Removal of Cd (II) Ions from Bioretention System by Clay and Soil Wettability

In this work, a silane modifier with benzyl substitutes (OFS-B) and linear substitutes (OFS-L) was used to modify bentonite clay and soil, and the results were characterized by Fourier transform-infrared absorption spectroscopy (FT-IR) and powder-X-ray diffraction (XRD) analysis. A contact angle analysis was performed to determine the wettability of modified clay and soil. The findings revealed that silane-modified OFS-L clay and soil produced wettable surfaces, while OFS-B exhibited hydrophobic properties. These clays and soils were used in a bioretention system for Cd (II) removal. In the study, seven different types of bioretention systems, including natural, OFS-L, and OFS-B modified clay and soil, as well as natural, OFS-L, and OFS-B modified soil, were applied to Cyperus alternifolius plants without an additional layer. The removal capacity of Cd (II) was measured in the following order: modified clay > modified soil > original clay/soil > no layer, i.e., 99.48%, 92.22%, 88.10/78.5%, and 30.0%, respectively. OFS-L removed more Cd (II) than OFS-B during the modification. OFS-L now improves the bioavailability and accumulation of Cd (II) in the plant (18.5 µg/g) and has a higher chlorophyll-b concentration (1.92 mg/g fresh weight) than other systems. The wettable clay exhibited clay leaching into the various levels of the bioretention system. In the bioretention system, benzyl substituted clay prevented the penetration of water and formed a Cd (II) agglomeration. When compared to non-wettable modifiers, these results indicated that wettable clay material could be a capable material for removing Cd (II).

PERENCANAAN INSTALASI PENGOLAHAN AIR LIMBAH (IPAL) DOMESTIK DENGAN METODE CONSTRUCTED WETLAND DI PERUMAHAN BUMI CIRUAS PERMAI 1 KABUPATEN SERANG

Peningkatan pencemaran lingkungan yang terjadi di Kecamatan Ciruas berakibat pada penurunan kualitas air sungai di wilayah Kecamatan Ciruas. Kontribusi pencemaran terjadi dikarenakan belum adanya sarana pengolahan air limbah yang maksimal. Perumahan BCP 1 adalah salah satu penghasil limbah domestik berupa limbah grey water dan black water. Perumahan ini belum terdapat fasilitas pengolahan baik limbah grey water dan black water. Oleh karena itu, diperlukan sistem pengolahan air limbah grey water yang tepat dan efisien. Salah satu alternatifnya adalah dengan metode subsurface flow wetland. Penelitian ini bertujuan untuk mengetahui volume air limbah yang dihasilkan oleh masyarakat Perumahan BCP 1 dan untuk membuat desain pengolahan air limbah. Penelitian pengolahan limbah domestik ini menggunakan tanaman rumput payung (Cyperus alternifolius). Perencanaan IPAL di Perumahan BCP 1 mempertimbangkan aspek kualitas air limbah domestik yang dihasilkan setiap harinya. Kualitas air limbah domestik menunjukkan nilai COD 19,8 mg/L; BOD 12,75 mg/L; TSS 84 mg/L dan pH 7,6. Kemudian dilakukan analisis perhitungan masing-masing unit IPAL yang akan direncanakan di perumahan BCP 1 agar sesuai dengan kriteria baku mutu sesuai dengan Peraturan Menteri Lingkungan Hidup dan Kehutanan Republik Indonesia No. P.68/MENLHK-SETJEN/2016. Sistem IPAL direncanakan terdiri dari unit bak ekualisasi, Subsurface Flow Constructed Wetland dengan tanaman Cyperus alternifolius, dan kolam penampungan. Hasil perencanaan menunjukkan efisiensi pengolahan untuk TSS sebesar 88%; BOD sebesar 12,75 mg/L; COD sebesar 19,8 mg/L; pH sebesar 7,6. Dengan efisiensi tersebut effluent limbah cair IPAL telah memenuhi baku mutu yang ditentukan. Anggaran biaya yang dibutuhkan untuk pembangunan IPAL adalah Rp. 588.191.894.

