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The presence of heavy metals in surface water, which is common in mining area pose harmful effect to human health and the environment. Recently, cocopeat has been studied as an effective sorbent material for removing heavy metals from wastewater. In this study, kinetic was done by analyzing the distribution of the heavy metal in sorbent material and liquid phase after mixing 50 mg/L solution of lead (Pb2+) and zinc (Zn2+)in single solute system with 0.1 g of coco-peat, that were consequently shaken at 5, 10, 15, 30, 60, 120, 180 and 360 minutes. To determine the equilibrium adsorption isotherm for each heavy metal, the solutions of 10, 20, 30,40 and 50 mg/L of Pb2+ and Zn2+ were prepared separately. Two different pH levels (natural pH, and pH 4) were setto describe the sorption behavior of Pb2+ and Zn2+ of each heavy metal.Using data from batch experiments, appropriate kinetic (time dependency) and equilibrium (isotherm) models were fitted on the sorbent material and liquid phase concentrations to determine adsorption parameters. Pseudo second-order kinetic model fitted well to the kinetic data due to chemisorption that happened during experiments. In other hand, Langmuir model fitted well to the equilibrium, this indicates that the sorption of lead and zinc on coco peat is monolayer and that the adsorbent’s surface is homogenous. The increase of heavy metals adsorption following the increase of pH might be due to negative charge of coco peat surface. Pb2+ adsorbed more than Zn2+ because ion with high hydration enthalpy will have smaller amount of ion adsorbed. The hydration enthalpies for Pb2+ and Zn2+ are 23 kJ/kg and 113 kJ/kg, receptively. Considering all the factors that we have discussed, cocopeat has high efficiency to remove the heavy metals from wastewater. Keywords: Coco-peat, adsorption, batch experiment, kinetic, equilibrium.

This paper investigates on Pb concentrations and mobility in soil of overall Yogyakarta City, Indonesia. The objectives of this study include to investigate Pb concentrations in the surface soil throughout Yogyakarta and to study their possible sources and potential environmental impacts. The soil samples from 168 locations in Yogyakarta was obtained, representing different land use and traffic conditions. Spatial analysis and sequential extraction analysis were performed. Generally, contour pattern of Pb value clearly shows that high value is concentrated in the middle and few north part of the study area, confirmed by traffic condition in the study area. In general, the results of sequential extraction analysis shows that Pb was predominantly associated with exchangeable fraction. The presence of lead in the exchangeable fractions may pose a serious environmental concern since they are highly soluble and potentially bio-available in the soil of study area. Keywords: Soil, lead contamination, GIS, sequential extraction.

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The eruptions of Merapi Volcano began in late October 2010 and continued into early November 2010. Among parts of materials ejected by Merapi Volcano, volcanic ash is considered to be a respiratory health hazard because of several potentially toxic components: respirable crystalline silica and metals. The objective of this study is to review the grain size of volcanic ash and to analyze the composition of volcanic ash which is suspected to carry a variety of potentially toxic elements. The result of this study shows that very fine grain size of volcanic ash were detected which has a potential to become respiratory problem trigger. The heavy metals were also detected in ash samples. On the other hand, total sulfur content was also considered high and the source of this sulfur was sulfur dioxide during eruption. Keywords: Merapi volcano, eruption, volcanic ash, health hazard, toxic elements.

Logam berat yang berasal dari dekomposisi sampah mempunyai dampak yang buruk bagi lingkungan terutama tanah dimana pencemar akan dapat terdistribusi baik secara lateral maupun vertikal oleh aliran air. Penelitian ini bertujuan untuk mengevaluasi pencemaran tanah oleh logam berat yaitu Pb, Cu, Zn dan Cd di sekitar tempat pembuangan akhir (TPA) sampah di Piyungan, Bantul, Yogyakarta. Sampel tanah diambil secara intensif sebanyak 75 sampel yang diperoleh dari 15 titik pemboran. Sampel tanah diambil dari tiga zona yakni upper slope (PU) yang berada di atas TPA, zona interface (PI) yang berhubungan langsung dengan TPA dan zona downslope (PD) yang berada di bawah TPA. Sampel tanah yang langsung berhubungan dengan TPA sampah (sampel PI) menunjukkan konsentrasi logam berat yang lebih tinggi dibandingkan dengan bagian upper slope (PU) maupun downslope (PD) dari area TPA sampah. Hasil penelitian juga menunjukkan bahwa konsentrasi Pb Cu dan Zn dalam sampel tanah masih berada kondisi normal atau alamiah. Hasil penelitian juga menunjukkan bahwa secara umum, konsentrasi logam berat terakumulasi pada kedalaman 25 cm dan kemudian menurun pada kedalaman 50 cm sampai 100 cm. Kondisi lapangan menunjukkan bahwa infiltrasi dari air lindi sebagai hasil dari dekomposisi sampah merupakan sumber utama pencemaran logam berat pada tanah di daerah penelitian. Secara umum, sifat fisik dan kimia tanah di daerah penelitian mempunyai potensi yang cukup baik dalam menahan migrasi logam berat ke dalam tanah, namun demikian adanya perubahan besaran infiltrasi air hujan akan dapat berpotensi memobilisasi logam berat sehingga dapat mencemari airtanah dalam jangka waktu yang lama. Kata kunci: pencemaran, logam, tanah, sampah, tpa

Kecamatan Gedangsari, Gunungkidul, Yogyakarta merupakan daerah yang didominasi oleh perbukitan dan sering mengalami tanah longsor. Penelitian ini bertujuan untuk melakukan pemetaan kerawanan tanah longsor di daerah penelitian dengan metode Analytical Hierarchy Process (AHP). Parameter yang digunakan dalam pembobotan dan perhitungan AHP meliputi parameter jenis batuan atau litologi, kemiringan lereng, dan tata guna lahan. Hasil perhitungan pembobotan AHP menunjukkan bahwa kemiringan lereng menduduki peringkat paling tinggi, disusul oleh jenis batuan, dan tata guna lahan. Peta kerawanan tanah longsor menunjukkan bahwa Desa Tegalrejo dan Mertelu didominasi oleh zona kerawanan tanah longsor yang tinggi, sedangkan desa yang lain berada di zona kerawanan sedang hingga rendah. Hasil pemetaan ini dapat digunakan oleh masyarakat dan pemerintah setempat sebagai dasar tindakan mitigasi dan pengembangan wilayah.