Heavy Metals in Surface Soils of Kota Bharu Landfill Site and its Relations to The Growth and Macronutrients Uptake of Acacia Mangium

A study of heavy metals distribution in landfill surface soil, surface water and landfill leachate and its relations to Acacia mangium growth and macronutrients uptake was conducted in a landfill in Kota Bharu, Kelantan. Five heavy metals, particularly Fe, Cr, Zn, Cu and Cd was analyzed in this study and results shows elevated heavy metals concentration level compared to the control surface soil. The distribution of the heavy metals in the surface soil from the landfill varies throughout the study site. The concentration decreased prominently in the river sediment adjacent to the landfill. The concentration of Fe was the highest that ranged between 1993.4 – 2404.6μg/g, followed by Zn, 18.08 – 54.10 μg/g; Cr, 2.67 – 62.10 μg/g; Cu, 5.21 – 18.60 μg/g and Cd, 0.70 – 1.52 μg/g of soil dry weight. However, compared to DOE soil threshold concentration, this landfill was only slightly contaminated with Cd that exceeds the threshold with an average of 0.94 μg/g. Heavy metals speciation by sequential extraction of landfill surface ii soil shows that the surface soil was not yet contaminated with heavy metals as the anthropogenic fraction is less than 30% of the total concentration of heavy metals of the surface soil and mainly attached to the organic matter. Concentration of heavy metals in landfill leachate shows higher level than the surface water. However, the levels of heavy metals in both water samples were still considered as low compared to other landfills due to dilution by rain and river nearby. Cu concentrations in water samples were generally higher than other heavy metals that ranged between 0.03 – 6.14 mg/L whereas Cd and Cr were generally very low, below detectable limits. The level of accumulation in A. mangium leaves was highest for Fe that ranged between 139.5 – 537.6 μg/g, followed by Cr 45.54 – 357.3 μg/g, Zn 29.36 - 57.23μg/g, Cu 6.88 - 15.61μg/g and Cd 1.63 - 3.48μg/g. However, Fe shows no significant difference in the level of accumulation between landfill and control plants. Heavy metals accumulation level in A. mangium leaves have very wide range dependent on the leaves sampled. However, from the soil-plant concentration ratio, heavy metals uptakes by A. mangium in landfill site were found higher than control plants especially for Cr and Cd. Generally the concentration of heavy metals was found so much higher in the plants tissues rather than in the landfill surface soil and landfill leachate or surface water. Relation between heavy metals accumulation in A. mangium and growth and macronutrient uptake was not demonstrated this study as the N, P, K level in control and landfill site do not show any significant correlation with heavy metals concentrations. Uptakes of N and P in landfill A. mangium were found higher than control but on the contrary, K was found higher iii in control plants. Growth of A.mangium in landfill was slightly different with control plants as there are tendency of A. mangium in landfill site to produce many branches, leaves and incisive increase of trunk diameter whereas, control plants tends to gained heights very quick. This is due to different soil type and climatic factors influence rather than heavy metals level in the plants’ tissue. This study also proposed A. mangium is tolerant to Cd and Cr however the use of A. mangium as general bioindicator for heavy metals was not probable as only Cd and Cr was highly accumulated. A. mangium can be used for phytoremediation of low contaminated soil as shown in his study. Furthermore, landfill site is this study found it suitable to be used as A. mangium culture site

Acacia mangium Willd. and Melaleuca cajuputi Powell as potential heavy metal accumulators in sewage sludge-contaminated soils

