, sodium, potassium, total iron, manganese and, in the microbiological analysis, the presence of coliforms. In addition, the applied methodology compared the results of this and other studies found with the same theme, with the maximum limits provided for in Ordinance No. 888/2021 of the Ministry of Health of Brazil. The results showed an excellent quality of the condensate water, approaching in most parameters of drinking water, and thus, it can be used for non-potable purposes such as: garden irrigation, floor washing, replacement in cooling towers, among others.

Quality Testing of Raw and Filtered Grey-water Emerging from Kitchen Sink: A Case Study

The limited freshwater supplies in arid regions have created alternative water management strategies. Data indicates that grey-water generation varies from 39-85% in various countries. Grey-water treatment and reuse can be a helpful nonpotable water source for toilet draining, watering gardens, car and floor washing, etc. Treated grey-water should be clean, hygienic, environment-friendly and cost-effective. The goal of this research is (i) to test the parameters of raw grey-water (ii) create a filter bed (iii) test parameters of treated grey-water (iv) Compare the parameters of raw and treated grey-water (v) describe the area of use.

Degradation of recalcitrant textile azo-dyes by fenton-based process followed by biochar polishing

The use of advanced oxidative processes (AOPs) is an efficient alternative for the treatment of textile wastewaters. The aim of this study was to assess the dye removal efficiency of a Fenton-based degradation process followed by a polishing step using biochar prepared from rice husk. Six recalcitrant textile dyes - Reactive Red 195 (D1), Synolon Brown S2 (D2), Orange Remazol RGB (D3), Yellow Synozol K3 (D4), Reactive Orange (D5), and Reactive Black 5 (D6) – were treated with Fenton and photo-Fenton processes (with and without biochar polishing) under optimized conditions. The results showed a general efficiency ranking: photo-Fenton + biochar ≈ Fenton + biochar > photo-Fenton ≈ Fenton. The Fenton process was also efficient for the regeneration of the dye-saturated biochar. The photo-Fenton + biochar process achieved the following color removal percentages: D1 (98.8%), D2 (99.7%), D3 (98.9%), D4 (96.3%), D5 (94.2%) and D6 (94.8%). This process was applied to a real conventionally-treated textile wastewater and analysis showed a reduction in BOD (87.5% degradation), COD (62.5% degradation) and color (93.5% mean removal). These results reveal the possibility for the reuse of the treated water for non-potable industrial uses, for example, floor washing or the cleaning of machines and toilet areas.

RAINWATER REUSE SYSTEM FOR SMALL RESIDENCES (70 m²) IN THE MUNICIPALITY OF RIO VERDE, GOIÁS, CENTRO-WEST, BRAZIL

A escassez da água vem sendo debatida e argumentada em vários lugares, mostrando a necessidade de ações voltadas ao uso eficiente deste recurso. Assim, o objetivo deste trabalho foi realizar a captação, armazenamento e reuso da água captada de telhado para residência do projeto “Minha Casa, Minha Vida” (70 m2) no município de Rio Verde, Goiás. Foram utilizados dados de precipitação média mensal de 19 anos (1996 - 2015). Simulou-se o armazenamento máximo para assegurar o período de estiagem. Estimou-se o consumo médio de água semanal considerando de 1 a 3 pessoas por residência. Considerou-se como consumo de água lavagem de carro, gramado ou jardim, descarga na bacia, máquina de lavar roupa e lavagem de piso. Nos meses de maior precipitação (novembro-março), conseguiu atender à necessidade das pessoas na residência, e ainda armazenar para aproveitar nos períodos de estiagem. Os meses de fevereiro, março, abril e dezembro, atingiu a capacidade de armazenamento do reservatório (20.000 L) apenas para a residência com 1 e 2 pessoas, para 3 pessoas apenas o mês de março a caixa d’água encheu completamente, sendo assim, supriu as necessidades nos meses de estiagem, onde a demanda não atingiu a capacidade do reservatório. Assim o reuso da água do telhado propicia na economia de água nobre e economia a médio prazo, além de assegurar picos de enchente no período chuvoso.

