S.H. Fauziah

Challenges and issues in moving towards sustainable landfilling in a transitory country - Malaysia

Malaysia disposes of 28 500 tonnes of municipal solid waste directly into landfills daily. This fact alone necessitates sustainable landfills to avoid adverse impacts on the population and the environment. The aim of the present study was to elucidate the issues and challenges faced by waste managers in moving towards sustainable landfilling in Malaysia. Various factors influence the management of a landfill. Among them is the human factor, which includes attitude and public participation. Although Malaysia’s economy is developing rapidly, public concern and awareness are not evolving in parallel and therefore participation towards sustainable waste management through the ‘reduce, reuse and recycle’ approach (3Rs) is severely lacking. Consequently, landfill space is exhausted earlier than scheduled and this is no longer sustainable in terms of security of disposal. Challenges also arise from the lack of funding and the increase in the price of land. Thus, most waste managers normally aim for ‘just enough’ to comply with the regulations. Investment for the establishment of landfills generally is minimized since landfilling operations are considered uneconomical after closure. Institutional factors also hamper the practice of sustainable landfilling in the country where 3Rs is not mandatory and waste separation is totally absent. Although there are huge obstacles to be dealt with in moving towards sustainable landfilling in Malaysia, recent developments in waste management policy and regulations have indicated that positive changes are possible in the near future. Consequently, with the issues solved and challenges tackled, landfills in Malaysia can then be managed effectively in a more sustainable manner.

Characterization and toxicological evaluation of leachate from closed sanitary landfill

Landfilling is a major option in waste management hierarchy in developing nations. It generates leachate, which has the potential of polluting watercourses. This study analysed the physico-chemical components of leachate from a closed sanitary landfill in Malaysia, in relation to evaluating the toxicological impact on fish species namely Pangasius sutchi S., 1878 and Clarias batrachus L., 1758. The leachate samples were taken from Air Hitam Sanitary Landfill (AHSL) and the static method of acute toxicity testing was experimented on both fish species at different leachate concentrations. Each fish had an average of 1.3 ± 0.2 g wet weight and length of 5.0 ± 0.1 cm. Histology of the fishes was examined by analysing the gills of the response (dead) group, using the Harris haemtoxylin and eosin (H&E) method. Finneys’ Probit method was utilized as a statistical tool to evaluate the data from the fish test. The physico-chemical analysis of the leachate recorded pH 8.2 ± 0.3, biochemical oxygen demand 3500 ± 125 mg L−1, COD 10 234 ± 175 mg L−1, ammonical nitrogen of 880 ± 74 mg L−1, benzene 0.22 ± 0.1 mg L−1 and toluene 1.2 ± 0.4 mg L−1. The 50% lethality concentration (LC50) values calculated after 96 h exposure were 3.2% (v/v) and 5.9% (v/v) of raw leachate on P. sutchi and C. batrachus, respectively. The H&E staining showed denaturation of the nucleus and cytoplasm of the gills of the response groups. Leachate from the sanitary landfill was toxic to both fish species. The P. sutchi and C. batrachus may be used as indicator organisms for leachate pollution in water.

Marine debris composition and abundance: A case study of selected beaches in Port Dickson, Malaysia

Malaysia has a long coastline and is well known for its beautiful beaches which play different roles, depending on the characteristics and location. With increasing population and rapid development, the beaches are experiencing threats from pollution. One of the most visible threats is due to solid waste disposal. A scientific quantitative dataset of marine debris in Malaysia is, however, very rare. Therefore, a study on marine debris was conducted on two beaches in Port Dickson, Malaysia, from January to March 2010. The objective of the study was to compare the density of waste on two selected beaches with different economic activities. Teluk Kemang and Pasir Panjang are recreational and fishing beaches, respectively. Pasir Panjang received at least 2 units of debris for every 2 m2 (0.495 ± 0.108 items m−2), weighing 46.079 ± 12.507 g m−2. Debris found in Teluk Kemang was lower than that of Pasir Panjang with 1 unit of waste for every 2 m2 (0.262 ± 0.045 items m−2), weighing 2.067 ± 1.238 g m−2. Based on the number of items, plastics were the most abundant type of debris at 64% in Teluk Kemang and 46% in Pasir Panjang. In terms of weight, paper was higher (48%) than plastic (43%) in Teluk Kemang, while the highest percentage of debris found on Pasir Panjang beach was bulky waste (54%). The number of items and weight of debris were higher in Pasir Panjang due to the abundance of huge and heavy abandoned nets from fishing activities left on the beach. Daily clean-ups of Teluk Kemang, a popular recreational beach, contributed to significantly lower amounts of debris found there. On the whole, types of waste found on both beaches were similar. However, the percentage and amount of each wastes type varied between the two beaches. The results indicated that the density of waste is highly dependable on the economic activities of the relevant beaches.

