Phytoremediation

Post-mining site at Okayama Prefecture of Japan

Phytoremediation is one of remediation technology that uses the plant to clean contaminated sites. The impact of Industrial Revolution introducing amount hazardous compounds into the environment. This hazardous pollutants consist of a variety of organic compounds and heavy metals, which pose serious risks to human health. Phytoremediation technique has developed because of it the low-cost application, natural cleanup technique methods using solar energy transport which are most useful at shallow sites, and low levels of contamination. The mechanisms of phytoremediation depend on the type of contaminant, bioavailability and soil properties. Primarily, the uptake of contaminants in plants occurs through the root system, which the principal mechanisms for preventing toxicity are found. In particularly mechanisms on phytoremediation are varied, including phytoextraction, rhizofiltration, phytovolatilization, phytostabilization, phytodegradation, hydraulic control, and rhizodegradation.

Phytoextraction also called phytoaccumulation, it refers to the uptake and translocation of metal contaminants in the soil by plant roots into the above-ground portions of the plants. This mechanism becomes primarily used for the contaminated soils treatment. Rhizofi
ltration is similar to phytoextraction, but the plants are used primarily to address contaminated ground water rather than soil. Phytovolatilization mechanism involves the use of plants to take up contaminants from the soil, transforming them into volatile forms and transpiring them into the atmosphere. Phytostabilization is the use of certain plant species to immobilize contaminants in the soil and ground water through absorption and accumulation by roots, adsorption onto roots, or precipitation within the root zone of plants (rhizosphere). Phytodegradation also referred to as phytotransformation. It involves the degradation of complex organic molecules to simple molecules or the incorporation of these molecules into plant tissues. In hydraulic control mechanism of groundwater contamination by plant canopies through increased transpiration reduces infiltration of precipitation or increases transpiration of groundwater, thus reducing contaminant migration from the site in groundwater plumes. The last scheme of phytoremediation mechanism is Rhizodegradation also referred to as phytostimulation refers to the breakdown of contaminants within the plant root zone or rhizosphere. It is believed to be carried out by bacteria or other microorganisms whose numbers typically flourish in the rhizosphere. It can also be seen as plant-assisted bioremediation, the stimulation of microbial and fungal degradation by the release of exudates/enzymes into the root zone (rhizosphere).

Multipurpose of Miscanthus Perennial Grass

Miscanthus is one of perennial grass plant which produces large of biomass. The development of energy alternative based on biomass, Miscanthus, becomes potential grass species in future prospect. There are many advantages which Miscanthus have, such as this grass categorized as low demand nutrients input, with a poor quality of land still have higher yields, and also have tough persistence including in cold weather. The result from Saga et al. (2014), showed under cool temperature Miscanthus photosynthesis ability is higher other C4 grasses such as maize and sugarcane. Based on that categorized Miscanthus also used in the marginal land to stabilize and covering land in wildlife. Even this grass produce large biomass, to keep the sustainable in the nutrient cycle in harvest technique should be considerate to remain the rhizome in the soil as nutrient source. Moreover, the development of bioproduct becomes coproduct such as chemical and material is a great future. Development the biomass resource as bioproduct should considerate other issues such as conflict with food, stable supply, and for industrialized it should work economically. Miscanthus with the beneficial based on the character, have a great challenge leading the biorefinery schema.

Another scenario for utilization Miscanthus perennial grass plant is producing biomass in term reducing greenhouse gas emission. Greenhouse gasses contributed in earth warming and simultaneously make climate changed. Concentration gasses that trapped in the atmosphere, day by day increased. Through photosynthesis, carbon dioxide in the atmosphere will change become photosynthates or biomass. Miscanthus is a grass with high of yield with soil C sequestration rate, until 503 kg/ha which almost twice than Japanese cedar forest. The concept for mitigating the concentration from agriculture sector is utilization biomass which accumulates carbon in soil and biomass. So that high yield in Miscanthus is equal with the purpose mitigation greenhouse concept. Real application in Miscanthus planting still needs burning process for maintaining Miscanthus vegetation in grassland. Research that calculates carbon dynamics as affected by burning explained that after burning soil C not burning and soil CH4 and N2O flux did not increase after burning. It showed deep explanation that during burning, even CH4 and N2O were emitted but higher soil C accumulation still stored. Compared with Japanese cedar forest soil C accumulation in semi-natural grassland has significantly higher which indicated Miscanthus grass should become a potential sector in mitigated greenhouse gasses.

Miscanthus sinensis pioneer grass

Hokkaido is the northern main island in Japan, which have low population than another main island in Japan. And also have a low temperature in long time than another area, sometimes extreme weather occurred. With this special environment condition, make Hokkaido becomes the main focus in Agriculture sectors. Moreover, Hokkaido suitable to becomes primary industries based biorefinery. Integrated multipurpose that concerning in mitigation greenhouse gasses, also feedstock production to fuel, adding value becomes chemicals and materials through bioprocess appropriate with the future plan. Research and development, involving the Miscanthus proposed for biorefinery schema or development as global warming mitigation effort still needed. Indeed, Hokkaido with exceptional condition becomes one of a suitable area to develop a future plan with Miscanthus grass as a potential commodity.

Global Warming? What About in The Arctic Region

Arctic is a special region which has many definitions based on the aspects likes astronomically, climatologically, and also botanically. Briefly, the arctic is Polaris mostly located in the north pole. Different with the southern polar region which mostly ice-covered continental, in northern pole surrounded by ocean.

Continuously emitted carbon dioxide and other greenhouse gasses in atmosphere finally also give impact in the arctic environment. Most of the heat energy from earth surface is absorbed by greenhouse gasses which become the barrier so that the heat becomes back to the surface and surface becomes warmer. This process should be in long-term process but nowdays scientists knew that already happen the impact of global warming. IPCC in 2001 have declared that climate change in the polar region is predicted becomes the largest and most rapid than another region on earth, as consequence will cause major ecological, physical, sociological and economic impact, particularly in the arctic region.

Warming in the arctic giving impact in physical climate such as; rising temperatures, until now over past half century the temperatures was increased 3-4°C on winter in Alaska; rising the river flow, this happen because the ice slowly melting; declining snow cover; increasing precipitation; thawing the permafrost that caused much erosion in arctic area and the most famous is rising sea level, the impact to be greater than in global average. In natural system, ecosystem structure and composition changes, after ice-covered land becomes melting it was open land space so that there are much vegetation grow, it is mean in some part agricultural and forestry will be increased due to a longer and warmer growing season and slowly it will cause an exchange in social life for indigenous people in arctic region.

In the summarize, it is clearly that global warming gives impact in natural, physical also a social aspect in the arctic region. Moreover, it will be a great challenge in economic aspect. Nowdays, we are more focused the changes that happen in the terrestrial ecosystem, it should become a way of thinking that it needs synergy research so that the strong approach can initiate in all area include arctic area. Mitigation effort and adaptation effort could be carried out simultaneously to minimize the impact and changes.