The Analysis of Content of Heavy Metals Cadmium (cd) in the Flow of the River Barumun Labuhanbatu Selatan

The number of community activities in the area of River Barumun Labuhanbatu South will produce heavy metals in the waters and will accumulate to the bottom of the waters in the sediment. This study discusses the content of heavy metal Cd in sungai Barumun Labuhanbatu Selatan. The research was conducted in December 2020 until January 2021 in the region of the waters of the River Barumun Labuhanbatu Selatan. The process of sampling using purposive sampling method. Data analysis was done descriptively by looking at the results of the measurements of some parameters of the waters and the test results of water samples in the laboratory by comparing the quality standard according to the Decision of the Minister of Environment No. 51 Year 2004. As for the test sediment samples in the laboratory compared with the raw quality of the concentration of heavy metals in the sediment IADC/CEDA 1997. The results of the heavy metal concentration of Cd in the surface water ranged 0,003-0,068 mg/l, the concentration of heavy metal cadmium in water depth of 5 meters has a range of 0.007-to 0.058 mg/l.

ANALISIS MUTU SEDIMEN HABITAT KERANG DARAH (Anadara granosa L) DENGAN REBURIAL TEST (Sediment Quality Analysis for Habitat of Blood Cockle (Anadara granosa L) by Reburial Test)

ABSTRAKPenelitian dilakukan untuk mengkaji mutu sedimen habitat kerang darah (Anadara granosa L) berdasarkan preferensi reburial. Uji dilakukan terhadap sedimen yang berasal dari Estuari Wakak-Plumbon di Kabupaten Kendal dan sedimen dari Pulau Panjang, Kabupaten Jepara, Jawa Tengah.Hasil pengujian menunjukkan bahwa kerang darah yang dipapar dalam sedimen dari estuari Wakak-Plumbon dan Pulau Panjang tidak menunjukkan kegagalan dalam upaya membenamkan diri (reburial failured) setelah dipapar selama 48 jam. Perbedaan hanya terjadi dalam waktu adaptasi sebelum membenamkan diri. Kerang darah umumnya membutuhkan waktu yang lebih lama untuk adaptasi sebelum membenamkan diri pada sedimen yang berasal dari Estuari Wakak-Plumbon dibanding dari Pulau Panjang.Kata kunci: Habitat, kerang darah, reburialABSTRACTThis research conducted to determine quality of sediment for habitat of blood cockle based on reburial reference. Test done to sediment from Wakak-Plumbon estuary on Kabupaten Kendal and from Panjang Island, Kabupaten Jepara, Central Java. The results showed that blood cockle exposed to sediment from two location are not different in reburial failured, but different in time needed for adaptation before reburial. Anadara granosa needed more time to adapted, before reburial in Wakak-Plumbon sediment.Keywords: habitat, blood cockle, reburial

Methane hydrate formation in a test sediment of sand and clay at various levels of water saturation

Kinetics of methane hydrate formation with different ratios of silica sand and clay and different water saturations were studied. At suitable temperature and methane gas pressure, water in the void spaces of silica sand packing and intercalated area of clay were converted into hydrate. It was observed that the rate of hydrate formation increases with higher void space in the packing, and addition of clay in test sediment decreases water to hydrate conversion as well as rate of hydrate formation. Maximum water to hydrate conversion of 60.0% was achieved in pure silica sand bed at 75% water saturation. Presence of fine clay particles is expected to reduce the void spaces and thus may hinder effective mass transfer of hydrate forming gases in the bed. However, it is also possible that the bentonite clay used in this work may actually inhibit hydrate growth. Additional experiments in stirred tank reactor were carried out to understand the inhibiting effect of bentonite clay for hydrate formation.