Plastic debris in the coastal environment: The invincible threat? Abundance of buried plastic debris on Malaysian beaches

Studies on marine debris have gained worldwide attention since many types of debris have found their way into the food chain of higher organisms. Thus, it is crucial that more focus is given to this area in order to curb contaminations in sea food. This study was conducted to quantify plastic debris buried in sand at selected beaches in Malaysia. Marine debris was identified according to size range and distribution, and this information was related to preventive actions to improve marine waste issues. For the purpose of this study, comparison of plastic waste abundance between a recreational beach and fish-landing beaches was also carried out, since the different beach types represent different activities that produce debris. Six beaches along the Malaysian coastline were selected for this study. The plastic types in this study were related to the functions of the beach. While recreational beaches have abundant quantities of plastic film, foamed plastic including polystyrene, and plastic fragment, fish-landing beaches accumulated line and foamed plastic. A total of 2542 pieces (265.30 g m-2) of small plastic debris were collected from all six beaches, with the highest number from Kuala Terengganu, at 879 items m-2 on Seberang Takir Beach, followed by Batu Burok Beach with 780 items m-2. Findings from studies of Malaysian beaches have provided a clearer understanding of the distribution of plastic debris. This demonstrates that commitments and actions, such as practices of the ‘reduce, reuse, recycle’ (3R) approach, supporting public awareness programmes and beach clean-up activities, are essential in order to reduce and prevent plastic debris pollution.

Leachate risk and identification of accumulated heavy metals in Pangasius sutchi

Pollutants put great stress on the environment, especially the aquatic ecosystem; therefore, the ease with which pollutants migrate in water is a subject of global concern. In this study, leachate from landfill that was analyzed with the objective of understanding the potential impact to the environment was tested on Pangasius sutchi. Heavy metals available at various concentrations in raw leachate samples of both closed and active landfills necessitated the determination of their degree of bioaccumulation in this fish species in order to enrich the risk data on toxicity of effluents. Zinc (3.2 µg g−1), iron (2.1 µg g−1) and chromium (0.24 µg g−1) detected in the fish within 96 h of acute exposure is of concern. A histopathology test on excised liver of P. sutchi indicated cellular disruption from normal stain. Heterogeneous effluents like leachate may affect not only groundwater but can endanger aquatic ecosystems, especially in some regions where improper waste disposal and treatment allow the flow of leachate into surface water courses. Though metals might be beneficial to organisms, the extent at which they can accumulate in leachate-exposed fish is a risk and can initiate metal toxicity in aquatic life.

Biodegradation of benzo[a]pyrene by bacterial consortium isolated from mangrove sediment

ABSTRACT Benzo[a]pyrene is a high-molecular-weight polycyclic aromatic hydrocarbon highly recalcitrant in nature and thus harms the ecosystem and/or human health. Therefore, its removal from the marine environment is crucial. This research focuses on benzo[a]pyrene degradation by using enriched bacterial isolates in consortium under saline conditions. Bacterial isolates capable of using benzo[a]pyrene as sole source of carbon and energy were isolated from enriched mangrove sediment. These isolates were identified as Ochrobactrum anthropi, Stenotrophomonas acidaminiphila, and Aeromonas salmonicida ss salmonicida. Isolated O. anthropi and S. acidaminiphila degraded 26% and 20%, respectively, of an initial benzo[a]pyrene concentration of 20 mg/L after 8 days of incubation in seawater (28 ppm of NaCl). Meanwhile, the bacterial consortium decomposed 41% of an initial 50 mg/L benzo[a]pyrene concentration after 8 days of incubation in seawater (28 ppm of NaCl). The degradation efficiency of benzo[a]pyrene increased to 54%, when phenanthrene was supplemented as a co-metabolic substrate. The order of biodegradation rate by temperature was 30°C > 25°C > 35°C. Our results suggest that co-metabolism by the consortium could be a promising biodegradation strategy for benzo[a]pyrene in seawater.

Removal of bisphenol A and 2,4-Di-tert-butylphenol from landfill leachate using plant- based coagulant:

Landfill leachate contain persistent organic pollutants (POPs), namely, bisphenol A (BPA) and 2,4-Di-tert-butylphenol, which exceed the permissible limits. Thus, such landfill leachate must be treated before it is released into natural water courses. This article reports on investigations about the removal efficiency of POPs such as BPA and 2,4-Di-tert-butylphenol from leachate using locust bean gum (LBG) in comparison with alum. The vital experimental variables (pH, coagulant dosage and stirring speed) were optimised by applying response surface methodology equipped with the Box–Behnken design to reduce the POPs from leachate. An empirical quadratic polynomial model could accurately model the surface response with R2 values of 0.928 and 0.954 to reduce BPA and 2,4-Di-tert-butylphenol, respectively. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were performed on treated flocs for further understanding. FTIR analysis revealed that the bridging of pollutant particles could be due to the explicit adsorption and bridging via hydrogen bonding of a coagulation mechanism. SEM micrographs indicated that the flocs produced by LBG have a rough cloudy surface and numerous micro-pores compared with alum, which enabled the capture and removal of POPs from leachate. Results showed that the reduction efficiencies for BPA and 2,4-Di-tert-butylphenol at pH 7.5 were 76% and 84% at LBG dosage of 500 mg·L−1 and 400 mg·L−1, respectively. Coagulant dosage and pH variation have a significant effect on POPs reduction in leachate. Coagulation/flocculation using LBG could be applied for POPs reduction in leachate as a pre-treatment prior to advanced treatments.

