Using Some Mobile Applications for Teaching Mathematics During COVID-19 Pandemic Through Providing a Suitable Environment

The coronavirus disease 2019 (COVID-19) pandemic and other crises create problems for the normal teaching process in the class. In this case, alternate teaching techniques such as mobile applications are required for continuing the teaching and learning process. This research focuses on teaching mathematics in class 12 by using applications (available on mobiles, laptops, desk tops, iPads etc.), namely Phone, Viber, WhatsApp and Messenger so as to provide an appropriate teaching environment. Class 12 in Gawher Preparatory School (both scientific and literary branches) in Erbil City, Kurdistan Region-Iraq was selected for this study. The sample sizes for both scientific and literary branches during the academic year 2019-2020 were 31 and 53, respectively. Pre and post tests were administrated to check pupils’ achievements. Videos were prepared and uploaded to the teaching groups in Viber and Messenger. Suitable environments for teaching mathematics to class 12 were provided via direct communication, and questions and answers were provided. The results revealed that average scores for pre and post tests for the scientific branch were 20 % and 63.33 %, respectively; while for the literary branch were 17.5 % and 50.83 %, respectively. The mobile applications experimented with have led to the enhancement of the mathematics teaching process outside normal classes and particularly during the COVID-19 lockdown periods and crisis. Also, COVID-19 lockdowns decreased noise pollution, water consumption, production of wastewater, generation of solid waste, and expenditures at schools. Additionally, a number of problems, benefits, and recommendations have been outlined; for instance, providing internet and continuous electricity for schools, supplying mobile phones or laptops for pupils with reasonable prices, and running training courses for teachers and pupils are essential.

Water consumption, wastewater generation and characterization of a slaughterhouse for resource conservation and recovery

This study is an overview of a beef-based slaughterhouse's processes and operations, from animal reception to product dispatch, including water consumption over 105 days. On average, 1,114 L/buffalo is required for slaughter and processing. Corresponding wastewater generation is between 916 and 1,089 L. Water consumption per buffalo decreases with increasing numbers of buffalos slaughtered per day, and in some operations – e.g., plant washing, personal hygiene, canteen, and knife and instrument washing – is independent of the number of buffalo slaughtered. In contrast, refrigeration depends partly on the numbers slaughtered. Wastewater characterization from each slaughterhouse process and operation was carried out over three months, and wastewater physico-chemical characteristics from individual operations are presented.

Modelling temperature dynamics in sewer systems – comparing mechanistic and conceptual modelling approaches

The vast majority of the energy consumed for urban water services is used to heat tap water. Heat recovery from wastewater is consequently an area of rapidly growing concern, both in research and by commercial interest, promoting the path towards a circular economy. To facilitate a system-wide evaluation of heat recovery from wastewater, this paper compares two one-dimensional models (mechanistic and conceptual) that can describe wastewater temperature dynamics in sewer pipe systems. The models are applied to successfully predict downstream wastewater temperature for sewer stretches in two Swedish cities (Linköping & Malmö). The root mean squared errors for the mechanistic model (Linköping Dataset1 – 0.33 °C; Linköping Dataset2 – 0.28 °C; Malmö – 0.40 °C) and the conceptual model (Linköping Dataset1 – 0.32 °C; Linköping Dataset2 – 0.20 °C; Malmö – 0.44 °C) indicate that both models have similar predictive capabilities, encouraging the use of conceptual models to reduce data requirements and model calibration efforts. Both models are freely distributed and can be easily integrated with wastewater generation and treatment models to facilitate system-wide wastewater temperature dynamics analysis.

Comparison of Agro-Wastes For Dewatering Enhancement For Dredged Sludge From Sewers

With the increasing wastewater generation from domestic and industrial activities due to the rapid economic development, the generation of sludge, in particular dredged sludge from municipal sewer system, has been an issue in developing countries. This study evaluated the enhancement of sewer’s sludge dewatering via mixing the sludge with different agro-wastes, including corn core powder, rice husk powder, bagasse powder and peanut shell powder. The addition of these agro-waste powders helped decrease the sludge’s moisture contents up to 17% after mixing with the ratio of 1:3, 1:5 or 1:7. Statistical analysis revealed the impacts of both additive types and mixing ratio on moisture content reduction. Among the four types of agro-waste, rice husk was shown to be the best additive to dredge sludges with highest reduction of heavy metal concentration and moisture content. The addition of agro-waste powders to enhance the dewatering of sludges is quite promising in the context of promoting waste reuse and energy saving.

Using 3D CityGML for the Modeling of the Food Waste and Wastewater Generation—A Case Study for the City of Montréal

The paper explains a workflow to simulate the food energy water (FEW) nexus for an urban district combining various data sources like 3D city models, particularly the City Geography Markup Language (CityGML) data model from the Open Geospatial Consortium, Open StreetMap and Census data. A long term vision is to extend the CityGML data model by developing a FEW Application Domain Extension (FEW ADE) to support future FEW simulation workflows such as the one explained in this paper. Together with the mentioned simulation workflow, this paper also identifies some necessary FEW related parameters for the future development of a FEW ADE. Furthermore, relevant key performance indicators are investigated, and the relevant datasets necessary to calculate these indicators are studied. Finally, different calculations are performed for the downtown borough Ville-Marie in the city of Montréal (Canada) for the domains of food waste (FW) and wastewater (WW) generation. For this study, a workflow is developed to calculate the energy generation from anaerobic digestion of FW and WW. In the first step, the data collection and preparation was done. Here relevant data for georeferencing, data for model set-up, and data for creating the required usage libraries, like food waste and wastewater generation per person, were collected. The next step was the data integration and calculation of the relevant parameters, and lastly, the results were visualized for analysis purposes. As a use case to support such calculations, the CityGML level of detail two model of Montréal is enriched with information such as building functions and building usages from OpenStreetMap. The calculation of the total residents based on the CityGML model as the main input for Ville-Marie results in a population of 72,606. The statistical value for 2016 was 89,170, which corresponds to a deviation of 15.3%. The energy recovery potential of FW is about 24,024 GJ/year, and that of wastewater is about 1,629 GJ/year, adding up to 25,653 GJ/year. Relating values to the calculated number of inhabitants in Ville-Marie results in 330.9 kWh/year for FW and 22.4 kWh/year for wastewater, respectively.

