Wastewater treatment aims to eliminate as many suspended solids as possible from the remaining water, known as effluent, before it is released into the environment. Pond oxidation methods have been practically proven successful for the wastewater treatment process because of their low construction and maintenance costs. This study aimed to investigate the degradation of wastewater pollutants through an oxidation pond treatment system. The purpose was to observe the relationship between the concentration of bacteria which are phototrophic and coliform, chemical oxygen demand (COD), and dissolved oxygen (DO). In this paper, a modified model consist of a set of an ordinary differential equation (ODE) has been developed by incorporating the Monod Equation. The model was solved numerically using the 4th order Runge Kutta method embedded in the MATLAB software. The sum of squared estimate of errors (SSE) for the modified model was compared with the SSE of the existing model. The results revealed that the modified model demonstrated a lower SSE compared to the existing model. Thus, the modified mathematical model gives better result than the existing model. The model provides an excellent approximation for concentration needed for an oxidized pond to produce good water quality.

Reverse osmosis is a treatment process to produce highly purified water in wastewater management. However, the depth study on exploring and visualization of the publication in this area has not been made in detail. Hence, this study is designed to assess the worldwide research trends of the reverse osmosis field in terms of publication output, keywords, journals, countries, institutions, collaborations, research areas, authors, document types, and languages. This study aims to analyze the distribution patterns of reverse osmosis journal articles, the terminology, and the research topics. A bibliometric analysis was conducted on 6,939 research articles obtained from the Web of Science (WOS) database that were published from 1970 to 2019. The bibliometric map and network were generated using VOSviewer software. Results have shown that the most related keywords are desalination and nanofiltration. The most preferred journal with 40,314 total citations was published by Elsevier. Researchers from the United States contributed the most global publications. The most productive academic institution was the National University of Singapore among 25 leading countries. The reverse osmosis topic is mostly used in Engineering and Water Resources area. The researchers from South Korea were the most productive authors in this area. The findings of this study will enable interested researchers to understand the performance of reverse osmosis research worldwide and provide recommendations for further research.

The wastewater treatment process is aimed to reduce pollution to the appropriate level. An oxidation pond system can treat contaminants in wastewater. Oxidation ponds are use sunlight, bacteria, and algae to treat wastewater. This study developed an improved mathematical model and a graphical user interface (GUI), called oxi-P GUI to predict the wastewater treatment process in an oxidation pond. The correlation between dissolved oxygen (DO), chemical oxygen demand (COD), coliform bacteria, as well as concentrations of phototrophic bacteria (PSB) were examined. In MATLAB software, a revised model consisting of ordinary differential equations (ODEs) set of integrating the Monod equation was numerically solved utilising the fourth order Runge-Kutta method. The current model's root mean square error (RMSE) values were compared to the suggested model's RMSE values for model validation. The model offered a more accurate estimate than the existing model of changes in the amount of concentration in oxidation pond, which was necessary to produce acceptable water quality. A wastewater management personnel may use GUI to track water quality and determine the most effective wastewater treatment mechanism. Additionally, this user-friendly GUI will give a better understanding about the treatment process, especially to people with less programming skills.