Waste disposal in Malaysia faces serious challenges and has caused soil pollution. There are currently over 6 million cubic meters of sewage sludge in Malaysia requiring safe disposal. Phytoremediation is the use of plants to remediate polluted soils and this approach has not been practised in Malaysia. This study aimed to assess the potential and viability of two tropical timber species to remediate heavy metal contaminated soil. A greenhouse and field experiments were conducted to evaluate Acacia mangium Willd and Melaleuca cajuputi Powell to extract heavy metals namely Zinc (Zn), Copper (Cu) and Cadmium (Cd) from sewage sludge contaminated soils. Results showed that under greenhouse conditions, both species are tolerant to Zn, Cu and Cd and could accumulate high concentrations of these elements especially in the roots. The leaves of A. mangium accumulated 156.96mg/kg of Zn and 135.20mg/kg in M. cajuputi leaves. In the roots, the concentrations were 266.25mg/kg and 137.19mg/kg, respectively. Accumulation of Zn in the stems of A. mangium was 102.24mg/kg and 107.50mg/kg for M. cajuputi. Accumulation of Cu in the leaves of A. mangium was higher (20.74mg/kg) than in M. cajuputi (9.53mg/kg) and in the roots it was 25.29mg/kg and 20.85mg/kg, respectively. The stems of M. cajuputi accumulated more Cu (19.27mg/kg) than A. mangium (14.01mg/kg). The accumulation of Cd in the stems and roots were greater in M. cajuputi with concentrations of 1.78mg/kg and 2.05mg/kg, compared in A. mangium at 1.51 mg/kg and 1.66 mg/kg, respectively. Accumulation of Cd in the leaves of A. mangium was slightly higher (1.93mg/kg) than M. cajuputi (1.66mg/kg). The study under field conditions shows that stems of A. mangium accumulated up to 130.0mg/kg of Zn and in the leaves it was up to 100.0 mg/kg. Accumulation of Cu by A. mangium in the stems was about 17.0mg/kg and in the leaves was about 22.0mg/kg. The accumulation of Cd in the stems was 1.23 - 1.62mg/kg. However, Cd accumulation in the A. mangium leaves was 0.3 - 1.6mg/kg. Accumulation of Zn in M. cajuputi leaves was higher (80 - 100.0mg/kg) than in the stems (60 - 70.0mg/kg). The stems of M. cajuputi accumulated 9.0 - 22.0mg/kg Cu and in the leaves it was 4.0 - 15.0mg/kg. While Cd accumulation in the stems was 0.30 - 0.45mg/kg and in leaves it was 0.25 - 0.4mg/kg. In the greenhouse experiment, both species show low ability to accumulate Cu and Cd as reflected by low BCF (BCF ≤ 1) but translocate high amounts of all three elements to the shoots as shown by high TF (TF ≥ 1). On the other hand, in the field experiment, A. mangium showed good ability (BCF ≥ 1) for extracting Zn and Cd but only Zn for M. cajuputi. However, M. cajuputi stems accumulated more heavy metals compared to the leaves indicating that the heavy metals can be stored for a longer period. Phytoextraction efficiency of A. mangium was better than M. cajuputi as the biomass generated in the field experiment after 12 months was about 72 tonnes/ha compared to only 4 tonnes/ha in case of M. cajuputi. It was estimated that A. mangium is able to extract 16.49kg/ha Zn, 2.80kg/ha Cu and 0.12kg/ha Cd per year whereas M. cajuputi could only extract 12.91kg/ha/year, 2.65kg/ha/year and 0.06kg/ha/year of the three heavy metals, respectively. The trees also affect mobility of Zn, Cu and Cd in the soil as shown by high fractions of the ionic and reducible forms of these metals at the beginning. The mobility reduced at the end of the study where these two fractions were reduced to about 2% from 69% for Cu and about 23% from 53% for Cd but Zn remained the same. Principal component analysis of the soil chemical properties shows humic acids played an important role (1st component) in heavy metal stabilization in the soil after planting and the effects of pH and CEC on metal mobility were reduced (2nd component) thus lowering the risk of these elements from spreading. The cost-effective economic evaluation of A. mangium in this study for a 10-year rotation period was estimated to cost only MYR 231,800.00/ha compared to MYR 3 million/ha using the conventional soil remediation techniques. Within this period, over 35, 800 tonnes of carbon/ha was produced that could generate returns of about MYR 1.9 million/ha. Timber production was estimated at 25,300m3/ha and could generate returns of about MYR 6.33 million/ha. Hence, this study shows that phytoremediation using trees species is economically viable for disposal of sewage sludge

Efficiency and feasibility of Acacia mangium in extracting heavy metals from contaminated soil

Contamination of soil by heavy metals commonly occurs and remediation is required before the soil is suitable for normal use. Phytoremediation is a low cost and reliable technique to remediate contaminated soil but this technique is not yet commonly used in Malaysia. In addition, phytoremediation using timber species are rarely reported. This study aims to evaluate the efficiency and feasibility of Acacia mangium, a renowned timber species in Malaysia to remediate heavy metals namely Zn, Cu and Cd contaminated soil. A pilot study was conducted in which over 200 saplings of A. mangium were planted in rows on a sewage sludge disposal site with distance of 2m apart. The growth of the trees planted was recorded for 12 months and total aboveground biomass was determined at the end of the experiment period. Results show that A. mangium accumulates 200mg/kg of Zn, 40mg/kg of Cu and 2.0mg/kg of Cd in their aboveground biomass. Thus it can be estimated that 339t/ha of biomass would be required to remove 79.8kg/ha of Zn; 1173t/ha and 1165t/ha of biomass to remove 46.9kg/ha and 2.33kg/ha for Cu and Cd, respectively. This study shows that a hectare of A. mangium plantation could generate aboveground biomass over 2,044t/ha within just 3 years, which is above the requirement needed to remove Zn, Cu and Cd of the amount stated above. Furthermore, if the biomass estimation was set to a 10-year period, over 31,000t/ha could be produced with over 25,300m3 of timber which could generate a substantial income for the remediation project and have high potential for this soil remediation technique to be commercialized

