Influence of Reaction Time, Temperature And Heavy Metal On Characteristics of Cellulose- And Wood-Derived Hydrochars From Hydrothermal Carbonization

Hydrothermal carbonization (HTC) is a promising technique to convert biomass into valuable solid fuels. In this work, cellulose and wood-derived hydrochars were synthesized under hydrothermal carbonization conditions with different temperatures (200-250 ℃), reaction times (6 h or 12 h) and to determine their influence on hydrochars. Heavy metal element zinc is chosen to introduce into samples to simulate the heavy metal accumulate in biomass. The physical, chemical, and combustion properties of the hydrochars revealed that the majority of cellulose and wood conversion occurs at first 6 h, and faster conversion occurs at higher temperatures. The content of fixed carbon in the cellulose-derived hydrochar is higher than in wood-derived hydrochar. Moreover, cellulose is easier to be carbonized during HTC reaction than wood. O/C and H/C ratios of all hydrochars were similar to those of lignite and decreased with increasing reaction temperature. The composition of solids recovered after 12 h is similar at all temperatures, consisting primarily of sp2 carbons (furanic and aromatic groups) and alkyl groups. When a large amount of metal is introduced, part of the metal is combined with the energetic group, while the rest condense on the surface of the sample as zinc ions.

ANALISIS SEDIMEN DAN PERUBAHAN KONDISI LINGKUNGAN:DAERAH KASUS DELTA MAHAKAM KALIMANTAN TIMUR

Delta Mahakam mempunyai sumberdaya minyak dan gas bumi serta sumberdaya laut lainnya. Hutan mangrove di kawasan Delta Mahakam merupakan salah satu parameter kelestarian lingkungan. Pembukaan lahan mangrove Delta Mahakam untuk daerah pertambakan ikan, pemukiman, dermaga, dan industri, serta untuk alur pelayaran mengakibatkan berkurangnya tanaman mangrove, perubahan dinamika sedimentasi dan lingkungan kawasan pesisir. Kawasan yang rusak diperkirakan lebih dari 80 persen. Sekitar 20 persen dari luas sekitar 1.400 kilometer persegi, hutan mangrove yang masih baik. Ini adalah sebagai bukti Delta Mahakam mengalami proses destruktif. Sebanyak 15 contoh sedimen permukaan dan 2 contoh air permukaan diambil dari lokasi dekat dengan kegiatan industri perminyakan dan daerah hunian telah dianalisis unsur utama dan unsur logam berat. Berdasarkan analisis unsur utama dan unsur logam berat ke 15 contoh sedimen tersebut mengandung unsur silika (SiO2) >50% dan unsur air raksa (Hg) < 2000 ppb. Ke 2 contoh air mengandung unsur logam berat Cadmium (Cd) antara 0 ppb dan 54 ppb, dan Hg antara 1 ppb – 2 ppb. Merujuk pada baku mutu air laut dan baku mutu sedimen maka kualitas air laut dan sedimen Delta Mahakam masih dalam batas normal atau dikatagorikan sebagai kondisi belum tercemar. Jadi perubahan kondisi lingkungan Delta Mahakam tidak memberikan dampak terhadap kuallitas baku mutu sediment dan air secara kimiawi, Kata kunci: analisis unsur utama, analisis unsur logam berat, perubahan lingkungan, Delta Mahakam, Kalimantan Timur The Mahakam Delta has natural resources of oil and gas and other marine resources. Mangroves of the Delta Mahakam is one of an environmental indicator Deforestation of mangroves of Delta Mahakam for fishery ponds, settlements, harbor, industries, and for marine transports cause to decrease of those mangroves, changes of dynamics of sedimentation and coastal environments. Mangroves are about 80% in bad condition and whereas 20% of them are in still good condition from total areas of 1.400 km square. This indicates that the Delta Mahakam is in destructive processes. 15 samples from surfacial sediment and 2 samples from surface water taken from locations where close to oil industry fields and settlement areas were analyzed for major and heavy metal elements. According to the analyses those 15 samples, they content elements of silica (SiO2) >50% and mercury (Hg) <2000 ppb. The two samples of water content elements of cadmium (Cd) from 0 ppb – 54 ppb, and Hg from 1 ppb – 2 ppb. Referring to the standard of seawater and sediment quality the water and sediment of the Mahakam Delta are in good condition or no pollution. In fact, changes of the Mahakam Delta environmental condition do not cause impacts to the quality of seawater and sediment of the Mahakam Delta. Keywords: major element analyses, heavy metal element analyses, environmental changes, the Mahakam Delta, East Kalimantan

