4 RESULTS
4.5 Current and emerging trends of biochar use in wastewater
Biochar remains to be not widely used wastewater treatment technology and re-quires still more considerable number of tests and research works. For its further application, there are several environmental concerns and future advancement aspects that should be considered in researching. In addition to the existing en-vironmental concerns, there are certain advised directions for future development that are outlined by Wang et al, 2020 in the Figure 3.
The first concept is the cost. Currently biochar production requires noticeable amount of preparation, including feedstock preparation, pre-treatment, pyrolysis of the feedstock and other possible additional steps, for example chemical of physical modification of the biochar, that increases overall biochar’ cost.
Hence, in the future development it would be important to consider and work with this production prices as they have a direct impact on the biochar’s wide applica-bility as a water treatment technology.
FIGURE 3. Environmental concerns and future development directions (Wang et al. 2018)
Biochar’s performance is directly linked to the feedstock, production conditions and its modifications, thus it is relevant to more thoroughly research the impact
En vi ronm en tal c once rns and fu tu re d ev el op m en t d ire ct io ns Cost Perfomance Sustainability
Stability
Co-contaminats
of these variables on the biochar’s performance and test new possible technolo-gies that could enhance that.
For the practical application of the biochar, its stability and stability of its modifi-cations should be considered and evaluated. For biochar’s feedstock can be used agricultural waste products, industrial by-products, municipal wastes. How-ever, compounds from the feedstock can significantly impact the biochar’s per-formance or even in some cases lead to additional contamination, for example in the case from biochar was derived from sewage sludge and contains heavy met-als that during biochar’s application can flow out. Thus, the safety of the biochar’s application should be thoroughly evaluated and researched (Ok et al. 2018, 423-431).
Most of the current researches on the biochar, evaluate its removal efficiency only on certain chemical compound. However, it is evident that wastewater influ-ent almost always is contaminated with several pollutant. Thus, there is a notice-able importance in conducting more practical test and research about biochar’s efficiency in case of several types of pollutants.
Number of demonstrated modifications of the biochar (Figure 1) shows that if biochar is still in researching phase, there is possibility to find more effective mod-ifications to improve biochar’s performance that usually includes increased sur-face area, sursur-face sorption sites or porosity.
Even if biochar’s is considered as relatively sustainable and renewable practice compare to many other technologies, it still requires conducting more test and research on its possible applications and circular use. Currently biochar’s recov-ery and desorption are not resolved and possesses certain challenges for its sus-tainable utilization (Wang et al 2018).
5 CONCLUSIONS
Biochar is an emerging technology that becomes more and more prevalent. How-ever, there is still need in its research due to flexibility and versatility of this ma-terial and its productions methods. This research attempted to present possible applications of the biochar in wastewater treatment and summarize biochar’s ad-vantages, features, and possible difficulties with its implementation.
Currently, most of the research about biochar focuses on its application in soil remediation and soil improvement, while application of the biochar in the wastewater treatment only starts to gain more and more interest. Due to high importance of enabling sufficient water quality and presence of many variables that have an impact on the efficiency and the performance of the biochar there is a notable need in a thorough research and funding in this field.
As biochar application in the wastewater treatment research grows, there are cer-tain existing environmental concerns as well as outlined directions that are needed to be considered during current testing and researching phase of the bi-ochar. Safety of the biochar’s application should be thoroughly evaluated due to possible risks. In addition, potential assessment and possible solutions to bio-chars recovery and desorption should be tested.
Most of the studied articles research and evaluate biochar’s performance and removal efficiency of only one type of contaminant. However, wastewater is mainly contaminated with various pollutants. Hence, it is considerably important to research more about biochar’s performance on the removal of several types of the contaminants.
To conclude, biochar’s is a promising technology that is versatile and adaptable, with wide range of possible application. However, it still requires considerable research to evaluate all possible risks and concerns and enable its efficient per-formance in wastewater treatment.
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APPENDICES
Appendix 1. Sustainable production of biochar figure (Pacific Northwest National