The pollution level of wastewater from dairy processing enterprises of the Tyumen Region

The agro-industrial complex has a huge potential for increasing the efficiency of the use of natural resources, which means it is a good platform for introducing the best available technologies. The main problem is the formation of wastewater. Since dairy enterprises use large enough volumes of water to process containers, equipment, for floor washing as well as use them to cool dairy products. Naturally, the main pollutants are organic compounds. Wastewater from dairy processing plants contains: suspended solids (solids from dairy processing), fats (their content varies depending on the variety of products produced by the enterprise), nitrogen (in the form of amino groups of protein compounds). The pH of the water itself also changes, the value of this indicator will also vary from the volume and range of products. As a result, it was revealed that in the production of 53982 tons of dairy products per year, 496929,2 tons of wastewater is formed, which is 9 times more than the volume of the companys production. In addition, most enterprises in the Tyumen Region do not have an opportunity to drain the resulting wastewater into the central sewage treatment plants for various reasons. This is either a tens of times excess of discharge standards, or the lack of sewage treatment facilities in the settlements where the enterprises are located. In this regard, enterprises of the agro-industrial complex are sources of pollution not only of the atmosphere, soil, but also of water bodies, so the wastewater of dairy plants should be treated and discharged with minimal risk of environmental pollution.

Usable rainwater volume; results of a hydrological study conducted at the Universidad de Santander, Bucaramanga, Colombia

This study was carried out at the “Universidad de Santander”, in Bucaramanga, Colombia, to calculate the volume of rainwater capturable from the roofs of five campus buildings, as the blueprints for these surfaces were available to obtain their areas. Roof areas were first obtained for the Guane, Motilón, Arhuaco, Chibcha and Yariguíes buildings, from which rainwater can be captured. Intensity, duration, and frequency curves from the “Instituto de Hidrología, Meteorología y Estudios Ambientales” were then used to calculate a design flow, yielding the diameter of the pipe necessary to evacuate the water captured. In addition, data from the “Universidad de Santander” meteorological station was evaluated to obtain monthly rainfall figures. The highest-yielding structure was the Motilón building, with approximately 80 m3 in the months of May and November, 2018, as this structure has the largest roof area, and the area experienced its greatest quantity of rain during these months. The total accumulation predicted by the study was 1837.96 m3 annually, sufficient to suggest the possibility of its use in restrooms, gardens, and floor washing at the “Universidad de Santander”, Bucaramanga, Colombia. The volume of water calculated is variable on a yearly basis, and was estimated by means of one year of rainfall readings from the university’s meteorological station. Hydraulic structures designed for the purpose of capturing this water would require a specific study, taking into account the records of other nearby meteorological stations, and making necessary provision for the storage of water in excess of expected volumes.

Análise do potencial de redução do consumo de água potável pelo aproveitamento de águas pluviais e reúso de águas cinzas na Rodoviária do Plano Piloto de Brasília - DF

Este trabalho teve como objetivo caracterizar os usos-finais de água da Rodoviária do Plano Piloto de Brasília e, com isso, realizou uma análise comparativa do potencial de redução de água potável entre sistemas de aproveitamento de águas pluviais e sistemas de reúso de águas cinzas em diferentes cenários de usos não potáveis. Para tanto, o desenvolvimento do estudo foi dividido em duas etapas: i) levantamento de dados de consumo; e ii) avaliação do potencial de redução do consumo de água por meio do aproveitamento da água pluvial e do reúso de águas cinzas na Rodoviária do Plano Piloto. Os resultados demonstraram que cerca de 80% do consumo anual de água da rodoviária é proveniente dos usos de água para lavagem de pisos, vasos sanitários e mictórios (3.229 m³). Com base nos dados coletados de frequências de usos, população que utilizou o banheiro e vazão dos equipamentos foi possível gerar indicadores de consumo de água lavatório (0,18 l/p/d), vaso sanitário (0,54 l/p/d), mictórios (0,13 l/p/d), lavagem de pisos (0,41 l/m²/dia) e de banheiros (0,05 l/m²/dia). Baseado nos dados coletados, foi possível estimar o potencial de redução do consumo de água potável pelo aproveitamento de águas pluviais e reúso de águas cinzas em limpeza de pisos (Cenário 1), para descarga de vasos sanitários e mictórios (Cenário 2) e descarga em vasos sanitários, mictórios e para limpeza de pisos (Cenário 3). Em geral, sistemas de aproveitamento de água pluvial promoveram maiores reduções no consumo de água potável, variando de 601 a 3.229 m3/ano.

