Grass filtration in parallel with VFCW technology for community wastewater treatment through the king’s initiative nature-by-nature process K. Chunkao a, *, O. Phewnil a , T. Pattamapitoon a , N. Semvimol b and W. Wararam b a Department of Environmental Science, Faculty of Environment, Kasetsart University, Bangkok 10900, Thailand b The King’s Royally Initiated Laem Phak Bia Environmental Research and Development (Royal LERD) Project, The Chaipattana Foundation, Ban Laem District, Phetchaburi Province 76100, Thailand *Corresponding author. E-mail: prof.kasemc@gmail.com Abstract The 15-year research is aimed to apply the Vertical Flow Constructed Wetland (VFCW) technology along with grow- ing Star, Kallar, Coast couch grasses for community wastewater treatment as obtained from Phetchaburi municipal after anaerobic digesting inside the 18.5 km High-density Polyethylene (HDPE) pipe. The results found that pH value did not evidently show any change of influent to effluent among grass species but drastic change due to treatment efficiency in Biological Oxygen Demand (BOD), Total Kjeldahl Nitrogen (TKD), Total Phosphorus (TP), and Total Pot- assium (TK) due to supporting rapidly growing of Star, Kallar, and Coast couch grasses, and also some parts of organic forms to escape from the VFCW technical units as volatile gaseous chemicals; and precipitating down to the VFCW technical unit beds as sludge. The Star and Coast couch grasses showed higher potential in community wastewater treatment efficiency than Kallar grass but treating power were not different in wide ranges. Besides, the heavy metals (Pb, Cd, Hg as example) were contaminated in both treated wastewater and sludge (sediment). However, the influent and effluent as inflow and outflow of VFCW technical units found very low contamination but three grasses (Star, Kallar, and Coast couch) showed their eligibility in treating heavy metals, especially when their age at 45-day growth as the same findings of treating BOD, TKN, TP, and TK according to meet highest treatment efficiency at age of 45 days. In other words, the harvesting age at 45 days was not only reached the maximum treatment efficiency as well as maximum grass biomass but also kept away from heavy contamination. Key words: community wastewater treatment, grass filtration, VFCW technology INTRODUCTION An increase of Thai population has been exploded from 1950 to 2013 which was approximated 0.8 million per year. Undoubtedly, forest lands were trespassed in using for traditionally growing agricultural crops with without care for keeping soil in place which could be the basic cause of losing plant nutrients. The previous statements resulted to gain less productivity of growing crops that made farmers poor and uneducated persons to reside such infertile land. Surely, they moved into the city for better job opportunity that made dense-populated community and becoming the huge point sources of wastewater, solid wastes, visual pollution, air pollution, and social problems. Among those worse environmental problems, waste- water has been taken in the most serious problem in causing stream pollution around the Kingdom of Thailand. Anyway, field observation revealed that wastewater of these water sources have seriously been polluted from their settling big cities. Besides, the industrial factories which were localized close to the water sources could make worse water pollution in everywhere around the country due to the direct drainage the effluent from factories without treating. Also, the amount of wastewater was about © IWA Publishing 2015 Water Practice & Technology Vol 10 No 4 633 doi: 10.2166/wpt.2015.071 Downloaded from https://iwaponline.com/wpt/article-pdf/10/4/633/382222/wpt0100633.pdf by guest on 15 June 2020