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All Journal Jurnal Geografi Biosaintifika: Journal of Biology & Biology Education
Sudrajat Sudrajat
Department of Environmental Geography, Faculty of Geography, Universitas Gadjah Mada, Indonesia
Agriculture, Biological Sciences & Forestry Earth & Planetary Sciences Education Environmental Science Social Sciences Other

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Potential of Soil Bacteria as Mercury Bioremediation Agent in Traditional Gold Mining Winardi Winardi; Eko Haryono; Sudrajat Sudrajat; Endang Sutariningsih Soetarto
Biosaintifika: Journal of Biology & Biology Education Vol 11, No 1 (2019): April 2019
Publisher : Department of Biology, Faculty of Mathematics and Sciences, Semarang State University . Ro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/biosaintifika.v11i1.16688

Abstract

Mandor Village has developed as a tradisional gold mining area since years ago. It involved activities that have led to extreme land condition and the release of mining residues, i.e., mercury, to the soils. The study examined the potential of soil bacteria as mercury bioremediation agent based on their population and activity in former mines with different ages. The bacterial population was measured by isolating soil bacteria on solid media using the pour plate method, and the colonies were enumerated during the incubation. The Nutrient Agar (NA) medium was used to obtain the total population, whereas the Salt Base Solution (SBS) was to determine the presence of mercury-tolerant bacteria. The addition of HgCl2 affected the number of the colonies. The colony only grew until the concentration of HgCl2 reached 5 mg/l, and the total colony was larger in older mines. The observation of bacterial activity showed that biotransformation performance was lower when the concentration of mercury was the same as its natural presence in soils (0.1-0.5 mg/l) compared with higher mercury level (1 mg/l). The research showed that lower mercury concentrations in nature reduced the natural ability of bacteria to transform pollutants. This study provides information that can assist the development of a technological approach to control mercury pollution in former traditional gold mines in an environmentally friendly manner using indigenous soil bacteria.
In Situ Bioremediation Strategies for the Recovery of Mercury-contaminated Land in Abandoned Traditional Gold Mines in Indonesia Winardi Winardi; Eko Haryono; Sudrajat Sudrajat; Endang Sutariningsih Soetarto
Biosaintifika: Journal of Biology & Biology Education Vol 12, No 3 (2020): December 2020
Publisher : Department of Biology, Faculty of Mathematics and Sciences, Semarang State University . Ro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/biosaintifika.v12i3.25229

Abstract

Traditional gold mining activities release mercury into the environment, creating a major concern for the Indonesian governments today. In situ bioremediation, which draws on the activities of indigenous soil bacteria for the recovery of mercury-contaminated land, has never been conducted intensively in the country. This research set out to determine the most efficient in situ bioremediation strategy for this purpose. It took place in Mandor Village, Landak Regency, Kalimantan Barat-Indonesia. During the experiment, four groups of sampling plots were made into triplicate and given various treatments: a. nutrient addition, b. aeration, c. pH neutralization, and d. without nutrient addition and aeration as a control. pH neutralization was conducted in all sampling plots by adding lime until soil pH of ±7 was achieved. The experiment was performed during both rainy and dry seasons to determine the influence of seasonal weather. Total mercury levels of each plot were measured on day 0, 30, 60, 90, and 120, and the effects of treatments and time on mercury depletion were analyzed by two-way ANOVA (P0.05), followed by a post hoc test to identify the best treatment and optimum time for in situ bioremediation. The results showed that the best time to conduct this bioremediation was in the rainy season by applying nutrient addition and aeration for 90 days on soils with neutral pH; these stimulations could remove ±89.6% of the mercury. This bioremediation technique is a novel technological approach in land recovery that local governments can adopt to restore soils contaminated with mercury from traditional gold mining.  
A Study on the Protection of Terraced Agricultural Land Based on Local Wisdom in Argapura, Majalengka Regency Sudrajat Sudrajat
JURNAL GEOGRAFI Vol. 18 No. 1 (2026): JURNAL GEOGRAFI
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jg.v18i1.67692

Abstract

Currently, the role of local wisdom in agricultural land protection practices appears to be diminishing due to modernization, generational changes, and shifts in agricultural production orientation, posing a challenge to the sustainability of agriculture. This study aims to: (1) examine the types of land degradation occurring in terraced lands; (2) analyze the types of local wisdom-based land protection practices still applied by terraced land farmers; and (3) assess the influence of local wisdom-based land protection on the productivity of terraced agricultural land. From a population of 504 farmers, a sample of 100 was selected using Slovin’s formula with a 10% margin of error through simple random sampling. Additionally, 10 key informants were included, comprising farmers, farmer group leaders, and village officials. Primary data were collected using semi-structured questionnaires and in-depth interviews with informants. Sensitivity tests were conducted to ensure data consistency and validity. Data were processed using SPSS 28, and the results were presented in graphs and analyzed using descriptive qualitative methods, supported by findings from in-depth interviews. The study found that soil erosion and micro-landslides on terrace embankments are the most dominant types of land degradation experienced by farmers, which significantly affect agricultural productivity. To address these issues, farmers implement local wisdom-based land protection practices, including constructing bench terraces, using organic fertilizers derived from agricultural waste, collaboratively repairing irrigation channels, and prohibiting the burning of waste. Empirically, these practices have been able to maintain and even improve agricultural productivity.
Co-Authors Eko Haryono Eko Haryono Endang Sutariningsih Soetarto Winardi Winardi Winardi Winardi