Reuse of Treated Wastewater in Metal-Mechanics Industry: A Technical-Economic Evaluation

Metal-mechanical industries are intensive in the consumption of water and, consequently, in the wastewaters production. Thus, reuse is essential because it preserves the environmental resources, diminishing the water footprint of the obtained products. Despite the advanced techniques, the economic cost limits the wastewater treatment to the most common techniques. This study evaluated the technical potential and costs involved in the reuse of wastewater in a metal-mechanical industry. Mistakes were found in the reagents dosage, what precluded reuse of the treated wastewater. The optimum condition for coagulation/flocculation was evaluated using the bench scale jar test. The parameters of wastewater, such as turbidity, pH, alkalinity, hardness, electrical conductivity, chloride and total solids were evaluated. The ideal condition was tested at the plant and some adjustments were made. The improvements resulted in 50.96% cost reduction of wastewater treatment without new investments. Also, the treatment became faster and more efficient. The wastewater achieved the standards for reuse in toilet flushing and floor washing.

Indicadores de consumo de água e análise comparativa entre o aproveitamento de águas pluviais e o reúso de águas cinzas em edificações de ensino do Campus Darcy Ribeiro - UnB

Este trabalho teve como objetivo caracterizar os usos-finais de água em edificações de ensino superiordo Campus Universitário Darcy Ribeiro da Universidade de Brasília e, com isso, realizar uma análisecomparativa do desempenho de sistemas de aproveitamento de águas pluviais (AAP) e de reúso deáguas cinzas (RAC). Para tanto, o estudo se dividiu em três etapas. Na primeira etapa, indicadores deconsumo predial foram gerados com base no consumo faturado, área construída e população de cadaedificação analisada. Usos-finais de água foram estimados por meio de questionários e entrevistassemiestruturadas. Na segunda etapa, foram realizadas uma série de simulações para verificar aeconomia de água para diferentes sistemas AAP e RAC baseando-se em três cenários de usos nãopotáveis: i) Irrigação e lavagem de pisos (Cenário 1); ii) Descarga sanitária (Cenário 2); e iii) Irrigação,lavagem de pisos e descarga sanitária (Cenário 3). Na terceira etapa, foi realizada uma análisecomparativa do desempenho dos sistemas na redução do consumo de água. Os resultados mostraramque, para o Cenário 1, ambos os sistemas conseguem suprir toda a demanda de água. Porém, a maioriados sistemas não são capazes suprir toda a demanda dos Cenários 2 e 3. Em geral, o aproveitamentode águas pluviais apresentou um melhor desempenho, promovendo economia de 137 a 19.510 m3/ano,dependendo da grandeza da edificação.

Observations and impacts of bleach washing on indoor chlorine chemistry.

Ambient levels of chlorinated gases and aerosol components were measured by online chemical ionization and aerosol mass spectrometers after an indoor floor were repeatedly washed with a commercial bleach solution. Gaseous chlorine (Cl2 , 10's of ppbv) and hypochlorous acid (HOCl, 100's of ppbv) arise after floor washing, along with nitryl chloride (ClNO2 ), dichlorine monoxide (Cl2 O), and chloramines (NHCl2 , NCl3 ). Much higher mixing ratios would prevail in a room with lower and more commonly encountered air exchange rates than that observed in the study (12.7h-1 ). Coincident with the formation of gas-phase species, particulate chlorine levels also rise. Cl2 , ClNO2 , NHCl2 , and NCl3 exist in the headspace of the bleach solution, whereas HOCl was only observed after floor washing. HOCl decays away 1.4 times faster than the air exchange rate, indicative of uptake onto room surfaces, and consistent with the well-known chlorinating ability of HOCl. Photochemical box modeling captures the temporal profiles of Cl2 and HOCl very well and indicates that the OH, Cl, and ClO gas-phase radical concentrations in the indoor environment could be greatly enhanced (>106 and 105 cm-3 for OH and Cl, respectively) in such washing conditions, dependent on the amount of indoor illumination.

