Application of pesticide in paddy fields: a Southeast Asia case study review.

Pesticides are widely employed in rice crops since the ecosystem and surroundings of paddy promote insects, weeds, and fungal and bacterial pathogens. Each commonly utilised pesticide possesses different uses. For instance, fungicides control fungal issues, herbicides curb weed growth, and insecticides destroy and repel insects. Although several ways to categorise them exist, pesticides are typically classified according to their chemical compositions. Rice production remains one of the most dominant crops grown in most Southeast Asian countries as it is a staple food. Nonetheless, the crop is highly dependent on pesticides, leading to growing concerns over the potential adverse effects of pesticides on the environment and human health. Despite the availability of numerous studies on the subject, a comprehensive understanding of the specific effects of pesticides on paddy fields in Southeast Asia is still lacking. Consequently, reviewing existing knowledge is necessary for synthesising and identifying research gaps to better inform policymakers, farmers, and other stakeholders in the agricultural sector. The objectives of the present review paper were to review the interactions between pesticides and the environment by understanding the physical and chemical properties of the chemicals, compare pesticide transportation modes in air, water, and soil and how they affect the environment, and evaluate and discuss the effects of pesticides on non-targeted organisms. This study assessed pesticide innovation reported between 1945 and 2021 for a better understanding of the utilisation of the chemicals over time. The pesticides assessed in this study were classified based on their chemical compounds, such as organochlorines, organophosphates, carbamates, and pyrethroid. This review could provide a comprehensive understanding of the interactions between pesticides and the environment and their impacts on non-targeted organisms.

Environmental Remediation Potential of Ferrous Sulfate Waste as an Eco-Friendly Coagulant for the Removal of NH3-N and COD from the Rubber Processing Effluent.

The present study was conducted to determine the potential of utilizing the FeSO4·7H2O waste from the titanium manufacturing industry as an effective coagulant for treating industrial effluent. In this study, the secondary rubber processing effluent (SRPE) was treated using ferrous sulfate (FeSO4·7H2O) waste from the titanium oxide manufacturing industry. The FeSO4·7H2O waste coagulation efficiency was evaluated on the elimination of ammoniacal nitrogen (NH3-N) and chemical oxygen demand (COD) from SRPE. The central composite design (CCD) of experiments was employed to design the coagulation experiments with varying coagulation time, coagulant doses, and temperature. The coagulation experiments were optimized on the optimal elimination of NH3-N and COD using response surface methodology (RSM). Results showed that coagulant doses and temperature significantly influenced NH3-N and COD elimination from SRPE. The highest NH3-N and COD removal obtained were 98.19% and 93.86%, respectively, at the optimized coagulation experimental conditions of coagulation time 70 min, coagulant doses 900 mg/L, and temperature 62 °C. The residual NH3-N and COD in treated SPRE were found below the specified industrial effluent discharge limits set by DoE, Malaysia. Additionally, the sludge generated after coagulation of SRPE contains essential plant nutrients. The present study's finding showed that FeSO4·7H2O waste generated as an industrial byproduct in a titanium oxide manufacturing industry could be utilized as an eco-friendly coagulant in treating industrial effluent.

Removal of COD, BOD and nutrients in swine manure wastewater using freshwater green microalgae

@#Aims:The aim of this study was to investigate the effectiveness of freshwater green microalgae in remediating swine manure wastewater. Two different species of freshwater green microalgae (Scenedesmus quadricaudaand Stigeocloniumsp.) were used in this study.Methodology and results:Laboratory experiments were performed to compare the growth rate and nutrients (total phosphorus, ammonia nitrogen, nitrate nitrogen and nitrite nitrogen) uptake by these two species of microalgae in swine manure wastewater. Experimental work was carried out for 14 days at room temperature of 30±1 °C with about 1520 Lux of light intensity. The results showed that both microalgae grew well in swine manure wastewater. S.quadricaudaperformed better in remediating swine manure wastewater, by reducing 83.99% of COD, 80.39% of BOD5, 84.78% of total phosphorus (TP), 91.79% of ammonia nitrogen (NH3-N), 89.79% of nitrate nitrogen (NO3-N) and 87.14% of nitrite nitrogen (NO2-N) compared to Stigeocloniumsp. which was only able to remove 79.26% of COD, 76.27% of BOD5,75.17% of TP, 86.42% of NH3-N, 84.38% of NO3-N and 82.38 NO2-N.Conclusion, significance and impact of study:The results of this study indicate that these two species of microalgae have potential to be used in the remediation of swine manure wastewate