Growth performance, biomass and phytoextraction efficiency of Acacia mangium and Melaleuca cajuputi in remediating heavy metal contaminated soil

Heavy metals are very toxic and soil contaminated with sewage sludge urgently need remediation in order to avoid related health hazards. Phytoremediation is a low cost and reliable technique to remediate heavy metal contamination. However phytoremediation using timber species was rarely reported and its efficiency was questionable. A field study was conducted to examine the efficiency of two timber species namely Acacia mangium and Melaleuca cajuputi in phytoextraction of Zn, Cu and Cd from contaminated soil. Two hundred of A. mangium and M. cajuputi were planted on sewage sludge disposal site and the growth was recorded for 12 months before at the end total biomass of each species was determined. Results show in 12 months, about 72 and 4 t ha−1 of aboveground biomass can be produced by A. mangium and M. cajuputi, respectively. Both species show potential for phytoremediation, however A. mangium is more efficient compared to M. cajuputi where efficiency of A. mangium to remove Zn was 24.4, 6.2 for Cu and 9.5% for Cd. As for M. cajuputi the efficiency was 1.3, 0.3 and 0.14% for Zn, Cu and Cd, respectively. It is projected that A. mangium require 5, 17 and 20 years to remove 79.82 kg ha−1 of Zn, 46.94 kg ha−1 of Cu and 2.33 kg ha−1 of Cd, respectively

Assessment of Melaleuca cajuputi as heavy metals phytoremediator for sewage sludge contaminated soil

In 2011, total marine capture landings in Peninsular Malaysia decreased by 3.9% which amounted to 1,373,105 tonnes as compared to 1,428,881 tonnes in 2010. The decline is connected to marine pollution which mainly comes from land based sources. Coastal forests play an important role affecting the marine ecosystem health and need to be conserved as a buffer to minimize pollution input into marine ecosystem. Heath forest, a type of coastal forest that receives less attention compared to mangroves, also has similar role. Melaleuca cajuputi that dominates heath forest has high potential as a phytoremediator of heavy metals and also has high economic values. A greenhouse experiment was conducted to evaluate the potential of this species to extract heavy metals namely Zn and Cd from soil. Four levels of treatment were prepared where the test media was mixed with different amounts of sewage sludge (v/v) namely; T1 (control-soil only), T2 (30% sludge +70% soil), T3 (50% sludge + 50% soil) and T4 (70% sludge + 30% soil). After 90 days of experimental period, the accumulation of Zn was found to be high in the roots (137.19 mg kg-1), followed by the leaves (135.0 mg kg-1) and stems (102.24 mg kg-1). As for Cd the highest concentration was in the roots (2.05 mg kg-1), stems (1.78 mg kg-1) and leaves (1.66 mg kg-1). The species Transfer Factor (TF) values in the greenhouse experiment were > 1 but the Bio-Concentration Factor (BCF) values are≤ 1. This result shows that M. cajuputi is tolerant to Zn and Cd toxicity (low BCF) but able to transfer these elements (high TF) to the shoots for removal by leaf fall or by harvesting the shoots. In addition, the accumulation of Zn and Cd were high in the roots which suggests that Zn and Cd were efficiently immobilized (in the roots) from entering the marine ecosystem

Study of diversity and morphometry in edible bivalves and gastropods from a coastal wetland in Sarawak

Diversity and morphometry of edible, bivalve and gastropod classes of molluscs were investigated from July 2010 to January 2012, for a particular set of bivalve species, at selected coastal divisions of Sarawak including Kuching, Sibu, Mukah, Bintulu, Miri, Limbang, and Lawas. A total of 41 edible species were recorded and identified from 11 families of gastropods represented by 21 species, and from 12 families of bivalves represented by 20 species. For bivalves, species of the family Cyrenidae (Geloina erosa, G. expansa and G. bengalensis) were the most widely distributed bivalve species. The gastropod family Potamididae (Cerithidea obtusa, C. quadrata, C. rizophorarum and Telescopium telescopium) was also commonly observed over the entire seven divisions. Species diversity was found to be highest in Bintulu division for both classes, having 13 species of gastropods and 11 species of bivalves. Jaccard’s index showed high similarity amongst the edible bivalves for Limbang division with Miri division (0.75), and for Limbang with Lawas (0.75). For gastropods, Sibu versus Mukah showed high similarity (0.50). Morphometric study of the bivalves indicated that VPM/SL and LCT/SL features were applicable as an identification key to differentiate between Geloina spp. This morphometric identification key could be developed further for identification of other species in the mollusc family