Plastic Debris Pollution on Recreational Beaches: A Malaysian Case Study

The significance of marine debris presence particularly plastic in marine ecosystem calls for proper monitoring strategies to establish a solid foundation for mitigation measures. The objectives of this paper are to study plastic debris distribution while correlating it to the level of awareness on marine pollution among beach users. It is aimed to investigate the impacts of tourism activities and the abundance of plastic debris on the beach. To quantify plastic debris on the beach, five points with duplicates were taken for three consecutive months. These sand samples were sieved through 1.00mm, 2.80mm and 4.7mm apertures. On the other hand, questionnaires were distributed to 625 beach users to study the awareness on issues related to marine pollution. Results indicated that the most crowded site accumulated the highest number of plastic debris (59 items), ranging between 1.00mm to 2.8mm (48% of the total weight of plastic). Debris sizing 4.75mm and more only contributed 41% of the total weight. Questionnaires data revealed that 2.4% of the respondents admitted to leave waste on the beach particularly if no garbage bins are provided, while the majority (92%) collect and throw the waste elsewhere. As for the cause of polluted beaches, 56% believed it is due to the indifferent attitude of the beach users that 20% of the respondents felt that stricter law should be enforced. It can be concluded that the number of plastic debris is highly influenced by the number of beach users. On the other hand, though it is lower in weight, smaller debris makes the largest number of items on the beach. While public believe that more stringent enforcement should be in place, an efficient waste management is also vital to prevent further detrimental impacts of plastic debris to the marine ecosystem.

Effect of Interaction between Earthworm and Microbes on the Degradation Time of Agro-Waste

Impact of macro-organisms in biological processes had been considerably studied but some of the discrete interactions that exist between macro- and micro-organisms still remain complex and sometimes elusive. Agro-waste is a type of waste that remains highly inevitable in our society and its disposal is a subject of concern. Therefore, this study aimed to degrade sugarcane bagasse which is a significant agro-waste in Malaysia, while trying to understand the interaction between microbes and earthworm utilized in the bioprocess. Sugarcane bagasse was blended with spent tea in equal ratio before composting with the aid of Eudrilus eugeniae and introduced microbial consortia. Though varied, pH values across the amendments tended towards alkaline state, just as the available Phosphorus (P) and exchangeable Potassium (K) increased in the value. Total organic carbon (TOC) across the amendments showed reduction in value; 47% in TS (tea and sugarcane bagasse), whereas 25% in TS6M (Tea + sugarcane bagasse + 6 microbes) and 68% in TS3M (tea bagasse + 3 microbes). However, weight loss in Eudrilus eugeinae was found to be proportional to the reduced time of degradation. TS3M at 33% worm weight loss was recorded at 11 day degradation time, than TS6M (27%) and TS (16%) that showed 13 and 20 days degradation time respectively. Weight loss in earthworm is correlated with microbial interaction and can be a reflection of rate decomposition of organic components of agro-waste in a vermicomposting process.

Closure and post-closure of landfills in Malaysia: lessons learnt.

The disposal of approximately 90% of more than 30,000 tonnes of municipal solid waste (MSW) generated daily into 167 sanitary and non-sanitary landfills depict the importance of landfill in Malaysia. The objective of this paper is to explore issues pertaining to the closure and post-closure of landfills in Malaysia using four types of disposal facilities. The closure of a properly planned Air Hitam Sanitary Landfill (AHSL) saw the management of the closure and post-closure activities at the utmost efficiency. The landfill has become the blueprint of energy conversion technology with a capability of 2MW. Unfortunately, closure of non-sanitary disposal sites were not as successful as that in AHSL. Kundang landfill, a non-sanitary landfill was ordered to be closed immediately in 2007 since it continues to contaminate the surrounding area. Regardless of its non-active status, untreated leachate with 280 440.00 g/day of COD pollutes the river which may affect the environmental quality of the area. Similar scenario was also observed at other sites, namely two reclaimed ex-mining land for commercial and residential area. One was operating as dumping area before its closure in 2000. It was developed and converted into residential and commercial area including terrace houses, high rise apartments, and commercial buildings. Improper planning of the closure resulted with contamination of arsenic (64.4 mg/kg) and mercury (11.5 mg/kg) to the surrounding soil. Another case study saw extensive reclamation of an ex-mining pond with MSW including domestic, industrial, and construction debris. The lack of appropriate planning of the conversion of the land-use resulted with contamination of surface water with hydrogen sulphide alarmed the residents. The area recorded presence of hydrogen sulphide gas which reached approximately 200 ppm. Thus, it can be concluded that proper closure and post-closure strategies are crucial for landfills and disposal sites. The need for proper policies and guidelines on post-closure and the uniformity of these regulations would ensure standardised landfill remediation with minimal environmental impacts.