LIBS TECHNIQUE FOR DETERMINATION PB CONCENTRATION IN SOIL SAMPLES NEAR CONTAMINATION SITE

This paper reports the analysis of heavy metal from contamination soil using laser ablation technique. The soil samples were taken at various distances (200-1000 m) and depths (10-50 cm) from Port Dickson power station area in Negeri Sembilan-Malaysia. All samples were dried and pelletized prior to excitation. Calibration was carried out by injected pure powder of Pb into the soil matrix. A Q-switched Nd:YAG laser was employed to ablate the sample. Maya spectrometer with resolution of 0.2 nm was utilized to record the emission spectrum of fluorescence beam. The quantitative results of laser induced breakdown spectroscopy (LIBS) technique were validate via flame atomic absorption spectroscopy (FAAS) analysis which shown in a good agreement. The detected heavy metal element of lead also identified to be lower than the threshold limit set by DOE and Europe standard and yet the studied area is established to be among the lowest pollutant area in worldwide.

PM2.5 Pollution Level of Heavy Metals in Atmospheric Particles in Taiyuan

PM2.5 particulate matters were collected in Taiyuan from November 2012 to October 2013. The total concentrations of seven kinds of typical heavy metal element (Fe, Pb, Mn, Cu, Ni, Cr, Cd) in particles were quantified by acid digestion method, then determined by flame atomic absorption spectrophotometer. The results showed that the concentration of PM2.5 in Taiyuan was six times higher than the Ambient Air Quality Standard (GB 3095-2012) II, and the atmospheric particles in Taiyuan are high in Fe, Pb, Cu, Mn, followed by Ni, Cr, Cd. The concentrations of Fe, Cd, Cu, Mn, Ni, Cr in industrial area were high, while the contents of Pb was high in commercial area, all of them were low in educational and residential area.

A Technique Method of Recycling Sylvite Zinc Plating Waste Liquid in Laboratory

It introduces a kind of technique method that recycling sylvite zinc plating waste liquid laboratory, involving the fields in electroplating and comprehensive utilization of waste liquid. It includes the following steps: first add hydrogen peroxide and activated carbon into waste liquid to remove the organic matter in it, and then reduce the solution’s temperature with refrigeration film, and filter out the solid contents. Add NaOH solid, NaHSO3 into the solution, through chemical reactions, precipitate the heavy metal element, and finally get distilled water through distillation. It can make the recycled materials be reused, such as distilled water, boric acid, etc., and as to nonrecyclables, such as heavy metal ions (Cu2+, Cr3+), bury them deep that disposing harmless.

Research on Material Properties and Soil Heavy Metal Pollution in Cities with Spread Evolution Model

In this paper, mainly research the surface soil heavy metal pollution in cities. First of all ,we find out the spatial distribution of eight kinds of main metal elements in the urban; we adopt the improved gray model to establish evaluation system about urban pollution heavy metal element degree, and then to evaluate the pollution degree of heavy metal element in the city area. Eight heavy metals have been in dimension reduction by means of correlation analysis and principal component analysis, comprehensive variables can be got. By calculating the rotating component matrix, we got objective reason of metal contamination. We analyzed transmission characteristics of heavy metal pollutants and build model to determine the location of the pollution sources. We introduced the field theory the basic assumption , calculated various factors which lead to the change of one point of concentration. The differential equation model can be got which reacted geological environment evolution mode through the mass conservation. Finally we determine the location of the pollution sources and the evolution of the urban geological environment mode.