Applicability of domestic grey water reuse for alleviation of water crisis in Dhaka City

Overdependency on ground water resources for meeting the daily water demand in Dhaka City is leading to excessive pressure on ground water aquifer systems and is deepening the ground water table every year. This paper focuses on how reuse of grey water generated from different sources of domestic purposes every day can alter the considerable daily water demand in this city. Sampling and characterization of grey water was accomplished according to different types of residential sources such as water from brushing, bathing, floor washing and laundry. In Dhaka City, household average grey water generation is 85 L per capita per day, which is 60% of the total waste water generated in a house in a day. After reclamation, this grey water can be reused for toilet flushing, gardening, car washing and fire fighting, which can play a crucial role of meeting city water demand since reusable grey water generation is around two times greater than the total demand of water for those purposes. During characterization, emphasis was given to the determination of basic parameters like pH, turbidity, colour, solid content, bio-chemical oxygen demand (BOD), chemical oxygen demand (COD), total coliform (TC) and faecal coliform (FC). Among all the grey water sources, laundry water was found to be the most contaminated. Aesthetic quality of grey water is another issue of public acceptance.

The potential for decentralized reclamation and reuse of household greywater in peri‐urban areas of Bangkok

AbstractA survey was conducted of 400 households in the peri‐urban area of Bangkok to investigate typical household water consumption, daily water use activities, public perception towards wastewater reuse and detergent consumption. Four categories of greywater, including cooking, dish washing, bathing and laundry washing wastewater, their properties and potential application for reuse were examined. Average water consumption was estimated to be 208 L/person/day. The wastewater was already reused in 42% of households, and that laundry wastewater was widely used for plant watering and floor washing. More than 80% of households accepted the use of treated greywater, while 50% of households did not accept the use of treated blackwater. Biochemical oxygen demand (BOD), chemical oxygen demand (COD) and suspended solid (SS) were high in cooking, dish washing and laundry, and lower in bathing wastewater, while anionic surfactant were high in laundry and dish washing wastewater. The finding results clearly demonstrate the possibility of greywater reclamation and reuse in the area.

High performance achieved by microbes to separate laundry effluents resulting in producing high water quality in a compact area

Chemical treatment enhanced with air-flotation can produce acceptable water quality for laundry effluents in a compact area. However, the stringent discharge limit of chemical oxygen demand (COD) level for direct discharge into surface water was always beyond the scope of this separation. By undertaking biological treatment before chemical separation, the amount of sludge generated from flotation resulted in a reduction of 35% for a daily flow of 100m3. COD levels can be reduced to meet the stringent local requirement to less than 80mg/L. Bacteria play a major role as a primary degrader to reduce pollutant, dye and toxicant in terms of COD from the effluent even at a dissolved oxygen (DO) level below 2mg/L during the operation time. The higher trophic level microbes such as flagellate, ciliate, rotifer, vorticella and nematode were successfully introduced from a sewage treatment plant (STP) to recycle the laundry effluent. Biological recycling of the pollutants from the trade effluents was cost effective and environmentally friendly by converting them into biomass derived from the microbes. Furthermore, the very clear water produced with a low COD level from the treated effluents can be utilized for various applications such as flushing, floor washing, plantations or others.