Replacement of Chemical Fertilizer by Beverage Sludge to Reduce Environmental Pollution

Wastewater generation from beverage industries is on the rise as the demand and consumption surge worldwide. The typical ingredients of beverages are carbonated water, saccharides, sweetener, fruit pulp, flavoring agent, color, preservatives, and salts. Only 20% concentration of the mixture goes to the bottle and the remaining becomes wastewater. However, nutrients and organics remain in wastewater and are left in sludge after going through ETP. The presence of these nutrients makes the beverage sludge useful for the cultivation that can not only decrease the application of chemical fertilizers but also combat the environmental pollution. Indian spinach and Okra have been cultivated in six different mixtures containing beverage sludge and soil to study their effects on growth, yield, food value and nutrient. Soil nutrients, organic content, EC, and pH have been analyzed to assess the suitability of sludge for cultivation. The control treatment was designed by 100% soil and gradually 20, 40, 60, 80 and 100% soil were replaced by beverage sludge in other treatments. The maximum growth of Indian Spinach and Okra was observed 120% and 125% higher at 38 days after sowing on the treatment of 80% sludge and 20% soil compared to the control treatment. Similarly, the maximum yield of Indian spinach and Okra was computed to be nine and two times higher than the control on the same treatment. Food values (ascorbic acid, β- carotene, and protein) and nutrients (Fe, Ca, Mg, K, P and Zn) were found to increase with the increasing amount of beverage sludge while those satisfy the standards of USDA. Without using any kind of fertilizer in low grade soil, the beverage sludge has shown the potentiality in both growth and yield. It turns out that beverage sludge can be used as a substitute for chemical fertilizer with an optimum amount of 80%.

Microalgae cultivation in wastewater effluent from tilapia culture pond for enhanced bioethanol production

The large number of wastewaters are generated because of the various production processes. Vegetable and fish processing can be considered an important industry for wastewater generation. The essential method for completing this waste is to digest the organic matter using anaerobic digestion followed by aerobic wastewater treatment processes; however, wastewater from tilapia culture pond retains considerable quantities of inorganic substances, particularly nutrients like nitrogen and phosphorus. The optimal conditions for cultivating Chlorella vulgaris from wastewater treatment effluent from tilapia culture pond were investigated in this study. The appropriate conditions were found to be 10% initial stock suspension, 20 cm depth, and 12 days of culture conditions. C. vulgaris had an optical density of 0.649, a cell density of 17.68 × 105 cells/mL, and biomass of 0.376 ± 94.21 mg/L after cultivation. Discharged wastewater from the fishpond was utilized for the improved growth of microalgae and obtained biomass was used for bioethanol production. This study verified that fishpond wastewater is the best source of nutrients for algal mass production and biofuel applications.

AN OVERVIEW ON DAIRY INDUSTRY WASTEWATER AND ITS INDIAN SCENARIO

The dairy industry continues to grow with the growing population. It is considered the most polluting industry in terms of water consumption and wastewater generation. It generates about 6 to 10 litres of organically loaded effluent per litre of milk processed depending upon the products manufactured. Indian Standard (IS) 8682:1977 gives the guidelines for the treatment and disposal of dairy wastewater to protect the environment. The dairy effluent generally has dilutions of milk products generated from washing of floor, storage means such as cans, tanks, milk spillage, liquid effluent of cheese, paneer and yoghurt production called whey. It has high Chemical Oxygen Demand (COD) due to presence of organic contents because of fats, proteins and carbohydrates. To reduce the effect of the dairy wastewater on the environment, it is necessary to adapt some advanced techniques. Generally, all the food industries including the dairy industry look upto the membrane processes to recycle and reuse the wastewater. Membrane filtration is not only used for reclamation and reuse but also for fractionation of whey, recovery from cleaning solutions and various other processes. Thus, this paper is a mini review which gives various details about the dairy industry wastewater.

Assessment and reform of greywater reuse policies and practice: a case study from Sharjah, United Arab Emirates

This article presents an assessment of one of the earliest greywater reuse (GWR) experiences in Sharjah, United Arab Emirates (UAE). In 2003, the Sharjah Electricity and Water Authority (SEWA) imposed a compulsory GWR program on various categories of new buildings in the city. However, implementation of the program faced significant resistance and setbacks and remained limited to about 200 buildings, representing less than 2% water savings. In the analysis presented in this study, the need for GWR was assessed through analyzing SEWA's water supply and demand projections, conducting a 12-month water use survey of 285,000 Sharjah residents from about 140 nationalities, and identifying the areas in the city with intense water use. In addition, analysis and reforms of the various aspects of SEWA's GWR reuse policies and practice were presented and discussed. Reforming the policy to increase GWR to about 10% water savings can lead to significant reductions in desalinated water consumption and wastewater generation and consequently significant reductions in desalination cost (35 million USD/y), energy consumption (225,840 MWh/year) and CO2 emissions (120 ton/year). The case study presented in the article can serve as a reference to guide GWR policies and practice, especially for local authorities in developing countries.