KHẢ NĂNG CHỐNG CHỊU, HIỆU QUẢ XỬ LÝ CHẤT Ô NHIỄM TRONG NƯỚC THẢI CHĂN NUÔI SAU BIOGAS CỦA THỦY TRÚC (Cyperus alternifolius) VÀ CỎ NẾN (Typha orientalis)

Từ thực trạng chất lượng nước thải sau biogas tại các trang trại chăn nuôi lợn, nghiên cứu đã lựa chọn hai loài thực vật thủy sinh để xử lý nước thải theo định hướng nghiên cứu ứng dụng công nghệ bãi lọc trồng cây nhân tạo. Thí nghiệm được thiết kế nhằm đánh giá khả năng chống chịu COD, NH4+ và pH của Thủy trúc (Cyperus alternifolius) và Cỏ nến (Typha orientalis) thông qua khả năng sinh trưởng ở các nồng độ khác nhau. Cả hai loài thực vật cho sinh khối ổn định trong dải pH từ 5 đến 9, nồng độ COD đến 1000 mg/L và nồng độ NH4+ từ 50 đến 250 mg/L. Hiệu suất xử lý TSS (Total Suspended Solids – Tổng chất rắn lơ lửng), COD (Chemical Oxygen Demand – Nhu cầu oxy hóa học), NH4+, T-N (Total Nitrogen – Tổng nitơ) của Thủy trúc tương ứng là 85,9%, 76,8%, 76,8%, 66,8% và Cỏ nến là 85,4%, 66,5%, 61,5%, 52,0%. Chất lượng nước thải sau xử lý đều đạt quy chuẩn cho phép đối với nước thải chăn nuôi (QCVN62-MT:2016/BTNMT, cột B). Tuy nhiên, Thủy trúc có ưu thế hơn nhờ khả năng chống chịu tối ưu, hiệu quả xử lý và thời gian xử lý các chất ô nhiễm của loài thực vật này.

Efficiency of Cyperus alternifolius, Typha latifolia, and Juncus inflexus in the removal of nitrate from surface water

Nitrate is one of the most toxic and pathogenic substances in drinking water. Nitrate levels have increased significantly in groundwater and surface water because of the high usage of nitrogenous fertilizers, which have lethal effects on human health. Therefore, the removal of this toxic material from surface water is absolutely essential. The goal of this paper is to evaluate the efficiency of three aquatic plant species, called Cyperus alternifolius, Typha latifolia, and Juncus inflexus, in the removal of nitrate from surface water. This experiment has been carried out in the laboratory scale using a hydroponics method. To do this, the water samples containing nitrate were collected and evaluated before and after the treatment to see the effects of these three plants on both the nitrate removal and the pH variation of water. The results show that all the plants can remove excessive levels of nitrate from the surface water. The comparison of the results has revealed that T. latifolia plant has higher ability to remove nitrate from water than C. alternifolius and J. inflexus. It was observed that the nitrate removal efficiency of T. latifolia was 95%, J. inflexus was 85%, and C. alternifolius was 70% after 10 days. Moreover, it was observed that the pH values of the treated water have been affected by these plants. The results of this study can be employed for further improvement of surface water quality, thereby lowering water purification time and costs as well as decreasing the nitrate-related diseases significantly.

Integrated constructed wetlands treating industrial wastewater from seed production

The performance of an integrated wastewater treatment system composed of horizontal subsurface flow constructed wetland (HSSFCW), floating constructed wetland (FCW), and anaerobic baffled reactor (ABR) was studied for pollutant removal from seed production wastewater. Cyperus alternifolius (Umbrella Papyrus) plants were used in the HSSFCW, and Vetiveria zizanioides (Vetiver grass) in the FCW. The ABR was fed with 25 m3/d wastewater from its equalization tank. The average raw wastewater organic loading rate was 0.208 kg-COD/d. Grab wastewater samples were collected twice weekly for three months from each unit's inlet and outlet. The system's performance in removing biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), turbidity, nitrate, phosphate, and ammonium was studied. The average removal efficiencies obtained were 95.5% BOD5, 94.6% COD, 86.2% TSS, 76.6% turbidity, 82.4% nitrate, 76% phosphate, and 32.9% ammonium. The results show that integrating ABR, HSSFCW, and FCW improves pollutant removal from seed production wastewater, and the treated water can be used for agricultural purposes.

