Khai Ern Lee

Reactive Dye Removal Using Inorganic–Organic Composite Material: Kinetics, Mechanism, and Optimization

An inorganic–organic composite material (MCPAM) consisting of magnesium chloride and polyacrylamide, was applied to remove reactive dye (Cibacron Red FN-R) from aqueous solution through coagulation–flocculation process. MCPAM with the ratio of 90% MgCl2/10% PAM was the best ratio in removing reactive dye. Kinetics of reactive dye removal was investigated using pseudo-kinetics model and it fits pseudo-second-order reaction model. The mechanism of reactive dye removal was investigated through physicochemical properties of supernatant, flocs, and sludge. The change of conductivity and pH denotes the interactions between reactive dye and MCPAM. The chemical structure, settling, and microstructure of sludge indicate the formation of sludge during coagulation–flocculation process. The settled sludge volume and sludge volume index (SVI) that of MCPAM was lower than that of MgCl2. The flocs formed using MCPAM was also relatively compact and larger in size compared to that of MgCl2. The reactive dye removal was optimized through central composite design whereby color removal (%) and chemical oxygen demand (COD) reduction (%) were optimized by five operating factors, namely, concentration of dye, pH, dosage of MCPAM, agitation speed, and agitation time. The optimal values reported for color removal (%) and COD reduction (%) were of 97–98% and 60–81%, respectively.

Environmental Scan and Framework of Watershed Risk Assessment in Malaysia

Water is not only a resource, it is a life source; therefore, the water should be healthy, secure, and sustainable for people. Watersheds are nature’s boundaries for surface water supplies, and thus, the quality of the drinking water at a consumer’s tap depends on the quality of watershed. The risk assessment which is a process used to define the probability and magnitude of adverse effects of an environment from stressors can be used to estimate the costs and benefits of changes in a watershed in terms of risk. This chapter describes the source of pollution and the framework for assessing risk in Malaysian watershed.

An Integrated Approach for Stakeholder Participation in Watershed Management

Water is an essential element for life. However, the rapid urbanization and industrial development in the past decades have put stress on water resources. Water resource management is intended to solve watershed problems on a sustainable basis, and these problems can be categorized into lack of water (quantity), deterioration in water quality, ecological effects, poor public participation, and low output economic value for investment in watershed-related activities. Involvement of stakeholders is of utmost importance to ensure no one is left behind in the sustainable management of water resources. Hence, an integrated approach has emerged as a shift from the structural approach to a nonstructural approach, that is, from engineering-based solutions to community-based solutions, aiming to induce policy-driven institutional change, particularly the coordination and integration of multiple stakeholders toward sustainable watershed management

Institutional Arrangement and Legal Framework for the Management of Watersheds in Malaysia

Due to inadequate planning, rapid development and urbanization have polluted watersheds. Hence, watersheds must be managed properly to ensure their sustainability, by taking into account the importance of landscape and ecology and different socio-economic conditions, culture and religion. Among others, one of the ways to enhance watershed management is via adequate institutional arrangement and legal framework. This chapter has selected Malaysia as a case study, and by focusing on the discharge of pollutants, this chapter demonstrates how both federal and state governments complement each other to strengthen the regulatory framework in preventing pollution in watersheds. While the federal government regulates the discharge from manufacturing processes, the state government regulates activities that are not covered by the federal government, such as aquaculture and farming.