Evaluation of an Electrochemical Advanced Oxidation Process for the Organic Matter Removal from Dairy Wastewater

The dairy industries are associated with the generation of large volumes of wastewater. The water in these industries is used throughout all steps like cleaning, sanitization, heating, cooling and floor washing. One of the principal characteristic of this wastewater is the high organic matter bio and non biodegradable. After sampling and analyzing the wastewater discharge, the ratio BOD5/COD= 0.39 suggests a difficult problem for the wastewater disposal. Moreover the reuse potential with this quality is null. In this paper authors report the first steps to evaluate an advance oxidation process (AOP) for farḿs wastewater No. 1 of "La Cuenca Lechera de Ensenada Baja California", using a DSA electrode of Ti/IrO2/Ta2O5. The characterization of wastewater used extraction by partitions methods indicating the presence of organic compounds like fatty acids, esters, alcohols, aldehydes, ketones, amines and other nitrogen-containing compounds in such proportions that a AOP seems to have good prospect of success. The electrochemical study using cyclic voltammetry indicated the presence of oxidizable organic compounds and using differential pulse voltammetry also direct oxidations seems to be attributable to nitrogen compounds, among others.

Novel approach for the treatment and recycle of wastewater from soya edible oil refinery industry—An economic perspective

The soya edible oil manufacturing industries with a capacity of 18,000 tones/annum, generate wastewaters and solid wastes. The streams of wastewater originate primarily after several processes viz. soap splitting, floor washing, cooling tower and boiler. The wastewater from cooling tower, boiler sections and solid wastes can be recycled and reused after essential preliminary treatment. In this study, we observed that wastewater from the site of study and other peripheral streams did not conform to the legislated permissible limits prescribed for discharge, by the Central Pollution Control Board, Government of India. Hence, we adopted certain novel measures to enhance the treatment efficacy of the effluent treatment plant (ETP). The overall percentage removal of COD, TDS, and O&G was 94–98, 92–97 and 97–99%, respectively. Moreover the fixed capital cost of ETP was estimated 50 lakhs—Indian Rupees (Rs.) and annual operation and maintenance cost was estimated Rs. 10.356 lakhs, the cost of treatment of 1 m 3 wastewater was Rs. 82.67 (U$ dollar = 1.79). Further recycle, recovery and reuse of water were adopted to achieve the target of zero discharge for ecological and economical gains.

Reuse of treated sewage in Delhi city: Microbial evaluation of STPs and reuse options

Microbiological quality of the treated wastewater is an important parameter for its reuse. The data on the Fecal Coliform (FC) and Fecal Streptococcus (FS) at different stages of treatment in the Sewage Treatment Plants (STPs) in Delhi watershed is not available, therefore in the present study microbial profiling of STPs was carried out to assess the effluent quality for present and future reuse options. This study further evaluates the water quality profiles at different stages of treatment for l6 STPs in Delhi city. These STPs are based on conventional Activated Sludge Process (ASP), extended aeration, physical, chemical and biological treatment (BIOFORE), Trickling Filter and Oxidation Pond. The primary effluent quality produced from most of the STPs was suitable for Soil Aquifer Treatment (SAT). Extended Hydraulic Retention Time (HRT) as a result of low inflow to the STPs was responsible for high turbidity, COD and BOD 5 removal. Conventional ASP based STPs achieved 1.66 log FC and 1.06 log FS removal. STPs with extended aeration treatment process produced better quality effluent with maximum 4 log order reduction in FC and FS levels. “Kondli” and “Nilothi” STPs employing ASP, produced better quality secondary effluent as compared to other STPs based on similar treatment process. Oxidation Pond based STPs showed better FC and FS removals, whereas good physiochemical quality was achieved during the first half of the treatment. Based upon physical, chemical and microbiological removal efficiencies, actual integrated efficiency (IE a) of each STP was determined to evaluate its suitability for reuse for irrigation purposes. Except “Mehrauli” and “Oxidation Pond”, effluents from all other STPs require tertiary treatment for further reuse. Possible reuse options, depending upon the geographical location, proximity of facilities of potential users based on the beneficial uses, and sub-soil types, etc. for the Delhi city have been investigated, which include artificial groundwater recharge, aquaculture, horticulture and industrial uses such as floor washing, boiler feed, and cooling towers, etc.