Assessment of the Effects of Ornamental Wetland Polyculture Combinations on Urban Sewage Treatment

Previous studies have shown that wetland plants can treat wastewater in a cost-effective and sustainable way, however, the studies on the performance of ornamental wetland plant diversity in treating urban sewage were scarce. Therefore, this study was conducted to assess and select wetland polyculture combination that was effective in urban sewage treatment in subtropical areas. We formed five combinations out of six ornamental wetland plant species including Thalia dealbata, Cyperus alternifolius, Iris pseudacorus, Lythrum sastlicaria, Nymphaea tetragona, and Zantedeschia aethiopica. The growth state and removal effects of each plant combination were systematically measured and assessed. The results indicated all the combinations exhibited remarkable total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH­4+-N), and chemical oxygen demand chromium (CODcr) removal rate of 70.75%-77.67%, 63.86%-73.71%, 69.73%-76.85%, and 57.28%-75.69%, respectively. Additionally, pH was reduced to 7.54-8.00 in the sewage. The purification effect reached the best during 30-36th day. The comprehensive assessment showed the mixture of Thalia dealbata + Cyperus alternifolius, closely followed by Thalia dealbata + Cyperus alternifolius+ Lythrum sastlicaria, was highly effective at extracting various pollutants, and both of them could be used as favorable combinations to convert eutrophication and purify municipal wastewater. Linear regression showed that TP, TP, NH­4+-N, and CODcr. were significantly related to plant biomass, indicating that plant biomass essential indicator for screening purification plants. Our study highlighted the importance of plant diversity in biological wastewater treatment, however the competition between plants was suggested to take into consideration in future studies.

Post treatment of anaerobically treated brewery effluent using pilot scale horizontal subsurface flow constructed wetland system

The anaerobic process is considered to be a sustainable technology for the treatment of wastewaters rich in organic matter mainly due to its lower energy consumption and production of value-added products such as biogas and organic fertilizer. However, it cannot be seen as providing ‘complete’ environmental solution as its treated effluents would typically not meet the desired discharge limits in terms of residual carbon, nutrients and other pollutants. This has given impetus to subsequent post treatment in order to meet the environmental standards and protect the receiving water bodies and environment. The aim of this study was to evaluate the post-treatment potential of a pilot scale two-stage horizontal subsurface flow constructed wetland (HSSFCW) system planted with Cyperus alternifolius and Typha latifolia, respectively, for enhanced removal of residual carbon and nutrient from an up-flow anaerobic sludge blanket (UASB) reactor treated brewery effluent. A pilot scale two-stage HSSFCW was integrated with the UASB reactor, and its performance efficiency was assessed for the removal of total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), ammonium–nitrogen (NH4–N), total phosphorous (TP), and orthophosphate (PO43−). Macrophytes aboveground biomass and nutrient accumulation potential were also determined following standard methods. The results from this study showed that Cyperus alternifolius planted CW cell removed 68.5% TSS, 74.2% COD, 55.7% TN, 68.6% NH4–N, 41.1% TP and 48.1% PO43−. Moreover, further polishing with Typha latifolia planted CW cell enhanced the removal efficiencies to 89% TSS, 92% COD, 83.6% TN, 92.9% NH4–N, 74.4% TP, and 79.5% PO43−. Strong linearity and Pearson correlation was found between macrophyte biomass and nutrient accumulation in each CW cell (Cyperus alternifolius: R2 = 0.91, r = 0.97 for TN; R2 = 0.92, r = 0.96 for TP; and Typha latifolia: R2 = 0.96, r = 0.98 for TN and TP), and showed substantial nutrient reduction with cumulative nutrient accumulation of 1290 gTNm−2 and 708.7 gTPm−2 in the complete system. The performance of the pilot CW system as a tertiary treatment for brewery wastewater showed that the effluent meets the permissible discharge standards throughout the year excluding phosphorous.